staging: IIO: DAC: New driver for the AD5504 and AD55041 High Voltage DACs

Changes since V1:

IIO: DAC: Apply review feedback from Jonathan

Fix array size and declare const.
Fix reversed dacY_powerdown read back.
Use individual attribute groups instead of is_visible.
Fix event naming and add the _en file.

Changes since V2:

IIO: DAC: AD5504 use proper event type

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 511 insertions, 0 deletions

diff --git a/drivers/staging/iio/dac/Kconfig b/drivers/staging/iio/dac/Kconfig
index 67defcb..1b0188a 100644
--- a/drivers/staging/iio/dac/Kconfig
+++ b/drivers/staging/iio/dac/Kconfig
@@ -21,6 +21,16 @@ config AD5446
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5446.
 
+config AD5504
+	tristate "Analog Devices AD5504/AD5501 DAC SPI driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD5504, AD5501,
+	  High Voltage Digital to Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5504.
+
 config MAX517
 	tristate "Maxim MAX517/518/519 DAC driver"
 	depends on I2C && EXPERIMENTAL
diff --git a/drivers/staging/iio/dac/Makefile b/drivers/staging/iio/dac/Makefile
index 1197aef..020df4a 100644
--- a/drivers/staging/iio/dac/Makefile
+++ b/drivers/staging/iio/dac/Makefile
@@ -3,5 +3,6 @@
 #
 
 obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
+obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
 obj-$(CONFIG_MAX517) += max517.o
diff --git a/drivers/staging/iio/dac/ad5504.c b/drivers/staging/iio/dac/ad5504.c
new file mode 100644
index 0000000..153c36e
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5504.c
@@ -0,0 +1,426 @@
+/*
+ * AD5504, AD5501 High Voltage Digital to Analog Converter
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "dac.h"
+#include "ad5504.h"
+
+static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val)
+{
+	u16 tmp = cpu_to_be16(AD5504_CMD_WRITE |
+			      AD5504_ADDR(addr) |
+			      (val & AD5504_RES_MASK));
+
+	return spi_write(spi, (u8 *)&tmp, 2);
+}
+
+static int ad5504_spi_read(struct spi_device *spi, u8 addr, u16 *val)
+{
+	u16 tmp = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
+	int ret;
+	struct spi_transfer	t = {
+			.tx_buf		= &tmp,
+			.rx_buf		= val,
+			.len		= 2,
+		};
+	struct spi_message	m;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	ret = spi_sync(spi, &m);
+
+	*val = be16_to_cpu(*val) & AD5504_RES_MASK;
+
+	return ret;
+}
+
+static ssize_t ad5504_write_dac(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	long readin;
+	int ret;
+
+	ret = strict_strtol(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	ret = ad5504_spi_write(st->spi, this_attr->address, readin);
+	return ret ? ret : len;
+}
+
+static ssize_t ad5504_read_dac(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret;
+	u16 val;
+
+	ret = ad5504_spi_read(st->spi, this_attr->address, &val);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t ad5504_read_powerdown_mode(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+
+	const char mode[][14] = {"20kohm_to_gnd", "three_state"};
+
+	return sprintf(buf, "%s\n", mode[st->pwr_down_mode]);
+}
+
+static ssize_t ad5504_write_powerdown_mode(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	int ret;
+
+	if (sysfs_streq(buf, "20kohm_to_gnd"))
+		st->pwr_down_mode = AD5504_DAC_PWRDN_20K;
+	else if (sysfs_streq(buf, "three_state"))
+		st->pwr_down_mode = AD5504_DAC_PWRDN_3STATE;
+	else
+		ret = -EINVAL;
+
+	return ret ? ret : len;
+}
+
+static ssize_t ad5504_read_dac_powerdown(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sprintf(buf, "%d\n",
+			!(st->pwr_down_mask & (1 << this_attr->address)));
+}
+
+static ssize_t ad5504_write_dac_powerdown(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t len)
+{
+	long readin;
+	int ret;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	ret = strict_strtol(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	if (readin == 0)
+		st->pwr_down_mask |= (1 << this_attr->address);
+	else if (readin == 1)
+		st->pwr_down_mask &= ~(1 << this_attr->address);
+	else
+		ret = -EINVAL;
+
+	ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL,
+				AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
+				AD5504_DAC_PWR(st->pwr_down_mask));
+
+	/* writes to the CTRL register must be followed by a NOOP */
+	ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0);
+
+	return ret ? ret : len;
+}
+
+static ssize_t ad5504_show_scale(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+	/* Corresponds to Vref / 2^(bits) */
+	unsigned int scale_uv = (st->vref_mv * 1000) >> AD5505_BITS;
+
+	return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
+}
+static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5504_show_scale, NULL, 0);
+
+static ssize_t ad5504_show_name(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5504_state *st = iio_dev_get_devdata(indio_dev);
+
+	return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
+}
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad5504_show_name, NULL, 0);
+
+#define IIO_DEV_ATTR_OUT_RW_RAW(_num, _show, _store, _addr)		\
+	IIO_DEVICE_ATTR(out##_num##_raw,				\
+			S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_OUT_RW_RAW(0, ad5504_read_dac,
+	ad5504_write_dac, AD5504_ADDR_DAC0);
+static IIO_DEV_ATTR_OUT_RW_RAW(1, ad5504_read_dac,
+	ad5504_write_dac, AD5504_ADDR_DAC1);
+static IIO_DEV_ATTR_OUT_RW_RAW(2, ad5504_read_dac,
+	ad5504_write_dac, AD5504_ADDR_DAC2);
+static IIO_DEV_ATTR_OUT_RW_RAW(3, ad5504_read_dac,
+	ad5504_write_dac, AD5504_ADDR_DAC3);
+
+static IIO_DEVICE_ATTR(out_powerdown_mode, S_IRUGO |
+			S_IWUSR, ad5504_read_powerdown_mode,
+			ad5504_write_powerdown_mode, 0);
+
+static IIO_CONST_ATTR(out_powerdown_mode_available,
+			"20kohm_to_gnd three_state");
+
+#define IIO_DEV_ATTR_DAC_POWERDOWN(_num, _show, _store, _addr)		\
+	IIO_DEVICE_ATTR(out##_num##_powerdown,				\
+			S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_DAC_POWERDOWN(0, ad5504_read_dac_powerdown,
+				   ad5504_write_dac_powerdown, 0);
+static IIO_DEV_ATTR_DAC_POWERDOWN(1, ad5504_read_dac_powerdown,
+				   ad5504_write_dac_powerdown, 1);
+static IIO_DEV_ATTR_DAC_POWERDOWN(2, ad5504_read_dac_powerdown,
+				   ad5504_write_dac_powerdown, 2);
+static IIO_DEV_ATTR_DAC_POWERDOWN(3, ad5504_read_dac_powerdown,
+				   ad5504_write_dac_powerdown, 3);
+
+static struct attribute *ad5504_attributes[] = {
+	&iio_dev_attr_out0_raw.dev_attr.attr,
+	&iio_dev_attr_out1_raw.dev_attr.attr,
+	&iio_dev_attr_out2_raw.dev_attr.attr,
+	&iio_dev_attr_out3_raw.dev_attr.attr,
+	&iio_dev_attr_out0_powerdown.dev_attr.attr,
+	&iio_dev_attr_out1_powerdown.dev_attr.attr,
+	&iio_dev_attr_out2_powerdown.dev_attr.attr,
+	&iio_dev_attr_out3_powerdown.dev_attr.attr,
+	&iio_dev_attr_out_powerdown_mode.dev_attr.attr,
+	&iio_const_attr_out_powerdown_mode_available.dev_attr.attr,
+	&iio_dev_attr_out_scale.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad5504_attribute_group = {
+	.attrs = ad5504_attributes,
+};
+
+static struct attribute *ad5501_attributes[] = {
+	&iio_dev_attr_out0_raw.dev_attr.attr,
+	&iio_dev_attr_out0_powerdown.dev_attr.attr,
+	&iio_dev_attr_out_powerdown_mode.dev_attr.attr,
+	&iio_const_attr_out_powerdown_mode_available.dev_attr.attr,
+	&iio_dev_attr_out_scale.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad5501_attribute_group = {
+	.attrs = ad5501_attributes,
+};
+
+static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
+static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
+
+static struct attribute *ad5504_ev_attributes[] = {
+	&iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
+	&iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ad5504_ev_attribute_group = {
+	.attrs = ad5504_ev_attributes,
+};
+
+static void ad5504_interrupt_bh(struct work_struct *work_s)
+{
+	struct ad5504_state *st = container_of(work_s,
+		struct ad5504_state, work_alarm);
+
+	iio_push_event(st->indio_dev, 0,
+			IIO_UNMOD_EVENT_CODE(IIO_EV_CLASS_TEMP,
+			0,
+			IIO_EV_TYPE_THRESH,
+			IIO_EV_DIR_RISING),
+			st->last_timestamp);
+
+	enable_irq(st->spi->irq);
+}
+
+static int ad5504_interrupt(struct iio_dev *dev_info,
+		int index,
+		s64 timestamp,
+		int no_test)
+{
+	struct ad5504_state *st = dev_info->dev_data;
+
+	st->last_timestamp = timestamp;
+	schedule_work(&st->work_alarm);
+	return 0;
+}
+
+IIO_EVENT_SH(ad5504, &ad5504_interrupt);
+
+static int __devinit ad5504_probe(struct spi_device *spi)
+{
+	struct ad5504_platform_data *pdata = spi->dev.platform_data;
+	struct ad5504_state *st;
+	int ret, voltage_uv = 0;
+
+	st = kzalloc(sizeof(*st), GFP_KERNEL);
+	if (st == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	spi_set_drvdata(spi, st);
+
+	st->reg = regulator_get(&spi->dev, "vcc");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret)
+			goto error_put_reg;
+
+		voltage_uv = regulator_get_voltage(st->reg);
+	}
+
+	if (voltage_uv)
+		st->vref_mv = voltage_uv / 1000;
+	else if (pdata)
+		st->vref_mv = pdata->vref_mv;
+	else
+		dev_warn(&spi->dev, "reference voltage unspecified\n");
+
+	st->spi = spi;
+	st->indio_dev = iio_allocate_device();
+	if (st->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_disable_reg;
+	}
+	st->indio_dev->dev.parent = &spi->dev;
+
+	st->indio_dev->attrs = spi_get_device_id(st->spi)->driver_data
+		== ID_AD5501 ? &ad5501_attribute_group :
+		&ad5504_attribute_group;
+	st->indio_dev->dev_data = (void *)(st);
+	st->indio_dev->driver_module = THIS_MODULE;
+	st->indio_dev->modes = INDIO_DIRECT_MODE;
+	st->indio_dev->num_interrupt_lines = 1;
+	st->indio_dev->event_attrs = &ad5504_ev_attribute_group,
+
+	ret = iio_device_register(st->indio_dev);
+	if (ret)
+		goto error_free_dev;
+
+	if (spi->irq) {
+		INIT_WORK(&st->work_alarm, ad5504_interrupt_bh);
+
+		ret = iio_register_interrupt_line(spi->irq,
+				st->indio_dev,
+				0,
+				IRQF_TRIGGER_FALLING,
+				spi_get_device_id(st->spi)->name);
+		if (ret)
+			goto error_unreg_iio_device;
+
+		iio_add_event_to_list(&iio_event_ad5504,
+				&st->indio_dev->interrupts[0]->ev_list);
+	}
+
+	return 0;
+
+error_unreg_iio_device:
+	iio_device_unregister(st->indio_dev);
+error_free_dev:
+	iio_free_device(st->indio_dev);
+error_disable_reg:
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+error_put_reg:
+	if (!IS_ERR(st->reg))
+		regulator_put(st->reg);
+
+	kfree(st);
+error_ret:
+	return ret;
+}
+
+static int __devexit ad5504_remove(struct spi_device *spi)
+{
+	struct ad5504_state *st = spi_get_drvdata(spi);
+
+	if (spi->irq)
+		iio_unregister_interrupt_line(st->indio_dev, 0);
+
+	iio_device_unregister(st->indio_dev);
+
+	if (!IS_ERR(st->reg)) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+
+	kfree(st);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5504_id[] = {
+	{"ad5504", ID_AD5504},
+	{"ad5501", ID_AD5501},
+	{}
+};
+
+static struct spi_driver ad5504_driver = {
+	.driver = {
+		   .name = "ad5504",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = ad5504_probe,
+	.remove = __devexit_p(ad5504_remove),
+	.id_table = ad5504_id,
+};
+
+static __init int ad5504_spi_init(void)
+{
+	return spi_register_driver(&ad5504_driver);
+}
+module_init(ad5504_spi_init);
+
+static __exit void ad5504_spi_exit(void)
+{
+	spi_unregister_driver(&ad5504_driver);
+}
+module_exit(ad5504_spi_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/iio/dac/ad5504.h b/drivers/staging/iio/dac/ad5504.h
new file mode 100644
index 0000000..d2fac63
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5504.h
@@ -0,0 +1,74 @@
+/*
+ * AD5504 SPI DAC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef SPI_AD5504_H_
+#define SPI_AD5504_H_
+
+#define AD5505_BITS			12
+#define AD5504_RES_MASK			((1 << (AD5505_BITS)) - 1)
+
+#define AD5504_CMD_READ			(1 << 15)
+#define AD5504_CMD_WRITE		(0 << 15)
+#define AD5504_ADDR(addr)		((addr) << 12)
+
+/* Registers */
+#define AD5504_ADDR_NOOP		0
+#define AD5504_ADDR_DAC0		1
+#define AD5504_ADDR_DAC1		2
+#define AD5504_ADDR_DAC2		3
+#define AD5504_ADDR_DAC3		4
+#define AD5504_ADDR_ALL_DAC		5
+#define AD5504_ADDR_CTRL		7
+
+/* Control Register */
+#define AD5504_DAC_PWR(ch)		((ch) << 2)
+#define AD5504_DAC_PWRDWN_MODE(mode)	((mode) << 6)
+#define AD5504_DAC_PWRDN_20K		0
+#define AD5504_DAC_PWRDN_3STATE		1
+
+/*
+ * TODO: struct ad5504_platform_data needs to go into include/linux/iio
+ */
+
+struct ad5504_platform_data {
+	u16				vref_mv;
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @us:			spi_device
+ * @reg:		supply regulator
+ * @vref_mv:		actual reference voltage used
+ * @work_alarm:		bh work structure for event handling
+ * @last_timestamp:	timestamp of last event interrupt
+ * @pwr_down_mask	power down mask
+ * @pwr_down_mode	current power down mode
+ */
+
+struct ad5504_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*spi;
+	struct regulator		*reg;
+	unsigned short			vref_mv;
+	struct work_struct		work_alarm;
+	s64				last_timestamp;
+	unsigned			pwr_down_mask;
+	unsigned			pwr_down_mode;
+};
+
+/**
+ * ad5504_supported_device_ids:
+ */
+
+enum ad5504_supported_device_ids {
+	ID_AD5504,
+	ID_AD5501,
+};
+
+#endif /* SPI_AD5504_H_ */