iio: Move ad7476 driver out of staging

The ad7476 driver is a driver for simple single channel ADCs. The driver does
not export any experimental or custom ABI files nor do the static code check
tools report any issues, so move the driver out of staging.

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

3 files changed, 293 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index d0ae71ec2aa0..f98c493efff8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -30,6 +30,20 @@ config AD7791
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad7791.
 
+config AD7476
+	tristate "Analog Devices AD7475/6/7/8 AD7466/7/8 and AD7495 ADC driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices
+	  AD7475, AD7476, AD7477, AD7478, AD7466, AD7467, AD7468, AD7495
+	  SPI analog to digital converters (ADC).
+	  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 ad7476.
+
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index f187ff6c2a16..9824a70f4fd8 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -4,5 +4,6 @@
 
 obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
 obj-$(CONFIG_AD7266) += ad7266.o
+obj-$(CONFIG_AD7476) += ad7476.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
new file mode 100644
index 000000000000..a33a4066ebe2
--- /dev/null
+++ b/drivers/iio/adc/ad7476.c
@@ -0,0 +1,278 @@
+/*
+ * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#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/module.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>
+
+#define RES_MASK(bits)	((1 << (bits)) - 1)
+
+struct ad7476_chip_info {
+	unsigned int			int_vref_uv;
+	struct iio_chan_spec		channel[2];
+};
+
+struct ad7476_state {
+	struct spi_device		*spi;
+	const struct ad7476_chip_info	*chip_info;
+	struct regulator		*reg;
+	struct spi_transfer		xfer;
+	struct spi_message		msg;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * Make the buffer large enough for one 16 bit sample and one 64 bit
+	 * aligned 64 bit timestamp.
+	 */
+	unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
+			____cacheline_aligned;
+};
+
+enum ad7476_supported_device_ids {
+	ID_AD7466,
+	ID_AD7467,
+	ID_AD7468,
+	ID_AD7495
+};
+
+static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7476_state *st = iio_priv(indio_dev);
+	s64 time_ns;
+	int b_sent;
+
+	b_sent = spi_sync(st->spi, &st->msg);
+	if (b_sent < 0)
+		goto done;
+
+	time_ns = iio_get_time_ns();
+
+	if (indio_dev->scan_timestamp)
+		((s64 *)st->data)[1] = time_ns;
+
+	iio_push_to_buffer(indio_dev->buffer, st->data);
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int ad7476_scan_direct(struct ad7476_state *st)
+{
+	int ret;
+
+	ret = spi_sync(st->spi, &st->msg);
+	if (ret)
+		return ret;
+
+	return be16_to_cpup((__be16 *)st->data);
+}
+
+static int ad7476_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	int ret;
+	struct ad7476_state *st = iio_priv(indio_dev);
+	int scale_uv;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		if (iio_buffer_enabled(indio_dev))
+			ret = -EBUSY;
+		else
+			ret = ad7476_scan_direct(st);
+		mutex_unlock(&indio_dev->mlock);
+
+		if (ret < 0)
+			return ret;
+		*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
+			RES_MASK(st->chip_info->channel[0].scan_type.realbits);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		if (!st->chip_info->int_vref_uv) {
+			scale_uv = regulator_get_voltage(st->reg);
+			if (scale_uv < 0)
+				return scale_uv;
+		} else {
+			scale_uv = st->chip_info->int_vref_uv;
+		}
+		scale_uv >>= chan->scan_type.realbits;
+		*val =  scale_uv / 1000;
+		*val2 = (scale_uv % 1000) * 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	return -EINVAL;
+}
+
+#define AD7476_CHAN(bits)					\
+	{							\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
+	IIO_CHAN_INFO_SCALE_SHARED_BIT,				\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = bits,				\
+		.storagebits = 16,				\
+		.shift = 13 - bits,				\
+	},							\
+}
+
+static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
+	[ID_AD7466] = {
+		.channel[0] = AD7476_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7467] = {
+		.channel[0] = AD7476_CHAN(10),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7468] = {
+		.channel[0] = AD7476_CHAN(8),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7495] = {
+		.channel[0] = AD7476_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+		.int_vref_uv = 2500000,
+	},
+};
+
+static const struct iio_info ad7476_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &ad7476_read_raw,
+};
+
+static int __devinit ad7476_probe(struct spi_device *spi)
+{
+	struct ad7476_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	st = iio_priv(indio_dev);
+	st->chip_info =
+		&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	st->reg = regulator_get(&spi->dev, "vcc");
+	if (IS_ERR(st->reg)) {
+		ret = PTR_ERR(st->reg);
+		goto error_free_dev;
+	}
+
+	ret = regulator_enable(st->reg);
+	if (ret)
+		goto error_put_reg;
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st->spi = spi;
+
+	/* Establish that the iio_dev is a child of the spi device */
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channel;
+	indio_dev->num_channels = 2;
+	indio_dev->info = &ad7476_info;
+	/* Setup default message */
+
+	st->xfer.rx_buf = &st->data;
+	st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
+
+	spi_message_init(&st->msg);
+	spi_message_add_tail(&st->xfer, &st->msg);
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			&ad7476_trigger_handler, NULL);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_ring_unregister;
+	return 0;
+
+error_ring_unregister:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+	regulator_disable(st->reg);
+error_put_reg:
+	regulator_put(st->reg);
+error_free_dev:
+	iio_device_free(indio_dev);
+
+error_ret:
+	return ret;
+}
+
+static int __devexit ad7476_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad7476_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	regulator_disable(st->reg);
+	regulator_put(st->reg);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad7476_id[] = {
+	{"ad7466", ID_AD7466},
+	{"ad7467", ID_AD7467},
+	{"ad7468", ID_AD7468},
+	{"ad7475", ID_AD7466},
+	{"ad7476", ID_AD7466},
+	{"ad7476a", ID_AD7466},
+	{"ad7477", ID_AD7467},
+	{"ad7477a", ID_AD7467},
+	{"ad7478", ID_AD7468},
+	{"ad7478a", ID_AD7468},
+	{"ad7495", ID_AD7495},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7476_id);
+
+static struct spi_driver ad7476_driver = {
+	.driver = {
+		.name	= "ad7476",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7476_probe,
+	.remove		= __devexit_p(ad7476_remove),
+	.id_table	= ad7476_id,
+};
+module_spi_driver(ad7476_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7475/6/7/8(A) AD7466/7/8 ADC");
+MODULE_LICENSE("GPL v2");