[PATCH 1/2] iio: dac: add TI DAC5755 family support

[PATCH 1/2] iio: dac: add TI DAC5755 family support

[Sean Nyekjaer]

This patch adds support for the Texas Intruments DAC5755 Family.

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
---
 drivers/iio/dac/Kconfig      |  10 +
 drivers/iio/dac/Makefile     |   1 +
 drivers/iio/dac/ti-dac5571.c | 443 +++++++++++++++++++++++++++++++++++
 3 files changed, 454 insertions(+)
 create mode 100644 drivers/iio/dac/ti-dac5571.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 3ff8a32f1385..c77c6cf1d2ba 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -335,6 +335,16 @@ config TI_DAC082S085
 
 	  If compiled as a module, it will be called ti-dac082s085.
 
+config TI_DAC5571
+	tristate "Texas Instruments 8/10/12/16-bit 1/2/4-channel DAC driver"
+	depends on I2C
+	help
+	  Driver for the Texas Instruments
+	  DAC5571, DAC6571, DAC7571, DAC5574, DAC6574, DAC7574, DAC5573,
+	  DAC6573, DAC7573, DAC8571, DAC8574.
+
+	  If compiled as a module, it will be called ti-dac5571.
+
 config VF610_DAC
 	tristate "Vybrid vf610 DAC driver"
 	depends on OF
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 4397e2114344..57aa230d34ab 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -37,4 +37,5 @@ obj-$(CONFIG_MCP4922) += mcp4922.o
 obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
 obj-$(CONFIG_STM32_DAC) += stm32-dac.o
 obj-$(CONFIG_TI_DAC082S085) += ti-dac082s085.o
+obj-$(CONFIG_TI_DAC5571) += ti-dac5571.o
 obj-$(CONFIG_VF610_DAC) += vf610_dac.o
diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
new file mode 100644
index 000000000000..5ce110fe1bab
--- /dev/null
+++ b/drivers/iio/dac/ti-dac5571.c
@@ -0,0 +1,443 @@
+/*
+ * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
+ *
+ * Copyright (C) 2018 Prevas A/S
+ *
+ * http://www.ti.com/lit/ds/symlink/dac5571.pdf
+ * http://www.ti.com/lit/ds/symlink/dac6571.pdf
+ * http://www.ti.com/lit/ds/symlink/dac7571.pdf
+ * http://www.ti.com/lit/ds/symlink/dac5574.pdf
+ * http://www.ti.com/lit/ds/symlink/dac6574.pdf
+ * http://www.ti.com/lit/ds/symlink/dac7574.pdf
+ * http://www.ti.com/lit/ds/symlink/dac5573.pdf
+ * http://www.ti.com/lit/ds/symlink/dac6573.pdf
+ * http://www.ti.com/lit/ds/symlink/dac7573.pdf
+ *
+ * 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/iio/iio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+enum chip_id {
+	single_8bit, single_10bit, single_12bit,
+	quad_8bit, quad_10bit, quad_12bit
+};
+
+#define DAC5571_SINGLE_CHANNEL		1
+#define DAC5571_QUAD_CHANNEL		4
+
+struct dac5571_spec {
+	u8 num_channels;
+	u8 resolution;
+};
+
+static const struct dac5571_spec dac5571_spec[] = {
+	[single_8bit]  = {.num_channels = 1, .resolution =  8},
+	[single_10bit] = {.num_channels = 1, .resolution = 10},
+	[single_12bit] = {.num_channels = 1, .resolution = 12},
+	[quad_8bit]    = {.num_channels = 4, .resolution =  8},
+	[quad_10bit]   = {.num_channels = 4, .resolution = 10},
+	[quad_12bit]   = {.num_channels = 4, .resolution = 12},
+};
+
+struct dac5571_data {
+	struct i2c_client *client;
+	int id;
+	struct mutex lock;
+	struct regulator *vref;
+	u16 val[4];
+	bool powerdown;
+	u8 powerdown_mode;
+	struct dac5571_spec const *spec;
+	int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
+	int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
+	u8 buf[3] ____cacheline_aligned;
+};
+
+#define DAC5571_POWERDOWN(mode)		((mode) + 1)
+#define DAC5571_POWERDOWN_FLAG		BIT(0)
+#define DAC5571_CHANNEL_SELECT		1
+#define DAC5571_LOADMODE_DIRECT		BIT(4)
+#define DAC5571_SINGLE_PWRDWN_BITS	4
+#define DAC5571_QUAD_PWRDWN_BITS	6
+
+static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
+{
+	unsigned int shift;
+
+	shift = 12 - data->spec->resolution;
+	data->buf[1] = val << shift;
+	data->buf[0] = val >> (8 - shift);
+
+	if (i2c_master_send(data->client, data->buf, 2) != 2)
+		return -EIO;
+
+	return 0;
+}
+
+
+static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
+{
+	unsigned int shift;
+
+	shift = 16 - data->spec->resolution;
+	data->buf[2] = val << shift;
+	data->buf[1] = (val >> (8 - shift));
+	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
+		       DAC5571_LOADMODE_DIRECT;
+
+	if (i2c_master_send(data->client, data->buf, 3) != 3)
+		return -EIO;
+
+	return 0;
+}
+
+static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
+{
+	unsigned int shift;
+
+	shift = 12 - data->spec->resolution;
+	data->buf[1] = 0;
+	data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
+
+	if (i2c_master_send(data->client, data->buf, 2) != 2)
+		return -EIO;
+
+	return 0;
+}
+
+static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
+{
+	unsigned int shift;
+
+	shift = 16 - data->spec->resolution;
+	data->buf[2] = 0;
+	data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
+	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
+		       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
+
+	if (i2c_master_send(data->client, data->buf, 3) != 3)
+		return -EIO;
+
+	return 0;
+}
+
+static const char *const dac5571_powerdown_modes[] = {
+	"1kohm_to_gnd", "100kohm_to_gnd", "three_state",
+};
+
+static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+
+	return data->powerdown_mode;
+}
+
+static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      unsigned int mode)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+	int ret = 0;
+
+	if (data->powerdown_mode == mode)
+		return 0;
+
+	mutex_lock(&data->lock);
+	if (data->powerdown) {
+		ret = data->dac5571_pwrdwn(data, chan->channel,
+					   DAC5571_POWERDOWN(mode));
+		if (ret)
+			goto out;
+	}
+	data->powerdown_mode = mode;
+
+ out:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static const struct iio_enum dac5571_powerdown_mode = {
+	.items = dac5571_powerdown_modes,
+	.num_items = ARRAY_SIZE(dac5571_powerdown_modes),
+	.get = dac5571_get_powerdown_mode,
+	.set = dac5571_set_powerdown_mode,
+};
+
+static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      char *buf)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", data->powerdown);
+}
+
+static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       const char *buf, size_t len)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+	bool powerdown;
+	int ret;
+
+	ret = strtobool(buf, &powerdown);
+	if (ret)
+		return ret;
+
+	if (data->powerdown == powerdown)
+		return len;
+
+	mutex_lock(&data->lock);
+	if (powerdown)
+		ret = data->dac5571_pwrdwn(data, chan->channel,
+			    DAC5571_POWERDOWN(data->powerdown_mode));
+	else
+		ret = data->dac5571_cmd(data, chan->channel, data->val[0]);
+	if (ret)
+		goto out;
+
+	data->powerdown = powerdown;
+
+ out:
+	mutex_unlock(&data->lock);
+
+	return ret ? ret : len;
+}
+
+
+static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
+	{
+		.name	   = "powerdown",
+		.read	   = dac5571_read_powerdown,
+		.write	   = dac5571_write_powerdown,
+		.shared	   = IIO_SHARED_BY_TYPE,
+	},
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
+	IIO_ENUM_AVAILABLE("powerdown_mode", &dac5571_powerdown_mode),
+	{},
+};
+
+#define dac5571_CHANNEL(chan, name) {				\
+	.type = IIO_VOLTAGE,					\
+	.channel = (chan),					\
+	.address = (chan),					\
+	.indexed = true,					\
+	.output = true,						\
+	.datasheet_name = name,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.ext_info = dac5571_ext_info,				\
+}
+
+static const struct iio_chan_spec dac5571_channels[] = {
+	dac5571_CHANNEL(0, "A"),
+	dac5571_CHANNEL(1, "B"),
+	dac5571_CHANNEL(2, "C"),
+	dac5571_CHANNEL(3, "D"),
+};
+
+static int dac5571_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*val = data->val[chan->channel];
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		ret = regulator_get_voltage(data->vref);
+		if (ret < 0)
+			return ret;
+
+		*val = ret / 1000;
+		*val2 = data->spec->resolution;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int dac5571_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct dac5571_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (data->val[chan->channel] == val)
+			return 0;
+
+		if (val >= (1 << data->spec->resolution) || val < 0)
+			return -EINVAL;
+
+		if (data->powerdown)
+			return -EBUSY;
+
+		mutex_lock(&data->lock);
+		ret = data->dac5571_cmd(data, chan->channel, val);
+		if (ret == 0)
+			data->val[chan->channel] = val;
+		mutex_unlock(&data->lock);
+		return ret;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
+				     struct iio_chan_spec const *chan,
+				     long mask)
+{
+	return IIO_VAL_INT;
+}
+
+static const struct iio_info dac5571_info = {
+	.read_raw = dac5571_read_raw,
+	.write_raw = dac5571_write_raw,
+	.write_raw_get_fmt = dac5571_write_raw_get_fmt,
+};
+
+static int dac5571_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	const struct dac5571_spec *spec;
+	struct dac5571_data *data;
+	struct iio_dev *indio_dev;
+	int ret, i;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	indio_dev->dev.parent = dev;
+	indio_dev->dev.of_node = client->dev.of_node;
+	indio_dev->info = &dac5571_info;
+	indio_dev->name = id->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = dac5571_channels;
+
+	spec = &dac5571_spec[id->driver_data];
+	indio_dev->num_channels = spec->num_channels;
+	data->spec = spec;
+
+	data->vref = devm_regulator_get(dev, "vref");
+	if (IS_ERR(data->vref))
+		return PTR_ERR(data->vref);
+
+	ret = regulator_enable(data->vref);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&data->lock);
+
+	switch (spec->num_channels) {
+	case DAC5571_SINGLE_CHANNEL:
+		data->dac5571_cmd = dac5571_cmd_single;
+		data->dac5571_pwrdwn = dac5571_pwrdwn_single;
+		break;
+	case DAC5571_QUAD_CHANNEL:
+		data->dac5571_cmd = dac5571_cmd_quad;
+		data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
+		break;
+	default:
+		goto err;
+	}
+
+	for (i = 0; i < spec->num_channels; i++) {
+		ret = data->dac5571_cmd(data, i, 0);
+		if (ret) {
+			dev_err(dev, "failed to initialize channel %d to 0\n", i);
+			goto err;
+		}
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto err;
+
+	return 0;
+
+ err:
+	regulator_disable(data->vref);
+	return ret;
+}
+
+static int dac5571_remove(struct i2c_client *i2c)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
+	struct dac5571_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	regulator_disable(data->vref);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id dac5571_of_id[] = {
+	{.compatible = "ti,dac5571"},
+	{.compatible = "ti,dac6571"},
+	{.compatible = "ti,dac7571"},
+	{.compatible = "ti,dac5574"},
+	{.compatible = "ti,dac6574"},
+	{.compatible = "ti,dac7574"},
+	{.compatible = "ti,dac5573"},
+	{.compatible = "ti,dac6573"},
+	{.compatible = "ti,dac7573"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, dac5571_of_id);
+#endif
+
+static const struct i2c_device_id dac5571_id[] = {
+	{"dac5571", single_8bit},
+	{"dac6571", single_10bit},
+	{"dac7571", single_12bit},
+	{"dac5574", quad_8bit},
+	{"dac6574", quad_10bit},
+	{"dac7574", quad_12bit},
+	{"dac5573", quad_8bit},
+	{"dac6573", quad_10bit},
+	{"dac7573", quad_12bit},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, dac5571_id);
+
+static struct i2c_driver dac5571_driver = {
+	.driver = {
+		   .name = "ti-dac5571",
+	},
+	.probe	  = dac5571_probe,
+	.remove   = dac5571_remove,
+	.id_table = dac5571_id,
+};
+module_i2c_driver(dac5571_driver);
+
+MODULE_AUTHOR("Sean Nyekjaer <sean.nyekjaer@prevas.dk>");
+MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.0

[PATCH 2/2] iio: ti-dac5571: Add DT binding documentation

[Sean Nyekjaer]

Adding binding documentation for Texas Instruments DAC5571 Family

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/iio/dac/ti,dac5571.txt           | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt

diff --git a/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt
new file mode 100644
index 000000000000..03af6b9a4d07
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt
@@ -0,0 +1,24 @@
+* Texas Instruments DAC5571 Family
+
+Required properties:
+ - compatible: Should contain
+    "ti,dac5571"
+    "ti,dac6571"
+    "ti,dac7571"
+    "ti,dac5574"
+    "ti,dac6574"
+    "ti,dac7574"
+    "ti,dac5573"
+    "ti,dac6573"
+    "ti,dac7573"
+ - reg: Should contain the DAC I2C address
+
+Optional properties:
+ - vref-supply: The regulator supply for DAC reference voltage
+
+Example:
+dac@0 {
+	compatible = "ti,dac5571";
+	reg = <0x4C>;
+	vref-supply = <&vdd_supply>;
+};
-- 
2.17.0

Re: [PATCH 1/2] iio: dac: add TI DAC5755 family support

[Jonathan Cameron]

On Tue,  1 May 2018 10:15:53 +0200
Sean Nyekjaer <sean.nyekjaer@prevas.dk> wrote:

> This patch adds support for the Texas Intruments DAC5755 Family.
Umm. Title wise, this seems to be the driver for the 5571.
I'll rename it and change this text.
> 
> Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>

There are a few minor things inline.  I'll clean them up whilst
applying.  See inline.

Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan

> ---
>  drivers/iio/dac/Kconfig      |  10 +
>  drivers/iio/dac/Makefile     |   1 +
>  drivers/iio/dac/ti-dac5571.c | 443 +++++++++++++++++++++++++++++++++++
>  3 files changed, 454 insertions(+)
>  create mode 100644 drivers/iio/dac/ti-dac5571.c
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index 3ff8a32f1385..c77c6cf1d2ba 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -335,6 +335,16 @@ config TI_DAC082S085
>  
>  	  If compiled as a module, it will be called ti-dac082s085.
>  
> +config TI_DAC5571
> +	tristate "Texas Instruments 8/10/12/16-bit 1/2/4-channel DAC driver"
> +	depends on I2C
> +	help
> +	  Driver for the Texas Instruments
> +	  DAC5571, DAC6571, DAC7571, DAC5574, DAC6574, DAC7574, DAC5573,
> +	  DAC6573, DAC7573, DAC8571, DAC8574.
> +
> +	  If compiled as a module, it will be called ti-dac5571.
> +
>  config VF610_DAC
>  	tristate "Vybrid vf610 DAC driver"
>  	depends on OF
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 4397e2114344..57aa230d34ab 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -37,4 +37,5 @@ obj-$(CONFIG_MCP4922) += mcp4922.o
>  obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
>  obj-$(CONFIG_STM32_DAC) += stm32-dac.o
>  obj-$(CONFIG_TI_DAC082S085) += ti-dac082s085.o
> +obj-$(CONFIG_TI_DAC5571) += ti-dac5571.o
>  obj-$(CONFIG_VF610_DAC) += vf610_dac.o
> diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> new file mode 100644
> index 000000000000..5ce110fe1bab
> --- /dev/null
> +++ b/drivers/iio/dac/ti-dac5571.c
> @@ -0,0 +1,443 @@
> +/*
> + * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
> + *
> + * Copyright (C) 2018 Prevas A/S
> + *
> + * http://www.ti.com/lit/ds/symlink/dac5571.pdf
> + * http://www.ti.com/lit/ds/symlink/dac6571.pdf
> + * http://www.ti.com/lit/ds/symlink/dac7571.pdf
> + * http://www.ti.com/lit/ds/symlink/dac5574.pdf
> + * http://www.ti.com/lit/ds/symlink/dac6574.pdf
> + * http://www.ti.com/lit/ds/symlink/dac7574.pdf
> + * http://www.ti.com/lit/ds/symlink/dac5573.pdf
> + * http://www.ti.com/lit/ds/symlink/dac6573.pdf
> + * http://www.ti.com/lit/ds/symlink/dac7573.pdf
> + *
> + * 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/iio/iio.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/regulator/consumer.h>
> +
> +enum chip_id {
> +	single_8bit, single_10bit, single_12bit,
> +	quad_8bit, quad_10bit, quad_12bit
> +};
> +
> +#define DAC5571_SINGLE_CHANNEL		1
> +#define DAC5571_QUAD_CHANNEL		4

These two defines seem a little pointless. I'll clear them out.

> +
> +struct dac5571_spec {
> +	u8 num_channels;
> +	u8 resolution;
> +};
> +
> +static const struct dac5571_spec dac5571_spec[] = {
> +	[single_8bit]  = {.num_channels = 1, .resolution =  8},
> +	[single_10bit] = {.num_channels = 1, .resolution = 10},
> +	[single_12bit] = {.num_channels = 1, .resolution = 12},
> +	[quad_8bit]    = {.num_channels = 4, .resolution =  8},
> +	[quad_10bit]   = {.num_channels = 4, .resolution = 10},
> +	[quad_12bit]   = {.num_channels = 4, .resolution = 12},
> +};
> +
> +struct dac5571_data {
> +	struct i2c_client *client;
> +	int id;
> +	struct mutex lock;
> +	struct regulator *vref;
> +	u16 val[4];
> +	bool powerdown;
> +	u8 powerdown_mode;
> +	struct dac5571_spec const *spec;
> +	int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
> +	int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
> +	u8 buf[3] ____cacheline_aligned;
> +};
> +
> +#define DAC5571_POWERDOWN(mode)		((mode) + 1)
> +#define DAC5571_POWERDOWN_FLAG		BIT(0)
> +#define DAC5571_CHANNEL_SELECT		1
> +#define DAC5571_LOADMODE_DIRECT		BIT(4)
> +#define DAC5571_SINGLE_PWRDWN_BITS	4
> +#define DAC5571_QUAD_PWRDWN_BITS	6
> +
> +static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
> +{
> +	unsigned int shift;
> +
> +	shift = 12 - data->spec->resolution;
> +	data->buf[1] = val << shift;
> +	data->buf[0] = val >> (8 - shift);
> +
> +	if (i2c_master_send(data->client, data->buf, 2) != 2)
> +		return -EIO;
> +
> +	return 0;
> +}
> +

Should only be one blank line here. If this is all I find I'll clean it up.

> +
> +static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
> +{
> +	unsigned int shift;
> +
> +	shift = 16 - data->spec->resolution;
> +	data->buf[2] = val << shift;
> +	data->buf[1] = (val >> (8 - shift));
> +	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
> +		       DAC5571_LOADMODE_DIRECT;
> +
> +	if (i2c_master_send(data->client, data->buf, 3) != 3)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
> +{
> +	unsigned int shift;
> +
> +	shift = 12 - data->spec->resolution;
> +	data->buf[1] = 0;
> +	data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
> +
> +	if (i2c_master_send(data->client, data->buf, 2) != 2)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
> +{
> +	unsigned int shift;
> +
> +	shift = 16 - data->spec->resolution;
> +	data->buf[2] = 0;
> +	data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
> +	data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
> +		       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
> +
> +	if (i2c_master_send(data->client, data->buf, 3) != 3)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static const char *const dac5571_powerdown_modes[] = {
> +	"1kohm_to_gnd", "100kohm_to_gnd", "three_state",
> +};
> +
> +static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
> +				      const struct iio_chan_spec *chan)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +
> +	return data->powerdown_mode;
> +}
> +
> +static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
> +				      const struct iio_chan_spec *chan,
> +				      unsigned int mode)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +	int ret = 0;
> +
> +	if (data->powerdown_mode == mode)
> +		return 0;
> +
> +	mutex_lock(&data->lock);
> +	if (data->powerdown) {
> +		ret = data->dac5571_pwrdwn(data, chan->channel,
> +					   DAC5571_POWERDOWN(mode));
> +		if (ret)
> +			goto out;
> +	}
> +	data->powerdown_mode = mode;
> +
> + out:
> +	mutex_unlock(&data->lock);
> +
> +	return ret;
> +}
> +
> +static const struct iio_enum dac5571_powerdown_mode = {
> +	.items = dac5571_powerdown_modes,
> +	.num_items = ARRAY_SIZE(dac5571_powerdown_modes),
> +	.get = dac5571_get_powerdown_mode,
> +	.set = dac5571_set_powerdown_mode,
> +};
> +
> +static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
> +				      uintptr_t private,
> +				      const struct iio_chan_spec *chan,
> +				      char *buf)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", data->powerdown);
> +}
> +
> +static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
> +				       uintptr_t private,
> +				       const struct iio_chan_spec *chan,
> +				       const char *buf, size_t len)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +	bool powerdown;
> +	int ret;
> +
> +	ret = strtobool(buf, &powerdown);
> +	if (ret)
> +		return ret;
> +
> +	if (data->powerdown == powerdown)
> +		return len;
> +
> +	mutex_lock(&data->lock);
> +	if (powerdown)
> +		ret = data->dac5571_pwrdwn(data, chan->channel,
> +			    DAC5571_POWERDOWN(data->powerdown_mode));
> +	else
> +		ret = data->dac5571_cmd(data, chan->channel, data->val[0]);
> +	if (ret)
> +		goto out;
> +
> +	data->powerdown = powerdown;
> +
> + out:
> +	mutex_unlock(&data->lock);
> +
> +	return ret ? ret : len;
> +}
> +
> +
> +static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
> +	{
> +		.name	   = "powerdown",
> +		.read	   = dac5571_read_powerdown,
> +		.write	   = dac5571_write_powerdown,
> +		.shared	   = IIO_SHARED_BY_TYPE,
> +	},
> +	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
> +	IIO_ENUM_AVAILABLE("powerdown_mode", &dac5571_powerdown_mode),
> +	{},
> +};
> +
> +#define dac5571_CHANNEL(chan, name) {				\
> +	.type = IIO_VOLTAGE,					\
> +	.channel = (chan),					\
> +	.address = (chan),					\
> +	.indexed = true,					\
> +	.output = true,						\
> +	.datasheet_name = name,					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +	.ext_info = dac5571_ext_info,				\
> +}
> +
> +static const struct iio_chan_spec dac5571_channels[] = {
> +	dac5571_CHANNEL(0, "A"),
> +	dac5571_CHANNEL(1, "B"),
> +	dac5571_CHANNEL(2, "C"),
> +	dac5571_CHANNEL(3, "D"),
> +};
> +
> +static int dac5571_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		*val = data->val[chan->channel];
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = regulator_get_voltage(data->vref);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = ret / 1000;
> +		*val2 = data->spec->resolution;
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int dac5571_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long mask)
> +{
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (data->val[chan->channel] == val)
> +			return 0;
> +
> +		if (val >= (1 << data->spec->resolution) || val < 0)
> +			return -EINVAL;
> +
> +		if (data->powerdown)
> +			return -EBUSY;
> +
> +		mutex_lock(&data->lock);
> +		ret = data->dac5571_cmd(data, chan->channel, val);
> +		if (ret == 0)
> +			data->val[chan->channel] = val;
> +		mutex_unlock(&data->lock);
> +		return ret;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
> +				     struct iio_chan_spec const *chan,
> +				     long mask)
> +{
> +	return IIO_VAL_INT;
> +}
> +
> +static const struct iio_info dac5571_info = {
> +	.read_raw = dac5571_read_raw,
> +	.write_raw = dac5571_write_raw,
> +	.write_raw_get_fmt = dac5571_write_raw_get_fmt,
> +};
> +
> +static int dac5571_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	const struct dac5571_spec *spec;
> +	struct dac5571_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret, i;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +	data->client = client;
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->dev.of_node = client->dev.of_node;
> +	indio_dev->info = &dac5571_info;
> +	indio_dev->name = id->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = dac5571_channels;
> +
> +	spec = &dac5571_spec[id->driver_data];
> +	indio_dev->num_channels = spec->num_channels;
> +	data->spec = spec;
> +
> +	data->vref = devm_regulator_get(dev, "vref");
> +	if (IS_ERR(data->vref))
> +		return PTR_ERR(data->vref);
> +
> +	ret = regulator_enable(data->vref);
> +	if (ret < 0)
> +		return ret;
> +
> +	mutex_init(&data->lock);
> +
> +	switch (spec->num_channels) {
> +	case DAC5571_SINGLE_CHANNEL:
> +		data->dac5571_cmd = dac5571_cmd_single;
> +		data->dac5571_pwrdwn = dac5571_pwrdwn_single;
> +		break;
> +	case DAC5571_QUAD_CHANNEL:
> +		data->dac5571_cmd = dac5571_cmd_quad;
> +		data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
> +		break;
> +	default:
> +		goto err;
> +	}
> +
> +	for (i = 0; i < spec->num_channels; i++) {
> +		ret = data->dac5571_cmd(data, i, 0);
> +		if (ret) {
> +			dev_err(dev, "failed to initialize channel %d to 0\n", i);
> +			goto err;
> +		}
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> + err:
> +	regulator_disable(data->vref);
> +	return ret;
> +}
> +
> +static int dac5571_remove(struct i2c_client *i2c)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
> +	struct dac5571_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	regulator_disable(data->vref);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id dac5571_of_id[] = {
> +	{.compatible = "ti,dac5571"},
> +	{.compatible = "ti,dac6571"},
> +	{.compatible = "ti,dac7571"},
> +	{.compatible = "ti,dac5574"},
> +	{.compatible = "ti,dac6574"},
> +	{.compatible = "ti,dac7574"},
> +	{.compatible = "ti,dac5573"},
> +	{.compatible = "ti,dac6573"},
> +	{.compatible = "ti,dac7573"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, dac5571_of_id);
> +#endif
> +
> +static const struct i2c_device_id dac5571_id[] = {
> +	{"dac5571", single_8bit},
> +	{"dac6571", single_10bit},
> +	{"dac7571", single_12bit},
> +	{"dac5574", quad_8bit},
> +	{"dac6574", quad_10bit},
> +	{"dac7574", quad_12bit},
> +	{"dac5573", quad_8bit},
> +	{"dac6573", quad_10bit},
> +	{"dac7573", quad_12bit},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, dac5571_id);
> +
> +static struct i2c_driver dac5571_driver = {
> +	.driver = {
> +		   .name = "ti-dac5571",
> +	},
> +	.probe	  = dac5571_probe,
> +	.remove   = dac5571_remove,
> +	.id_table = dac5571_id,
> +};
> +module_i2c_driver(dac5571_driver);
> +
> +MODULE_AUTHOR("Sean Nyekjaer <sean.nyekjaer@prevas.dk>");
> +MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
> +MODULE_LICENSE("GPL v2");

Re: [PATCH 2/2] iio: ti-dac5571: Add DT binding documentation

[Jonathan Cameron]

On Tue,  1 May 2018 10:15:54 +0200
Sean Nyekjaer <sean.nyekjaer@prevas.dk> wrote:

> Adding binding documentation for Texas Instruments DAC5571 Family
> 
> Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
> Reviewed-by: Rob Herring <robh@kernel.org>

Applied to the togreg branch of iio.git and pushed out as testing.

Thanks,

Jonathan

> ---
>  .../bindings/iio/dac/ti,dac5571.txt           | 24 +++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt
> new file mode 100644
> index 000000000000..03af6b9a4d07
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.txt
> @@ -0,0 +1,24 @@
> +* Texas Instruments DAC5571 Family
> +
> +Required properties:
> + - compatible: Should contain
> +    "ti,dac5571"
> +    "ti,dac6571"
> +    "ti,dac7571"
> +    "ti,dac5574"
> +    "ti,dac6574"
> +    "ti,dac7574"
> +    "ti,dac5573"
> +    "ti,dac6573"
> +    "ti,dac7573"
> + - reg: Should contain the DAC I2C address
> +
> +Optional properties:
> + - vref-supply: The regulator supply for DAC reference voltage
> +
> +Example:
> +dac@0 {
> +	compatible = "ti,dac5571";
> +	reg = <0x4C>;
> +	vref-supply = <&vdd_supply>;
> +};