[PATCH v4] iio: add m62332 DAC driver

[PATCH v4] iio: add m62332 DAC driver

[Dmitry Eremin-Solenikov]

m62332 is a simple 2-channel DAC used on several Sharp Zaurus boards to
control LCD voltage, backlight and sound. The driver use regulators to
control the reference voltage and enabling/disabling the DAC.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---

Changes since v3:

 * Use IIO_CHAN_INFO_OFFSET to represent DAC output more precisely
 * Handle regulator_get_voltage() error
 * Minor changes in m62332_set_value()

 drivers/iio/dac/Kconfig  |  10 ++
 drivers/iio/dac/Makefile |   1 +
 drivers/iio/dac/m62332.c | 269 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 280 insertions(+)
 create mode 100644 drivers/iio/dac/m62332.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 13471a7..e701e28 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -142,6 +142,16 @@ config AD7303
 	  To compile this driver as module choose M here: the module will be called
 	  ad7303.
 
+config M62332
+	tristate "Mitsubishi M62332 DAC driver"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Mitsubishi M62332
+	  (I2C 8-Bit DACs with rail-to-rail outputs).
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called m62332.
+
 config MAX517
 	tristate "Maxim MAX517/518/519/520/521 DAC driver"
 	depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 52be7e1..63ae056 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o
 obj-$(CONFIG_AD7303) += ad7303.o
+obj-$(CONFIG_M62332) += m62332.o
 obj-$(CONFIG_MAX517) += max517.o
 obj-$(CONFIG_MAX5821) += max5821.o
 obj-$(CONFIG_MCP4725) += mcp4725.o
diff --git a/drivers/iio/dac/m62332.c b/drivers/iio/dac/m62332.c
new file mode 100644
index 0000000..c23d7fa
--- /dev/null
+++ b/drivers/iio/dac/m62332.c
@@ -0,0 +1,269 @@
+/*
+ *  m62332.c - Support for Mitsubishi m62332 DAC
+ *
+ *  Copyright (c) 2014 Dmitry Eremin-Solenikov
+ *
+ *  Based on max517 driver:
+ *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+
+#include <linux/regulator/consumer.h>
+
+#define M62332_CHANNELS 2
+
+struct m62332_data {
+	struct i2c_client	*client;
+	u16			vref_mv;
+	struct regulator	*vcc;
+	struct mutex		mutex;
+	u8			raw[M62332_CHANNELS];
+#ifdef CONFIG_PM_SLEEP
+	u8			save[M62332_CHANNELS];
+#endif
+};
+
+static int m62332_set_value(struct iio_dev *indio_dev,
+	u8 val, int channel)
+{
+	struct m62332_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	u8 outbuf[2];
+	int res;
+
+	if (val == data->raw[channel])
+		return 0;
+
+	outbuf[0] = channel;
+	outbuf[1] = val;
+
+	mutex_lock(&data->mutex);
+
+	if (val) {
+		res = regulator_enable(data->vcc);
+		if (res)
+			goto out;
+	}
+
+	res = i2c_master_send(client, outbuf, 2);
+	if (res >= 0 && res != 2)
+		res = -EIO;
+	if (res < 0)
+		goto out;
+
+	data->raw[channel] = val;
+
+	if (!val)
+		regulator_disable(data->vcc);
+
+	mutex_unlock(&data->mutex);
+
+	return 0;
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return res;
+}
+
+static int m62332_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct m62332_data *data = iio_priv(indio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		/* Corresponds to Vref / 2^(bits) */
+		*val = data->vref_mv;
+		*val2 = 8;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	case IIO_CHAN_INFO_RAW:
+		*val = data->raw[chan->channel];
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = 1;
+		return IIO_VAL_INT;
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static int m62332_write_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val < 0 || val > 255)
+			return -EINVAL;
+
+		ret = m62332_set_value(indio_dev, val, chan->channel);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int m62332_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct m62332_data *data = iio_priv(indio_dev);
+	int ret;
+
+	data->save[0] = data->raw[0];
+	data->save[1] = data->raw[1];
+
+	ret = m62332_set_value(indio_dev, 0, 0);
+	if (ret < 0)
+		return ret;
+
+	return m62332_set_value(indio_dev, 0, 1);
+}
+
+static int m62332_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct m62332_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = m62332_set_value(indio_dev, data->save[0], 0);
+	if (ret < 0)
+		return ret;
+
+	return m62332_set_value(indio_dev, data->save[1], 1);
+}
+
+static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
+#define M62332_PM_OPS (&m62332_pm_ops)
+#else
+#define M62332_PM_OPS NULL
+#endif
+
+static const struct iio_info m62332_info = {
+	.read_raw = m62332_read_raw,
+	.write_raw = m62332_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define M62332_CHANNEL(chan) {				\
+	.type = IIO_VOLTAGE,				\
+	.indexed = 1,					\
+	.output = 1,					\
+	.channel = (chan),				\
+	.datasheet_name = "CH" #chan,			\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+		BIT(IIO_CHAN_INFO_SCALE) |		\
+		BIT(IIO_CHAN_INFO_OFFSET),		\
+}
+
+static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = {
+	M62332_CHANNEL(0),
+	M62332_CHANNEL(1)
+};
+
+static int m62332_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct m62332_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	mutex_init(&data->mutex);
+
+	data->vcc = devm_regulator_get(&client->dev, "VCC");
+	if (IS_ERR(data->vcc))
+		return PTR_ERR(data->vcc);
+
+	/* establish that the iio_dev is a child of the i2c device */
+	indio_dev->dev.parent = &client->dev;
+
+	indio_dev->num_channels = M62332_CHANNELS;
+	indio_dev->channels = m62332_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &m62332_info;
+
+	ret = regulator_get_voltage(data->vcc);
+	if (ret < 0)
+		return ret;
+	data->vref_mv = ret / 1000; /* mV */
+
+	ret = iio_map_array_register(indio_dev, client->dev.platform_data);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto err;
+
+	return 0;
+
+err:
+	iio_map_array_unregister(indio_dev);
+	return ret;
+}
+
+static int m62332_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+	iio_map_array_unregister(indio_dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id m62332_id[] = {
+	{ "m62332", },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, m62332_id);
+
+static struct i2c_driver m62332_driver = {
+	.driver = {
+		.name	= "m62332",
+		.pm	= M62332_PM_OPS,
+	},
+	.probe		= m62332_probe,
+	.remove		= m62332_remove,
+	.id_table	= m62332_id,
+};
+module_i2c_driver(m62332_driver);
+
+MODULE_AUTHOR("Dmitry Eremin-Solenikov");
+MODULE_DESCRIPTION("M62332 8-bit DAC");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4

Re: [PATCH v4] iio: add m62332 DAC driver

[Jonathan Cameron]

On 14/05/15 15:21, Dmitry Eremin-Solenikov wrote:
> m62332 is a simple 2-channel DAC used on several Sharp Zaurus boards to
> control LCD voltage, backlight and sound. The driver use regulators to
> control the reference voltage and enabling/disabling the DAC.
> 
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Looks good to me.

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

I'd still like to clean up the write_raw function to handle more
types, but it's not critical for this driver!

Jonathan

p.s. Whilst it is still only pushed out as testing, I'm happy to
add acks / reviewed-bys.  I tend to try and move things along on
weekends as I rarely get more than the odd hour during the week these
days, but that can lead to me applying versions with minor changes
without letting them sit on the list very long!
> ---
> 
> Changes since v3:
> 
>  * Use IIO_CHAN_INFO_OFFSET to represent DAC output more precisely
>  * Handle regulator_get_voltage() error
>  * Minor changes in m62332_set_value()
> 
>  drivers/iio/dac/Kconfig  |  10 ++
>  drivers/iio/dac/Makefile |   1 +
>  drivers/iio/dac/m62332.c | 269 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 280 insertions(+)
>  create mode 100644 drivers/iio/dac/m62332.c
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index 13471a7..e701e28 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -142,6 +142,16 @@ config AD7303
>  	  To compile this driver as module choose M here: the module will be called
>  	  ad7303.
>  
> +config M62332
> +	tristate "Mitsubishi M62332 DAC driver"
> +	depends on I2C
> +	help
> +	  If you say yes here you get support for the Mitsubishi M62332
> +	  (I2C 8-Bit DACs with rail-to-rail outputs).
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called m62332.
> +
>  config MAX517
>  	tristate "Maxim MAX517/518/519/520/521 DAC driver"
>  	depends on I2C
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 52be7e1..63ae056 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -16,6 +16,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
>  obj-$(CONFIG_AD5791) += ad5791.o
>  obj-$(CONFIG_AD5686) += ad5686.o
>  obj-$(CONFIG_AD7303) += ad7303.o
> +obj-$(CONFIG_M62332) += m62332.o
>  obj-$(CONFIG_MAX517) += max517.o
>  obj-$(CONFIG_MAX5821) += max5821.o
>  obj-$(CONFIG_MCP4725) += mcp4725.o
> diff --git a/drivers/iio/dac/m62332.c b/drivers/iio/dac/m62332.c
> new file mode 100644
> index 0000000..c23d7fa
> --- /dev/null
> +++ b/drivers/iio/dac/m62332.c
> @@ -0,0 +1,269 @@
> +/*
> + *  m62332.c - Support for Mitsubishi m62332 DAC
> + *
> + *  Copyright (c) 2014 Dmitry Eremin-Solenikov
> + *
> + *  Based on max517 driver:
> + *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +
> +#include <linux/regulator/consumer.h>
> +
> +#define M62332_CHANNELS 2
> +
> +struct m62332_data {
> +	struct i2c_client	*client;
> +	u16			vref_mv;
> +	struct regulator	*vcc;
> +	struct mutex		mutex;
> +	u8			raw[M62332_CHANNELS];
> +#ifdef CONFIG_PM_SLEEP
> +	u8			save[M62332_CHANNELS];
> +#endif
> +};
> +
> +static int m62332_set_value(struct iio_dev *indio_dev,
> +	u8 val, int channel)
> +{
> +	struct m62332_data *data = iio_priv(indio_dev);
> +	struct i2c_client *client = data->client;
> +	u8 outbuf[2];
> +	int res;
> +
> +	if (val == data->raw[channel])
> +		return 0;
> +
> +	outbuf[0] = channel;
> +	outbuf[1] = val;
> +
> +	mutex_lock(&data->mutex);
> +
> +	if (val) {
> +		res = regulator_enable(data->vcc);
> +		if (res)
> +			goto out;
> +	}
> +
> +	res = i2c_master_send(client, outbuf, 2);
> +	if (res >= 0 && res != 2)
> +		res = -EIO;
> +	if (res < 0)
> +		goto out;
> +
> +	data->raw[channel] = val;
> +
> +	if (!val)
> +		regulator_disable(data->vcc);
> +
> +	mutex_unlock(&data->mutex);
> +
> +	return 0;
> +
> +out:
> +	mutex_unlock(&data->mutex);
> +
> +	return res;
> +}
> +
> +static int m62332_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val,
> +			   int *val2,
> +			   long m)
> +{
> +	struct m62332_data *data = iio_priv(indio_dev);
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_SCALE:
> +		/* Corresponds to Vref / 2^(bits) */
> +		*val = data->vref_mv;
> +		*val2 = 8;
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	case IIO_CHAN_INFO_RAW:
> +		*val = data->raw[chan->channel];
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_OFFSET:
> +		*val = 1;
> +		return IIO_VAL_INT;
> +	default:
> +		break;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int m62332_write_raw(struct iio_dev *indio_dev,
> +	struct iio_chan_spec const *chan, int val, int val2, long mask)
> +{
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (val < 0 || val > 255)
> +			return -EINVAL;
> +
> +		ret = m62332_set_value(indio_dev, val, chan->channel);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int m62332_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct m62332_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	data->save[0] = data->raw[0];
> +	data->save[1] = data->raw[1];
> +
> +	ret = m62332_set_value(indio_dev, 0, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	return m62332_set_value(indio_dev, 0, 1);
> +}
> +
> +static int m62332_resume(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct m62332_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = m62332_set_value(indio_dev, data->save[0], 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	return m62332_set_value(indio_dev, data->save[1], 1);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
> +#define M62332_PM_OPS (&m62332_pm_ops)
> +#else
> +#define M62332_PM_OPS NULL
> +#endif
> +
> +static const struct iio_info m62332_info = {
> +	.read_raw = m62332_read_raw,
> +	.write_raw = m62332_write_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +#define M62332_CHANNEL(chan) {				\
> +	.type = IIO_VOLTAGE,				\
> +	.indexed = 1,					\
> +	.output = 1,					\
> +	.channel = (chan),				\
> +	.datasheet_name = "CH" #chan,			\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
> +		BIT(IIO_CHAN_INFO_SCALE) |		\
> +		BIT(IIO_CHAN_INFO_OFFSET),		\
> +}
> +
> +static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = {
> +	M62332_CHANNEL(0),
> +	M62332_CHANNEL(1)
> +};
> +
> +static int m62332_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct m62332_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +	data = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +	data->client = client;
> +
> +	mutex_init(&data->mutex);
> +
> +	data->vcc = devm_regulator_get(&client->dev, "VCC");
> +	if (IS_ERR(data->vcc))
> +		return PTR_ERR(data->vcc);
> +
> +	/* establish that the iio_dev is a child of the i2c device */
> +	indio_dev->dev.parent = &client->dev;
> +
> +	indio_dev->num_channels = M62332_CHANNELS;
> +	indio_dev->channels = m62332_channels;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &m62332_info;
> +
> +	ret = regulator_get_voltage(data->vcc);
> +	if (ret < 0)
> +		return ret;
> +	data->vref_mv = ret / 1000; /* mV */
> +
> +	ret = iio_map_array_register(indio_dev, client->dev.platform_data);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	iio_map_array_unregister(indio_dev);
> +	return ret;
> +}
> +
> +static int m62332_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_map_array_unregister(indio_dev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id m62332_id[] = {
> +	{ "m62332", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, m62332_id);
> +
> +static struct i2c_driver m62332_driver = {
> +	.driver = {
> +		.name	= "m62332",
> +		.pm	= M62332_PM_OPS,
> +	},
> +	.probe		= m62332_probe,
> +	.remove		= m62332_remove,
> +	.id_table	= m62332_id,
> +};
> +module_i2c_driver(m62332_driver);
> +
> +MODULE_AUTHOR("Dmitry Eremin-Solenikov");
> +MODULE_DESCRIPTION("M62332 8-bit DAC");
> +MODULE_LICENSE("GPL v2");
>