staging:iio: Move the ad7298 driver out of staging

The driver does not expose any custom API to userspace and none of the standard
static code checker tools report any issues, so move it out of staging.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 421 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index ef5200a..cd5eed6 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -18,6 +18,18 @@ config AD7266
 	  Say yes here to build support for Analog Devices AD7265 and AD7266
 	  ADCs.
 
+config AD7298
+	tristate "Analog Devices AD7298 ADC driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices AD7298
+	  8 Channel ADC with temperature sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7298.
+
 config AD7791
 	tristate "Analog Devices AD7791 ADC driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 54ac7bb..3256dc6 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -4,6 +4,7 @@
 
 obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
 obj-$(CONFIG_AD7266) += ad7266.o
+obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7476) += ad7476.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AD7887) += ad7887.o
diff --git a/drivers/iio/adc/ad7298.c b/drivers/iio/adc/ad7298.c
new file mode 100644
index 0000000..441a9a2
--- /dev/null
+++ b/drivers/iio/adc/ad7298.c
@@ -0,0 +1,408 @@
+/*
+ * AD7298 SPI ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <linux/platform_data/ad7298.h>
+
+#define AD7298_WRITE	(1 << 15) /* write to the control register */
+#define AD7298_REPEAT	(1 << 14) /* repeated conversion enable */
+#define AD7298_CH(x)	(1 << (13 - (x))) /* channel select */
+#define AD7298_TSENSE	(1 << 5) /* temperature conversion enable */
+#define AD7298_EXTREF	(1 << 2) /* external reference enable */
+#define AD7298_TAVG	(1 << 1) /* temperature sensor averaging enable */
+#define AD7298_PDD	(1 << 0) /* partial power down enable */
+
+#define AD7298_MAX_CHAN		8
+#define AD7298_BITS		12
+#define AD7298_STORAGE_BITS	16
+#define AD7298_INTREF_mV	2500
+
+#define AD7298_CH_TEMP		9
+
+#define RES_MASK(bits)	((1 << (bits)) - 1)
+
+struct ad7298_state {
+	struct spi_device		*spi;
+	struct regulator		*reg;
+	unsigned			ext_ref;
+	struct spi_transfer		ring_xfer[10];
+	struct spi_transfer		scan_single_xfer[3];
+	struct spi_message		ring_msg;
+	struct spi_message		scan_single_msg;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	unsigned short			rx_buf[12] ____cacheline_aligned;
+	unsigned short			tx_buf[2];
+};
+
+#define AD7298_V_CHAN(index)						\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.channel = index,					\
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
+		IIO_CHAN_INFO_SCALE_SHARED_BIT,				\
+		.address = index,					\
+		.scan_index = index,					\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 12,					\
+			.storagebits = 16,				\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+static const struct iio_chan_spec ad7298_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT |
+			IIO_CHAN_INFO_OFFSET_SEPARATE_BIT,
+		.address = AD7298_CH_TEMP,
+		.scan_index = -1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+		},
+	},
+	AD7298_V_CHAN(0),
+	AD7298_V_CHAN(1),
+	AD7298_V_CHAN(2),
+	AD7298_V_CHAN(3),
+	AD7298_V_CHAN(4),
+	AD7298_V_CHAN(5),
+	AD7298_V_CHAN(6),
+	AD7298_V_CHAN(7),
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+};
+
+/**
+ * ad7298_update_scan_mode() setup the spi transfer buffer for the new scan mask
+ **/
+static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
+	const unsigned long *active_scan_mask)
+{
+	struct ad7298_state *st = iio_priv(indio_dev);
+	int i, m;
+	unsigned short command;
+	int scan_count;
+
+	/* Now compute overall size */
+	scan_count = bitmap_weight(active_scan_mask, indio_dev->masklength);
+
+	command = AD7298_WRITE | st->ext_ref;
+
+	for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
+		if (test_bit(i, active_scan_mask))
+			command |= m;
+
+	st->tx_buf[0] = cpu_to_be16(command);
+
+	/* build spi ring message */
+	st->ring_xfer[0].tx_buf = &st->tx_buf[0];
+	st->ring_xfer[0].len = 2;
+	st->ring_xfer[0].cs_change = 1;
+	st->ring_xfer[1].tx_buf = &st->tx_buf[1];
+	st->ring_xfer[1].len = 2;
+	st->ring_xfer[1].cs_change = 1;
+
+	spi_message_init(&st->ring_msg);
+	spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
+	spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
+
+	for (i = 0; i < scan_count; i++) {
+		st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
+		st->ring_xfer[i + 2].len = 2;
+		st->ring_xfer[i + 2].cs_change = 1;
+		spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
+	}
+	/* make sure last transfer cs_change is not set */
+	st->ring_xfer[i + 1].cs_change = 0;
+
+	return 0;
+}
+
+/**
+ * ad7298_trigger_handler() bh of trigger launched polling to ring buffer
+ *
+ * Currently there is no option in this driver to disable the saving of
+ * timestamps within the ring.
+ **/
+static irqreturn_t ad7298_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7298_state *st = iio_priv(indio_dev);
+	s64 time_ns = 0;
+	int b_sent;
+
+	b_sent = spi_sync(st->spi, &st->ring_msg);
+	if (b_sent)
+		goto done;
+
+	if (indio_dev->scan_timestamp) {
+		time_ns = iio_get_time_ns();
+		memcpy((u8 *)st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
+			&time_ns, sizeof(time_ns));
+	}
+
+	iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
+
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
+{
+	int ret;
+	st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref |
+				   (AD7298_CH(0) >> ch));
+
+	ret = spi_sync(st->spi, &st->scan_single_msg);
+	if (ret)
+		return ret;
+
+	return be16_to_cpu(st->rx_buf[0]);
+}
+
+static int ad7298_scan_temp(struct ad7298_state *st, int *val)
+{
+	int ret;
+	__be16 buf;
+
+	buf = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE |
+			  AD7298_TAVG | st->ext_ref);
+
+	ret = spi_write(st->spi, (u8 *)&buf, 2);
+	if (ret)
+		return ret;
+
+	buf = cpu_to_be16(0);
+
+	ret = spi_write(st->spi, (u8 *)&buf, 2);
+	if (ret)
+		return ret;
+
+	usleep_range(101, 1000); /* sleep > 100us */
+
+	ret = spi_read(st->spi, (u8 *)&buf, 2);
+	if (ret)
+		return ret;
+
+	*val = sign_extend32(be16_to_cpu(buf), 11);
+
+	return 0;
+}
+
+static int ad7298_get_ref_voltage(struct ad7298_state *st)
+{
+	int vref;
+
+	if (st->ext_ref) {
+		vref = regulator_get_voltage(st->reg);
+		if (vref < 0)
+			return vref;
+
+		return vref / 1000;
+	} else {
+		return AD7298_INTREF_mV;
+	}
+}
+
+static int ad7298_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	int ret;
+	struct ad7298_state *st = iio_priv(indio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+			ret = -EBUSY;
+		} else {
+			if (chan->address == AD7298_CH_TEMP)
+				ret = ad7298_scan_temp(st, val);
+			else
+				ret = ad7298_scan_direct(st, chan->address);
+		}
+		mutex_unlock(&indio_dev->mlock);
+
+		if (ret < 0)
+			return ret;
+
+		if (chan->address != AD7298_CH_TEMP)
+			*val = ret & RES_MASK(AD7298_BITS);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*val = ad7298_get_ref_voltage(st);
+			*val2 = chan->scan_type.realbits;
+			return IIO_VAL_FRACTIONAL_LOG2;
+		case IIO_TEMP:
+			*val = ad7298_get_ref_voltage(st);
+			*val2 = 10;
+			return IIO_VAL_FRACTIONAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		*val = 1093 - 2732500 / ad7298_get_ref_voltage(st);
+		return IIO_VAL_INT;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info ad7298_info = {
+	.read_raw = &ad7298_read_raw,
+	.update_scan_mode = ad7298_update_scan_mode,
+	.driver_module = THIS_MODULE,
+};
+
+static int __devinit ad7298_probe(struct spi_device *spi)
+{
+	struct ad7298_platform_data *pdata = spi->dev.platform_data;
+	struct ad7298_state *st;
+	struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
+	int ret;
+
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	if (pdata && pdata->ext_ref)
+		st->ext_ref = AD7298_EXTREF;
+
+	if (st->ext_ref) {
+		st->reg = regulator_get(&spi->dev, "vref");
+		if (IS_ERR(st->reg)) {
+			ret = PTR_ERR(st->reg);
+			goto error_free;
+		}
+		ret = regulator_enable(st->reg);
+		if (ret)
+			goto error_put_reg;
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st->spi = spi;
+
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ad7298_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad7298_channels);
+	indio_dev->info = &ad7298_info;
+
+	/* Setup default message */
+
+	st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
+	st->scan_single_xfer[0].len = 2;
+	st->scan_single_xfer[0].cs_change = 1;
+	st->scan_single_xfer[1].tx_buf = &st->tx_buf[1];
+	st->scan_single_xfer[1].len = 2;
+	st->scan_single_xfer[1].cs_change = 1;
+	st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
+	st->scan_single_xfer[2].len = 2;
+
+	spi_message_init(&st->scan_single_msg);
+	spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
+	spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
+	spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			&ad7298_trigger_handler, NULL);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_cleanup_ring;
+
+	return 0;
+
+error_cleanup_ring:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+	if (st->ext_ref)
+		regulator_disable(st->reg);
+error_put_reg:
+	if (st->ext_ref)
+		regulator_put(st->reg);
+error_free:
+	iio_device_free(indio_dev);
+
+	return ret;
+}
+
+static int __devexit ad7298_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad7298_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	if (st->ext_ref) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad7298_id[] = {
+	{"ad7298", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7298_id);
+
+static struct spi_driver ad7298_driver = {
+	.driver = {
+		.name	= "ad7298",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7298_probe,
+	.remove		= __devexit_p(ad7298_remove),
+	.id_table	= ad7298_id,
+};
+module_spi_driver(ad7298_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7298 ADC");
+MODULE_LICENSE("GPL v2");