Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/spi-2.6

14 files changed, 3542 insertions, 0 deletions

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 48f446d..283c089 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -44,6 +44,8 @@ source "drivers/char/Kconfig"
 
 source "drivers/i2c/Kconfig"
 
+source "drivers/spi/Kconfig"
+
 source "drivers/w1/Kconfig"
 
 source "drivers/hwmon/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 7fc3f0f..7c45050 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_FUSION)		+= message/
 obj-$(CONFIG_IEEE1394)		+= ieee1394/
 obj-y				+= cdrom/
 obj-$(CONFIG_MTD)		+= mtd/
+obj-$(CONFIG_SPI)		+= spi/
 obj-$(CONFIG_PCCARD)		+= pcmcia/
 obj-$(CONFIG_DIO)		+= dio/
 obj-$(CONFIG_SBUS)		+= sbus/
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 21d55ed..2c67402 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -11,6 +11,19 @@ menuconfig INPUT_TOUCHSCREEN
 
 if INPUT_TOUCHSCREEN
 
+config TOUCHSCREEN_ADS7846
+	tristate "ADS 7846 based touchscreens"
+	depends on SPI_MASTER
+	help
+	  Say Y here if you have a touchscreen interface using the
+	  ADS7846 controller, and your board-specific initialization
+	  code includes that in its table of SPI devices.
+
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ads7846.
+
 config TOUCHSCREEN_BITSY
 	tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
 	depends on SA1100_BITSY
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 6842869..5e5557c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -4,6 +4,7 @@
 
 # Each configuration option enables a list of files.
 
+obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)	+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)	+= corgi_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)	+= gunze.o
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
new file mode 100644
index 0000000..dd8c6a9
--- /dev/null
+++ b/drivers/input/touchscreen/ads7846.c
@@ -0,0 +1,625 @@
+/*
+ * ADS7846 based touchscreen and sensor driver
+ *
+ * Copyright (c) 2005 David Brownell
+ *
+ * Using code from:
+ *  - corgi_ts.c
+ *	Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *	Copyright (C) 2002 MontaVista Software
+ *	Copyright (C) 2004 Texas Instruments
+ *	Copyright (C) 2005 Dirk Behme
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
+
+#ifdef	CONFIG_ARM
+#include <asm/mach-types.h>
+#ifdef	CONFIG_ARCH_OMAP
+#include <asm/arch/gpio.h>
+#endif
+
+#else
+#define	set_irq_type(irq,type)	do{}while(0)
+#endif
+
+
+/*
+ * This code has been lightly tested on an ads7846.
+ * Support for ads7843 and ads7845 has only been stubbed in.
+ *
+ * Not yet done:  investigate the values reported.  Are x/y/pressure
+ * event values sane enough for X11?  How accurate are the temperature
+ * and voltage readings?  (System-specific calibration should support
+ * accuracy of 0.3 degrees C; otherwise it's 2.0 degrees.)
+ *
+ * app note sbaa036 talks in more detail about accurate sampling...
+ * that ought to help in situations like LCDs inducing noise (which
+ * can also be helped by using synch signals) and more generally.
+ */
+
+#define	TS_POLL_PERIOD	msecs_to_jiffies(10)
+
+struct ts_event {
+	/* For portability, we can't read 12 bit values using SPI (which
+	 * would make the controller deliver them as native byteorder u16
+	 * with msbs zeroed).  Instead, we read them as two 8-byte values,
+	 * which need byteswapping then range adjustment.
+	 */
+	__be16 x;
+	__be16 y;
+	__be16 z1, z2;
+};
+
+struct ads7846 {
+	struct input_dev	input;
+	char			phys[32];
+
+	struct spi_device	*spi;
+	u16			model;
+	u16			vref_delay_usecs;
+	u16			x_plate_ohms;
+
+	struct ts_event		tc;
+
+	struct spi_transfer	xfer[8];
+	struct spi_message	msg;
+
+	spinlock_t		lock;
+	struct timer_list	timer;		/* P: lock */
+	unsigned		pendown:1;	/* P: lock */
+	unsigned		pending:1;	/* P: lock */
+// FIXME remove "irq_disabled"
+	unsigned		irq_disabled:1;	/* P: lock */
+};
+
+/* leave chip selected when we're done, for quicker re-select? */
+#if	0
+#define	CS_CHANGE(xfer)	((xfer).cs_change = 1)
+#else
+#define	CS_CHANGE(xfer)	((xfer).cs_change = 0)
+#endif
+
+/*--------------------------------------------------------------------------*/
+
+/* The ADS7846 has touchscreen and other sensors.
+ * Earlier ads784x chips are somewhat compatible.
+ */
+#define	ADS_START		(1 << 7)
+#define	ADS_A2A1A0_d_y		(1 << 4)	/* differential */
+#define	ADS_A2A1A0_d_z1		(3 << 4)	/* differential */
+#define	ADS_A2A1A0_d_z2		(4 << 4)	/* differential */
+#define	ADS_A2A1A0_d_x		(5 << 4)	/* differential */
+#define	ADS_A2A1A0_temp0	(0 << 4)	/* non-differential */
+#define	ADS_A2A1A0_vbatt	(2 << 4)	/* non-differential */
+#define	ADS_A2A1A0_vaux		(6 << 4)	/* non-differential */
+#define	ADS_A2A1A0_temp1	(7 << 4)	/* non-differential */
+#define	ADS_8_BIT		(1 << 3)
+#define	ADS_12_BIT		(0 << 3)
+#define	ADS_SER			(1 << 2)	/* non-differential */
+#define	ADS_DFR			(0 << 2)	/* differential */
+#define	ADS_PD10_PDOWN		(0 << 0)	/* lowpower mode + penirq */
+#define	ADS_PD10_ADC_ON		(1 << 0)	/* ADC on */
+#define	ADS_PD10_REF_ON		(2 << 0)	/* vREF on + penirq */
+#define	ADS_PD10_ALL_ON		(3 << 0)	/* ADC + vREF on */
+
+#define	MAX_12BIT	((1<<12)-1)
+
+/* leave ADC powered up (disables penirq) between differential samples */
+#define	READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
+	| ADS_12_BIT | ADS_DFR)
+
+static const u8	read_y  = READ_12BIT_DFR(y)  | ADS_PD10_ADC_ON;
+static const u8	read_z1 = READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON;
+static const u8	read_z2 = READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON;
+static const u8	read_x  = READ_12BIT_DFR(x)  | ADS_PD10_PDOWN;	/* LAST */
+
+/* single-ended samples need to first power up reference voltage;
+ * we leave both ADC and VREF powered
+ */
+#define	READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
+	| ADS_12_BIT | ADS_SER)
+
+static const u8	ref_on = READ_12BIT_DFR(x) | ADS_PD10_ALL_ON;
+static const u8	ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN;
+
+/*--------------------------------------------------------------------------*/
+
+/*
+ * Non-touchscreen sensors only use single-ended conversions.
+ */
+
+struct ser_req {
+	u8			command;
+	u16			scratch;
+	__be16			sample;
+	struct spi_message	msg;
+	struct spi_transfer	xfer[6];
+};
+
+static int ads7846_read12_ser(struct device *dev, unsigned command)
+{
+	struct spi_device	*spi = to_spi_device(dev);
+	struct ads7846		*ts = dev_get_drvdata(dev);
+	struct ser_req		*req = kzalloc(sizeof *req, SLAB_KERNEL);
+	int			status;
+	int			sample;
+	int 			i;
+
+	if (!req)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&req->msg.transfers);
+
+	/* activate reference, so it has time to settle; */
+	req->xfer[0].tx_buf = &ref_on;
+	req->xfer[0].len = 1;
+	req->xfer[1].rx_buf = &req->scratch;
+	req->xfer[1].len = 2;
+
+	/*
+	 * for external VREF, 0 usec (and assume it's always on);
+	 * for 1uF, use 800 usec;
+	 * no cap, 100 usec.
+	 */
+	req->xfer[1].delay_usecs = ts->vref_delay_usecs;
+
+	/* take sample */
+	req->command = (u8) command;
+	req->xfer[2].tx_buf = &req->command;
+	req->xfer[2].len = 1;
+	req->xfer[3].rx_buf = &req->sample;
+	req->xfer[3].len = 2;
+
+	/* REVISIT:  take a few more samples, and compare ... */
+
+	/* turn off reference */
+	req->xfer[4].tx_buf = &ref_off;
+	req->xfer[4].len = 1;
+	req->xfer[5].rx_buf = &req->scratch;
+	req->xfer[5].len = 2;
+
+	CS_CHANGE(req->xfer[5]);
+
+	/* group all the transfers together, so we can't interfere with
+	 * reading touchscreen state; disable penirq while sampling
+	 */
+	for (i = 0; i < 6; i++)
+		spi_message_add_tail(&req->xfer[i], &req->msg);
+
+	disable_irq(spi->irq);
+	status = spi_sync(spi, &req->msg);
+	enable_irq(spi->irq);
+
+	if (req->msg.status)
+		status = req->msg.status;
+	sample = be16_to_cpu(req->sample);
+	sample = sample >> 4;
+	kfree(req);
+
+	return status ? status : sample;
+}
+
+#define SHOW(name) static ssize_t \
+name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+	ssize_t v = ads7846_read12_ser(dev, \
+			READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
+	if (v < 0) \
+		return v; \
+	return sprintf(buf, "%u\n", (unsigned) v); \
+} \
+static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
+
+SHOW(temp0)
+SHOW(temp1)
+SHOW(vaux)
+SHOW(vbatt)
+
+/*--------------------------------------------------------------------------*/
+
+/*
+ * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
+ * to retrieve touchscreen status.
+ *
+ * The SPI transfer completion callback does the real work.  It reports
+ * touchscreen events and reactivates the timer (or IRQ) as appropriate.
+ */
+
+static void ads7846_rx(void *ads)
+{
+	struct ads7846	*ts = ads;
+	unsigned	Rt;
+	unsigned	sync = 0;
+	u16		x, y, z1, z2;
+	unsigned long	flags;
+
+	/* adjust:  12 bit samples (left aligned), built from
+	 * two 8 bit values writen msb-first.
+	 */
+	x = be16_to_cpu(ts->tc.x) >> 4;
+	y = be16_to_cpu(ts->tc.y) >> 4;
+	z1 = be16_to_cpu(ts->tc.z1) >> 4;
+	z2 = be16_to_cpu(ts->tc.z2) >> 4;
+
+	/* range filtering */
+	if (x == MAX_12BIT)
+		x = 0;
+
+	if (x && z1 && ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
+		/* compute touch pressure resistance using equation #2 */
+		Rt = z2;
+		Rt -= z1;
+		Rt *= x;
+		Rt *= ts->x_plate_ohms;
+		Rt /= z1;
+		Rt = (Rt + 2047) >> 12;
+	} else
+		Rt = 0;
+
+	/* NOTE:  "pendown" is inferred from pressure; we don't rely on
+	 * being able to check nPENIRQ status, or "friendly" trigger modes
+	 * (both-edges is much better than just-falling or low-level).
+	 *
+	 * REVISIT:  some boards may require reading nPENIRQ; it's
+	 * needed on 7843.  and 7845 reads pressure differently...
+	 *
+	 * REVISIT:  the touchscreen might not be connected; this code
+	 * won't notice that, even if nPENIRQ never fires ...
+	 */
+	if (!ts->pendown && Rt != 0) {
+		input_report_key(&ts->input, BTN_TOUCH, 1);
+		sync = 1;
+	} else if (ts->pendown && Rt == 0) {
+		input_report_key(&ts->input, BTN_TOUCH, 0);
+		sync = 1;
+	}
+
+	if (Rt) {
+		input_report_abs(&ts->input, ABS_X, x);
+		input_report_abs(&ts->input, ABS_Y, y);
+		input_report_abs(&ts->input, ABS_PRESSURE, Rt);
+		sync = 1;
+	}
+	if (sync)
+		input_sync(&ts->input);
+
+#ifdef	VERBOSE
+	if (Rt || ts->pendown)
+		pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
+			x, y, Rt, Rt ? "" : " UP");
+#endif
+
+	/* don't retrigger while we're suspended */
+	spin_lock_irqsave(&ts->lock, flags);
+
+	ts->pendown = (Rt != 0);
+	ts->pending = 0;
+
+	if (ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
+		if (ts->pendown)
+			mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+		else if (ts->irq_disabled) {
+			ts->irq_disabled = 0;
+			enable_irq(ts->spi->irq);
+		}
+	}
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static void ads7846_timer(unsigned long handle)
+{
+	struct ads7846	*ts = (void *)handle;
+	int		status = 0;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+	if (!ts->pending) {
+		ts->pending = 1;
+		if (!ts->irq_disabled) {
+			ts->irq_disabled = 1;
+			disable_irq(ts->spi->irq);
+		}
+		status = spi_async(ts->spi, &ts->msg);
+		if (status)
+			dev_err(&ts->spi->dev, "spi_async --> %d\n",
+					status);
+	}
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs)
+{
+	ads7846_timer((unsigned long) handle);
+	return IRQ_HANDLED;
+}
+
+/*--------------------------------------------------------------------------*/
+
+static int
+ads7846_suspend(struct spi_device *spi, pm_message_t message)
+{
+	struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+
+	spi->dev.power.power_state = message;
+
+	/* are we waiting for IRQ, or polling? */
+	if (!ts->pendown) {
+		if (!ts->irq_disabled) {
+			ts->irq_disabled = 1;
+			disable_irq(ts->spi->irq);
+		}
+	} else {
+		/* polling; force a final SPI completion;
+		 * that will clean things up neatly
+		 */
+		if (!ts->pending)
+			mod_timer(&ts->timer, jiffies);
+
+		while (ts->pendown || ts->pending) {
+			spin_unlock_irqrestore(&ts->lock, flags);
+			udelay(10);
+			spin_lock_irqsave(&ts->lock, flags);
+		}
+	}
+
+	/* we know the chip's in lowpower mode since we always
+	 * leave it that way after every request
+	 */
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+	return 0;
+}
+
+static int ads7846_resume(struct spi_device *spi)
+{
+	struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+
+	ts->irq_disabled = 0;
+	enable_irq(ts->spi->irq);
+	spi->dev.power.power_state = PMSG_ON;
+	return 0;
+}
+
+static int __devinit ads7846_probe(struct spi_device *spi)
+{
+	struct ads7846			*ts;
+	struct ads7846_platform_data	*pdata = spi->dev.platform_data;
+	struct spi_transfer		*x;
+	int				i;
+
+	if (!spi->irq) {
+		dev_dbg(&spi->dev, "no IRQ?\n");
+		return -ENODEV;
+	}
+
+	if (!pdata) {
+		dev_dbg(&spi->dev, "no platform data?\n");
+		return -ENODEV;
+	}
+
+	/* don't exceed max specified sample rate */
+	if (spi->max_speed_hz > (125000 * 16)) {
+		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
+				(spi->max_speed_hz/16)/1000);
+		return -EINVAL;
+	}
+
+	/* We'd set the wordsize to 12 bits ... except that some controllers
+	 * will then treat the 8 bit command words as 12 bits (and drop the
+	 * four MSBs of the 12 bit result).  Result: inputs must be shifted
+	 * to discard the four garbage LSBs.
+	 */
+
+	if (!(ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL)))
+		return -ENOMEM;
+
+	dev_set_drvdata(&spi->dev, ts);
+
+	ts->spi = spi;
+	spi->dev.power.power_state = PMSG_ON;
+
+	init_timer(&ts->timer);
+	ts->timer.data = (unsigned long) ts;
+	ts->timer.function = ads7846_timer;
+
+	ts->model = pdata->model ? : 7846;
+	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
+	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
+
+	init_input_dev(&ts->input);
+
+	ts->input.dev = &spi->dev;
+	ts->input.name = "ADS784x Touchscreen";
+	snprintf(ts->phys, sizeof ts->phys, "%s/input0", spi->dev.bus_id);
+	ts->input.phys = ts->phys;
+
+	ts->input.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
+	ts->input.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+	input_set_abs_params(&ts->input, ABS_X,
+			pdata->x_min ? : 0,
+			pdata->x_max ? : MAX_12BIT,
+			0, 0);
+	input_set_abs_params(&ts->input, ABS_Y,
+			pdata->y_min ? : 0,
+			pdata->y_max ? : MAX_12BIT,
+			0, 0);
+	input_set_abs_params(&ts->input, ABS_PRESSURE,
+			pdata->pressure_min, pdata->pressure_max, 0, 0);
+
+	input_register_device(&ts->input);
+
+	/* set up the transfers to read touchscreen state; this assumes we
+	 * use formula #2 for pressure, not #3.
+	 */
+	x = ts->xfer;
+
+	/* y- still on; turn on only y+ (and ADC) */
+	x->tx_buf = &read_y;
+	x->len = 1;
+	x++;
+	x->rx_buf = &ts->tc.y;
+	x->len = 2;
+	x++;
+
+	/* turn y+ off, x- on; we'll use formula #2 */
+	if (ts->model == 7846) {
+		x->tx_buf = &read_z1;
+		x->len = 1;
+		x++;
+		x->rx_buf = &ts->tc.z1;
+		x->len = 2;
+		x++;
+
+		x->tx_buf = &read_z2;
+		x->len = 1;
+		x++;
+		x->rx_buf = &ts->tc.z2;
+		x->len = 2;
+		x++;
+	}
+
+	/* turn y- off, x+ on, then leave in lowpower */
+	x->tx_buf = &read_x;
+	x->len = 1;
+	x++;
+	x->rx_buf = &ts->tc.x;
+	x->len = 2;
+	x++;
+
+	CS_CHANGE(x[-1]);
+
+	for (i = 0; i < x - ts->xfer; i++)
+		spi_message_add_tail(&ts->xfer[i], &ts->msg);
+	ts->msg.complete = ads7846_rx;
+	ts->msg.context = ts;
+
+	if (request_irq(spi->irq, ads7846_irq, SA_SAMPLE_RANDOM,
+				spi->dev.bus_id, ts)) {
+		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
+		input_unregister_device(&ts->input);
+		kfree(ts);
+		return -EBUSY;
+	}
+	set_irq_type(spi->irq, IRQT_FALLING);
+
+	dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
+
+	/* take a first sample, leaving nPENIRQ active; avoid
+	 * the touchscreen, in case it's not connected.
+	 */
+	(void) ads7846_read12_ser(&spi->dev,
+			  READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
+
+	/* ads7843/7845 don't have temperature sensors, and
+	 * use the other sensors a bit differently too
+	 */
+	if (ts->model == 7846) {
+		device_create_file(&spi->dev, &dev_attr_temp0);
+		device_create_file(&spi->dev, &dev_attr_temp1);
+	}
+	if (ts->model != 7845)
+		device_create_file(&spi->dev, &dev_attr_vbatt);
+	device_create_file(&spi->dev, &dev_attr_vaux);
+
+	return 0;
+}
+
+static int __devexit ads7846_remove(struct spi_device *spi)
+{
+	struct ads7846		*ts = dev_get_drvdata(&spi->dev);
+
+	ads7846_suspend(spi, PMSG_SUSPEND);
+	free_irq(ts->spi->irq, ts);
+	if (ts->irq_disabled)
+		enable_irq(ts->spi->irq);
+
+	if (ts->model == 7846) {
+		device_remove_file(&spi->dev, &dev_attr_temp0);
+		device_remove_file(&spi->dev, &dev_attr_temp1);
+	}
+	if (ts->model != 7845)
+		device_remove_file(&spi->dev, &dev_attr_vbatt);
+	device_remove_file(&spi->dev, &dev_attr_vaux);
+
+	input_unregister_device(&ts->input);
+	kfree(ts);
+
+	dev_dbg(&spi->dev, "unregistered touchscreen\n");
+	return 0;
+}
+
+static struct spi_driver ads7846_driver = {
+	.driver = {
+		.name	= "ads7846",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ads7846_probe,
+	.remove		= __devexit_p(ads7846_remove),
+	.suspend	= ads7846_suspend,
+	.resume		= ads7846_resume,
+};
+
+static int __init ads7846_init(void)
+{
+	/* grr, board-specific init should stay out of drivers!! */
+
+#ifdef	CONFIG_ARCH_OMAP
+	if (machine_is_omap_osk()) {
+		/* GPIO4 = PENIRQ; GPIO6 = BUSY */
+		omap_request_gpio(4);
+		omap_set_gpio_direction(4, 1);
+		omap_request_gpio(6);
+		omap_set_gpio_direction(6, 1);
+	}
+	// also TI 1510 Innovator, bitbanging through FPGA
+	// also Nokia 770
+	// also Palm Tungsten T2
+#endif
+
+	// PXA:
+	// also Dell Axim X50
+	// also HP iPaq H191x/H192x/H415x/H435x
+	// also Intel Lubbock (additional to UCB1400; as temperature sensor)
+	// also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
+
+	// Atmel at91sam9261-EK uses ads7843
+
+	// also various AMD Au1x00 devel boards
+
+	return spi_register_driver(&ads7846_driver);
+}
+module_init(ads7846_init);
+
+static void __exit ads7846_exit(void)
+{
+	spi_unregister_driver(&ads7846_driver);
+
+#ifdef	CONFIG_ARCH_OMAP
+	if (machine_is_omap_osk()) {
+		omap_free_gpio(4);
+		omap_free_gpio(6);
+	}
+#endif
+
+}
+module_exit(ads7846_exit);
+
+MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 9a2aa40..5038e90 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -47,6 +47,22 @@ config MTD_MS02NV
 	  accelerator.  Say Y here if you have a DECstation 5000/2x0 or a
 	  DECsystem 5900 equipped with such a module.
 
+config MTD_DATAFLASH
+	tristate "Support for AT45xxx DataFlash"
+	depends on MTD && SPI_MASTER && EXPERIMENTAL
+	help
+	  This enables access to AT45xxx DataFlash chips, using SPI.
+	  Sometimes DataFlash chips are packaged inside MMC-format
+	  cards; at this writing, the MMC stack won't handle those.
+
+config MTD_M25P80
+	tristate "Support for M25 SPI Flash"
+	depends on MTD && SPI_MASTER && EXPERIMENTAL
+	help
+	  This enables access to ST M25P80 and similar SPI flash chips,
+	  used for program and data storage.  Set up your spi devices
+	  with the right board-specific platform data.
+
 config MTD_SLRAM
 	tristate "Uncached system RAM"
 	depends on MTD
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index e38db34..7c5ed21 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -23,3 +23,5 @@ obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
 obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLKMTD)	+= blkmtd.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
+obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
+obj-$(CONFIG_MTD_M25P80)	+= m25p80.o
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
new file mode 100644
index 0000000..d5f2408
--- /dev/null
+++ b/drivers/mtd/devices/m25p80.c
@@ -0,0 +1,582 @@
+/*
+ * MTD SPI driver for ST M25Pxx flash chips
+ *
+ * Author: Mike Lavender, mike@steroidmicros.com
+ *
+ * Copyright (c) 2005, Intec Automation Inc.
+ *
+ * Some parts are based on lart.c by Abraham Van Der Merwe
+ *
+ * Cleaned up and generalized based on mtd_dataflash.c
+ *
+ * This code is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/flash.h>
+
+#include <asm/semaphore.h>
+
+
+/* NOTE: AT 25F and SST 25LF series are very similar,
+ * but commands for sector erase and chip id differ...
+ */
+
+#define FLASH_PAGESIZE		256
+
+/* Flash opcodes. */
+#define	OPCODE_WREN		6	/* Write enable */
+#define	OPCODE_RDSR		5	/* Read status register */
+#define	OPCODE_READ		3	/* Read data bytes */
+#define	OPCODE_PP		2	/* Page program */
+#define	OPCODE_SE		0xd8	/* Sector erase */
+#define	OPCODE_RES		0xab	/* Read Electronic Signature */
+#define	OPCODE_RDID		0x9f	/* Read JEDEC ID */
+
+/* Status Register bits. */
+#define	SR_WIP			1	/* Write in progress */
+#define	SR_WEL			2	/* Write enable latch */
+#define	SR_BP0			4	/* Block protect 0 */
+#define	SR_BP1			8	/* Block protect 1 */
+#define	SR_BP2			0x10	/* Block protect 2 */
+#define	SR_SRWD			0x80	/* SR write protect */
+
+/* Define max times to check status register before we give up. */
+#define	MAX_READY_WAIT_COUNT	100000
+
+
+#ifdef CONFIG_MTD_PARTITIONS
+#define	mtd_has_partitions()	(1)
+#else
+#define	mtd_has_partitions()	(0)
+#endif
+
+/****************************************************************************/
+
+struct m25p {
+	struct spi_device	*spi;
+	struct semaphore	lock;
+	struct mtd_info		mtd;
+	unsigned		partitioned;
+	u8			command[4];
+};
+
+static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
+{
+	return container_of(mtd, struct m25p, mtd);
+}
+
+/****************************************************************************/
+
+/*
+ * Internal helper functions
+ */
+
+/*
+ * Read the status register, returning its value in the location
+ * Return the status register value.
+ * Returns negative if error occurred.
+ */
+static int read_sr(struct m25p *flash)
+{
+	ssize_t retval;
+	u8 code = OPCODE_RDSR;
+	u8 val;
+
+	retval = spi_write_then_read(flash->spi, &code, 1, &val, 1);
+
+	if (retval < 0) {
+		dev_err(&flash->spi->dev, "error %d reading SR\n",
+				(int) retval);
+		return retval;
+	}
+
+	return val;
+}
+
+
+/*
+ * Set write enable latch with Write Enable command.
+ * Returns negative if error occurred.
+ */
+static inline int write_enable(struct m25p *flash)
+{
+	u8	code = OPCODE_WREN;
+
+	return spi_write_then_read(flash->spi, &code, 1, NULL, 0);
+}
+
+
+/*
+ * Service routine to read status register until ready, or timeout occurs.
+ * Returns non-zero if error.
+ */
+static int wait_till_ready(struct m25p *flash)
+{
+	int count;
+	int sr;
+
+	/* one chip guarantees max 5 msec wait here after page writes,
+	 * but potentially three seconds (!) after page erase.
+	 */
+	for (count = 0; count < MAX_READY_WAIT_COUNT; count++) {
+		if ((sr = read_sr(flash)) < 0)
+			break;
+		else if (!(sr & SR_WIP))
+			return 0;
+
+		/* REVISIT sometimes sleeping would be best */
+	}
+
+	return 1;
+}
+
+
+/*
+ * Erase one sector of flash memory at offset ``offset'' which is any
+ * address within the sector which should be erased.
+ *
+ * Returns 0 if successful, non-zero otherwise.
+ */
+static int erase_sector(struct m25p *flash, u32 offset)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "%s: %s at 0x%08x\n", flash->spi->dev.bus_id,
+			__FUNCTION__, offset);
+
+	/* Wait until finished previous write command. */
+	if (wait_till_ready(flash))
+		return 1;
+
+	/* Send write enable, then erase commands. */
+	write_enable(flash);
+
+	/* Set up command buffer. */
+	flash->command[0] = OPCODE_SE;
+	flash->command[1] = offset >> 16;
+	flash->command[2] = offset >> 8;
+	flash->command[3] = offset;
+
+	spi_write(flash->spi, flash->command, sizeof(flash->command));
+
+	return 0;
+}
+
+/****************************************************************************/
+
+/*
+ * MTD implementation
+ */
+
+/*
+ * Erase an address range on the flash chip.  The address range may extend
+ * one or more erase sectors.  Return an error is there is a problem erasing.
+ */
+static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct m25p *flash = mtd_to_m25p(mtd);
+	u32 addr,len;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
+			flash->spi->dev.bus_id, __FUNCTION__, "at",
+			(u32)instr->addr, instr->len);
+
+	/* sanity checks */
+	if (instr->addr + instr->len > flash->mtd.size)
+		return -EINVAL;
+	if ((instr->addr % mtd->erasesize) != 0
+			|| (instr->len % mtd->erasesize) != 0) {
+		return -EINVAL;
+	}
+
+	addr = instr->addr;
+	len = instr->len;
+
+  	down(&flash->lock);
+
+	/* now erase those sectors */
+	while (len) {
+		if (erase_sector(flash, addr)) {
+			instr->state = MTD_ERASE_FAILED;
+			up(&flash->lock);
+			return -EIO;
+		}
+
+		addr += mtd->erasesize;
+		len -= mtd->erasesize;
+	}
+
+  	up(&flash->lock);
+
+	instr->state = MTD_ERASE_DONE;
+	mtd_erase_callback(instr);
+
+	return 0;
+}
+
+/*
+ * Read an address range from the flash chip.  The address range
+ * may be any size provided it is within the physical boundaries.
+ */
+static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
+	size_t *retlen, u_char *buf)
+{
+	struct m25p *flash = mtd_to_m25p(mtd);
+	struct spi_transfer t[2];
+	struct spi_message m;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
+			flash->spi->dev.bus_id, __FUNCTION__, "from",
+			(u32)from, len);
+
+	/* sanity checks */
+	if (!len)
+		return 0;
+
+	if (from + len > flash->mtd.size)
+		return -EINVAL;
+
+	spi_message_init(&m);
+	memset(t, 0, (sizeof t));
+
+	t[0].tx_buf = flash->command;
+	t[0].len = sizeof(flash->command);
+	spi_message_add_tail(&t[0], &m);
+
+	t[1].rx_buf = buf;
+	t[1].len = len;
+	spi_message_add_tail(&t[1], &m);
+
+	/* Byte count starts at zero. */
+	if (retlen)
+		*retlen = 0;
+
+	down(&flash->lock);
+
+	/* Wait till previous write/erase is done. */
+	if (wait_till_ready(flash)) {
+		/* REVISIT status return?? */
+		up(&flash->lock);
+		return 1;
+	}
+
+	/* NOTE:  OPCODE_FAST_READ (if available) is faster... */
+
+	/* Set up the write data buffer. */
+	flash->command[0] = OPCODE_READ;
+	flash->command[1] = from >> 16;
+	flash->command[2] = from >> 8;
+	flash->command[3] = from;
+
+	spi_sync(flash->spi, &m);
+
+	*retlen = m.actual_length - sizeof(flash->command);
+
+  	up(&flash->lock);
+
+	return 0;
+}
+
+/*
+ * Write an address range to the flash chip.  Data must be written in
+ * FLASH_PAGESIZE chunks.  The address range may be any size provided
+ * it is within the physical boundaries.
+ */
+static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
+	size_t *retlen, const u_char *buf)
+{
+	struct m25p *flash = mtd_to_m25p(mtd);
+	u32 page_offset, page_size;
+	struct spi_transfer t[2];
+	struct spi_message m;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
+			flash->spi->dev.bus_id, __FUNCTION__, "to",
+			(u32)to, len);
+
+	if (retlen)
+		*retlen = 0;
+
+	/* sanity checks */
+	if (!len)
+		return(0);
+
+	if (to + len > flash->mtd.size)
+		return -EINVAL;
+
+	spi_message_init(&m);
+	memset(t, 0, (sizeof t));
+
+	t[0].tx_buf = flash->command;
+	t[0].len = sizeof(flash->command);
+	spi_message_add_tail(&t[0], &m);
+
+	t[1].tx_buf = buf;
+	spi_message_add_tail(&t[1], &m);
+
+  	down(&flash->lock);
+
+	/* Wait until finished previous write command. */
+	if (wait_till_ready(flash))
+		return 1;
+
+	write_enable(flash);
+
+	/* Set up the opcode in the write buffer. */
+	flash->command[0] = OPCODE_PP;
+	flash->command[1] = to >> 16;
+	flash->command[2] = to >> 8;
+	flash->command[3] = to;
+
+	/* what page do we start with? */
+	page_offset = to % FLASH_PAGESIZE;
+
+	/* do all the bytes fit onto one page? */
+	if (page_offset + len <= FLASH_PAGESIZE) {
+		t[1].len = len;
+
+		spi_sync(flash->spi, &m);
+
+		*retlen = m.actual_length - sizeof(flash->command);
+	} else {
+		u32 i;
+
+		/* the size of data remaining on the first page */
+		page_size = FLASH_PAGESIZE - page_offset;
+
+		t[1].len = page_size;
+		spi_sync(flash->spi, &m);
+
+		*retlen = m.actual_length - sizeof(flash->command);
+
+		/* write everything in PAGESIZE chunks */
+		for (i = page_size; i < len; i += page_size) {
+			page_size = len - i;
+			if (page_size > FLASH_PAGESIZE)
+				page_size = FLASH_PAGESIZE;
+
+			/* write the next page to flash */
+			flash->command[1] = (to + i) >> 16;
+			flash->command[2] = (to + i) >> 8;
+			flash->command[3] = (to + i);
+
+			t[1].tx_buf = buf + i;
+			t[1].len = page_size;
+
+			wait_till_ready(flash);
+
+			write_enable(flash);
+
+			spi_sync(flash->spi, &m);
+
+			if (retlen)
+				*retlen += m.actual_length
+					- sizeof(flash->command);
+	        }
+ 	}
+
+	up(&flash->lock);
+
+	return 0;
+}
+
+
+/****************************************************************************/
+
+/*
+ * SPI device driver setup and teardown
+ */
+
+struct flash_info {
+	char		*name;
+	u8		id;
+	u16		jedec_id;
+	unsigned	sector_size;
+	unsigned	n_sectors;
+};
+
+static struct flash_info __devinitdata m25p_data [] = {
+	/* REVISIT: fill in JEDEC ids, for parts that have them */
+	{ "m25p05", 0x05, 0x0000, 32 * 1024, 2 },
+	{ "m25p10", 0x10, 0x0000, 32 * 1024, 4 },
+	{ "m25p20", 0x11, 0x0000, 64 * 1024, 4 },
+	{ "m25p40", 0x12, 0x0000, 64 * 1024, 8 },
+	{ "m25p80", 0x13, 0x0000, 64 * 1024, 16 },
+	{ "m25p16", 0x14, 0x0000, 64 * 1024, 32 },
+	{ "m25p32", 0x15, 0x0000, 64 * 1024, 64 },
+	{ "m25p64", 0x16, 0x2017, 64 * 1024, 128 },
+};
+
+/*
+ * board specific setup should have ensured the SPI clock used here
+ * matches what the READ command supports, at least until this driver
+ * understands FAST_READ (for clocks over 25 MHz).
+ */
+static int __devinit m25p_probe(struct spi_device *spi)
+{
+	struct flash_platform_data	*data;
+	struct m25p			*flash;
+	struct flash_info		*info;
+	unsigned			i;
+
+	/* Platform data helps sort out which chip type we have, as
+	 * well as how this board partitions it.
+	 */
+	data = spi->dev.platform_data;
+	if (!data || !data->type) {
+		/* FIXME some chips can identify themselves with RES
+		 * or JEDEC get-id commands.  Try them ...
+		 */
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: no chip id\n",
+				flash->spi->dev.bus_id);
+		return -ENODEV;
+	}
+
+	for (i = 0, info = m25p_data; i < ARRAY_SIZE(m25p_data); i++, info++) {
+		if (strcmp(data->type, info->name) == 0)
+			break;
+	}
+	if (i == ARRAY_SIZE(m25p_data)) {
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: unrecognized id %s\n",
+				flash->spi->dev.bus_id, data->type);
+		return -ENODEV;
+	}
+
+	flash = kzalloc(sizeof *flash, SLAB_KERNEL);
+	if (!flash)
+		return -ENOMEM;
+
+	flash->spi = spi;
+	init_MUTEX(&flash->lock);
+	dev_set_drvdata(&spi->dev, flash);
+
+	if (data->name)
+		flash->mtd.name = data->name;
+	else
+		flash->mtd.name = spi->dev.bus_id;
+
+	flash->mtd.type = MTD_NORFLASH;
+	flash->mtd.flags = MTD_CAP_NORFLASH;
+	flash->mtd.size = info->sector_size * info->n_sectors;
+	flash->mtd.erasesize = info->sector_size;
+	flash->mtd.erase = m25p80_erase;
+	flash->mtd.read = m25p80_read;
+	flash->mtd.write = m25p80_write;
+
+	dev_info(&spi->dev, "%s (%d Kbytes)\n", info->name,
+			flash->mtd.size / 1024);
+
+	DEBUG(MTD_DEBUG_LEVEL2,
+		"mtd .name = %s, .size = 0x%.8x (%uM) "
+			".erasesize = 0x%.8x (%uK) .numeraseregions = %d\n",
+		flash->mtd.name,
+		flash->mtd.size, flash->mtd.size / (1024*1024),
+		flash->mtd.erasesize, flash->mtd.erasesize / 1024,
+		flash->mtd.numeraseregions);
+
+	if (flash->mtd.numeraseregions)
+		for (i = 0; i < flash->mtd.numeraseregions; i++)
+			DEBUG(MTD_DEBUG_LEVEL2,
+				"mtd.eraseregions[%d] = { .offset = 0x%.8x, "
+				".erasesize = 0x%.8x (%uK), "
+				".numblocks = %d }\n",
+				i, flash->mtd.eraseregions[i].offset,
+				flash->mtd.eraseregions[i].erasesize,
+				flash->mtd.eraseregions[i].erasesize / 1024,
+				flash->mtd.eraseregions[i].numblocks);
+
+
+	/* partitions should match sector boundaries; and it may be good to
+	 * use readonly partitions for writeprotected sectors (BP2..BP0).
+	 */
+	if (mtd_has_partitions()) {
+		struct mtd_partition	*parts = NULL;
+		int			nr_parts = 0;
+
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+		static const char *part_probes[] = { "cmdlinepart", NULL, };
+
+		nr_parts = parse_mtd_partitions(&flash->mtd,
+				part_probes, &parts, 0);
+#endif
+
+		if (nr_parts <= 0 && data && data->parts) {
+			parts = data->parts;
+			nr_parts = data->nr_parts;
+		}
+
+		if (nr_parts > 0) {
+			for (i = 0; i < data->nr_parts; i++) {
+				DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
+					"{.name = %s, .offset = 0x%.8x, "
+						".size = 0x%.8x (%uK) }\n",
+					i, data->parts[i].name,
+					data->parts[i].offset,
+					data->parts[i].size,
+					data->parts[i].size / 1024);
+			}
+			flash->partitioned = 1;
+			return add_mtd_partitions(&flash->mtd, parts, nr_parts);
+		}
+	} else if (data->nr_parts)
+		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
+				data->nr_parts, data->name);
+
+	return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;
+}
+
+
+static int __devexit m25p_remove(struct spi_device *spi)
+{
+	struct m25p	*flash = dev_get_drvdata(&spi->dev);
+	int		status;
+
+	/* Clean up MTD stuff. */
+	if (mtd_has_partitions() && flash->partitioned)
+		status = del_mtd_partitions(&flash->mtd);
+	else
+		status = del_mtd_device(&flash->mtd);
+	if (status == 0)
+		kfree(flash);
+	return 0;
+}
+
+
+static struct spi_driver m25p80_driver = {
+	.driver = {
+		.name	= "m25p80",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe	= m25p_probe,
+	.remove	= __devexit_p(m25p_remove),
+};
+
+
+static int m25p80_init(void)
+{
+	return spi_register_driver(&m25p80_driver);
+}
+
+
+static void m25p80_exit(void)
+{
+	spi_unregister_driver(&m25p80_driver);
+}
+
+
+module_init(m25p80_init);
+module_exit(m25p80_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mike Lavender");
+MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
new file mode 100644
index 0000000..155737e
--- /dev/null
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -0,0 +1,629 @@
+/*
+ * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
+ *
+ * Largely derived from at91_dataflash.c:
+ *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+*/
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/flash.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+
+/*
+ * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
+ * each chip, which may be used for double buffered I/O; but this driver
+ * doesn't (yet) use these for any kind of i/o overlap or prefetching.
+ *
+ * Sometimes DataFlash is packaged in MMC-format cards, although the
+ * MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash
+ * protocols during enumeration.
+ */
+
+#define CONFIG_DATAFLASH_WRITE_VERIFY
+
+/* reads can bypass the buffers */
+#define OP_READ_CONTINUOUS	0xE8
+#define OP_READ_PAGE		0xD2
+
+/* group B requests can run even while status reports "busy" */
+#define OP_READ_STATUS		0xD7	/* group B */
+
+/* move data between host and buffer */
+#define OP_READ_BUFFER1		0xD4	/* group B */
+#define OP_READ_BUFFER2		0xD6	/* group B */
+#define OP_WRITE_BUFFER1	0x84	/* group B */
+#define OP_WRITE_BUFFER2	0x87	/* group B */
+
+/* erasing flash */
+#define OP_ERASE_PAGE		0x81
+#define OP_ERASE_BLOCK		0x50
+
+/* move data between buffer and flash */
+#define OP_TRANSFER_BUF1	0x53
+#define OP_TRANSFER_BUF2	0x55
+#define OP_MREAD_BUFFER1	0xD4
+#define OP_MREAD_BUFFER2	0xD6
+#define OP_MWERASE_BUFFER1	0x83
+#define OP_MWERASE_BUFFER2	0x86
+#define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
+#define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */
+
+/* write to buffer, then write-erase to flash */
+#define OP_PROGRAM_VIA_BUF1	0x82
+#define OP_PROGRAM_VIA_BUF2	0x85
+
+/* compare buffer to flash */
+#define OP_COMPARE_BUF1		0x60
+#define OP_COMPARE_BUF2		0x61
+
+/* read flash to buffer, then write-erase to flash */
+#define OP_REWRITE_VIA_BUF1	0x58
+#define OP_REWRITE_VIA_BUF2	0x59
+
+/* newer chips report JEDEC manufacturer and device IDs; chip
+ * serial number and OTP bits; and per-sector writeprotect.
+ */
+#define OP_READ_ID		0x9F
+#define OP_READ_SECURITY	0x77
+#define OP_WRITE_SECURITY	0x9A	/* OTP bits */
+
+
+struct dataflash {
+	u8			command[4];
+	char			name[24];
+
+	unsigned		partitioned:1;
+
+	unsigned short		page_offset;	/* offset in flash address */
+	unsigned int		page_size;	/* of bytes per page */
+
+	struct semaphore	lock;
+	struct spi_device	*spi;
+
+	struct mtd_info		mtd;
+};
+
+#ifdef CONFIG_MTD_PARTITIONS
+#define	mtd_has_partitions()	(1)
+#else
+#define	mtd_has_partitions()	(0)
+#endif
+
+/* ......................................................................... */
+
+/*
+ * Return the status of the DataFlash device.
+ */
+static inline int dataflash_status(struct spi_device *spi)
+{
+	/* NOTE:  at45db321c over 25 MHz wants to write
+	 * a dummy byte after the opcode...
+	 */
+	return spi_w8r8(spi, OP_READ_STATUS);
+}
+
+/*
+ * Poll the DataFlash device until it is READY.
+ * This usually takes 5-20 msec or so; more for sector erase.
+ */
+static int dataflash_waitready(struct spi_device *spi)
+{
+	int	status;
+
+	for (;;) {
+		status = dataflash_status(spi);
+		if (status < 0) {
+			DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
+					spi->dev.bus_id, status);
+			status = 0;
+		}
+
+		if (status & (1 << 7))	/* RDY/nBSY */
+			return status;
+
+		msleep(3);
+	}
+}
+
+/* ......................................................................... */
+
+/*
+ * Erase pages of flash.
+ */
+static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct dataflash	*priv = (struct dataflash *)mtd->priv;
+	struct spi_device	*spi = priv->spi;
+	struct spi_transfer	x = { .tx_dma = 0, };
+	struct spi_message	msg;
+	unsigned		blocksize = priv->page_size << 3;
+	u8			*command;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n",
+			spi->dev.bus_id,
+			instr->addr, instr->len);
+
+	/* Sanity checks */
+	if ((instr->addr + instr->len) > mtd->size
+			|| (instr->len % priv->page_size) != 0
+			|| (instr->addr % priv->page_size) != 0)
+		return -EINVAL;
+
+	spi_message_init(&msg);
+
+	x.tx_buf = command = priv->command;
+	x.len = 4;
+	spi_message_add_tail(&x, &msg);
+
+	down(&priv->lock);
+	while (instr->len > 0) {
+		unsigned int	pageaddr;
+		int		status;
+		int		do_block;
+
+		/* Calculate flash page address; use block erase (for speed) if
+		 * we're at a block boundary and need to erase the whole block.
+		 */
+		pageaddr = instr->addr / priv->page_size;
+		do_block = (pageaddr & 0x7) == 0 && instr->len <= blocksize;
+		pageaddr = pageaddr << priv->page_offset;
+
+		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
+		command[1] = (u8)(pageaddr >> 16);
+		command[2] = (u8)(pageaddr >> 8);
+		command[3] = 0;
+
+		DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
+			do_block ? "block" : "page",
+			command[0], command[1], command[2], command[3],
+			pageaddr);
+
+		status = spi_sync(spi, &msg);
+		(void) dataflash_waitready(spi);
+
+		if (status < 0) {
+			printk(KERN_ERR "%s: erase %x, err %d\n",
+				spi->dev.bus_id, pageaddr, status);
+			/* REVISIT:  can retry instr->retries times; or
+			 * giveup and instr->fail_addr = instr->addr;
+			 */
+			continue;
+		}
+
+		if (do_block) {
+			instr->addr += blocksize;
+			instr->len -= blocksize;
+		} else {
+			instr->addr += priv->page_size;
+			instr->len -= priv->page_size;
+		}
+	}
+	up(&priv->lock);
+
+	/* Inform MTD subsystem that erase is complete */
+	instr->state = MTD_ERASE_DONE;
+	mtd_erase_callback(instr);
+
+	return 0;
+}
+
+/*
+ * Read from the DataFlash device.
+ *   from   : Start offset in flash device
+ *   len    : Amount to read
+ *   retlen : About of data actually read
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
+			       size_t *retlen, u_char *buf)
+{
+	struct dataflash	*priv = (struct dataflash *)mtd->priv;
+	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
+	struct spi_message	msg;
+	unsigned int		addr;
+	u8			*command;
+	int			status;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
+		priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len));
+
+	*retlen = 0;
+
+	/* Sanity checks */
+	if (!len)
+		return 0;
+	if (from + len > mtd->size)
+		return -EINVAL;
+
+	/* Calculate flash page/byte address */
+	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
+		+ ((unsigned)from % priv->page_size);
+
+	command = priv->command;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
+		command[0], command[1], command[2], command[3]);
+
+	spi_message_init(&msg);
+
+	x[0].tx_buf = command;
+	x[0].len = 8;
+	spi_message_add_tail(&x[0], &msg);
+
+	x[1].rx_buf = buf;
+	x[1].len = len;
+	spi_message_add_tail(&x[1], &msg);
+
+	down(&priv->lock);
+
+	/* Continuous read, max clock = f(car) which may be less than
+	 * the peak rate available.  Some chips support commands with
+	 * fewer "don't care" bytes.  Both buffers stay unchanged.
+	 */
+	command[0] = OP_READ_CONTINUOUS;
+	command[1] = (u8)(addr >> 16);
+	command[2] = (u8)(addr >> 8);
+	command[3] = (u8)(addr >> 0);
+	/* plus 4 "don't care" bytes */
+
+	status = spi_sync(priv->spi, &msg);
+	up(&priv->lock);
+
+	if (status >= 0) {
+		*retlen = msg.actual_length - 8;
+		status = 0;
+	} else
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
+			priv->spi->dev.bus_id,
+			(unsigned)from, (unsigned)(from + len),
+			status);
+	return status;
+}
+
+/*
+ * Write to the DataFlash device.
+ *   to     : Start offset in flash device
+ *   len    : Amount to write
+ *   retlen : Amount of data actually written
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
+				size_t * retlen, const u_char * buf)
+{
+	struct dataflash	*priv = (struct dataflash *)mtd->priv;
+	struct spi_device	*spi = priv->spi;
+	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
+	struct spi_message	msg;
+	unsigned int		pageaddr, addr, offset, writelen;
+	size_t			remaining = len;
+	u_char			*writebuf = (u_char *) buf;
+	int			status = -EINVAL;
+	u8			*command;
+
+	DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
+		spi->dev.bus_id, (unsigned)to, (unsigned)(to + len));
+
+	*retlen = 0;
+
+	/* Sanity checks */
+	if (!len)
+		return 0;
+	if ((to + len) > mtd->size)
+		return -EINVAL;
+
+	spi_message_init(&msg);
+
+	x[0].tx_buf = command = priv->command;
+	x[0].len = 4;
+	spi_message_add_tail(&x[0], &msg);
+
+	pageaddr = ((unsigned)to / priv->page_size);
+	offset = ((unsigned)to % priv->page_size);
+	if (offset + len > priv->page_size)
+		writelen = priv->page_size - offset;
+	else
+		writelen = len;
+
+	down(&priv->lock);
+	while (remaining > 0) {
+		DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
+			pageaddr, offset, writelen);
+
+		/* REVISIT:
+		 * (a) each page in a sector must be rewritten at least
+		 *     once every 10K sibling erase/program operations.
+		 * (b) for pages that are already erased, we could
+		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
+		 * (c) WRITE to buffer could be done while waiting for
+		 *     a previous MWRITE/MWERASE to complete ...
+		 * (d) error handling here seems to be mostly missing.
+		 *
+		 * Two persistent bits per page, plus a per-sector counter,
+		 * could support (a) and (b) ... we might consider using
+		 * the second half of sector zero, which is just one block,
+		 * to track that state.  (On AT91, that sector should also
+		 * support boot-from-DataFlash.)
+		 */
+
+		addr = pageaddr << priv->page_offset;
+
+		/* (1) Maybe transfer partial page to Buffer1 */
+		if (writelen != priv->page_size) {
+			command[0] = OP_TRANSFER_BUF1;
+			command[1] = (addr & 0x00FF0000) >> 16;
+			command[2] = (addr & 0x0000FF00) >> 8;
+			command[3] = 0;
+
+			DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
+				command[0], command[1], command[2], command[3]);
+
+			status = spi_sync(spi, &msg);
+			if (status < 0)
+				DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
+					spi->dev.bus_id, addr, status);
+
+			(void) dataflash_waitready(priv->spi);
+		}
+
+		/* (2) Program full page via Buffer1 */
+		addr += offset;
+		command[0] = OP_PROGRAM_VIA_BUF1;
+		command[1] = (addr & 0x00FF0000) >> 16;
+		command[2] = (addr & 0x0000FF00) >> 8;
+		command[3] = (addr & 0x000000FF);
+
+		DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
+			command[0], command[1], command[2], command[3]);
+
+		x[1].tx_buf = writebuf;
+		x[1].len = writelen;
+		spi_message_add_tail(x + 1, &msg);
+		status = spi_sync(spi, &msg);
+		spi_transfer_del(x + 1);
+		if (status < 0)
+			DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
+				spi->dev.bus_id, addr, writelen, status);
+
+		(void) dataflash_waitready(priv->spi);
+
+
+#ifdef	CONFIG_DATAFLASH_WRITE_VERIFY
+
+		/* (3) Compare to Buffer1 */
+		addr = pageaddr << priv->page_offset;
+		command[0] = OP_COMPARE_BUF1;
+		command[1] = (addr & 0x00FF0000) >> 16;
+		command[2] = (addr & 0x0000FF00) >> 8;
+		command[3] = 0;
+
+		DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
+			command[0], command[1], command[2], command[3]);
+
+		status = spi_sync(spi, &msg);
+		if (status < 0)
+			DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
+				spi->dev.bus_id, addr, status);
+
+		status = dataflash_waitready(priv->spi);
+
+		/* Check result of the compare operation */
+		if ((status & (1 << 6)) == 1) {
+			printk(KERN_ERR "%s: compare page %u, err %d\n",
+				spi->dev.bus_id, pageaddr, status);
+			remaining = 0;
+			status = -EIO;
+			break;
+		} else
+			status = 0;
+
+#endif	/* CONFIG_DATAFLASH_WRITE_VERIFY */
+
+		remaining = remaining - writelen;
+		pageaddr++;
+		offset = 0;
+		writebuf += writelen;
+		*retlen += writelen;
+
+		if (remaining > priv->page_size)
+			writelen = priv->page_size;
+		else
+			writelen = remaining;
+	}
+	up(&priv->lock);
+
+	return status;
+}
+
+/* ......................................................................... */
+
+/*
+ * Register DataFlash device with MTD subsystem.
+ */
+static int __devinit
+add_dataflash(struct spi_device *spi, char *name,
+		int nr_pages, int pagesize, int pageoffset)
+{
+	struct dataflash		*priv;
+	struct mtd_info			*device;
+	struct flash_platform_data	*pdata = spi->dev.platform_data;
+
+	priv = (struct dataflash *) kzalloc(sizeof *priv, GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	init_MUTEX(&priv->lock);
+	priv->spi = spi;
+	priv->page_size = pagesize;
+	priv->page_offset = pageoffset;
+
+	/* name must be usable with cmdlinepart */
+	sprintf(priv->name, "spi%d.%d-%s",
+			spi->master->bus_num, spi->chip_select,
+			name);
+
+	device = &priv->mtd;
+	device->name = (pdata && pdata->name) ? pdata->name : priv->name;
+	device->size = nr_pages * pagesize;
+	device->erasesize = pagesize;
+	device->owner = THIS_MODULE;
+	device->type = MTD_DATAFLASH;
+	device->flags = MTD_CAP_NORFLASH;
+	device->erase = dataflash_erase;
+	device->read = dataflash_read;
+	device->write = dataflash_write;
+	device->priv = priv;
+
+	dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024);
+	dev_set_drvdata(&spi->dev, priv);
+
+	if (mtd_has_partitions()) {
+		struct mtd_partition	*parts;
+		int			nr_parts = 0;
+
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+		static const char *part_probes[] = { "cmdlinepart", NULL, };
+
+		nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0);
+#endif
+
+		if (nr_parts <= 0 && pdata && pdata->parts) {
+			parts = pdata->parts;
+			nr_parts = pdata->nr_parts;
+		}
+
+		if (nr_parts > 0) {
+			priv->partitioned = 1;
+			return add_mtd_partitions(device, parts, nr_parts);
+		}
+	} else if (pdata && pdata->nr_parts)
+		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
+				pdata->nr_parts, device->name);
+
+	return add_mtd_device(device) == 1 ? -ENODEV : 0;
+}
+
+/*
+ * Detect and initialize DataFlash device:
+ *
+ *   Device      Density         ID code          #Pages PageSize  Offset
+ *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
+ *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1025    264      9
+ *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
+ *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
+ *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
+ *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
+ *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
+ *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
+ */
+static int __devinit dataflash_probe(struct spi_device *spi)
+{
+	int status;
+
+	status = dataflash_status(spi);
+	if (status <= 0 || status == 0xff) {
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
+				spi->dev.bus_id, status);
+		if (status == 0xff)
+			status = -ENODEV;
+		return status;
+	}
+
+	/* if there's a device there, assume it's dataflash.
+	 * board setup should have set spi->max_speed_max to
+	 * match f(car) for continuous reads, mode 0 or 3.
+	 */
+	switch (status & 0x3c) {
+	case 0x0c:	/* 0 0 1 1 x x */
+		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
+		break;
+	case 0x14:	/* 0 1 0 1 x x */
+		status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9);
+		break;
+	case 0x1c:	/* 0 1 1 1 x x */
+		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
+		break;
+	case 0x24:	/* 1 0 0 1 x x */
+		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
+		break;
+	case 0x2c:	/* 1 0 1 1 x x */
+		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
+		break;
+	case 0x34:	/* 1 1 0 1 x x */
+		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
+		break;
+	case 0x38:	/* 1 1 1 x x x */
+	case 0x3c:
+		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
+		break;
+	/* obsolete AT45DB1282 not (yet?) supported */
+	default:
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
+				spi->dev.bus_id, status & 0x3c);
+		status = -ENODEV;
+	}
+
+	if (status < 0)
+		DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
+				spi->dev.bus_id, status);
+
+	return status;
+}
+
+static int __devexit dataflash_remove(struct spi_device *spi)
+{
+	struct dataflash	*flash = dev_get_drvdata(&spi->dev);
+	int			status;
+
+	DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id);
+
+	if (mtd_has_partitions() && flash->partitioned)
+		status = del_mtd_partitions(&flash->mtd);
+	else
+		status = del_mtd_device(&flash->mtd);
+	if (status == 0)
+		kfree(flash);
+	return status;
+}
+
+static struct spi_driver dataflash_driver = {
+	.driver = {
+		.name		= "mtd_dataflash",
+		.bus		= &spi_bus_type,
+		.owner		= THIS_MODULE,
+	},
+
+	.probe		= dataflash_probe,
+	.remove		= __devexit_p(dataflash_remove),
+
+	/* FIXME:  investigate suspend and resume... */
+};
+
+static int __init dataflash_init(void)
+{
+	return spi_register_driver(&dataflash_driver);
+}
+module_init(dataflash_init);
+
+static void __exit dataflash_exit(void)
+{
+	spi_unregister_driver(&dataflash_driver);
+}
+module_exit(dataflash_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Victor, David Brownell");
+MODULE_DESCRIPTION("MTD DataFlash driver");
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
new file mode 100644
index 0000000..b77dbd6
--- /dev/null
+++ b/drivers/spi/Kconfig
@@ -0,0 +1,109 @@
+#
+# SPI driver configuration
+#
+# NOTE:  the reason this doesn't show SPI slave support is mostly that
+# nobody's needed a slave side API yet.  The master-role API is not
+# fully appropriate there, so it'd need some thought to do well.
+#
+menu "SPI support"
+
+config SPI
+	bool "SPI support"
+	help
+	  The "Serial Peripheral Interface" is a low level synchronous
+	  protocol.  Chips that support SPI can have data transfer rates
+	  up to several tens of Mbit/sec.  Chips are addressed with a
+	  controller and a chipselect.  Most SPI slaves don't support
+	  dynamic device discovery; some are even write-only or read-only.
+
+	  SPI is widely used by microcontollers to talk with sensors,
+	  eeprom and flash memory, codecs and various other controller
+	  chips, analog to digital (and d-to-a) converters, and more.
+	  MMC and SD cards can be accessed using SPI protocol; and for
+	  DataFlash cards used in MMC sockets, SPI must always be used.
+
+	  SPI is one of a family of similar protocols using a four wire
+	  interface (select, clock, data in, data out) including Microwire
+	  (half duplex), SSP, SSI, and PSP.  This driver framework should
+	  work with most such devices and controllers.
+
+config SPI_DEBUG
+	boolean "Debug support for SPI drivers"
+	depends on SPI && DEBUG_KERNEL
+	help
+	  Say "yes" to enable debug messaging (like dev_dbg and pr_debug),
+	  sysfs, and debugfs support in SPI controller and protocol drivers.
+
+#
+# MASTER side ... talking to discrete SPI slave chips including microcontrollers
+#
+
+config SPI_MASTER
+#	boolean "SPI Master Support"
+	boolean
+	default SPI
+	help
+	  If your system has an master-capable SPI controller (which
+	  provides the clock and chipselect), you can enable that
+	  controller and the protocol drivers for the SPI slave chips
+	  that are connected.
+
+comment "SPI Master Controller Drivers"
+	depends on SPI_MASTER
+
+config SPI_BITBANG
+	tristate "Bitbanging SPI master"
+	depends on SPI_MASTER && EXPERIMENTAL
+	help
+	  With a few GPIO pins, your system can bitbang the SPI protocol.
+	  Select this to get SPI support through I/O pins (GPIO, parallel
+	  port, etc).  Or, some systems' SPI master controller drivers use
+	  this code to manage the per-word or per-transfer accesses to the
+	  hardware shift registers.
+
+	  This is library code, and is automatically selected by drivers that
+	  need it.  You only need to select this explicitly to support driver
+	  modules that aren't part of this kernel tree.
+
+config SPI_BUTTERFLY
+	tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
+	depends on SPI_MASTER && PARPORT && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  This uses a custom parallel port cable to connect to an AVR
+	  Butterfly <http://www.atmel.com/products/avr/butterfly>, an
+	  inexpensive battery powered microcontroller evaluation board.
+	  This same cable can be used to flash new firmware.
+
+config SPI_BUTTERFLY
+	tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
+	depends on SPI_MASTER && PARPORT && EXPERIMENTAL
+	select SPI_BITBANG
+	help
+	  This uses a custom parallel port cable to connect to an AVR
+	  Butterfly <http://www.atmel.com/products/avr/butterfly>, an
+	  inexpensive battery powered microcontroller evaluation board.
+	  This same cable can be used to flash new firmware.
+
+#
+# Add new SPI master controllers in alphabetical order above this line
+#
+
+
+#
+# There are lots of SPI device types, with sensors and memory
+# being probably the most widely used ones.
+#
+comment "SPI Protocol Masters"
+	depends on SPI_MASTER
+
+
+#
+# Add new SPI protocol masters in alphabetical order above this line
+#
+
+
+# (slave support would go here)
+
+endmenu # "SPI support"
+
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
new file mode 100644
index 0000000..c2c87e8
--- /dev/null
+++ b/drivers/spi/Makefile
@@ -0,0 +1,25 @@
+#
+# Makefile for kernel SPI drivers.
+#
+
+ifeq ($(CONFIG_SPI_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
+# small core, mostly translating board-specific
+# config declarations into driver model code
+obj-$(CONFIG_SPI_MASTER)		+= spi.o
+
+# SPI master controller drivers (bus)
+obj-$(CONFIG_SPI_BITBANG)		+= spi_bitbang.o
+obj-$(CONFIG_SPI_BUTTERFLY)		+= spi_butterfly.o
+# 	... add above this line ...
+
+# SPI protocol drivers (device/link on bus)
+# 	... add above this line ...
+
+# SPI slave controller drivers (upstream link)
+# 	... add above this line ...
+
+# SPI slave drivers (protocol for that link)
+# 	... add above this line ...
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
new file mode 100644
index 0000000..791c4dc
--- /dev/null
+++ b/drivers/spi/spi.c
@@ -0,0 +1,642 @@
+/*
+ * spi.c - SPI init/core code
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/autoconf.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/spi/spi.h>
+
+
+/* SPI bustype and spi_master class are registered after board init code
+ * provides the SPI device tables, ensuring that both are present by the
+ * time controller driver registration causes spi_devices to "enumerate".
+ */
+static void spidev_release(struct device *dev)
+{
+	const struct spi_device	*spi = to_spi_device(dev);
+
+	/* spi masters may cleanup for released devices */
+	if (spi->master->cleanup)
+		spi->master->cleanup(spi);
+
+	spi_master_put(spi->master);
+	kfree(dev);
+}
+
+static ssize_t
+modalias_show(struct device *dev, struct device_attribute *a, char *buf)
+{
+	const struct spi_device	*spi = to_spi_device(dev);
+
+	return snprintf(buf, BUS_ID_SIZE + 1, "%s\n", spi->modalias);
+}
+
+static struct device_attribute spi_dev_attrs[] = {
+	__ATTR_RO(modalias),
+	__ATTR_NULL,
+};
+
+/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
+ * and the sysfs version makes coldplug work too.
+ */
+
+static int spi_match_device(struct device *dev, struct device_driver *drv)
+{
+	const struct spi_device	*spi = to_spi_device(dev);
+
+	return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0;
+}
+
+static int spi_uevent(struct device *dev, char **envp, int num_envp,
+		char *buffer, int buffer_size)
+{
+	const struct spi_device		*spi = to_spi_device(dev);
+
+	envp[0] = buffer;
+	snprintf(buffer, buffer_size, "MODALIAS=%s", spi->modalias);
+	envp[1] = NULL;
+	return 0;
+}
+
+#ifdef	CONFIG_PM
+
+/*
+ * NOTE:  the suspend() method for an spi_master controller driver
+ * should verify that all its child devices are marked as suspended;
+ * suspend requests delivered through sysfs power/state files don't
+ * enforce such constraints.
+ */
+static int spi_suspend(struct device *dev, pm_message_t message)
+{
+	int			value;
+	struct spi_driver	*drv = to_spi_driver(dev->driver);
+
+	if (!drv->suspend)
+		return 0;
+
+	/* suspend will stop irqs and dma; no more i/o */
+	value = drv->suspend(to_spi_device(dev), message);
+	if (value == 0)
+		dev->power.power_state = message;
+	return value;
+}
+
+static int spi_resume(struct device *dev)
+{
+	int			value;
+	struct spi_driver	*drv = to_spi_driver(dev->driver);
+
+	if (!drv->resume)
+		return 0;
+
+	/* resume may restart the i/o queue */
+	value = drv->resume(to_spi_device(dev));
+	if (value == 0)
+		dev->power.power_state = PMSG_ON;
+	return value;
+}
+
+#else
+#define spi_suspend	NULL
+#define spi_resume	NULL
+#endif
+
+struct bus_type spi_bus_type = {
+	.name		= "spi",
+	.dev_attrs	= spi_dev_attrs,
+	.match		= spi_match_device,
+	.uevent		= spi_uevent,
+	.suspend	= spi_suspend,
+	.resume		= spi_resume,
+};
+EXPORT_SYMBOL_GPL(spi_bus_type);
+
+
+static int spi_drv_probe(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	return sdrv->probe(to_spi_device(dev));
+}
+
+static int spi_drv_remove(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	return sdrv->remove(to_spi_device(dev));
+}
+
+static void spi_drv_shutdown(struct device *dev)
+{
+	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);
+
+	sdrv->shutdown(to_spi_device(dev));
+}
+
+int spi_register_driver(struct spi_driver *sdrv)
+{
+	sdrv->driver.bus = &spi_bus_type;
+	if (sdrv->probe)
+		sdrv->driver.probe = spi_drv_probe;
+	if (sdrv->remove)
+		sdrv->driver.remove = spi_drv_remove;
+	if (sdrv->shutdown)
+		sdrv->driver.shutdown = spi_drv_shutdown;
+	return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(spi_register_driver);
+
+/*-------------------------------------------------------------------------*/
+
+/* SPI devices should normally not be created by SPI device drivers; that
+ * would make them board-specific.  Similarly with SPI master drivers.
+ * Device registration normally goes into like arch/.../mach.../board-YYY.c
+ * with other readonly (flashable) information about mainboard devices.
+ */
+
+struct boardinfo {
+	struct list_head	list;
+	unsigned		n_board_info;
+	struct spi_board_info	board_info[0];
+};
+
+static LIST_HEAD(board_list);
+static DECLARE_MUTEX(board_lock);
+
+
+/* On typical mainboards, this is purely internal; and it's not needed
+ * after board init creates the hard-wired devices.  Some development
+ * platforms may not be able to use spi_register_board_info though, and
+ * this is exported so that for example a USB or parport based adapter
+ * driver could add devices (which it would learn about out-of-band).
+ */
+struct spi_device *__init_or_module
+spi_new_device(struct spi_master *master, struct spi_board_info *chip)
+{
+	struct spi_device	*proxy;
+	struct device		*dev = master->cdev.dev;
+	int			status;
+
+	/* NOTE:  caller did any chip->bus_num checks necessary */
+
+	if (!spi_master_get(master))
+		return NULL;
+
+	proxy = kzalloc(sizeof *proxy, GFP_KERNEL);
+	if (!proxy) {
+		dev_err(dev, "can't alloc dev for cs%d\n",
+			chip->chip_select);
+		goto fail;
+	}
+	proxy->master = master;
+	proxy->chip_select = chip->chip_select;
+	proxy->max_speed_hz = chip->max_speed_hz;
+	proxy->irq = chip->irq;
+	proxy->modalias = chip->modalias;
+
+	snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id,
+			"%s.%u", master->cdev.class_id,
+			chip->chip_select);
+	proxy->dev.parent = dev;
+	proxy->dev.bus = &spi_bus_type;
+	proxy->dev.platform_data = (void *) chip->platform_data;
+	proxy->controller_data = chip->controller_data;
+	proxy->controller_state = NULL;
+	proxy->dev.release = spidev_release;
+
+	/* drivers may modify this default i/o setup */
+	status = master->setup(proxy);
+	if (status < 0) {
+		dev_dbg(dev, "can't %s %s, status %d\n",
+				"setup", proxy->dev.bus_id, status);
+		goto fail;
+	}
+
+	/* driver core catches callers that misbehave by defining
+	 * devices that already exist.
+	 */
+	status = device_register(&proxy->dev);
+	if (status < 0) {
+		dev_dbg(dev, "can't %s %s, status %d\n",
+				"add", proxy->dev.bus_id, status);
+		goto fail;
+	}
+	dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id);
+	return proxy;
+
+fail:
+	spi_master_put(master);
+	kfree(proxy);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(spi_new_device);
+
+/*
+ * Board-specific early init code calls this (probably during arch_initcall)
+ * with segments of the SPI device table.  Any device nodes are created later,
+ * after the relevant parent SPI controller (bus_num) is defined.  We keep
+ * this table of devices forever, so that reloading a controller driver will
+ * not make Linux forget about these hard-wired devices.
+ *
+ * Other code can also call this, e.g. a particular add-on board might provide
+ * SPI devices through its expansion connector, so code initializing that board
+ * would naturally declare its SPI devices.
+ *
+ * The board info passed can safely be __initdata ... but be careful of
+ * any embedded pointers (platform_data, etc), they're copied as-is.
+ */
+int __init
+spi_register_board_info(struct spi_board_info const *info, unsigned n)
+{
+	struct boardinfo	*bi;
+
+	bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
+	if (!bi)
+		return -ENOMEM;
+	bi->n_board_info = n;
+	memcpy(bi->board_info, info, n * sizeof *info);
+
+	down(&board_lock);
+	list_add_tail(&bi->list, &board_list);
+	up(&board_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_register_board_info);
+
+/* FIXME someone should add support for a __setup("spi", ...) that
+ * creates board info from kernel command lines
+ */
+
+static void __init_or_module
+scan_boardinfo(struct spi_master *master)
+{
+	struct boardinfo	*bi;
+	struct device		*dev = master->cdev.dev;
+
+	down(&board_lock);
+	list_for_each_entry(bi, &board_list, list) {
+		struct spi_board_info	*chip = bi->board_info;
+		unsigned		n;
+
+		for (n = bi->n_board_info; n > 0; n--, chip++) {
+			if (chip->bus_num != master->bus_num)
+				continue;
+			/* some controllers only have one chip, so they
+			 * might not use chipselects.  otherwise, the
+			 * chipselects are numbered 0..max.
+			 */
+			if (chip->chip_select >= master->num_chipselect
+					&& master->num_chipselect) {
+				dev_dbg(dev, "cs%d > max %d\n",
+					chip->chip_select,
+					master->num_chipselect);
+				continue;
+			}
+			(void) spi_new_device(master, chip);
+		}
+	}
+	up(&board_lock);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void spi_master_release(struct class_device *cdev)
+{
+	struct spi_master *master;
+
+	master = container_of(cdev, struct spi_master, cdev);
+	kfree(master);
+}
+
+static struct class spi_master_class = {
+	.name		= "spi_master",
+	.owner		= THIS_MODULE,
+	.release	= spi_master_release,
+};
+
+
+/**
+ * spi_alloc_master - allocate SPI master controller
+ * @dev: the controller, possibly using the platform_bus
+ * @size: how much driver-private data to preallocate; the pointer to this
+ * 	memory is in the class_data field of the returned class_device,
+ *	accessible with spi_master_get_devdata().
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers.  It's how they allocate
+ * an spi_master structure, prior to calling spi_add_master().
+ *
+ * This must be called from context that can sleep.  It returns the SPI
+ * master structure on success, else NULL.
+ *
+ * The caller is responsible for assigning the bus number and initializing
+ * the master's methods before calling spi_add_master(); and (after errors
+ * adding the device) calling spi_master_put() to prevent a memory leak.
+ */
+struct spi_master * __init_or_module
+spi_alloc_master(struct device *dev, unsigned size)
+{
+	struct spi_master	*master;
+
+	if (!dev)
+		return NULL;
+
+	master = kzalloc(size + sizeof *master, SLAB_KERNEL);
+	if (!master)
+		return NULL;
+
+	class_device_initialize(&master->cdev);
+	master->cdev.class = &spi_master_class;
+	master->cdev.dev = get_device(dev);
+	spi_master_set_devdata(master, &master[1]);
+
+	return master;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_master);
+
+/**
+ * spi_register_master - register SPI master controller
+ * @master: initialized master, originally from spi_alloc_master()
+ *
+ * SPI master controllers connect to their drivers using some non-SPI bus,
+ * such as the platform bus.  The final stage of probe() in that code
+ * includes calling spi_register_master() to hook up to this SPI bus glue.
+ *
+ * SPI controllers use board specific (often SOC specific) bus numbers,
+ * and board-specific addressing for SPI devices combines those numbers
+ * with chip select numbers.  Since SPI does not directly support dynamic
+ * device identification, boards need configuration tables telling which
+ * chip is at which address.
+ *
+ * This must be called from context that can sleep.  It returns zero on
+ * success, else a negative error code (dropping the master's refcount).
+ * After a successful return, the caller is responsible for calling
+ * spi_unregister_master().
+ */
+int __init_or_module
+spi_register_master(struct spi_master *master)
+{
+	static atomic_t		dyn_bus_id = ATOMIC_INIT(0);
+	struct device		*dev = master->cdev.dev;
+	int			status = -ENODEV;
+	int			dynamic = 0;
+
+	if (!dev)
+		return -ENODEV;
+
+	/* convention:  dynamically assigned bus IDs count down from the max */
+	if (master->bus_num == 0) {
+		master->bus_num = atomic_dec_return(&dyn_bus_id);
+		dynamic = 1;
+	}
+
+	/* register the device, then userspace will see it.
+	 * registration fails if the bus ID is in use.
+	 */
+	snprintf(master->cdev.class_id, sizeof master->cdev.class_id,
+		"spi%u", master->bus_num);
+	status = class_device_add(&master->cdev);
+	if (status < 0)
+		goto done;
+	dev_dbg(dev, "registered master %s%s\n", master->cdev.class_id,
+			dynamic ? " (dynamic)" : "");
+
+	/* populate children from any spi device tables */
+	scan_boardinfo(master);
+	status = 0;
+done:
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_register_master);
+
+
+static int __unregister(struct device *dev, void *unused)
+{
+	/* note: before about 2.6.14-rc1 this would corrupt memory: */
+	spi_unregister_device(to_spi_device(dev));
+	return 0;
+}
+
+/**
+ * spi_unregister_master - unregister SPI master controller
+ * @master: the master being unregistered
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers.
+ *
+ * This must be called from context that can sleep.
+ */
+void spi_unregister_master(struct spi_master *master)
+{
+	(void) device_for_each_child(master->cdev.dev, NULL, __unregister);
+	class_device_unregister(&master->cdev);
+	master->cdev.dev = NULL;
+}
+EXPORT_SYMBOL_GPL(spi_unregister_master);
+
+/**
+ * spi_busnum_to_master - look up master associated with bus_num
+ * @bus_num: the master's bus number
+ *
+ * This call may be used with devices that are registered after
+ * arch init time.  It returns a refcounted pointer to the relevant
+ * spi_master (which the caller must release), or NULL if there is
+ * no such master registered.
+ */
+struct spi_master *spi_busnum_to_master(u16 bus_num)
+{
+	if (bus_num) {
+		char			name[8];
+		struct kobject		*bus;
+
+		snprintf(name, sizeof name, "spi%u", bus_num);
+		bus = kset_find_obj(&spi_master_class.subsys.kset, name);
+		if (bus)
+			return container_of(bus, struct spi_master, cdev.kobj);
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(spi_busnum_to_master);
+
+
+/*-------------------------------------------------------------------------*/
+
+static void spi_complete(void *arg)
+{
+	complete(arg);
+}
+
+/**
+ * spi_sync - blocking/synchronous SPI data transfers
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers
+ *
+ * This call may only be used from a context that may sleep.  The sleep
+ * is non-interruptible, and has no timeout.  Low-overhead controller
+ * drivers may DMA directly into and out of the message buffers.
+ *
+ * Note that the SPI device's chip select is active during the message,
+ * and then is normally disabled between messages.  Drivers for some
+ * frequently-used devices may want to minimize costs of selecting a chip,
+ * by leaving it selected in anticipation that the next message will go
+ * to the same chip.  (That may increase power usage.)
+ *
+ * Also, the caller is guaranteeing that the memory associated with the
+ * message will not be freed before this call returns.
+ *
+ * The return value is a negative error code if the message could not be
+ * submitted, else zero.  When the value is zero, then message->status is
+ * also defined:  it's the completion code for the transfer, either zero
+ * or a negative error code from the controller driver.
+ */
+int spi_sync(struct spi_device *spi, struct spi_message *message)
+{
+	DECLARE_COMPLETION(done);
+	int status;
+
+	message->complete = spi_complete;
+	message->context = &done;
+	status = spi_async(spi, message);
+	if (status == 0)
+		wait_for_completion(&done);
+	message->context = NULL;
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_sync);
+
+#define	SPI_BUFSIZ	(SMP_CACHE_BYTES)
+
+static u8	*buf;
+
+/**
+ * spi_write_then_read - SPI synchronous write followed by read
+ * @spi: device with which data will be exchanged
+ * @txbuf: data to be written (need not be dma-safe)
+ * @n_tx: size of txbuf, in bytes
+ * @rxbuf: buffer into which data will be read
+ * @n_rx: size of rxbuf, in bytes (need not be dma-safe)
+ *
+ * This performs a half duplex MicroWire style transaction with the
+ * device, sending txbuf and then reading rxbuf.  The return value
+ * is zero for success, else a negative errno status code.
+ * This call may only be used from a context that may sleep.
+ *
+ * Parameters to this routine are always copied using a small buffer;
+ * performance-sensitive or bulk transfer code should instead use
+ * spi_{async,sync}() calls with dma-safe buffers.
+ */
+int spi_write_then_read(struct spi_device *spi,
+		const u8 *txbuf, unsigned n_tx,
+		u8 *rxbuf, unsigned n_rx)
+{
+	static DECLARE_MUTEX(lock);
+
+	int			status;
+	struct spi_message	message;
+	struct spi_transfer	x[2];
+	u8			*local_buf;
+
+	/* Use preallocated DMA-safe buffer.  We can't avoid copying here,
+	 * (as a pure convenience thing), but we can keep heap costs
+	 * out of the hot path ...
+	 */
+	if ((n_tx + n_rx) > SPI_BUFSIZ)
+		return -EINVAL;
+
+	spi_message_init(&message);
+	memset(x, 0, sizeof x);
+	if (n_tx) {
+		x[0].len = n_tx;
+		spi_message_add_tail(&x[0], &message);
+	}
+	if (n_rx) {
+		x[1].len = n_rx;
+		spi_message_add_tail(&x[1], &message);
+	}
+
+	/* ... unless someone else is using the pre-allocated buffer */
+	if (down_trylock(&lock)) {
+		local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
+		if (!local_buf)
+			return -ENOMEM;
+	} else
+		local_buf = buf;
+
+	memcpy(local_buf, txbuf, n_tx);
+	x[0].tx_buf = local_buf;
+	x[1].rx_buf = local_buf + n_tx;
+
+	/* do the i/o */
+	status = spi_sync(spi, &message);
+	if (status == 0) {
+		memcpy(rxbuf, x[1].rx_buf, n_rx);
+		status = message.status;
+	}
+
+	if (x[0].tx_buf == buf)
+		up(&lock);
+	else
+		kfree(local_buf);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_write_then_read);
+
+/*-------------------------------------------------------------------------*/
+
+static int __init spi_init(void)
+{
+	int	status;
+
+	buf = kmalloc(SPI_BUFSIZ, SLAB_KERNEL);
+	if (!buf) {
+		status = -ENOMEM;
+		goto err0;
+	}
+
+	status = bus_register(&spi_bus_type);
+	if (status < 0)
+		goto err1;
+
+	status = class_register(&spi_master_class);
+	if (status < 0)
+		goto err2;
+	return 0;
+
+err2:
+	bus_unregister(&spi_bus_type);
+err1:
+	kfree(buf);
+	buf = NULL;
+err0:
+	return status;
+}
+
+/* board_info is normally registered in arch_initcall(),
+ * but even essential drivers wait till later
+ *
+ * REVISIT only boardinfo really needs static linking. the rest (device and
+ * driver registration) _could_ be dynamically linked (modular) ... costs
+ * include needing to have boardinfo data structures be much more public.
+ */
+subsys_initcall(spi_init);
+
diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
new file mode 100644
index 0000000..f037e55
--- /dev/null
+++ b/drivers/spi/spi_bitbang.c
@@ -0,0 +1,472 @@
+/*
+ * spi_bitbang.c - polling/bitbanging SPI master controller driver utilities
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * FIRST PART (OPTIONAL):  word-at-a-time spi_transfer support.
+ * Use this for GPIO or shift-register level hardware APIs.
+ *
+ * spi_bitbang_cs is in spi_device->controller_state, which is unavailable
+ * to glue code.  These bitbang setup() and cleanup() routines are always
+ * used, though maybe they're called from controller-aware code.
+ *
+ * chipselect() and friends may use use spi_device->controller_data and
+ * controller registers as appropriate.
+ *
+ *
+ * NOTE:  SPI controller pins can often be used as GPIO pins instead,
+ * which means you could use a bitbang driver either to get hardware
+ * working quickly, or testing for differences that aren't speed related.
+ */
+
+struct spi_bitbang_cs {
+	unsigned	nsecs;	/* (clock cycle time)/2 */
+	u32		(*txrx_word)(struct spi_device *spi, unsigned nsecs,
+					u32 word, u8 bits);
+	unsigned	(*txrx_bufs)(struct spi_device *,
+					u32 (*txrx_word)(
+						struct spi_device *spi,
+						unsigned nsecs,
+						u32 word, u8 bits),
+					unsigned, struct spi_transfer *);
+};
+
+static unsigned bitbang_txrx_8(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u8		*tx = t->tx_buf;
+	u8			*rx = t->rx_buf;
+
+	while (likely(count > 0)) {
+		u8		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 1;
+	}
+	return t->len - count;
+}
+
+static unsigned bitbang_txrx_16(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u16		*tx = t->tx_buf;
+	u16			*rx = t->rx_buf;
+
+	while (likely(count > 1)) {
+		u16		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 2;
+	}
+	return t->len - count;
+}
+
+static unsigned bitbang_txrx_32(
+	struct spi_device	*spi,
+	u32			(*txrx_word)(struct spi_device *spi,
+					unsigned nsecs,
+					u32 word, u8 bits),
+	unsigned		ns,
+	struct spi_transfer	*t
+) {
+	unsigned		bits = spi->bits_per_word;
+	unsigned		count = t->len;
+	const u32		*tx = t->tx_buf;
+	u32			*rx = t->rx_buf;
+
+	while (likely(count > 3)) {
+		u32		word = 0;
+
+		if (tx)
+			word = *tx++;
+		word = txrx_word(spi, ns, word, bits);
+		if (rx)
+			*rx++ = word;
+		count -= 4;
+	}
+	return t->len - count;
+}
+
+/**
+ * spi_bitbang_setup - default setup for per-word I/O loops
+ */
+int spi_bitbang_setup(struct spi_device *spi)
+{
+	struct spi_bitbang_cs	*cs = spi->controller_state;
+	struct spi_bitbang	*bitbang;
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, SLAB_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		spi->controller_state = cs;
+	}
+	bitbang = spi_master_get_devdata(spi->master);
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+
+	/* spi_transfer level calls that work per-word */
+	if (spi->bits_per_word <= 8)
+		cs->txrx_bufs = bitbang_txrx_8;
+	else if (spi->bits_per_word <= 16)
+		cs->txrx_bufs = bitbang_txrx_16;
+	else if (spi->bits_per_word <= 32)
+		cs->txrx_bufs = bitbang_txrx_32;
+	else
+		return -EINVAL;
+
+	/* per-word shift register access, in hardware or bitbanging */
+	cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
+	if (!cs->txrx_word)
+		return -EINVAL;
+
+	/* nsecs = (clock period)/2 */
+	cs->nsecs = (1000000000/2) / (spi->max_speed_hz);
+	if (cs->nsecs > MAX_UDELAY_MS * 1000)
+		return -EINVAL;
+
+	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
+			__FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
+			spi->bits_per_word, 2 * cs->nsecs);
+
+	/* NOTE we _need_ to call chipselect() early, ideally with adapter
+	 * setup, unless the hardware defaults cooperate to avoid confusion
+	 * between normal (active low) and inverted chipselects.
+	 */
+
+	/* deselect chip (low or high) */
+	spin_lock(&bitbang->lock);
+	if (!bitbang->busy) {
+		bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+		ndelay(cs->nsecs);
+	}
+	spin_unlock(&bitbang->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_setup);
+
+/**
+ * spi_bitbang_cleanup - default cleanup for per-word I/O loops
+ */
+void spi_bitbang_cleanup(const struct spi_device *spi)
+{
+	kfree(spi->controller_state);
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_cleanup);
+
+static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct spi_bitbang_cs	*cs = spi->controller_state;
+	unsigned		nsecs = cs->nsecs;
+
+	return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * SECOND PART ... simple transfer queue runner.
+ *
+ * This costs a task context per controller, running the queue by
+ * performing each transfer in sequence.  Smarter hardware can queue
+ * several DMA transfers at once, and process several controller queues
+ * in parallel; this driver doesn't match such hardware very well.
+ *
+ * Drivers can provide word-at-a-time i/o primitives, or provide
+ * transfer-at-a-time ones to leverage dma or fifo hardware.
+ */
+static void bitbang_work(void *_bitbang)
+{
+	struct spi_bitbang	*bitbang = _bitbang;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&bitbang->lock, flags);
+	bitbang->busy = 1;
+	while (!list_empty(&bitbang->queue)) {
+		struct spi_message	*m;
+		struct spi_device	*spi;
+		unsigned		nsecs;
+		struct spi_transfer	*t = NULL;
+		unsigned		tmp;
+		unsigned		cs_change;
+		int			status;
+
+		m = container_of(bitbang->queue.next, struct spi_message,
+				queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&bitbang->lock, flags);
+
+		/* FIXME this is made-up ... the correct value is known to
+		 * word-at-a-time bitbang code, and presumably chipselect()
+		 * should enforce these requirements too?
+		 */
+		nsecs = 100;
+
+		spi = m->spi;
+		tmp = 0;
+		cs_change = 1;
+		status = 0;
+
+		list_for_each_entry (t, &m->transfers, transfer_list) {
+			if (bitbang->shutdown) {
+				status = -ESHUTDOWN;
+				break;
+			}
+
+			/* set up default clock polarity, and activate chip;
+			 * this implicitly updates clock and spi modes as
+			 * previously recorded for this device via setup().
+			 * (and also deselects any other chip that might be
+			 * selected ...)
+			 */
+			if (cs_change) {
+				bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
+				ndelay(nsecs);
+			}
+			cs_change = t->cs_change;
+			if (!t->tx_buf && !t->rx_buf && t->len) {
+				status = -EINVAL;
+				break;
+			}
+
+			/* transfer data.  the lower level code handles any
+			 * new dma mappings it needs. our caller always gave
+			 * us dma-safe buffers.
+			 */
+			if (t->len) {
+				/* REVISIT dma API still needs a designated
+				 * DMA_ADDR_INVALID; ~0 might be better.
+				 */
+				if (!m->is_dma_mapped)
+					t->rx_dma = t->tx_dma = 0;
+				status = bitbang->txrx_bufs(spi, t);
+			}
+			if (status != t->len) {
+				if (status > 0)
+					status = -EMSGSIZE;
+				break;
+			}
+			m->actual_length += status;
+			status = 0;
+
+			/* protocol tweaks before next transfer */
+			if (t->delay_usecs)
+				udelay(t->delay_usecs);
+
+			if (!cs_change)
+				continue;
+			if (t->transfer_list.next == &m->transfers)
+				break;
+
+			/* sometimes a short mid-message deselect of the chip
+			 * may be needed to terminate a mode or command
+			 */
+			ndelay(nsecs);
+			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+			ndelay(nsecs);
+		}
+
+		m->status = status;
+		m->complete(m->context);
+
+		/* normally deactivate chipselect ... unless no error and
+		 * cs_change has hinted that the next message will probably
+		 * be for this chip too.
+		 */
+		if (!(status == 0 && cs_change)) {
+			ndelay(nsecs);
+			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+			ndelay(nsecs);
+		}
+
+		spin_lock_irqsave(&bitbang->lock, flags);
+	}
+	bitbang->busy = 0;
+	spin_unlock_irqrestore(&bitbang->lock, flags);
+}
+
+/**
+ * spi_bitbang_transfer - default submit to transfer queue
+ */
+int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct spi_bitbang	*bitbang;
+	unsigned long		flags;
+
+	m->actual_length = 0;
+	m->status = -EINPROGRESS;
+
+	bitbang = spi_master_get_devdata(spi->master);
+	if (bitbang->shutdown)
+		return -ESHUTDOWN;
+
+	spin_lock_irqsave(&bitbang->lock, flags);
+	list_add_tail(&m->queue, &bitbang->queue);
+	queue_work(bitbang->workqueue, &bitbang->work);
+	spin_unlock_irqrestore(&bitbang->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
+
+/*----------------------------------------------------------------------*/
+
+/**
+ * spi_bitbang_start - start up a polled/bitbanging SPI master driver
+ * @bitbang: driver handle
+ *
+ * Caller should have zero-initialized all parts of the structure, and then
+ * provided callbacks for chip selection and I/O loops.  If the master has
+ * a transfer method, its final step should call spi_bitbang_transfer; or,
+ * that's the default if the transfer routine is not initialized.  It should
+ * also set up the bus number and number of chipselects.
+ *
+ * For i/o loops, provide callbacks either per-word (for bitbanging, or for
+ * hardware that basically exposes a shift register) or per-spi_transfer
+ * (which takes better advantage of hardware like fifos or DMA engines).
+ *
+ * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup and
+ * spi_bitbang_cleanup to handle those spi master methods.  Those methods are
+ * the defaults if the bitbang->txrx_bufs routine isn't initialized.
+ *
+ * This routine registers the spi_master, which will process requests in a
+ * dedicated task, keeping IRQs unblocked most of the time.  To stop
+ * processing those requests, call spi_bitbang_stop().
+ */
+int spi_bitbang_start(struct spi_bitbang *bitbang)
+{
+	int	status;
+
+	if (!bitbang->master || !bitbang->chipselect)
+		return -EINVAL;
+
+	INIT_WORK(&bitbang->work, bitbang_work, bitbang);
+	spin_lock_init(&bitbang->lock);
+	INIT_LIST_HEAD(&bitbang->queue);
+
+	if (!bitbang->master->transfer)
+		bitbang->master->transfer = spi_bitbang_transfer;
+	if (!bitbang->txrx_bufs) {
+		bitbang->use_dma = 0;
+		bitbang->txrx_bufs = spi_bitbang_bufs;
+		if (!bitbang->master->setup) {
+			bitbang->master->setup = spi_bitbang_setup;
+			bitbang->master->cleanup = spi_bitbang_cleanup;
+		}
+	} else if (!bitbang->master->setup)
+		return -EINVAL;
+
+	/* this task is the only thing to touch the SPI bits */
+	bitbang->busy = 0;
+	bitbang->workqueue = create_singlethread_workqueue(
+			bitbang->master->cdev.dev->bus_id);
+	if (bitbang->workqueue == NULL) {
+		status = -EBUSY;
+		goto err1;
+	}
+
+	/* driver may get busy before register() returns, especially
+	 * if someone registered boardinfo for devices
+	 */
+	status = spi_register_master(bitbang->master);
+	if (status < 0)
+		goto err2;
+
+	return status;
+
+err2:
+	destroy_workqueue(bitbang->workqueue);
+err1:
+	return status;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_start);
+
+/**
+ * spi_bitbang_stop - stops the task providing spi communication
+ */
+int spi_bitbang_stop(struct spi_bitbang *bitbang)
+{
+	unsigned	limit = 500;
+
+	spin_lock_irq(&bitbang->lock);
+	bitbang->shutdown = 0;
+	while (!list_empty(&bitbang->queue) && limit--) {
+		spin_unlock_irq(&bitbang->lock);
+
+		dev_dbg(bitbang->master->cdev.dev, "wait for queue\n");
+		msleep(10);
+
+		spin_lock_irq(&bitbang->lock);
+	}
+	spin_unlock_irq(&bitbang->lock);
+	if (!list_empty(&bitbang->queue)) {
+		dev_err(bitbang->master->cdev.dev, "queue didn't empty\n");
+		return -EBUSY;
+	}
+
+	destroy_workqueue(bitbang->workqueue);
+
+	spi_unregister_master(bitbang->master);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bitbang_stop);
+
+MODULE_LICENSE("GPL");
+
diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c
new file mode 100644
index 0000000..79a3c59
--- /dev/null
+++ b/drivers/spi/spi_butterfly.c
@@ -0,0 +1,423 @@
+/*
+ * spi_butterfly.c - parport-to-butterfly adapter
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/parport.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/flash.h>
+
+#include <linux/mtd/partitions.h>
+
+
+/*
+ * This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
+ * with a battery powered AVR microcontroller and lots of goodies.  You
+ * can use GCC to develop firmware for this.
+ *
+ * See Documentation/spi/butterfly for information about how to build
+ * and use this custom parallel port cable.
+ */
+
+#undef	HAVE_USI	/* nyet */
+
+
+/* DATA output bits (pins 2..9 == D0..D7) */
+#define	butterfly_nreset (1 << 1)		/* pin 3 */
+
+#define	spi_sck_bit	(1 << 0)		/* pin 2 */
+#define	spi_mosi_bit	(1 << 7)		/* pin 9 */
+
+#define	usi_sck_bit	(1 << 3)		/* pin 5 */
+#define	usi_mosi_bit	(1 << 4)		/* pin 6 */
+
+#define	vcc_bits	((1 << 6) | (1 << 5))	/* pins 7, 8 */
+
+/* STATUS input bits */
+#define	spi_miso_bit	PARPORT_STATUS_BUSY	/* pin 11 */
+
+#define	usi_miso_bit	PARPORT_STATUS_PAPEROUT	/* pin 12 */
+
+/* CONTROL output bits */
+#define	spi_cs_bit	PARPORT_CONTROL_SELECT	/* pin 17 */
+/* USI uses no chipselect */
+
+
+
+static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
+{
+	return spi->controller_data;
+}
+
+static inline int is_usidev(struct spi_device *spi)
+{
+#ifdef	HAVE_USI
+	return spi->chip_select != 1;
+#else
+	return 0;
+#endif
+}
+
+
+struct butterfly {
+	/* REVISIT ... for now, this must be first */
+	struct spi_bitbang	bitbang;
+
+	struct parport		*port;
+	struct pardevice	*pd;
+
+	u8			lastbyte;
+
+	struct spi_device	*dataflash;
+	struct spi_device	*butterfly;
+	struct spi_board_info	info[2];
+
+};
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * these routines may be slower than necessary because they're hiding
+ * the fact that there are two different SPI busses on this cable: one
+ * to the DataFlash chip (or AVR SPI controller), the other to the
+ * AVR USI controller.
+ */
+
+static inline void
+setsck(struct spi_device *spi, int is_on)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	u8			bit, byte = pp->lastbyte;
+
+	if (is_usidev(spi))
+		bit = usi_sck_bit;
+	else
+		bit = spi_sck_bit;
+
+	if (is_on)
+		byte |= bit;
+	else
+		byte &= ~bit;
+	parport_write_data(pp->port, byte);
+	pp->lastbyte = byte;
+}
+
+static inline void
+setmosi(struct spi_device *spi, int is_on)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	u8			bit, byte = pp->lastbyte;
+
+	if (is_usidev(spi))
+		bit = usi_mosi_bit;
+	else
+		bit = spi_mosi_bit;
+
+	if (is_on)
+		byte |= bit;
+	else
+		byte &= ~bit;
+	parport_write_data(pp->port, byte);
+	pp->lastbyte = byte;
+}
+
+static inline int getmiso(struct spi_device *spi)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+	int			value;
+	u8			bit;
+
+	if (is_usidev(spi))
+		bit = usi_miso_bit;
+	else
+		bit = spi_miso_bit;
+
+	/* only STATUS_BUSY is NOT negated */
+	value = !(parport_read_status(pp->port) & bit);
+	return (bit == PARPORT_STATUS_BUSY) ? value : !value;
+}
+
+static void butterfly_chipselect(struct spi_device *spi, int value)
+{
+	struct butterfly	*pp = spidev_to_pp(spi);
+
+	/* set default clock polarity */
+	if (value)
+		setsck(spi, spi->mode & SPI_CPOL);
+
+	/* no chipselect on this USI link config */
+	if (is_usidev(spi))
+		return;
+
+	/* here, value == "activate or not" */
+
+	/* most PARPORT_CONTROL_* bits are negated */
+	if (spi_cs_bit == PARPORT_CONTROL_INIT)
+		value = !value;
+
+	/* here, value == "bit value to write in control register"  */
+
+	parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
+}
+
+
+/* we only needed to implement one mode here, and choose SPI_MODE_0 */
+
+#define	spidelay(X)	do{}while(0)
+//#define	spidelay	ndelay
+
+#define	EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+static u32
+butterfly_txrx_word_mode0(struct spi_device *spi,
+		unsigned nsecs,
+		u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* override default partitioning with cmdlinepart */
+static struct mtd_partition partitions[] = { {
+	/* JFFS2 wants partitions of 4*N blocks for this device ... */
+
+	/* sector 0 = 8 pages * 264 bytes/page (1 block)
+	 * sector 1 = 248 pages * 264 bytes/page
+	 */
+	.name		= "bookkeeping",	// 66 KB
+	.offset		= 0,
+	.size		= (8 + 248) * 264,
+//	.mask_flags	= MTD_WRITEABLE,
+}, {
+	/* sector 2 = 256 pages * 264 bytes/page
+	 * sectors 3-5 = 512 pages * 264 bytes/page
+	 */
+	.name		= "filesystem",		// 462 KB
+	.offset		= MTDPART_OFS_APPEND,
+	.size		= MTDPART_SIZ_FULL,
+} };
+
+static struct flash_platform_data flash = {
+	.name		= "butterflash",
+	.parts		= partitions,
+	.nr_parts	= ARRAY_SIZE(partitions),
+};
+
+
+/* REVISIT remove this ugly global and its "only one" limitation */
+static struct butterfly *butterfly;
+
+static void butterfly_attach(struct parport *p)
+{
+	struct pardevice	*pd;
+	int			status;
+	struct butterfly	*pp;
+	struct spi_master	*master;
+	struct platform_device	*pdev;
+
+	if (butterfly)
+		return;
+
+	/* REVISIT:  this just _assumes_ a butterfly is there ... no probe,
+	 * and no way to be selective about what it binds to.
+	 */
+
+	/* FIXME where should master->cdev.dev come from?
+	 * e.g. /sys/bus/pnp0/00:0b, some PCI thing, etc
+	 * setting up a platform device like this is an ugly kluge...
+	 */
+	pdev = platform_device_register_simple("butterfly", -1, NULL, 0);
+
+	master = spi_alloc_master(&pdev->dev, sizeof *pp);
+	if (!master) {
+		status = -ENOMEM;
+		goto done;
+	}
+	pp = spi_master_get_devdata(master);
+
+	/*
+	 * SPI and bitbang hookup
+	 *
+	 * use default setup(), cleanup(), and transfer() methods; and
+	 * only bother implementing mode 0.  Start it later.
+	 */
+	master->bus_num = 42;
+	master->num_chipselect = 2;
+
+	pp->bitbang.master = spi_master_get(master);
+	pp->bitbang.chipselect = butterfly_chipselect;
+	pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
+
+	/*
+	 * parport hookup
+	 */
+	pp->port = p;
+	pd = parport_register_device(p, "spi_butterfly",
+			NULL, NULL, NULL,
+			0 /* FLAGS */, pp);
+	if (!pd) {
+		status = -ENOMEM;
+		goto clean0;
+	}
+	pp->pd = pd;
+
+	status = parport_claim(pd);
+	if (status < 0)
+		goto clean1;
+
+	/*
+	 * Butterfly reset, powerup, run firmware
+	 */
+	pr_debug("%s: powerup/reset Butterfly\n", p->name);
+
+	/* nCS for dataflash (this bit is inverted on output) */
+	parport_frob_control(pp->port, spi_cs_bit, 0);
+
+	/* stabilize power with chip in reset (nRESET), and
+	 * both spi_sck_bit and usi_sck_bit clear (CPOL=0)
+	 */
+	pp->lastbyte |= vcc_bits;
+	parport_write_data(pp->port, pp->lastbyte);
+	msleep(5);
+
+	/* take it out of reset; assume long reset delay */
+	pp->lastbyte |= butterfly_nreset;
+	parport_write_data(pp->port, pp->lastbyte);
+	msleep(100);
+
+
+	/*
+	 * Start SPI ... for now, hide that we're two physical busses.
+	 */
+	status = spi_bitbang_start(&pp->bitbang);
+	if (status < 0)
+		goto clean2;
+
+	/* Bus 1 lets us talk to at45db041b (firmware disables AVR)
+	 * or AVR (firmware resets at45, acts as spi slave)
+	 */
+	pp->info[0].max_speed_hz = 15 * 1000 * 1000;
+	strcpy(pp->info[0].modalias, "mtd_dataflash");
+	pp->info[0].platform_data = &flash;
+	pp->info[0].chip_select = 1;
+	pp->info[0].controller_data = pp;
+	pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
+	if (pp->dataflash)
+		pr_debug("%s: dataflash at %s\n", p->name,
+				pp->dataflash->dev.bus_id);
+
+#ifdef	HAVE_USI
+	/* even more custom AVR firmware */
+	pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000;
+	strcpy(pp->info[1].modalias, "butterfly");
+	// pp->info[1].platform_data = ... TBD ... ;
+	pp->info[1].chip_select = 2,
+	pp->info[1].controller_data = pp;
+	pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[1]);
+	if (pp->butterfly)
+		pr_debug("%s: butterfly at %s\n", p->name,
+				pp->butterfly->dev.bus_id);
+
+	/* FIXME setup ACK for the IRQ line ...  */
+#endif
+
+	// dev_info(_what?_, ...)
+	pr_info("%s: AVR Butterfly\n", p->name);
+	butterfly = pp;
+	return;
+
+clean2:
+	/* turn off VCC */
+	parport_write_data(pp->port, 0);
+
+	parport_release(pp->pd);
+clean1:
+	parport_unregister_device(pd);
+clean0:
+	(void) spi_master_put(pp->bitbang.master);
+done:
+	platform_device_unregister(pdev);
+	pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
+}
+
+static void butterfly_detach(struct parport *p)
+{
+	struct butterfly	*pp;
+	struct platform_device	*pdev;
+	int			status;
+
+	/* FIXME this global is ugly ... but, how to quickly get from
+	 * the parport to the "struct butterfly" associated with it?
+	 * "old school" driver-internal device lists?
+	 */
+	if (!butterfly || butterfly->port != p)
+		return;
+	pp = butterfly;
+	butterfly = NULL;
+
+#ifdef	HAVE_USI
+	spi_unregister_device(pp->butterfly);
+	pp->butterfly = NULL;
+#endif
+	spi_unregister_device(pp->dataflash);
+	pp->dataflash = NULL;
+
+	status = spi_bitbang_stop(&pp->bitbang);
+
+	/* turn off VCC */
+	parport_write_data(pp->port, 0);
+	msleep(10);
+
+	parport_release(pp->pd);
+	parport_unregister_device(pp->pd);
+
+	pdev = to_platform_device(pp->bitbang.master->cdev.dev);
+
+	(void) spi_master_put(pp->bitbang.master);
+
+	platform_device_unregister(pdev);
+}
+
+static struct parport_driver butterfly_driver = {
+	.name =		"spi_butterfly",
+	.attach =	butterfly_attach,
+	.detach =	butterfly_detach,
+};
+
+
+static int __init butterfly_init(void)
+{
+	return parport_register_driver(&butterfly_driver);
+}
+device_initcall(butterfly_init);
+
+static void __exit butterfly_exit(void)
+{
+	parport_unregister_driver(&butterfly_driver);
+}
+module_exit(butterfly_exit);
+
+MODULE_LICENSE("GPL");