Re: [PATCH v2] iio: potentiometer: add TI tpl0102 support

[Jonathan Cameron <jic23@kernel.org>]

On 22/02/16 01:32, Matt Ranostay wrote:
> Add support for the TI family of digital potentiometers.
> 
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
> Changes from v1:
> * Re-order alphabetically chipids
> * Removed unneeded local variable, and mask checks 
> * Use return code from regmap_read()
> * Switched to devm_iio_device_register()
> 
>  drivers/iio/potentiometer/Kconfig   |  12 +++
>  drivers/iio/potentiometer/Makefile  |   1 +
>  drivers/iio/potentiometer/tpl0102.c | 166 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 drivers/iio/potentiometer/tpl0102.c
> 
> diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
> index fd75db7..ffc735c 100644
> --- a/drivers/iio/potentiometer/Kconfig
> +++ b/drivers/iio/potentiometer/Kconfig
> @@ -17,4 +17,16 @@ config MCP4531
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called mcp4531.
>  
> +config TPL0102
> +	tristate "Texas Instruments digital potentiometer driver"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Say yes here to build support for the Texas Instruments
> +	  TPL0102, TPL0402
> +	  digital potentiometer chips.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called tpl0102.
> +
>  endmenu
> diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
> index 8afe492..b563b49 100644
> --- a/drivers/iio/potentiometer/Makefile
> +++ b/drivers/iio/potentiometer/Makefile
> @@ -4,3 +4,4 @@
>  
>  # When adding new entries keep the list in alphabetical order
>  obj-$(CONFIG_MCP4531) += mcp4531.o
> +obj-$(CONFIG_TPL0102) += tpl0102.o
> diff --git a/drivers/iio/potentiometer/tpl0102.c b/drivers/iio/potentiometer/tpl0102.c
> new file mode 100644
> index 0000000..313124b
> --- /dev/null
> +++ b/drivers/iio/potentiometer/tpl0102.c
> @@ -0,0 +1,166 @@
> +/*
> + * tpl0102.c - Support for Texas Instruments digital potentiometers
> + *
> + * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
> + *
> + * 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.
> + *
> + * TODO: enable/disable hi-z output control
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/iio.h>
> +
> +struct tpl0102_cfg {
> +	int wipers;
> +	int max_pos;
> +	int kohms;
> +};
> +
> +enum tpl0102_type {
> +	CAT5140_503,
> +	CAT5140_104,
> +	TPL0102_104,
> +	TPL0401_103,
> +};
> +
> +static const struct tpl0102_cfg tpl0102_cfg[] = {
> +	/* on-semiconductor parts */
> +	[CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
> +	[CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
> +	/* ti parts */
> +	[TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
> +	[TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
> +};
> +
> +struct tpl0102_data {
> +	struct regmap *regmap;
> +	unsigned long devid;
> +};
> +
> +static const struct regmap_config tpl0102_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +};
> +
> +#define TPL0102_CHANNEL(ch) {					\
> +	.type = IIO_RESISTANCE,					\
> +	.indexed = 1,						\
> +	.output = 1,						\
> +	.channel = (ch),					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +}
> +
> +static const struct iio_chan_spec tpl0102_channels[] = {
> +	TPL0102_CHANNEL(0),
> +	TPL0102_CHANNEL(1),
> +};
> +
> +static int tpl0102_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct tpl0102_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW: {
> +		int ret = regmap_read(data->regmap, chan->channel, val);
> +
> +		return ret ? ret : IIO_VAL_INT;
> +	}
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 1000 * tpl0102_cfg[data->devid].kohms;
> +		*val2 = tpl0102_cfg[data->devid].max_pos;
> +		return IIO_VAL_FRACTIONAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int tpl0102_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long mask)
> +{
> +	struct tpl0102_data *data = iio_priv(indio_dev);
> +
> +	if (mask != IIO_CHAN_INFO_RAW)
> +		return -EINVAL;
> +
> +	if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
> +		return -EINVAL;
> +
> +	return regmap_write(data->regmap, chan->channel, val);
> +}
> +
> +static const struct iio_info tpl0102_info = {
> +	.read_raw = tpl0102_read_raw,
> +	.write_raw = tpl0102_write_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int tpl0102_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct tpl0102_data *data;
> +	struct iio_dev *indio_dev;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_WORD_DATA))
> +		return -ENOTSUPP;
> +
> +	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->devid = id->driver_data;
> +	data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(dev, "regmap initialization failed\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->info = &tpl0102_info;
> +	indio_dev->channels = tpl0102_channels;
> +	indio_dev->num_channels = tpl0102_cfg[data->devid].wipers;
> +	indio_dev->name = client->name;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static const struct i2c_device_id tpl0102_id[] = {
> +	{ "cat5140-503", CAT5140_503 },
> +	{ "cat5140-104", CAT5140_104 },
> +	{ "tpl0102-104", TPL0102_104 },
> +	{ "tpl0401-103", TPL0401_103 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, tpl0102_id);
> +
> +static struct i2c_driver tpl0102_driver = {
> +	.driver = {
> +		.name = "tpl0102",
> +	},
> +	.probe = tpl0102_probe,
> +	.id_table = tpl0102_id,
> +};
> +
> +module_i2c_driver(tpl0102_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
> +MODULE_DESCRIPTION("TPL0102 digital potentiometer");
> +MODULE_LICENSE("GPL");
>