[PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[Paul Cercueil]

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
---
 .../devicetree/bindings/iio/dac/ad5592r.txt        | 43 ++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/ad5592r.txt

 v2: Fix indentation issue

diff --git a/Documentation/devicetree/bindings/iio/dac/ad5592r.txt b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
new file mode 100644
index 0000000..12b8d0e
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
@@ -0,0 +1,43 @@
+Analog Devices AD5592R/AD5593R DAC/ADC device driver
+
+Required properties for the AD5592R:
+	- compatible: Must be "adi,ad5592r"
+	- reg: SPI chip select number for the device
+	- spi-max-frequency: Max SPI frequency to use (< 30000000)
+	- spi-cpol: The AD5592R requires inverse clock polarity (CPOL) mode
+
+Required properties for the AD5593R:
+	- compatible: Must be "adi,ad5593r"
+	- reg: I2C address of the device
+
+Required properties for all supported chips:
+	- channel-modes: An array of eight 8-bit values (one per channel)
+	  describing the mode of each channel. Macros specifying the valid values
+	  can be found in <dt-bindings/iio/adi,ad5592r.h>.
+	  The following values are currently supported:
+		* CH_MODE_UNUSED (the pin is pulled down)
+		* CH_MODE_DAC
+		* CH_MODE_ADC
+		* CH_MODE_GPIO_TRISTATE
+
+Example:
+
+	#include <dt-bindings/iio/adi,ad5592r.h>
+
+	ad5592r@0 {
+		compatible = "adi,ad5592r";
+		reg = <0>;
+		spi-max-frequency = <1000000>;
+		spi-cpol;
+
+		channel-modes = /bits/ 8 <
+			CH_MODE_DAC
+			CH_MODE_ADC
+			CH_MODE_ADC
+			CH_MODE_UNUSED
+			CH_MODE_UNUSED
+			CH_MODE_UNUSED
+			CH_MODE_UNUSED
+			CH_MODE_UNUSED
+		>;
+	};
-- 
2.6.1

[PATCHv2 2/2] iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs

[Paul Cercueil]

This patch adds support for the AD5592R (spi) and AD5593R (i2c)
ADC/DAC devices.

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
---
 drivers/iio/dac/Kconfig               |  27 ++++
 drivers/iio/dac/Makefile              |   3 +
 drivers/iio/dac/ad5592r-base.c        | 289 ++++++++++++++++++++++++++++++++++
 drivers/iio/dac/ad5592r-base.h        |  56 +++++++
 drivers/iio/dac/ad5592r.c             | 126 +++++++++++++++
 drivers/iio/dac/ad5593r.c             | 121 ++++++++++++++
 include/dt-bindings/iio/adi,ad5592r.h |  13 ++
 7 files changed, 635 insertions(+)
 create mode 100644 drivers/iio/dac/ad5592r-base.c
 create mode 100644 drivers/iio/dac/ad5592r-base.h
 create mode 100644 drivers/iio/dac/ad5592r.c
 create mode 100644 drivers/iio/dac/ad5593r.c
 create mode 100644 include/dt-bindings/iio/adi,ad5592r.h

 v2: Introduced changes suggested by upstream feedback

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index e701e28..be7bb04 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -72,6 +72,33 @@ config AD5449
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5449.
 
+config AD5592R_BASE
+	tristate
+
+config AD5592R
+	tristate "Analog Devices AD5592R ADC/DAC driver"
+	depends on SPI_MASTER
+	depends on OF
+	select AD5592R_BASE
+	help
+	  Say yes here to build support for Analog Devices AD5592R
+	  Digital to Analog / Analog to Digital Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5592r.
+
+config AD5593R
+	tristate "Analog Devices AD5593R ADC/DAC driver"
+	depends on I2C
+	depends on OF
+	select AD5592R_BASE
+	help
+	  Say yes here to build support for Analog Devices AD5593R
+	  Digital to Analog / Analog to Digital Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5593r.
+
 config AD5504
 	tristate "Analog Devices AD5504/AD5501 DAC SPI driver"
 	depends on SPI
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 63ae056..ae00b67 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -11,6 +11,9 @@ obj-$(CONFIG_AD5064) += ad5064.o
 obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
 obj-$(CONFIG_AD5449) += ad5449.o
+obj-$(CONFIG_AD5592R_BASE) += ad5592r-base.o
+obj-$(CONFIG_AD5592R) += ad5592r.o
+obj-$(CONFIG_AD5593R) += ad5593r.o
 obj-$(CONFIG_AD5755) += ad5755.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c
new file mode 100644
index 0000000..c1132fd
--- /dev/null
+++ b/drivers/iio/dac/ad5592r-base.c
@@ -0,0 +1,289 @@
+/*
+ * AD5592R Digital <-> Analog converters driver
+ *
+ * Copyright 2014 Analog Devices Inc.
+ * Author: Paul Cercueil <paul.cercueil@analog.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+/*
+ * TODO:
+ *     - Add support for using channels as GPIOs
+ */
+
+#include "ad5592r-base.h"
+
+#include <dt-bindings/iio/adi,ad5592r.h>
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+
+static int ad5592r_set_channel_modes(struct ad5592r_state *st)
+{
+	const struct ad5592r_rw_ops *ops = st->ops;
+	int ret;
+	unsigned i;
+	struct iio_dev *iio_dev = iio_priv_to_dev(st);
+	u8 pulldown = 0, open_drain = 0, tristate = 0,
+	   dac = 0, adc = 0, gpio_in = 0, gpio_out = 0;
+	u16 read_back;
+
+	for (i = 0; i < st->num_channels; i++) {
+		switch (st->channel_modes[i]) {
+		case CH_MODE_DAC:
+			dac |= BIT(i);
+
+		/* fall-through */
+		case CH_MODE_ADC:
+			adc |= BIT(i);
+			break;
+
+		case CH_MODE_GPIO_OUT:
+			gpio_out |= BIT(i);
+
+		/* fall-through */
+		case CH_MODE_GPIO_IN:
+			gpio_in |= BIT(i);
+			break;
+
+		case CH_MODE_GPIO_OPEN_DRAIN:
+			open_drain |= BIT(i);
+			break;
+
+		case CH_MODE_GPIO_TRISTATE:
+			tristate |= BIT(i);
+			break;
+
+		default:
+			pulldown |= BIT(i);
+			break;
+		}
+	}
+
+	mutex_lock(&iio_dev->mlock);
+
+	/* Configure pins that we use */
+	ret = ops->reg_write(st, AD5592R_REG_DAC_EN, dac);
+	if (ret)
+		goto err_unlock;
+
+	ret = ops->reg_write(st, AD5592R_REG_ADC_EN, adc);
+	if (ret)
+		goto err_unlock;
+
+	ret = ops->reg_write(st, AD5592R_REG_GPIO_OUT_EN, gpio_out);
+	if (ret)
+		goto err_unlock;
+
+	ret = ops->reg_write(st, AD5592R_REG_GPIO_IN_EN, gpio_in);
+	if (ret)
+		goto err_unlock;
+
+	ret = ops->reg_write(st, AD5592R_REG_OPEN_DRAIN, open_drain);
+	if (ret)
+		goto err_unlock;
+
+	ret = ops->reg_write(st, AD5592R_REG_TRISTATE, tristate);
+	if (ret)
+		goto err_unlock;
+
+	/* Pull down unused pins to GND */
+	ret = ops->reg_write(st, AD5592R_REG_PULLDOWN, pulldown);
+	if (ret)
+		goto err_unlock;
+
+	/* Verify that we can read back at least one register */
+	ret = ops->reg_read(st, AD5592R_REG_ADC_EN, &read_back);
+	if (!ret && (read_back & 0xff) != adc)
+		ret = -EIO;
+
+err_unlock:
+	mutex_unlock(&iio_dev->mlock);
+	return ret;
+}
+
+static int ad5592r_write_raw(struct iio_dev *iio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	struct ad5592r_state *st = iio_priv(iio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val >= (1 << chan->scan_type.realbits) || val < 0)
+			return -EINVAL;
+
+		mutex_lock(&iio_dev->mlock);
+		ret = st->ops->dac_write(st, chan->address, val);
+		mutex_unlock(&iio_dev->mlock);
+		return ret;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad5592r_read_raw(struct iio_dev *iio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long m)
+{
+	struct ad5592r_state *st = iio_priv(iio_dev);
+	u16 read_val;
+	int ret;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&iio_dev->mlock);
+		ret = st->ops->adc_read(st, chan->channel, &read_val);
+		mutex_unlock(&iio_dev->mlock);
+		if (ret)
+			return ret;
+
+		if ((read_val >> 12 & 0x7) != chan->channel) {
+			dev_err(st->dev, "Error while reading channel %u\n",
+					chan->channel);
+			return -EIO;
+		}
+
+		read_val &= GENMASK(11, 0);
+
+		dev_dbg(st->dev, "ADC read: 0x%04hX\n", read_val);
+		*val = (int) read_val;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static void ad5592r_reset(struct ad5592r_state *st)
+{
+	struct iio_dev *iio_dev = iio_priv_to_dev(st);
+
+	mutex_lock(&iio_dev->mlock);
+	st->ops->reg_write(st, AD5592R_REG_RESET, 0xdac);
+	udelay(250);
+	mutex_unlock(&iio_dev->mlock);
+}
+
+static const struct iio_info ad5592r_info = {
+	.read_raw = ad5592r_read_raw,
+	.write_raw = ad5592r_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static void ad5592r_setup_channel(struct iio_dev *iio_dev,
+		struct iio_chan_spec *chan, bool output, unsigned id)
+{
+	chan->type = IIO_VOLTAGE;
+	chan->indexed = 1;
+	chan->output = output;
+	chan->channel = id;
+	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+	chan->address = id;
+	chan->scan_type.sign = 'u';
+	chan->scan_type.realbits = 12;
+	chan->scan_type.storagebits = 16;
+}
+
+static int ad5592r_alloc_channels(struct ad5592r_state *st)
+{
+	unsigned i, curr_channel = 0,
+		 num_channels = st->num_channels;
+	struct iio_dev *iio_dev = iio_priv_to_dev(st);
+	struct iio_chan_spec *channels;
+	int ret;
+
+	ret = of_property_read_u8_array(st->dev->of_node, "channel-modes",
+			st->channel_modes, num_channels);
+	if (ret)
+		return ret;
+
+	channels = devm_kzalloc(st->dev,
+			2 * num_channels * sizeof(*channels), GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	for (i = 0; i < num_channels; i++) {
+		switch (st->channel_modes[i]) {
+		case CH_MODE_DAC:
+			ad5592r_setup_channel(iio_dev, &channels[curr_channel],
+					true, curr_channel);
+			curr_channel++;
+			break;
+
+		case CH_MODE_ADC:
+			ad5592r_setup_channel(iio_dev, &channels[curr_channel],
+					false, curr_channel);
+			curr_channel++;
+
+		/* fall-through */
+		default:
+			continue;
+		}
+	}
+
+	iio_dev->num_channels = curr_channel;
+	iio_dev->channels = channels;
+
+	return 0;
+}
+
+int ad5592r_probe(struct device *dev, const char *name,
+		const struct ad5592r_rw_ops *ops)
+{
+	struct iio_dev *iio_dev;
+	struct ad5592r_state *st;
+	int ret;
+
+	iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(iio_dev);
+	st->dev = dev;
+	st->ops = ops;
+	st->num_channels = 8;
+	dev_set_drvdata(dev, iio_dev);
+
+	iio_dev->dev.parent = dev;
+	iio_dev->name = name;
+	iio_dev->info = &ad5592r_info;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+
+	ad5592r_reset(st);
+
+	ret = ad5592r_alloc_channels(st);
+	if (ret)
+		return ret;
+
+	ret = ad5592r_set_channel_modes(st);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, iio_dev);
+}
+EXPORT_SYMBOL_GPL(ad5592r_probe);
+
+int ad5592r_remove(struct device *dev)
+{
+	struct iio_dev *iio_dev = dev_get_drvdata(dev);
+	struct ad5592r_state *st = iio_priv(iio_dev);
+	unsigned int i;
+
+	/* Reset all channels */
+	for (i = 0; i < ARRAY_SIZE(st->channel_modes); i++)
+		st->channel_modes[i] = CH_MODE_UNUSED;
+
+	return ad5592r_set_channel_modes(st);
+}
+EXPORT_SYMBOL_GPL(ad5592r_remove);
+
+MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/ad5592r-base.h b/drivers/iio/dac/ad5592r-base.h
new file mode 100644
index 0000000..d722e0c
--- /dev/null
+++ b/drivers/iio/dac/ad5592r-base.h
@@ -0,0 +1,56 @@
+/*
+ * AD5592R / AD5593R Digital <-> Analog converters driver
+ *
+ * Copyright 2015 Analog Devices Inc.
+ * Author: Paul Cercueil <paul.cercueil@analog.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef __DRIVERS_IIO_DAC_AD5592R_BASE_H__
+#define __DRIVERS_IIO_DAC_AD5592R_BASE_H__
+
+#include <linux/types.h>
+#include <linux/cache.h>
+
+struct device;
+struct ad5592r_state;
+
+enum ad5592r_registers {
+	AD5592R_REG_NOOP		= 0x0,
+	AD5592R_REG_DAC_READBACK	= 0x1,
+	AD5592R_REG_ADC_SEQ		= 0x2,
+	AD5592R_REG_CTRL		= 0x3,
+	AD5592R_REG_ADC_EN		= 0x4,
+	AD5592R_REG_DAC_EN		= 0x5,
+	AD5592R_REG_PULLDOWN		= 0x6,
+	AD5592R_REG_LDAC		= 0x7,
+	AD5592R_REG_GPIO_OUT_EN		= 0x8,
+	AD5592R_REG_GPIO_SET		= 0x9,
+	AD5592R_REG_GPIO_IN_EN		= 0xA,
+	AD5592R_REG_PD			= 0xB,
+	AD5592R_REG_OPEN_DRAIN		= 0xC,
+	AD5592R_REG_TRISTATE		= 0xD,
+	AD5592R_REG_RESET		= 0xF,
+};
+
+struct ad5592r_rw_ops {
+	int (*dac_write)(struct ad5592r_state *st, unsigned chan, u16 value);
+	int (*adc_read)(struct ad5592r_state *st, unsigned chan, u16 *value);
+	int (*reg_write)(struct ad5592r_state *st, u8 reg, u16 value);
+	int (*reg_read)(struct ad5592r_state *st, u8 reg, u16 *value);
+};
+
+struct ad5592r_state {
+	struct device *dev;
+	unsigned int num_channels;
+	const struct ad5592r_rw_ops *ops;
+	u8 channel_modes[8];
+	__be16 spi_msg ____cacheline_aligned;
+};
+
+int ad5592r_probe(struct device *dev, const char *name,
+		const struct ad5592r_rw_ops *ops);
+int ad5592r_remove(struct device *dev);
+
+#endif /* __DRIVERS_IIO_DAC_AD5592R_BASE_H__ */
diff --git a/drivers/iio/dac/ad5592r.c b/drivers/iio/dac/ad5592r.c
new file mode 100644
index 0000000..0572a36
--- /dev/null
+++ b/drivers/iio/dac/ad5592r.c
@@ -0,0 +1,126 @@
+/*
+ * AD5592R Digital <-> Analog converters driver
+ *
+ * Copyright 2015 Analog Devices Inc.
+ * Author: Paul Cercueil <paul.cercueil@analog.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include "ad5592r-base.h"
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+
+static int ad5592r_dac_write(struct ad5592r_state *st, unsigned chan, u16 value)
+{
+	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
+
+	st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
+
+	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
+}
+
+static int ad5592r_adc_read(struct ad5592r_state *st, unsigned chan, u16 *value)
+{
+	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
+	int ret;
+
+	st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
+
+	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
+	if (ret)
+		return ret;
+
+	/* Invalid data */
+	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
+	if (ret)
+		return ret;
+
+	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
+	if (ret)
+		return ret;
+
+	*value = be16_to_cpu(st->spi_msg);
+
+	return 0;
+}
+
+static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
+{
+	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
+
+	st->spi_msg = cpu_to_be16((reg << 11) | value);
+
+	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
+}
+
+static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
+{
+	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
+	int ret;
+
+	st->spi_msg = cpu_to_be16(
+			(AD5592R_REG_LDAC << 11) | BIT(6) | (reg << 2));
+
+	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
+	if (ret)
+		return ret;
+
+	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
+	if (ret)
+		return ret;
+
+	if (value)
+		*value = be16_to_cpu(st->spi_msg);
+
+	return 0;
+}
+
+static const struct ad5592r_rw_ops ad5592r_rw_ops = {
+	.dac_write = ad5592r_dac_write,
+	.adc_read = ad5592r_adc_read,
+	.reg_write = ad5592r_reg_write,
+	.reg_read = ad5592r_reg_read,
+};
+
+static int ad5592r_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
+}
+
+static int ad5592r_spi_remove(struct spi_device *spi)
+{
+	return ad5592r_remove(&spi->dev);
+}
+
+static const struct spi_device_id ad5592r_spi_ids[] = {
+	{ .name = "ad5592r", },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
+
+static const struct of_device_id ad5592r_of_match[] = {
+	{ .compatible = "adi,ad5592r", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ad5592r_of_match);
+
+static struct spi_driver ad5592r_spi_driver = {
+	.driver = {
+		.name = "ad5592r",
+		.of_match_table = of_match_ptr(ad5592r_of_match),
+	},
+	.probe = ad5592r_spi_probe,
+	.remove = ad5592r_spi_remove,
+	.id_table = ad5592r_spi_ids,
+};
+module_spi_driver(ad5592r_spi_driver);
+
+MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c
new file mode 100644
index 0000000..6825834
--- /dev/null
+++ b/drivers/iio/dac/ad5593r.c
@@ -0,0 +1,121 @@
+/*
+ * AD5593R Digital <-> Analog converters driver
+ *
+ * Copyright 2015 Analog Devices Inc.
+ * Author: Paul Cercueil <paul.cercueil@analog.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include "ad5592r-base.h"
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#define AD5593R_MODE_CONF		(0 << 4)
+#define AD5593R_MODE_DAC_WRITE		(1 << 4)
+#define AD5593R_MODE_ADC_READBACK	(4 << 4)
+#define AD5593R_MODE_DAC_READBACK	(5 << 4)
+#define AD5593R_MODE_GPIO_READBACK	(6 << 4)
+#define AD5593R_MODE_REG_READBACK	(7 << 4)
+
+static int ad5593r_dac_write(struct ad5592r_state *st, unsigned chan, u16 value)
+{
+	struct i2c_client *i2c = to_i2c_client(st->dev);
+
+	return i2c_smbus_write_word_swapped(i2c,
+			AD5593R_MODE_DAC_WRITE | chan, value);
+}
+
+static int ad5593r_adc_read(struct ad5592r_state *st, unsigned chan, u16 *value)
+{
+	struct i2c_client *i2c = to_i2c_client(st->dev);
+	s32 val;
+
+	val = i2c_smbus_write_word_swapped(i2c,
+			AD5593R_MODE_CONF | AD5592R_REG_ADC_SEQ, BIT(chan));
+	if (val < 0)
+		return (int) val;
+
+	/* Invalid data */
+	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
+	if (val < 0)
+		return (int) val;
+
+	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
+	if (val < 0)
+		return (int) val;
+
+	*value = (u16) val;
+
+	return 0;
+}
+
+static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
+{
+	struct i2c_client *i2c = to_i2c_client(st->dev);
+
+	return i2c_smbus_write_word_swapped(i2c,
+			AD5593R_MODE_CONF | reg, value);
+}
+
+static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
+{
+	struct i2c_client *i2c = to_i2c_client(st->dev);
+	s32 val;
+
+	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg);
+	if (val < 0)
+		return (int) val;
+
+	*value = (u16) val;
+
+	return 0;
+}
+
+static const struct ad5592r_rw_ops ad5593r_rw_ops = {
+	.dac_write = ad5593r_dac_write,
+	.adc_read = ad5593r_adc_read,
+	.reg_write = ad5593r_reg_write,
+	.reg_read = ad5593r_reg_read,
+};
+
+static int ad5593r_i2c_probe(struct i2c_client *i2c,
+		const struct i2c_device_id *id)
+{
+	return ad5592r_probe(&i2c->dev, id->name, &ad5593r_rw_ops);
+}
+
+static int ad5593r_i2c_remove(struct i2c_client *i2c)
+{
+	return ad5592r_remove(&i2c->dev);
+}
+
+static const struct i2c_device_id ad5593r_i2c_ids[] = {
+	{ .name = "ad5593r", },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, ad5593r_i2c_ids);
+
+static const struct of_device_id ad5593r_of_match[] = {
+	{ .compatible = "adi,ad5593r", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ad5593r_of_match);
+
+static struct i2c_driver ad5593r_driver = {
+	.driver = {
+		.name = "ad5593r",
+		.of_match_table = of_match_ptr(ad5593r_of_match),
+	},
+	.probe = ad5593r_i2c_probe,
+	.remove = ad5593r_i2c_remove,
+	.id_table = ad5593r_i2c_ids,
+};
+module_i2c_driver(ad5593r_driver);
+
+MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/iio/adi,ad5592r.h b/include/dt-bindings/iio/adi,ad5592r.h
new file mode 100644
index 0000000..fcb6293
--- /dev/null
+++ b/include/dt-bindings/iio/adi,ad5592r.h
@@ -0,0 +1,13 @@
+
+#ifndef _DT_BINDINGS_ADI_AD5592R_H
+#define _DT_BINDINGS_ADI_AD5592R_H
+
+#define CH_MODE_UNUSED		0
+#define CH_MODE_DAC		1
+#define CH_MODE_ADC		2
+#define CH_MODE_GPIO_OUT	3
+#define CH_MODE_GPIO_IN		4
+#define CH_MODE_GPIO_OPEN_DRAIN	5
+#define CH_MODE_GPIO_TRISTATE	6
+
+#endif /* _DT_BINDINGS_ADI_AD5592R_H */
-- 
2.6.1

Re: [PATCHv2 2/2] iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs

[Jonathan Cameron]

On 13/10/15 10:38, Paul Cercueil wrote:
> This patch adds support for the AD5592R (spi) and AD5593R (i2c)
> ADC/DAC devices.
> 
> Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
A few minor questions inline...
> ---
>  drivers/iio/dac/Kconfig               |  27 ++++
>  drivers/iio/dac/Makefile              |   3 +
>  drivers/iio/dac/ad5592r-base.c        | 289 ++++++++++++++++++++++++++++++++++
>  drivers/iio/dac/ad5592r-base.h        |  56 +++++++
>  drivers/iio/dac/ad5592r.c             | 126 +++++++++++++++
>  drivers/iio/dac/ad5593r.c             | 121 ++++++++++++++
>  include/dt-bindings/iio/adi,ad5592r.h |  13 ++
>  7 files changed, 635 insertions(+)
>  create mode 100644 drivers/iio/dac/ad5592r-base.c
>  create mode 100644 drivers/iio/dac/ad5592r-base.h
>  create mode 100644 drivers/iio/dac/ad5592r.c
>  create mode 100644 drivers/iio/dac/ad5593r.c
>  create mode 100644 include/dt-bindings/iio/adi,ad5592r.h
> 
>  v2: Introduced changes suggested by upstream feedback
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index e701e28..be7bb04 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -72,6 +72,33 @@ config AD5449
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called ad5449.
>  
> +config AD5592R_BASE
> +	tristate
> +
> +config AD5592R
> +	tristate "Analog Devices AD5592R ADC/DAC driver"
> +	depends on SPI_MASTER
> +	depends on OF
> +	select AD5592R_BASE
> +	help
> +	  Say yes here to build support for Analog Devices AD5592R
> +	  Digital to Analog / Analog to Digital Converter.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ad5592r.
> +
> +config AD5593R
> +	tristate "Analog Devices AD5593R ADC/DAC driver"
> +	depends on I2C
> +	depends on OF
> +	select AD5592R_BASE
> +	help
> +	  Say yes here to build support for Analog Devices AD5593R
> +	  Digital to Analog / Analog to Digital Converter.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ad5593r.
> +
>  config AD5504
>  	tristate "Analog Devices AD5504/AD5501 DAC SPI driver"
>  	depends on SPI
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 63ae056..ae00b67 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -11,6 +11,9 @@ obj-$(CONFIG_AD5064) += ad5064.o
>  obj-$(CONFIG_AD5504) += ad5504.o
>  obj-$(CONFIG_AD5446) += ad5446.o
>  obj-$(CONFIG_AD5449) += ad5449.o
> +obj-$(CONFIG_AD5592R_BASE) += ad5592r-base.o
> +obj-$(CONFIG_AD5592R) += ad5592r.o
> +obj-$(CONFIG_AD5593R) += ad5593r.o
>  obj-$(CONFIG_AD5755) += ad5755.o
>  obj-$(CONFIG_AD5764) += ad5764.o
>  obj-$(CONFIG_AD5791) += ad5791.o
> diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c
> new file mode 100644
> index 0000000..c1132fd
> --- /dev/null
> +++ b/drivers/iio/dac/ad5592r-base.c
> @@ -0,0 +1,289 @@
> +/*
> + * AD5592R Digital <-> Analog converters driver
> + *
> + * Copyright 2014 Analog Devices Inc.
> + * Author: Paul Cercueil <paul.cercueil@analog.com>
> + *
> + * Licensed under the GPL-2.
> + */
> +
> +/*
> + * TODO:
> + *     - Add support for using channels as GPIOs
> + */
> +
> +#include "ad5592r-base.h"
> +
> +#include <dt-bindings/iio/adi,ad5592r.h>
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/iio/iio.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +
> +static int ad5592r_set_channel_modes(struct ad5592r_state *st)
> +{
> +	const struct ad5592r_rw_ops *ops = st->ops;
> +	int ret;
> +	unsigned i;
> +	struct iio_dev *iio_dev = iio_priv_to_dev(st);
> +	u8 pulldown = 0, open_drain = 0, tristate = 0,
> +	   dac = 0, adc = 0, gpio_in = 0, gpio_out = 0;
> +	u16 read_back;
> +
> +	for (i = 0; i < st->num_channels; i++) {
> +		switch (st->channel_modes[i]) {
> +		case CH_MODE_DAC:
> +			dac |= BIT(i);
> +
> +		/* fall-through */
> +		case CH_MODE_ADC:
> +			adc |= BIT(i);
> +			break;
> +
> +		case CH_MODE_GPIO_OUT:
> +			gpio_out |= BIT(i);
> +
> +		/* fall-through */
> +		case CH_MODE_GPIO_IN:
> +			gpio_in |= BIT(i);
> +			break;
> +
> +		case CH_MODE_GPIO_OPEN_DRAIN:
> +			open_drain |= BIT(i);
> +			break;
> +
> +		case CH_MODE_GPIO_TRISTATE:
> +			tristate |= BIT(i);
> +			break;
> +
> +		default:
> +			pulldown |= BIT(i);
> +			break;
> +		}
> +	}
> +
> +	mutex_lock(&iio_dev->mlock);
> +
> +	/* Configure pins that we use */
> +	ret = ops->reg_write(st, AD5592R_REG_DAC_EN, dac);
> +	if (ret)
> +		goto err_unlock;
> +
> +	ret = ops->reg_write(st, AD5592R_REG_ADC_EN, adc);
> +	if (ret)
> +		goto err_unlock;
> +
> +	ret = ops->reg_write(st, AD5592R_REG_GPIO_OUT_EN, gpio_out);
> +	if (ret)
> +		goto err_unlock;
> +
> +	ret = ops->reg_write(st, AD5592R_REG_GPIO_IN_EN, gpio_in);
> +	if (ret)
> +		goto err_unlock;
> +
> +	ret = ops->reg_write(st, AD5592R_REG_OPEN_DRAIN, open_drain);
> +	if (ret)
> +		goto err_unlock;
> +
> +	ret = ops->reg_write(st, AD5592R_REG_TRISTATE, tristate);
> +	if (ret)
> +		goto err_unlock;
> +
> +	/* Pull down unused pins to GND */
> +	ret = ops->reg_write(st, AD5592R_REG_PULLDOWN, pulldown);
> +	if (ret)
> +		goto err_unlock;
> +
> +	/* Verify that we can read back at least one register */
> +	ret = ops->reg_read(st, AD5592R_REG_ADC_EN, &read_back);
> +	if (!ret && (read_back & 0xff) != adc)
> +		ret = -EIO;
> +
> +err_unlock:
> +	mutex_unlock(&iio_dev->mlock);
> +	return ret;
> +}
> +
> +static int ad5592r_write_raw(struct iio_dev *iio_dev,
> +	struct iio_chan_spec const *chan, int val, int val2, long mask)
> +{
> +	struct ad5592r_state *st = iio_priv(iio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (val >= (1 << chan->scan_type.realbits) || val < 0)
> +			return -EINVAL;
> +
> +		mutex_lock(&iio_dev->mlock);
How do we know this is a DAC channel?  I guess it might fault, but it would
certainly be good to make this more obvious.  Unlike the other way around
below, writing an ADC channel value makes no sense!
> +		ret = st->ops->dac_write(st, chan->address, val);
> +		mutex_unlock(&iio_dev->mlock);
> +		return ret;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int ad5592r_read_raw(struct iio_dev *iio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val, int *val2, long m)
> +{
> +	struct ad5592r_state *st = iio_priv(iio_dev);
> +	u16 read_val;
> +	int ret;
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&iio_dev->mlock);
Is there anything to say this is an ADC channel rather than a DAC one?
Might not be a problem reading back from a dac, but then the comments
and naming need adjusting.

> +		ret = st->ops->adc_read(st, chan->channel, &read_val);
> +		mutex_unlock(&iio_dev->mlock);
> +		if (ret)
> +			return ret;
> +
> +		if ((read_val >> 12 & 0x7) != chan->channel) {
> +			dev_err(st->dev, "Error while reading channel %u\n",
> +					chan->channel);
> +			return -EIO;
> +		}
> +
> +		read_val &= GENMASK(11, 0);
> +
> +		dev_dbg(st->dev, "ADC read: 0x%04hX\n", read_val);
> +		*val = (int) read_val;
> +		return IIO_VAL_INT;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static void ad5592r_reset(struct ad5592r_state *st)
> +{
> +	struct iio_dev *iio_dev = iio_priv_to_dev(st);
> +
> +	mutex_lock(&iio_dev->mlock);
> +	st->ops->reg_write(st, AD5592R_REG_RESET, 0xdac);
> +	udelay(250);
> +	mutex_unlock(&iio_dev->mlock);
> +}
> +
> +static const struct iio_info ad5592r_info = {
> +	.read_raw = ad5592r_read_raw,
> +	.write_raw = ad5592r_write_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static void ad5592r_setup_channel(struct iio_dev *iio_dev,
> +		struct iio_chan_spec *chan, bool output, unsigned id)
> +{
> +	chan->type = IIO_VOLTAGE;
> +	chan->indexed = 1;
> +	chan->output = output;
> +	chan->channel = id;
> +	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> +	chan->address = id;
There is little purpose in providing an address value if it always
matches the channel value - just use that directly.

> +	chan->scan_type.sign = 'u';
> +	chan->scan_type.realbits = 12;
> +	chan->scan_type.storagebits = 16;
> +}
> +
> +static int ad5592r_alloc_channels(struct ad5592r_state *st)
> +{
> +	unsigned i, curr_channel = 0,
> +		 num_channels = st->num_channels;
> +	struct iio_dev *iio_dev = iio_priv_to_dev(st);
> +	struct iio_chan_spec *channels;
> +	int ret;
> +
> +	ret = of_property_read_u8_array(st->dev->of_node, "channel-modes",
> +			st->channel_modes, num_channels);
> +	if (ret)
> +		return ret;
> +
> +	channels = devm_kzalloc(st->dev,
> +			2 * num_channels * sizeof(*channels), GFP_KERNEL);
> +	if (!channels)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_channels; i++) {
> +		switch (st->channel_modes[i]) {
> +		case CH_MODE_DAC:
> +			ad5592r_setup_channel(iio_dev, &channels[curr_channel],
> +					true, curr_channel);
> +			curr_channel++;
> +			break;
> +
> +		case CH_MODE_ADC:
> +			ad5592r_setup_channel(iio_dev, &channels[curr_channel],
> +					false, curr_channel);
> +			curr_channel++;
> +
> +		/* fall-through */
> +		default:
> +			continue;
> +		}
> +	}
> +
> +	iio_dev->num_channels = curr_channel;
> +	iio_dev->channels = channels;
> +
> +	return 0;
> +}
> +
> +int ad5592r_probe(struct device *dev, const char *name,
> +		const struct ad5592r_rw_ops *ops)
> +{
> +	struct iio_dev *iio_dev;
> +	struct ad5592r_state *st;
> +	int ret;
> +
> +	iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
> +	if (!iio_dev)
> +		return -ENOMEM;
> +
> +	st = iio_priv(iio_dev);
> +	st->dev = dev;
> +	st->ops = ops;
> +	st->num_channels = 8;
> +	dev_set_drvdata(dev, iio_dev);
> +
> +	iio_dev->dev.parent = dev;
> +	iio_dev->name = name;
> +	iio_dev->info = &ad5592r_info;
> +	iio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ad5592r_reset(st);
> +
> +	ret = ad5592r_alloc_channels(st);
> +	if (ret)
> +		return ret;
> +
> +	ret = ad5592r_set_channel_modes(st);
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(dev, iio_dev);
> +}
> +EXPORT_SYMBOL_GPL(ad5592r_probe);
> +
> +int ad5592r_remove(struct device *dev)
> +{
> +	struct iio_dev *iio_dev = dev_get_drvdata(dev);
> +	struct ad5592r_state *st = iio_priv(iio_dev);
> +	unsigned int i;
> +
> +	/* Reset all channels */
> +	for (i = 0; i < ARRAY_SIZE(st->channel_modes); i++)
> +		st->channel_modes[i] = CH_MODE_UNUSED;
> +
> +	return ad5592r_set_channel_modes(st);
> +}
> +EXPORT_SYMBOL_GPL(ad5592r_remove);
> +
> +MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/dac/ad5592r-base.h b/drivers/iio/dac/ad5592r-base.h
> new file mode 100644
> index 0000000..d722e0c
> --- /dev/null
> +++ b/drivers/iio/dac/ad5592r-base.h
> @@ -0,0 +1,56 @@
> +/*
> + * AD5592R / AD5593R Digital <-> Analog converters driver
> + *
> + * Copyright 2015 Analog Devices Inc.
> + * Author: Paul Cercueil <paul.cercueil@analog.com>
> + *
> + * Licensed under the GPL-2.
> + */
> +
> +#ifndef __DRIVERS_IIO_DAC_AD5592R_BASE_H__
> +#define __DRIVERS_IIO_DAC_AD5592R_BASE_H__
> +
> +#include <linux/types.h>
> +#include <linux/cache.h>
> +
> +struct device;
> +struct ad5592r_state;
> +
> +enum ad5592r_registers {
> +	AD5592R_REG_NOOP		= 0x0,
> +	AD5592R_REG_DAC_READBACK	= 0x1,
> +	AD5592R_REG_ADC_SEQ		= 0x2,
> +	AD5592R_REG_CTRL		= 0x3,
> +	AD5592R_REG_ADC_EN		= 0x4,
> +	AD5592R_REG_DAC_EN		= 0x5,
> +	AD5592R_REG_PULLDOWN		= 0x6,
> +	AD5592R_REG_LDAC		= 0x7,
> +	AD5592R_REG_GPIO_OUT_EN		= 0x8,
> +	AD5592R_REG_GPIO_SET		= 0x9,
> +	AD5592R_REG_GPIO_IN_EN		= 0xA,
> +	AD5592R_REG_PD			= 0xB,
> +	AD5592R_REG_OPEN_DRAIN		= 0xC,
> +	AD5592R_REG_TRISTATE		= 0xD,
> +	AD5592R_REG_RESET		= 0xF,
> +};
> +
> +struct ad5592r_rw_ops {
> +	int (*dac_write)(struct ad5592r_state *st, unsigned chan, u16 value);
> +	int (*adc_read)(struct ad5592r_state *st, unsigned chan, u16 *value);
> +	int (*reg_write)(struct ad5592r_state *st, u8 reg, u16 value);
> +	int (*reg_read)(struct ad5592r_state *st, u8 reg, u16 *value);
> +};
> +
> +struct ad5592r_state {
> +	struct device *dev;
> +	unsigned int num_channels;
> +	const struct ad5592r_rw_ops *ops;
> +	u8 channel_modes[8];
> +	__be16 spi_msg ____cacheline_aligned;
> +};
> +
> +int ad5592r_probe(struct device *dev, const char *name,
> +		const struct ad5592r_rw_ops *ops);
> +int ad5592r_remove(struct device *dev);
> +
> +#endif /* __DRIVERS_IIO_DAC_AD5592R_BASE_H__ */
> diff --git a/drivers/iio/dac/ad5592r.c b/drivers/iio/dac/ad5592r.c
> new file mode 100644
> index 0000000..0572a36
> --- /dev/null
> +++ b/drivers/iio/dac/ad5592r.c
> @@ -0,0 +1,126 @@
> +/*
> + * AD5592R Digital <-> Analog converters driver
> + *
> + * Copyright 2015 Analog Devices Inc.
> + * Author: Paul Cercueil <paul.cercueil@analog.com>
> + *
> + * Licensed under the GPL-2.
> + */
> +
> +#include "ad5592r-base.h"
> +
> +#include <linux/bitops.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/spi/spi.h>
> +
> +static int ad5592r_dac_write(struct ad5592r_state *st, unsigned chan, u16 value)
> +{
> +	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
> +
> +	st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
> +
> +	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
> +}
> +
> +static int ad5592r_adc_read(struct ad5592r_state *st, unsigned chan, u16 *value)
> +{
> +	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
> +	int ret;
> +
> +	st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
> +
> +	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
> +	if (ret)
> +		return ret;
> +
> +	/* Invalid data */
> +	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
> +	if (ret)
> +		return ret;
> +
> +	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
> +	if (ret)
> +		return ret;
> +
> +	*value = be16_to_cpu(st->spi_msg);
> +
> +	return 0;
> +}
> +
> +static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
> +{
> +	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
> +
> +	st->spi_msg = cpu_to_be16((reg << 11) | value);
> +
> +	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
> +}
> +
> +static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
> +{
> +	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
> +	int ret;
> +
> +	st->spi_msg = cpu_to_be16(
> +			(AD5592R_REG_LDAC << 11) | BIT(6) | (reg << 2));
> +
> +	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
> +	if (ret)
> +		return ret;
> +
> +	ret = spi_read(spi, &st->spi_msg, sizeof(st->spi_msg));
> +	if (ret)
> +		return ret;
> +
> +	if (value)
> +		*value = be16_to_cpu(st->spi_msg);
> +
> +	return 0;
> +}
> +
> +static const struct ad5592r_rw_ops ad5592r_rw_ops = {
> +	.dac_write = ad5592r_dac_write,
> +	.adc_read = ad5592r_adc_read,
> +	.reg_write = ad5592r_reg_write,
> +	.reg_read = ad5592r_reg_read,
> +};
> +
> +static int ad5592r_spi_probe(struct spi_device *spi)
> +{
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +
> +	return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
> +}
> +
> +static int ad5592r_spi_remove(struct spi_device *spi)
> +{
> +	return ad5592r_remove(&spi->dev);
> +}
> +
> +static const struct spi_device_id ad5592r_spi_ids[] = {
> +	{ .name = "ad5592r", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
> +
> +static const struct of_device_id ad5592r_of_match[] = {
> +	{ .compatible = "adi,ad5592r", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, ad5592r_of_match);
> +
> +static struct spi_driver ad5592r_spi_driver = {
> +	.driver = {
> +		.name = "ad5592r",
> +		.of_match_table = of_match_ptr(ad5592r_of_match),
> +	},
> +	.probe = ad5592r_spi_probe,
> +	.remove = ad5592r_spi_remove,
> +	.id_table = ad5592r_spi_ids,
> +};
> +module_spi_driver(ad5592r_spi_driver);
> +
> +MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c
> new file mode 100644
> index 0000000..6825834
> --- /dev/null
> +++ b/drivers/iio/dac/ad5593r.c
> @@ -0,0 +1,121 @@
> +/*
> + * AD5593R Digital <-> Analog converters driver
> + *
> + * Copyright 2015 Analog Devices Inc.
> + * Author: Paul Cercueil <paul.cercueil@analog.com>
> + *
> + * Licensed under the GPL-2.
> + */
> +
> +#include "ad5592r-base.h"
> +
> +#include <linux/bitops.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +
> +#define AD5593R_MODE_CONF		(0 << 4)
> +#define AD5593R_MODE_DAC_WRITE		(1 << 4)
> +#define AD5593R_MODE_ADC_READBACK	(4 << 4)
> +#define AD5593R_MODE_DAC_READBACK	(5 << 4)
> +#define AD5593R_MODE_GPIO_READBACK	(6 << 4)
> +#define AD5593R_MODE_REG_READBACK	(7 << 4)
> +
> +static int ad5593r_dac_write(struct ad5592r_state *st, unsigned chan, u16 value)
> +{
> +	struct i2c_client *i2c = to_i2c_client(st->dev);
> +
> +	return i2c_smbus_write_word_swapped(i2c,
> +			AD5593R_MODE_DAC_WRITE | chan, value);
> +}
> +
> +static int ad5593r_adc_read(struct ad5592r_state *st, unsigned chan, u16 *value)
> +{
> +	struct i2c_client *i2c = to_i2c_client(st->dev);
> +	s32 val;
> +
> +	val = i2c_smbus_write_word_swapped(i2c,
> +			AD5593R_MODE_CONF | AD5592R_REG_ADC_SEQ, BIT(chan));
> +	if (val < 0)
> +		return (int) val;
> +
> +	/* Invalid data */
> +	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
> +	if (val < 0)
> +		return (int) val;
> +
> +	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK);
> +	if (val < 0)
> +		return (int) val;
> +
> +	*value = (u16) val;
> +
> +	return 0;
> +}
> +
> +static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
> +{
> +	struct i2c_client *i2c = to_i2c_client(st->dev);
> +
> +	return i2c_smbus_write_word_swapped(i2c,
> +			AD5593R_MODE_CONF | reg, value);
> +}
> +
> +static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
> +{
> +	struct i2c_client *i2c = to_i2c_client(st->dev);
> +	s32 val;
> +
> +	val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg);
> +	if (val < 0)
> +		return (int) val;
> +
> +	*value = (u16) val;
> +
> +	return 0;
> +}
> +
> +static const struct ad5592r_rw_ops ad5593r_rw_ops = {
> +	.dac_write = ad5593r_dac_write,
> +	.adc_read = ad5593r_adc_read,
> +	.reg_write = ad5593r_reg_write,
> +	.reg_read = ad5593r_reg_read,
> +};
> +
> +static int ad5593r_i2c_probe(struct i2c_client *i2c,
> +		const struct i2c_device_id *id)
> +{
> +	return ad5592r_probe(&i2c->dev, id->name, &ad5593r_rw_ops);
> +}
> +
> +static int ad5593r_i2c_remove(struct i2c_client *i2c)
> +{
> +	return ad5592r_remove(&i2c->dev);
> +}
> +
> +static const struct i2c_device_id ad5593r_i2c_ids[] = {
> +	{ .name = "ad5593r", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, ad5593r_i2c_ids);
> +
> +static const struct of_device_id ad5593r_of_match[] = {
> +	{ .compatible = "adi,ad5593r", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, ad5593r_of_match);
> +
> +static struct i2c_driver ad5593r_driver = {
> +	.driver = {
> +		.name = "ad5593r",
> +		.of_match_table = of_match_ptr(ad5593r_of_match),
> +	},
> +	.probe = ad5593r_i2c_probe,
> +	.remove = ad5593r_i2c_remove,
> +	.id_table = ad5593r_i2c_ids,
> +};
> +module_i2c_driver(ad5593r_driver);
> +
> +MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/dt-bindings/iio/adi,ad5592r.h b/include/dt-bindings/iio/adi,ad5592r.h
> new file mode 100644
> index 0000000..fcb6293
> --- /dev/null
> +++ b/include/dt-bindings/iio/adi,ad5592r.h
> @@ -0,0 +1,13 @@
> +
> +#ifndef _DT_BINDINGS_ADI_AD5592R_H
> +#define _DT_BINDINGS_ADI_AD5592R_H
> +
> +#define CH_MODE_UNUSED		0
> +#define CH_MODE_DAC		1
> +#define CH_MODE_ADC		2
> +#define CH_MODE_GPIO_OUT	3
> +#define CH_MODE_GPIO_IN		4
> +#define CH_MODE_GPIO_OPEN_DRAIN	5
> +#define CH_MODE_GPIO_TRISTATE	6
> +
> +#endif /* _DT_BINDINGS_ADI_AD5592R_H */
> 

Re: [PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[Jonathan Cameron]

On 13/10/15 10:37, Paul Cercueil wrote:
> Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Looks good to me, but as it is a little bit 'different' and we are
defining entirely new generic bindings (the channel modes stuff)
I would like some more input.  It might be overkill but we do
of course have the pinctl framework which covers this sort of
thing... Might be worth considering if using that to get the unified
bindings might make sense here...

cc'd Linus in case he wants to comment on this.

It would obviously be a very heavy weight solution to the problem
so I'm far from convinced it makes sense - or even fits the usecase
terrible well.  Just thought I'd mention the possibility.
> ---
>  .../devicetree/bindings/iio/dac/ad5592r.txt        | 43 ++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/ad5592r.txt
> 
>  v2: Fix indentation issue
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/ad5592r.txt b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
> new file mode 100644
> index 0000000..12b8d0e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
> @@ -0,0 +1,43 @@
> +Analog Devices AD5592R/AD5593R DAC/ADC device driver
> +
> +Required properties for the AD5592R:
> +	- compatible: Must be "adi,ad5592r"
> +	- reg: SPI chip select number for the device
> +	- spi-max-frequency: Max SPI frequency to use (< 30000000)
> +	- spi-cpol: The AD5592R requires inverse clock polarity (CPOL) mode
> +
> +Required properties for the AD5593R:
> +	- compatible: Must be "adi,ad5593r"
> +	- reg: I2C address of the device
> +
> +Required properties for all supported chips:
> +	- channel-modes: An array of eight 8-bit values (one per channel)
> +	  describing the mode of each channel. Macros specifying the valid values
> +	  can be found in <dt-bindings/iio/adi,ad5592r.h>.
> +	  The following values are currently supported:
> +		* CH_MODE_UNUSED (the pin is pulled down)
> +		* CH_MODE_DAC
> +		* CH_MODE_ADC
> +		* CH_MODE_GPIO_TRISTATE
> +
> +Example:
> +
> +	#include <dt-bindings/iio/adi,ad5592r.h>
> +
> +	ad5592r@0 {
> +		compatible = "adi,ad5592r";
> +		reg = <0>;
> +		spi-max-frequency = <1000000>;
> +		spi-cpol;
> +
> +		channel-modes = /bits/ 8 <
> +			CH_MODE_DAC
> +			CH_MODE_ADC
> +			CH_MODE_ADC
> +			CH_MODE_UNUSED
> +			CH_MODE_UNUSED
> +			CH_MODE_UNUSED
> +			CH_MODE_UNUSED
> +			CH_MODE_UNUSED
> +		>;
> +	};
> 

Re: [PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[Linus Walleij]

On Sun, Oct 25, 2015 at 2:31 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 13/10/15 10:37, Paul Cercueil wrote:
>> Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
> Looks good to me, but as it is a little bit 'different' and we are
> defining entirely new generic bindings (the channel modes stuff)
> I would like some more input.  It might be overkill but we do
> of course have the pinctl framework which covers this sort of
> thing... Might be worth considering if using that to get the unified
> bindings might make sense here...
>
> cc'd Linus in case he wants to comment on this.
>
> It would obviously be a very heavy weight solution to the problem
> so I'm far from convinced it makes sense - or even fits the usecase
> terrible well.  Just thought I'd mention the possibility.

There is something of a grey area between "definately pin control"
and "some extra pin hardware duct-taped to something else".

I guess that is natural, life is full of grey areas...

Basically if there are plenty of pins and functions, local solutions
to the problem will not scale. Then it is necessary to go ahead
and implement full pin control. Especially for say a big BGA
package or so with lots and lots of pins.

It is is a few pins or they just alter between similar functionality
(like different graphic modes) I think local solutions are OK.

There are other problems though, but I comment on these
separately.

Yours,
Linus Walleij

Re: [PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[Linus Walleij]

On Tue, Oct 27, 2015 at 5:13 PM, Linus Walleij <linus.walleij@linaro.org> wrote:

> There are other problems though, but I comment on these
> separately.

Was wrong about that. I think this can go in like this.

Later, this device may fork off a GPIO chip as well, but
we will deal with that whenever we run into it.

Yours,
Linus Walleij

Re: [PATCHv2 1/2] Documentation: ad5592r: Added devicetree bindings documentation

[Jonathan Cameron]

On 27/10/15 16:13, Linus Walleij wrote:
> On Sun, Oct 25, 2015 at 2:31 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>> On 13/10/15 10:37, Paul Cercueil wrote:
>>> Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
>> Looks good to me, but as it is a little bit 'different' and we are
>> defining entirely new generic bindings (the channel modes stuff)
>> I would like some more input.  It might be overkill but we do
>> of course have the pinctl framework which covers this sort of
>> thing... Might be worth considering if using that to get the unified
>> bindings might make sense here...
>>
>> cc'd Linus in case he wants to comment on this.
>>
>> It would obviously be a very heavy weight solution to the problem
>> so I'm far from convinced it makes sense - or even fits the usecase
>> terrible well.  Just thought I'd mention the possibility.
> 
> There is something of a grey area between "definately pin control"
> and "some extra pin hardware duct-taped to something else".
> 
> I guess that is natural, life is full of grey areas...
> 
> Basically if there are plenty of pins and functions, local solutions
> to the problem will not scale. Then it is necessary to go ahead
> and implement full pin control. Especially for say a big BGA
> package or so with lots and lots of pins.
> 
> It is is a few pins or they just alter between similar functionality
> (like different graphic modes) I think local solutions are OK.
Thanks Linus.  Makes sense