[PATCH] iio: adc: add max1117/max1118/max1119 ADC driver

[PATCH] iio: adc: add max1117/max1118/max1119 ADC driver

[Akinobu Mita]

This adds max1117/max1118/max1119 8-bit, dual-channel ADC driver.

Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
Cc: Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
---
 .../devicetree/bindings/iio/adc/max1118.txt        |  21 ++
 drivers/iio/adc/Kconfig                            |  12 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/max1118.c                          | 310 +++++++++++++++++++++
 4 files changed, 344 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/max1118.txt
 create mode 100644 drivers/iio/adc/max1118.c

diff --git a/Documentation/devicetree/bindings/iio/adc/max1118.txt b/Documentation/devicetree/bindings/iio/adc/max1118.txt
new file mode 100644
index 0000000..cf33d0b
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/max1118.txt
@@ -0,0 +1,21 @@
+* MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs
+
+Required properties:
+ - compatible: Should be one of
+	* "maxim,max1117"
+	* "maxim,max1118"
+	* "maxim,max1119"
+ - reg: spi chip select number for the device
+ - (max1118 only) vref-supply: The regulator supply for ADC reference voltage
+
+Recommended properties:
+ - spi-max-frequency: Definition as per
+		Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Example:
+adc@0 {
+	compatible = "maxim,max1118";
+	reg = <0>;
+	vref-supply = <&vdd_supply>;
+	spi-max-frequency = <1000000>;
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index dedae7a..66262d1 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -335,6 +335,18 @@ config MAX11100
 	  To compile this driver as a module, choose M here: the module will be
 	  called max11100.
 
+config MAX1118
+	tristate "Maxim max1117/max1118/max1119 ADCs driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Maxim max1117/max1118/max1119
+	  8-bit, dual-channel ADCs.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called max1118.
+
 config MAX1363
 	tristate "Maxim max1363 ADC driver"
 	depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d001262..5ef3470 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
 obj-$(CONFIG_LTC2485) += ltc2485.o
 obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX11100) += max11100.o
+obj-$(CONFIG_MAX1118) += max1118.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
diff --git a/drivers/iio/adc/max1118.c b/drivers/iio/adc/max1118.c
new file mode 100644
index 0000000..f2597b7
--- /dev/null
+++ b/drivers/iio/adc/max1118.c
@@ -0,0 +1,310 @@
+/*
+ * MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs driver
+ *
+ * Copyright (c) 2017 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1117-MAX1119.pdf
+ *
+ * SPI interface connections
+ *
+ * SPI                MAXIM
+ * Master  Direction  MAX1117/8/9
+ * ------  ---------  -----------
+ * nCS        -->     CNVST
+ * SCK        -->     SCLK
+ * MISO       <--     DOUT
+ * ------  ---------  -----------
+ */
+
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/regulator/consumer.h>
+
+enum max1118_id {
+	max1117,
+	max1118,
+	max1119,
+};
+
+struct max1118 {
+	struct spi_device *spi;
+	struct mutex lock;
+	struct regulator *reg;
+
+	u8 data ____cacheline_aligned;
+};
+
+#define MAX1118_CHANNEL(ch)						\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.channel = (ch),					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.scan_index = ch,					\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 8,					\
+			.storagebits = 8,				\
+		},							\
+	}
+
+static const struct iio_chan_spec max1118_channels[] = {
+	MAX1118_CHANNEL(0),
+	MAX1118_CHANNEL(1),
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static int max1118_read(struct spi_device *spi, int channel)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct max1118 *adc = iio_priv(indio_dev);
+	struct spi_transfer xfers[] = {
+		/*
+		 * To select CH1 for conversion, CNVST pin must be brought high
+		 * and low for a second time.
+		 */
+		{
+			.len = 0,
+			.delay_usecs = 1,	/* > CNVST Low Time 100 ns */
+			.cs_change = 1,
+		},
+		/*
+		 * The acquisition interval begins with the falling edge of
+		 * CNVST.  The total acquisition and conversion process takes
+		 * <7.5us.
+		 */
+		{
+			.len = 0,
+			.delay_usecs = 8,
+		},
+		{
+			.rx_buf = &adc->data,
+			.len = 1,
+		},
+	};
+	int ret;
+
+	if (channel == 0)
+		ret = spi_sync_transfer(spi, xfers + 1, 2);
+	else
+		ret = spi_sync_transfer(spi, xfers, 3);
+
+	if (ret)
+		return ret;
+
+	return adc->data;
+}
+
+static int max1118_get_vref_mV(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct max1118 *adc = iio_priv(indio_dev);
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	int vref_uV;
+
+	switch (id->driver_data) {
+	case max1117:
+		return 2048;
+	case max1119:
+		return 4096;
+	case max1118:
+		if (IS_ERR_OR_NULL(adc->reg))
+			return -EINVAL;
+
+		vref_uV = regulator_get_voltage(adc->reg);
+		if (vref_uV < 0)
+			return vref_uV;
+		return vref_uV / 1000;
+	}
+
+	return -ENODEV;
+}
+
+static int max1118_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int *val, int *val2, long mask)
+{
+	struct max1118 *adc = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&adc->lock);
+		*val = max1118_read(adc->spi, chan->channel);
+		mutex_unlock(&adc->lock);
+		if (*val < 0)
+			return *val;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = max1118_get_vref_mV(adc->spi);
+		if (*val < 0)
+			return *val;
+		*val2 = 8;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info max1118_info = {
+	.read_raw = max1118_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int max1118_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct max1118 *adc = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	if (!IS_ERR_OR_NULL(adc->reg))
+		return regulator_disable(adc->reg);
+
+	return 0;
+}
+
+static irqreturn_t max1118_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct max1118 *adc = iio_priv(indio_dev);
+	u8 data[16] = { }; /* 2x 8-bit ADC data + padding + 8 bytes timestamp */
+	int scan_index;
+	int i = 0;
+
+	mutex_lock(&adc->lock);
+
+	for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+			indio_dev->masklength) {
+		const struct iio_chan_spec *scan_chan =
+				&indio_dev->channels[scan_index];
+		int ret = max1118_read(adc->spi, scan_chan->channel);
+
+		if (ret < 0) {
+			dev_warn(&adc->spi->dev,
+				"failed to get conversion data\n");
+			goto out;
+		}
+
+		data[i] = ret;
+		i++;
+	}
+	iio_push_to_buffers_with_timestamp(indio_dev, data,
+					   iio_get_time_ns(indio_dev));
+out:
+	mutex_unlock(&adc->lock);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int max1118_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct max1118 *adc;
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	adc = iio_priv(indio_dev);
+	adc->spi = spi;
+	mutex_init(&adc->lock);
+
+	adc->reg = devm_regulator_get(&spi->dev, "vref");
+	if (PTR_ERR(adc->reg) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	if (IS_ERR_OR_NULL(adc->reg) && id->driver_data == max1118) {
+		dev_warn(&spi->dev, "max1118 requires vref-supply\n");
+	} else {
+		ret = regulator_enable(adc->reg);
+		if (ret)
+			return ret;
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->info = &max1118_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = max1118_channels;
+	indio_dev->num_channels = ARRAY_SIZE(max1118_channels);
+
+	/*
+	 * To reinitiate a conversion on CH0, it is necessary to allow for a
+	 * conversion to be complete and all of the data to be read out.  Once
+	 * a conversion has been completed, the MAX1117/MAX1118/MAX1119 will go
+	 * into AutoShutdown mode until the next conversion is initiated.
+	 */
+	max1118_read(spi, 0);
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					max1118_trigger_handler, NULL);
+	if (ret)
+		goto err_reg_disable;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto err_buffer_cleanup;
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+err_reg_disable:
+	if (!IS_ERR_OR_NULL(adc->reg))
+		regulator_disable(adc->reg);
+
+	return ret;
+}
+
+static const struct spi_device_id max1118_id[] = {
+	{ "max1117", max1117 },
+	{ "max1118", max1118 },
+	{ "max1119", max1119 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, max1118_id);
+
+#ifdef CONFIG_OF
+
+static const struct of_device_id max1118_dt_ids[] = {
+	{ .compatible = "maxim,max1117" },
+	{ .compatible = "maxim,max1118" },
+	{ .compatible = "maxim,max1119" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max1118_dt_ids);
+
+#endif
+
+static struct spi_driver max1118_spi_driver = {
+	.driver = {
+		.name = "max1118",
+		.of_match_table = of_match_ptr(max1118_dt_ids),
+	},
+	.probe = max1118_probe,
+	.remove = max1118_remove,
+	.id_table = max1118_id,
+};
+module_spi_driver(max1118_spi_driver);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("MAXIM MAX1117/MAX1118/MAX1119 ADCs driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

Re: [PATCH] iio: adc: add max1117/max1118/max1119 ADC driver

[Jonathan Cameron]

On 05/03/17 12:33, Akinobu Mita wrote:
> This adds max1117/max1118/max1119 8-bit, dual-channel ADC driver.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
> Cc: Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
> Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Hi Akinobu,

The SPI usage is 'unusual' enough that I'd like Mark Brown to take a quick
look and give a view on whether it will always work or not.
cc'd Mark and linux-spi.

A few other comments inline.

Thanks,

Jonathan
> ---
>  .../devicetree/bindings/iio/adc/max1118.txt        |  21 ++
>  drivers/iio/adc/Kconfig                            |  12 +
>  drivers/iio/adc/Makefile                           |   1 +
>  drivers/iio/adc/max1118.c                          | 310 +++++++++++++++++++++
>  4 files changed, 344 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/max1118.txt
>  create mode 100644 drivers/iio/adc/max1118.c
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/max1118.txt b/Documentation/devicetree/bindings/iio/adc/max1118.txt
> new file mode 100644
> index 0000000..cf33d0b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/max1118.txt
> @@ -0,0 +1,21 @@
> +* MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs
> +
> +Required properties:
> + - compatible: Should be one of
> +	* "maxim,max1117"
> +	* "maxim,max1118"
> +	* "maxim,max1119"
> + - reg: spi chip select number for the device
> + - (max1118 only) vref-supply: The regulator supply for ADC reference voltage
> +
> +Recommended properties:
> + - spi-max-frequency: Definition as per
> +		Documentation/devicetree/bindings/spi/spi-bus.txt
> +
> +Example:
> +adc@0 {
> +	compatible = "maxim,max1118";
> +	reg = <0>;
> +	vref-supply = <&vdd_supply>;
> +	spi-max-frequency = <1000000>;
> +};
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index dedae7a..66262d1 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -335,6 +335,18 @@ config MAX11100
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called max11100.
>  
> +config MAX1118
> +	tristate "Maxim max1117/max1118/max1119 ADCs driver"
> +	depends on SPI
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say yes here to build support for Maxim max1117/max1118/max1119
> +	  8-bit, dual-channel ADCs.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called max1118.
> +
>  config MAX1363
>  	tristate "Maxim max1363 ADC driver"
>  	depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index d001262..5ef3470 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -33,6 +33,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
>  obj-$(CONFIG_LTC2485) += ltc2485.o
>  obj-$(CONFIG_MAX1027) += max1027.o
>  obj-$(CONFIG_MAX11100) += max11100.o
> +obj-$(CONFIG_MAX1118) += max1118.o
>  obj-$(CONFIG_MAX1363) += max1363.o
>  obj-$(CONFIG_MCP320X) += mcp320x.o
>  obj-$(CONFIG_MCP3422) += mcp3422.o
> diff --git a/drivers/iio/adc/max1118.c b/drivers/iio/adc/max1118.c
> new file mode 100644
> index 0000000..f2597b7
> --- /dev/null
> +++ b/drivers/iio/adc/max1118.c
> @@ -0,0 +1,310 @@
> +/*
> + * MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs driver
> + *
> + * Copyright (c) 2017 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License.  See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1117-MAX1119.pdf
> + *
> + * SPI interface connections
> + *
> + * SPI                MAXIM
> + * Master  Direction  MAX1117/8/9
> + * ------  ---------  -----------
> + * nCS        -->     CNVST
> + * SCK        -->     SCLK
> + * MISO       <--     DOUT
> + * ------  ---------  -----------
> + */
> +
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +enum max1118_id {
> +	max1117,
> +	max1118,
> +	max1119,
> +};
> +
> +struct max1118 {
> +	struct spi_device *spi;
> +	struct mutex lock;
> +	struct regulator *reg;
> +
> +	u8 data ____cacheline_aligned;
> +};
> +
> +#define MAX1118_CHANNEL(ch)						\
> +	{								\
> +		.type = IIO_VOLTAGE,					\
> +		.indexed = 1,						\
> +		.channel = (ch),					\
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +		.scan_index = ch,					\
> +		.scan_type = {						\
> +			.sign = 'u',					\
> +			.realbits = 8,					\
> +			.storagebits = 8,				\
> +		},							\
> +	}
> +
> +static const struct iio_chan_spec max1118_channels[] = {
> +	MAX1118_CHANNEL(0),
> +	MAX1118_CHANNEL(1),
> +	IIO_CHAN_SOFT_TIMESTAMP(2),
> +};
> +
> +static int max1118_read(struct spi_device *spi, int channel)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct max1118 *adc = iio_priv(indio_dev);
> +	struct spi_transfer xfers[] = {
> +		/*
> +		 * To select CH1 for conversion, CNVST pin must be brought high
> +		 * and low for a second time.
> +		 */
> +		{
> +			.len = 0,
> +			.delay_usecs = 1,	/* > CNVST Low Time 100 ns */
> +			.cs_change = 1,
> +		},
> +		/*
> +		 * The acquisition interval begins with the falling edge of
> +		 * CNVST.  The total acquisition and conversion process takes
> +		 * <7.5us.
> +		 */
> +		{
> +			.len = 0,
Is this guaranteed to actually work?  I've no idea what the spi core
does with a zero length transfer.
> +			.delay_usecs = 8,
> +		},
> +		{
> +			.rx_buf = &adc->data,
> +			.len = 1,
> +		},
> +	};
> +	int ret;
> +
> +	if (channel == 0)
> +		ret = spi_sync_transfer(spi, xfers + 1, 2);
> +	else
> +		ret = spi_sync_transfer(spi, xfers, 3);
> +
> +	if (ret)
> +		return ret;
> +
> +	return adc->data;
> +}
> +
> +static int max1118_get_vref_mV(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct max1118 *adc = iio_priv(indio_dev);
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +	int vref_uV;
> +
> +	switch (id->driver_data) {
> +	case max1117:
> +		return 2048;
> +	case max1119:
> +		return 4096;
> +	case max1118:
> +		if (IS_ERR_OR_NULL(adc->reg))
> +			return -EINVAL;
Again, make it non optional and drop it.

If it really is optional, you should have two iio_info structures and
not have the scale available on one of them...
> +
> +		vref_uV = regulator_get_voltage(adc->reg);
> +		if (vref_uV < 0)
> +			return vref_uV;
> +		return vref_uV / 1000;
> +	}
> +
> +	return -ENODEV;
> +}
> +
> +static int max1118_read_raw(struct iio_dev *indio_dev,
> +			struct iio_chan_spec const *chan,
> +			int *val, int *val2, long mask)
> +{
> +	struct max1118 *adc = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&adc->lock);
> +		*val = max1118_read(adc->spi, chan->channel);
> +		mutex_unlock(&adc->lock);
> +		if (*val < 0)
> +			return *val;
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = max1118_get_vref_mV(adc->spi);
> +		if (*val < 0)
> +			return *val;
> +		*val2 = 8;
> +
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info max1118_info = {
> +	.read_raw = max1118_read_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int max1118_remove(struct spi_device *spi)
Code ordering is a little unusual.  Please move this to after the probe.
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct max1118 *adc = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	if (!IS_ERR_OR_NULL(adc->reg))
The regulator isn't optional so to have gotten here you have succesfully
acquired it or been passed a fake one.
> +		return regulator_disable(adc->reg);
> +
> +	return 0;
> +}
> +
> +static irqreturn_t max1118_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct max1118 *adc = iio_priv(indio_dev);
> +	u8 data[16] = { }; /* 2x 8-bit ADC data + padding + 8 bytes timestamp */
> +	int scan_index;
> +	int i = 0;
> +
> +	mutex_lock(&adc->lock);
> +
> +	for_each_set_bit(scan_index, indio_dev->active_scan_mask,
> +			indio_dev->masklength) {
> +		const struct iio_chan_spec *scan_chan =
> +				&indio_dev->channels[scan_index];
> +		int ret = max1118_read(adc->spi, scan_chan->channel);
> +
> +		if (ret < 0) {
> +			dev_warn(&adc->spi->dev,
> +				"failed to get conversion data\n");
> +			goto out;
> +		}
> +
> +		data[i] = ret;
> +		i++;
> +	}
> +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> +					   iio_get_time_ns(indio_dev));
> +out:
> +	mutex_unlock(&adc->lock);
> +
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int max1118_probe(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev;
> +	struct max1118 *adc;
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	adc = iio_priv(indio_dev);
> +	adc->spi = spi;
> +	mutex_init(&adc->lock);
> +
> +	adc->reg = devm_regulator_get(&spi->dev, "vref");
> +	if (PTR_ERR(adc->reg) == -EPROBE_DEFER)
> +		return -EPROBE_DEFER;
> +
> +	if (IS_ERR_OR_NULL(adc->reg) && id->driver_data == max1118) {
> +		dev_warn(&spi->dev, "max1118 requires vref-supply\n");
Not a warning as it's not optional.  Error out on this.
If one isn't specified, the regulator framework will feed you a fake
one anyway..

Looking further up, this should only be requested for the max1118, but
should be required for that one part.
> +	} else {
> +		ret = regulator_enable(adc->reg);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	spi_set_drvdata(spi, indio_dev);
> +
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->dev.parent = &spi->dev;
> +	indio_dev->info = &max1118_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = max1118_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(max1118_channels);
> +
> +	/*
> +	 * To reinitiate a conversion on CH0, it is necessary to allow for a
> +	 * conversion to be complete and all of the data to be read out.  Once
> +	 * a conversion has been completed, the MAX1117/MAX1118/MAX1119 will go
> +	 * into AutoShutdown mode until the next conversion is initiated.
> +	 */
> +	max1118_read(spi, 0);
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					max1118_trigger_handler, NULL);
> +	if (ret)
> +		goto err_reg_disable;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret)
> +		goto err_buffer_cleanup;
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +err_reg_disable:
Clean this up once you have made a failure to get the regulator drop out.
Needs to be dependent on the device type not whether there is a regulator
or not.
> +	if (!IS_ERR_OR_NULL(adc->reg))
> +		regulator_disable(adc->reg);
> +
> +	return ret;
> +}
> +
> +static const struct spi_device_id max1118_id[] = {
> +	{ "max1117", max1117 },
> +	{ "max1118", max1118 },
> +	{ "max1119", max1119 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(spi, max1118_id);
> +
> +#ifdef CONFIG_OF
> +
> +static const struct of_device_id max1118_dt_ids[] = {
> +	{ .compatible = "maxim,max1117" },
> +	{ .compatible = "maxim,max1118" },
> +	{ .compatible = "maxim,max1119" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, max1118_dt_ids);
> +
> +#endif
> +
> +static struct spi_driver max1118_spi_driver = {
> +	.driver = {
> +		.name = "max1118",
> +		.of_match_table = of_match_ptr(max1118_dt_ids),
> +	},
> +	.probe = max1118_probe,
> +	.remove = max1118_remove,
> +	.id_table = max1118_id,
> +};
> +module_spi_driver(max1118_spi_driver);
> +
> +MODULE_AUTHOR("Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
> +MODULE_DESCRIPTION("MAXIM MAX1117/MAX1118/MAX1119 ADCs driver");
> +MODULE_LICENSE("GPL v2");
> 

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Re: [PATCH] iio: adc: add max1117/max1118/max1119 ADC driver

[Akinobu Mita]

2017-03-05 23:31 GMT+09:00 Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>:
> On 05/03/17 12:33, Akinobu Mita wrote:
>> This adds max1117/max1118/max1119 8-bit, dual-channel ADC driver.
>>
>> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
>> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
>> Cc: Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>> Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>> Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
> Hi Akinobu,
>
> The SPI usage is 'unusual' enough that I'd like Mark Brown to take a quick
> look and give a view on whether it will always work or not.
> cc'd Mark and linux-spi.

Mark,

This new driver uses the zero length spi_transfers with the cs_change
flag set and/or the non-zero delay_usecs.  The actual code is written
in max1118_read().

1. The zero length transfer with the spi_transfer.cs_change set is
required in order to select CH1 for MAX1117/8/9.  In order to select
CH1, the chip select line must be brought high and low again without
transfer.

2. The zero length transfer with the spi_transfer.delay_usecs > 0 is
required for waiting the conversion to be complete.  The conversion
begins with the falling edge of the chip select.  During the conversion
process, SCLK is ignored by MAX1117/8/9.

This is tested with the two spi controller driver, spi-omap2-mcspi and
spi-xilinx.  But these usages are unusual as I couldn't find any spi
protocol drivers doing similar.  Do I abuse the SPI kernel API ?

> A few other comments inline.
>
> Thanks,
>
> Jonathan
>> ---
>>  .../devicetree/bindings/iio/adc/max1118.txt        |  21 ++
>>  drivers/iio/adc/Kconfig                            |  12 +
>>  drivers/iio/adc/Makefile                           |   1 +
>>  drivers/iio/adc/max1118.c                          | 310 +++++++++++++++++++++
>>  4 files changed, 344 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/iio/adc/max1118.txt
>>  create mode 100644 drivers/iio/adc/max1118.c
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/max1118.txt b/Documentation/devicetree/bindings/iio/adc/max1118.txt
>> new file mode 100644
>> index 0000000..cf33d0b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/max1118.txt
>> @@ -0,0 +1,21 @@
>> +* MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs
>> +
>> +Required properties:
>> + - compatible: Should be one of
>> +     * "maxim,max1117"
>> +     * "maxim,max1118"
>> +     * "maxim,max1119"
>> + - reg: spi chip select number for the device
>> + - (max1118 only) vref-supply: The regulator supply for ADC reference voltage
>> +
>> +Recommended properties:
>> + - spi-max-frequency: Definition as per
>> +             Documentation/devicetree/bindings/spi/spi-bus.txt
>> +
>> +Example:
>> +adc@0 {
>> +     compatible = "maxim,max1118";
>> +     reg = <0>;
>> +     vref-supply = <&vdd_supply>;
>> +     spi-max-frequency = <1000000>;
>> +};
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index dedae7a..66262d1 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -335,6 +335,18 @@ config MAX11100
>>         To compile this driver as a module, choose M here: the module will be
>>         called max11100.
>>
>> +config MAX1118
>> +     tristate "Maxim max1117/max1118/max1119 ADCs driver"
>> +     depends on SPI
>> +     select IIO_BUFFER
>> +     select IIO_TRIGGERED_BUFFER
>> +     help
>> +       Say yes here to build support for Maxim max1117/max1118/max1119
>> +       8-bit, dual-channel ADCs.
>> +
>> +       To compile this driver as a module, choose M here: the module will be
>> +       called max1118.
>> +
>>  config MAX1363
>>       tristate "Maxim max1363 ADC driver"
>>       depends on I2C
>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>> index d001262..5ef3470 100644
>> --- a/drivers/iio/adc/Makefile
>> +++ b/drivers/iio/adc/Makefile
>> @@ -33,6 +33,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
>>  obj-$(CONFIG_LTC2485) += ltc2485.o
>>  obj-$(CONFIG_MAX1027) += max1027.o
>>  obj-$(CONFIG_MAX11100) += max11100.o
>> +obj-$(CONFIG_MAX1118) += max1118.o
>>  obj-$(CONFIG_MAX1363) += max1363.o
>>  obj-$(CONFIG_MCP320X) += mcp320x.o
>>  obj-$(CONFIG_MCP3422) += mcp3422.o
>> diff --git a/drivers/iio/adc/max1118.c b/drivers/iio/adc/max1118.c
>> new file mode 100644
>> index 0000000..f2597b7
>> --- /dev/null
>> +++ b/drivers/iio/adc/max1118.c
>> @@ -0,0 +1,310 @@
>> +/*
>> + * MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs driver
>> + *
>> + * Copyright (c) 2017 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License.  See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1117-MAX1119.pdf
>> + *
>> + * SPI interface connections
>> + *
>> + * SPI                MAXIM
>> + * Master  Direction  MAX1117/8/9
>> + * ------  ---------  -----------
>> + * nCS        -->     CNVST
>> + * SCK        -->     SCLK
>> + * MISO       <--     DOUT
>> + * ------  ---------  -----------
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +enum max1118_id {
>> +     max1117,
>> +     max1118,
>> +     max1119,
>> +};
>> +
>> +struct max1118 {
>> +     struct spi_device *spi;
>> +     struct mutex lock;
>> +     struct regulator *reg;
>> +
>> +     u8 data ____cacheline_aligned;
>> +};
>> +
>> +#define MAX1118_CHANNEL(ch)                                          \
>> +     {                                                               \
>> +             .type = IIO_VOLTAGE,                                    \
>> +             .indexed = 1,                                           \
>> +             .channel = (ch),                                        \
>> +             .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
>> +             .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
>> +             .scan_index = ch,                                       \
>> +             .scan_type = {                                          \
>> +                     .sign = 'u',                                    \
>> +                     .realbits = 8,                                  \
>> +                     .storagebits = 8,                               \
>> +             },                                                      \
>> +     }
>> +
>> +static const struct iio_chan_spec max1118_channels[] = {
>> +     MAX1118_CHANNEL(0),
>> +     MAX1118_CHANNEL(1),
>> +     IIO_CHAN_SOFT_TIMESTAMP(2),
>> +};
>> +
>> +static int max1118_read(struct spi_device *spi, int channel)
>> +{
>> +     struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +     struct max1118 *adc = iio_priv(indio_dev);
>> +     struct spi_transfer xfers[] = {
>> +             /*
>> +              * To select CH1 for conversion, CNVST pin must be brought high
>> +              * and low for a second time.
>> +              */
>> +             {
>> +                     .len = 0,
>> +                     .delay_usecs = 1,       /* > CNVST Low Time 100 ns */
>> +                     .cs_change = 1,
>> +             },
>> +             /*
>> +              * The acquisition interval begins with the falling edge of
>> +              * CNVST.  The total acquisition and conversion process takes
>> +              * <7.5us.
>> +              */
>> +             {
>> +                     .len = 0,
> Is this guaranteed to actually work?  I've no idea what the spi core
> does with a zero length transfer.
>> +                     .delay_usecs = 8,
>> +             },
>> +             {
>> +                     .rx_buf = &adc->data,
>> +                     .len = 1,
>> +             },
>> +     };
>> +     int ret;
>> +
>> +     if (channel == 0)
>> +             ret = spi_sync_transfer(spi, xfers + 1, 2);
>> +     else
>> +             ret = spi_sync_transfer(spi, xfers, 3);
>> +
>> +     if (ret)
>> +             return ret;
>> +
>> +     return adc->data;
>> +}
>> +
>> +static int max1118_get_vref_mV(struct spi_device *spi)
>> +{
>> +     struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +     struct max1118 *adc = iio_priv(indio_dev);
>> +     const struct spi_device_id *id = spi_get_device_id(spi);
>> +     int vref_uV;
>> +
>> +     switch (id->driver_data) {
>> +     case max1117:
>> +             return 2048;
>> +     case max1119:
>> +             return 4096;
>> +     case max1118:
>> +             if (IS_ERR_OR_NULL(adc->reg))
>> +                     return -EINVAL;
> Again, make it non optional and drop it.
>
> If it really is optional, you should have two iio_info structures and
> not have the scale available on one of them...
>> +
>> +             vref_uV = regulator_get_voltage(adc->reg);
>> +             if (vref_uV < 0)
>> +                     return vref_uV;
>> +             return vref_uV / 1000;
>> +     }
>> +
>> +     return -ENODEV;
>> +}
>> +
>> +static int max1118_read_raw(struct iio_dev *indio_dev,
>> +                     struct iio_chan_spec const *chan,
>> +                     int *val, int *val2, long mask)
>> +{
>> +     struct max1118 *adc = iio_priv(indio_dev);
>> +
>> +     switch (mask) {
>> +     case IIO_CHAN_INFO_RAW:
>> +             mutex_lock(&adc->lock);
>> +             *val = max1118_read(adc->spi, chan->channel);
>> +             mutex_unlock(&adc->lock);
>> +             if (*val < 0)
>> +                     return *val;
>> +
>> +             return IIO_VAL_INT;
>> +     case IIO_CHAN_INFO_SCALE:
>> +             *val = max1118_get_vref_mV(adc->spi);
>> +             if (*val < 0)
>> +                     return *val;
>> +             *val2 = 8;
>> +
>> +             return IIO_VAL_FRACTIONAL_LOG2;
>> +     }
>> +
>> +     return -EINVAL;
>> +}
>> +
>> +static const struct iio_info max1118_info = {
>> +     .read_raw = max1118_read_raw,
>> +     .driver_module = THIS_MODULE,
>> +};
>> +
>> +static int max1118_remove(struct spi_device *spi)
> Code ordering is a little unusual.  Please move this to after the probe.
>> +{
>> +     struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +     struct max1118 *adc = iio_priv(indio_dev);
>> +
>> +     iio_device_unregister(indio_dev);
>> +     iio_triggered_buffer_cleanup(indio_dev);
>> +     if (!IS_ERR_OR_NULL(adc->reg))
> The regulator isn't optional so to have gotten here you have succesfully
> acquired it or been passed a fake one.
>> +             return regulator_disable(adc->reg);
>> +
>> +     return 0;
>> +}
>> +
>> +static irqreturn_t max1118_trigger_handler(int irq, void *p)
>> +{
>> +     struct iio_poll_func *pf = p;
>> +     struct iio_dev *indio_dev = pf->indio_dev;
>> +     struct max1118 *adc = iio_priv(indio_dev);
>> +     u8 data[16] = { }; /* 2x 8-bit ADC data + padding + 8 bytes timestamp */
>> +     int scan_index;
>> +     int i = 0;
>> +
>> +     mutex_lock(&adc->lock);
>> +
>> +     for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>> +                     indio_dev->masklength) {
>> +             const struct iio_chan_spec *scan_chan =
>> +                             &indio_dev->channels[scan_index];
>> +             int ret = max1118_read(adc->spi, scan_chan->channel);
>> +
>> +             if (ret < 0) {
>> +                     dev_warn(&adc->spi->dev,
>> +                             "failed to get conversion data\n");
>> +                     goto out;
>> +             }
>> +
>> +             data[i] = ret;
>> +             i++;
>> +     }
>> +     iio_push_to_buffers_with_timestamp(indio_dev, data,
>> +                                        iio_get_time_ns(indio_dev));
>> +out:
>> +     mutex_unlock(&adc->lock);
>> +
>> +     iio_trigger_notify_done(indio_dev->trig);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static int max1118_probe(struct spi_device *spi)
>> +{
>> +     struct iio_dev *indio_dev;
>> +     struct max1118 *adc;
>> +     const struct spi_device_id *id = spi_get_device_id(spi);
>> +     int ret;
>> +
>> +     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
>> +     if (!indio_dev)
>> +             return -ENOMEM;
>> +
>> +     adc = iio_priv(indio_dev);
>> +     adc->spi = spi;
>> +     mutex_init(&adc->lock);
>> +
>> +     adc->reg = devm_regulator_get(&spi->dev, "vref");
>> +     if (PTR_ERR(adc->reg) == -EPROBE_DEFER)
>> +             return -EPROBE_DEFER;
>> +
>> +     if (IS_ERR_OR_NULL(adc->reg) && id->driver_data == max1118) {
>> +             dev_warn(&spi->dev, "max1118 requires vref-supply\n");
> Not a warning as it's not optional.  Error out on this.
> If one isn't specified, the regulator framework will feed you a fake
> one anyway..
>
> Looking further up, this should only be requested for the max1118, but
> should be required for that one part.
>> +     } else {
>> +             ret = regulator_enable(adc->reg);
>> +             if (ret)
>> +                     return ret;
>> +     }
>> +
>> +     spi_set_drvdata(spi, indio_dev);
>> +
>> +     indio_dev->name = spi_get_device_id(spi)->name;
>> +     indio_dev->dev.parent = &spi->dev;
>> +     indio_dev->info = &max1118_info;
>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>> +     indio_dev->channels = max1118_channels;
>> +     indio_dev->num_channels = ARRAY_SIZE(max1118_channels);
>> +
>> +     /*
>> +      * To reinitiate a conversion on CH0, it is necessary to allow for a
>> +      * conversion to be complete and all of the data to be read out.  Once
>> +      * a conversion has been completed, the MAX1117/MAX1118/MAX1119 will go
>> +      * into AutoShutdown mode until the next conversion is initiated.
>> +      */
>> +     max1118_read(spi, 0);
>> +
>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +                                     max1118_trigger_handler, NULL);
>> +     if (ret)
>> +             goto err_reg_disable;
>> +
>> +     ret = iio_device_register(indio_dev);
>> +     if (ret)
>> +             goto err_buffer_cleanup;
>> +
>> +     return 0;
>> +
>> +err_buffer_cleanup:
>> +     iio_triggered_buffer_cleanup(indio_dev);
>> +err_reg_disable:
> Clean this up once you have made a failure to get the regulator drop out.
> Needs to be dependent on the device type not whether there is a regulator
> or not.
>> +     if (!IS_ERR_OR_NULL(adc->reg))
>> +             regulator_disable(adc->reg);
>> +
>> +     return ret;
>> +}
>> +
>> +static const struct spi_device_id max1118_id[] = {
>> +     { "max1117", max1117 },
>> +     { "max1118", max1118 },
>> +     { "max1119", max1119 },
>> +     {}
>> +};
>> +MODULE_DEVICE_TABLE(spi, max1118_id);
>> +
>> +#ifdef CONFIG_OF
>> +
>> +static const struct of_device_id max1118_dt_ids[] = {
>> +     { .compatible = "maxim,max1117" },
>> +     { .compatible = "maxim,max1118" },
>> +     { .compatible = "maxim,max1119" },
>> +     {},
>> +};
>> +MODULE_DEVICE_TABLE(of, max1118_dt_ids);
>> +
>> +#endif
>> +
>> +static struct spi_driver max1118_spi_driver = {
>> +     .driver = {
>> +             .name = "max1118",
>> +             .of_match_table = of_match_ptr(max1118_dt_ids),
>> +     },
>> +     .probe = max1118_probe,
>> +     .remove = max1118_remove,
>> +     .id_table = max1118_id,
>> +};
>> +module_spi_driver(max1118_spi_driver);
>> +
>> +MODULE_AUTHOR("Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
>> +MODULE_DESCRIPTION("MAXIM MAX1117/MAX1118/MAX1119 ADCs driver");
>> +MODULE_LICENSE("GPL v2");
>>
>

Re: [PATCH] iio: adc: add max1117/max1118/max1119 ADC driver

[Rob Herring]

On Sun, Mar 05, 2017 at 09:33:30PM +0900, Akinobu Mita wrote:
> This adds max1117/max1118/max1119 8-bit, dual-channel ADC driver.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
> Cc: Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
> Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
> ---
>  .../devicetree/bindings/iio/adc/max1118.txt        |  21 ++

Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

>  drivers/iio/adc/Kconfig                            |  12 +
>  drivers/iio/adc/Makefile                           |   1 +
>  drivers/iio/adc/max1118.c                          | 310 +++++++++++++++++++++
>  4 files changed, 344 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/max1118.txt
>  create mode 100644 drivers/iio/adc/max1118.c
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