Re: [PATCH v5] iio: potentiometer: add driver for Microchip MCP413X/414X/415X/416X/423X/424X/425X/426X

[Jonathan Cameron <jic23@kernel.org>]

On 23/03/16 08:57, Slawomir Stepien wrote:
> The following functionalities are supported:
>  - write, read from volatile memory
> 
> Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22060b.pdf
> 
> Signed-off-by: Slawomir Stepien <sst@poczta.fm>
One process comment below... And git actually copes fine with what you
did (I wondered which way it would go until I tried it :)

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

A very nice, clean driver.  Thanks for your hard work on this.

Note it is in a branch I happy to rebase for the next week, so if Joachim
in particular would like to add a reviewed by tag, I'd be delighted to append
it.  Often reviewers don't get enough credit in my opinion!

Jonathan

> ---
> Changes since v4:
> - Added necessary include files and sorted all includes
> - Added missing mutex unlock when there is CMDERR
> - mcp4131_write_raw spi_write/mutex_unlock/return refactor
> 
> Changes since v3:
> - Added 'potentiometer' to subject
> - Replaced mcp4131_exec with spi_write and mcp4131_read
> - Narrowed mutex locking and unlocking places
> 
> Changes since v2:
> - Removed unnecessary parentheses in MCP4131_WIPER_SHIFT macro
> - Replaced the rx and tx SPI buffers with one buf that is ____cacheline_aligned
> - Changed mutex locking position
> - Replaced the devid with pointer to model configuration
> - Removed positive ("Registered" & "Unregistered") dev_info prints
> - Removed the mcp4131_remove callback
> 
> Changes since v1:
> - One line summary changed
> - Fixed module name and OF compatible
> - Based code on Peter Rosin's code from mcp4531.c
> - No additional sysfs attributes
> - Deleted not used devid struct memeber
> - Changed mcp4131_exec function arguments:
>  - write value is now u16
>  - no need to pass return buffer array - rx array from mcp4131_data is used
> - Added missing new line characters to dev_info
Funnily enough, this is the only thing I can find wrong in this patch.
Should not introduce an additional --- as you have done here.
The version stuff should simply have a blank line between it and the stats ;)


> ---
>  .../bindings/iio/potentiometer/mcp4131.txt         |  84 ++++
>  drivers/iio/potentiometer/Kconfig                  |  18 +
>  drivers/iio/potentiometer/Makefile                 |   1 +
>  drivers/iio/potentiometer/mcp4131.c                | 494 +++++++++++++++++++++
>  4 files changed, 597 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/potentiometer/mcp4131.txt
>  create mode 100644 drivers/iio/potentiometer/mcp4131.c
> 
> diff --git a/Documentation/devicetree/bindings/iio/potentiometer/mcp4131.txt b/Documentation/devicetree/bindings/iio/potentiometer/mcp4131.txt
> new file mode 100644
> index 0000000..3ccba16
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/potentiometer/mcp4131.txt
> @@ -0,0 +1,84 @@
> +* Microchip MCP413X/414X/415X/416X/423X/424X/425X/426X Digital Potentiometer
> +  driver
> +
> +The node for this driver must be a child node of a SPI controller, hence
> +all mandatory properties described in
> +
> +        Documentation/devicetree/bindings/spi/spi-bus.txt
> +
> +must be specified.
> +
> +Required properties:
> +	- compatible:  	Must be one of the following, depending on the
> +			model:
> +			"microchip,mcp4131-502"
> +			"microchip,mcp4131-103"
> +			"microchip,mcp4131-503"
> +			"microchip,mcp4131-104"
> +			"microchip,mcp4132-502"
> +			"microchip,mcp4132-103"
> +			"microchip,mcp4132-503"
> +			"microchip,mcp4132-104"
> +			"microchip,mcp4141-502"
> +			"microchip,mcp4141-103"
> +			"microchip,mcp4141-503"
> +			"microchip,mcp4141-104"
> +			"microchip,mcp4142-502"
> +			"microchip,mcp4142-103"
> +			"microchip,mcp4142-503"
> +			"microchip,mcp4142-104"
> +			"microchip,mcp4151-502"
> +			"microchip,mcp4151-103"
> +			"microchip,mcp4151-503"
> +			"microchip,mcp4151-104"
> +			"microchip,mcp4152-502"
> +			"microchip,mcp4152-103"
> +			"microchip,mcp4152-503"
> +			"microchip,mcp4152-104"
> +			"microchip,mcp4161-502"
> +			"microchip,mcp4161-103"
> +			"microchip,mcp4161-503"
> +			"microchip,mcp4161-104"
> +			"microchip,mcp4162-502"
> +			"microchip,mcp4162-103"
> +			"microchip,mcp4162-503"
> +			"microchip,mcp4162-104"
> +			"microchip,mcp4231-502"
> +			"microchip,mcp4231-103"
> +			"microchip,mcp4231-503"
> +			"microchip,mcp4231-104"
> +			"microchip,mcp4232-502"
> +			"microchip,mcp4232-103"
> +			"microchip,mcp4232-503"
> +			"microchip,mcp4232-104"
> +			"microchip,mcp4241-502"
> +			"microchip,mcp4241-103"
> +			"microchip,mcp4241-503"
> +			"microchip,mcp4241-104"
> +			"microchip,mcp4242-502"
> +			"microchip,mcp4242-103"
> +			"microchip,mcp4242-503"
> +			"microchip,mcp4242-104"
> +			"microchip,mcp4251-502"
> +			"microchip,mcp4251-103"
> +			"microchip,mcp4251-503"
> +			"microchip,mcp4251-104"
> +			"microchip,mcp4252-502"
> +			"microchip,mcp4252-103"
> +			"microchip,mcp4252-503"
> +			"microchip,mcp4252-104"
> +			"microchip,mcp4261-502"
> +			"microchip,mcp4261-103"
> +			"microchip,mcp4261-503"
> +			"microchip,mcp4261-104"
> +			"microchip,mcp4262-502"
> +			"microchip,mcp4262-103"
> +			"microchip,mcp4262-503"
> +			"microchip,mcp4262-104"
> +
> +Example:
> +mcp4131: mcp4131@0 {
> +	compatible = "mcp4131-502";
> +	reg = <0>;
> +	spi-max-frequency = <500000>;
> +};
> diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
> index fd75db7..5ef181a 100644
> --- a/drivers/iio/potentiometer/Kconfig
> +++ b/drivers/iio/potentiometer/Kconfig
> @@ -5,6 +5,24 @@
>  
>  menu "Digital potentiometers"
>  
> +config MCP4131
> +	tristate "Microchip MCP413X/414X/415X/416X/423X/424X/425X/426X Digital Potentiometer driver"
> +	depends on SPI
> +	help
> +	  Say yes here to build support for the Microchip
> +	  MCP4131, MCP4132,
> +	  MCP4141, MCP4142,
> +	  MCP4151, MCP4152,
> +	  MCP4161, MCP4162,
> +	  MCP4231, MCP4232,
> +	  MCP4241, MCP4242,
> +	  MCP4251, MCP4252,
> +	  MCP4261, MCP4262,
> +	  digital potentiomenter chips.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called mcp4131.
> +
>  config MCP4531
>  	tristate "Microchip MCP45xx/MCP46xx Digital Potentiometer driver"
>  	depends on I2C
> diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
> index 8afe492..cd5c80b 100644
> --- a/drivers/iio/potentiometer/Makefile
> +++ b/drivers/iio/potentiometer/Makefile
> @@ -3,4 +3,5 @@
>  #
>  
>  # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_MCP4131) += mcp4131.o
>  obj-$(CONFIG_MCP4531) += mcp4531.o
> diff --git a/drivers/iio/potentiometer/mcp4131.c b/drivers/iio/potentiometer/mcp4131.c
> new file mode 100644
> index 0000000..4e7e2c6
> --- /dev/null
> +++ b/drivers/iio/potentiometer/mcp4131.c
> @@ -0,0 +1,494 @@
> +/*
> + * Industrial I/O driver for Microchip digital potentiometers
> + *
> + * Copyright (c) 2016 Slawomir Stepien
> + * Based on: Peter Rosin's code from mcp4531.c
> + *
> + * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22060b.pdf
> + *
> + * DEVID	#Wipers	#Positions	Resistor Opts (kOhm)
> + * mcp4131	1	129		5, 10, 50, 100
> + * mcp4132	1	129		5, 10, 50, 100
> + * mcp4141	1	129		5, 10, 50, 100
> + * mcp4142	1	129		5, 10, 50, 100
> + * mcp4151	1	257		5, 10, 50, 100
> + * mcp4152	1	257		5, 10, 50, 100
> + * mcp4161	1	257		5, 10, 50, 100
> + * mcp4162	1	257		5, 10, 50, 100
> + * mcp4231	2	129		5, 10, 50, 100
> + * mcp4232	2	129		5, 10, 50, 100
> + * mcp4241	2	129		5, 10, 50, 100
> + * mcp4242	2	129		5, 10, 50, 100
> + * mcp4251	2	257		5, 10, 50, 100
> + * mcp4252	2	257		5, 10, 50, 100
> + * mcp4261	2	257		5, 10, 50, 100
> + * mcp4262	2	257		5, 10, 50, 100
> + *
> + * 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.
> + */
> +
> +/*
> + * TODO:
> + * 1. Write wiper setting to EEPROM for EEPROM capable models.
> + */
> +
> +#include <linux/cache.h>
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/types.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/spi/spi.h>
> +
> +#define MCP4131_WRITE		(0x00 << 2)
> +#define MCP4131_READ		(0x03 << 2)
> +
> +#define MCP4131_WIPER_SHIFT	4
> +#define MCP4131_CMDERR(r)	((r[0]) & 0x02)
> +#define MCP4131_RAW(r)		((r[0]) == 0xff ? 0x100 : (r[1]))
> +
> +struct mcp4131_cfg {
> +	int wipers;
> +	int max_pos;
> +	int kohms;
> +};
> +
> +enum mcp4131_type {
> +	MCP413x_502 = 0,
> +	MCP413x_103,
> +	MCP413x_503,
> +	MCP413x_104,
> +	MCP414x_502,
> +	MCP414x_103,
> +	MCP414x_503,
> +	MCP414x_104,
> +	MCP415x_502,
> +	MCP415x_103,
> +	MCP415x_503,
> +	MCP415x_104,
> +	MCP416x_502,
> +	MCP416x_103,
> +	MCP416x_503,
> +	MCP416x_104,
> +	MCP423x_502,
> +	MCP423x_103,
> +	MCP423x_503,
> +	MCP423x_104,
> +	MCP424x_502,
> +	MCP424x_103,
> +	MCP424x_503,
> +	MCP424x_104,
> +	MCP425x_502,
> +	MCP425x_103,
> +	MCP425x_503,
> +	MCP425x_104,
> +	MCP426x_502,
> +	MCP426x_103,
> +	MCP426x_503,
> +	MCP426x_104,
> +};
> +
> +static const struct mcp4131_cfg mcp4131_cfg[] = {
> +	[MCP413x_502] = { .wipers = 1, .max_pos = 128, .kohms =   5, },
> +	[MCP413x_103] = { .wipers = 1, .max_pos = 128, .kohms =  10, },
> +	[MCP413x_503] = { .wipers = 1, .max_pos = 128, .kohms =  50, },
> +	[MCP413x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
> +	[MCP414x_502] = { .wipers = 1, .max_pos = 128, .kohms =   5, },
> +	[MCP414x_103] = { .wipers = 1, .max_pos = 128, .kohms =  10, },
> +	[MCP414x_503] = { .wipers = 1, .max_pos = 128, .kohms =  50, },
> +	[MCP414x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
> +	[MCP415x_502] = { .wipers = 1, .max_pos = 256, .kohms =   5, },
> +	[MCP415x_103] = { .wipers = 1, .max_pos = 256, .kohms =  10, },
> +	[MCP415x_503] = { .wipers = 1, .max_pos = 256, .kohms =  50, },
> +	[MCP415x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
> +	[MCP416x_502] = { .wipers = 1, .max_pos = 256, .kohms =   5, },
> +	[MCP416x_103] = { .wipers = 1, .max_pos = 256, .kohms =  10, },
> +	[MCP416x_503] = { .wipers = 1, .max_pos = 256, .kohms =  50, },
> +	[MCP416x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
> +	[MCP423x_502] = { .wipers = 2, .max_pos = 128, .kohms =   5, },
> +	[MCP423x_103] = { .wipers = 2, .max_pos = 128, .kohms =  10, },
> +	[MCP423x_503] = { .wipers = 2, .max_pos = 128, .kohms =  50, },
> +	[MCP423x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
> +	[MCP424x_502] = { .wipers = 2, .max_pos = 128, .kohms =   5, },
> +	[MCP424x_103] = { .wipers = 2, .max_pos = 128, .kohms =  10, },
> +	[MCP424x_503] = { .wipers = 2, .max_pos = 128, .kohms =  50, },
> +	[MCP424x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
> +	[MCP425x_502] = { .wipers = 2, .max_pos = 256, .kohms =   5, },
> +	[MCP425x_103] = { .wipers = 2, .max_pos = 256, .kohms =  10, },
> +	[MCP425x_503] = { .wipers = 2, .max_pos = 256, .kohms =  50, },
> +	[MCP425x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
> +	[MCP426x_502] = { .wipers = 2, .max_pos = 256, .kohms =   5, },
> +	[MCP426x_103] = { .wipers = 2, .max_pos = 256, .kohms =  10, },
> +	[MCP426x_503] = { .wipers = 2, .max_pos = 256, .kohms =  50, },
> +	[MCP426x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
> +};
> +
> +struct mcp4131_data {
> +	struct spi_device *spi;
> +	const struct mcp4131_cfg *cfg;
> +	struct mutex lock;
> +	u8 buf[2] ____cacheline_aligned;
> +};
> +
> +#define MCP4131_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 mcp4131_channels[] = {
> +	MCP4131_CHANNEL(0),
> +	MCP4131_CHANNEL(1),
> +};
> +
> +static int mcp4131_read(struct spi_device *spi, void *buf, size_t len)
> +{
> +	struct spi_transfer t = {
> +		.tx_buf = buf, /* We need to send addr, cmd and 12 bits */
> +		.rx_buf	= buf,
> +		.len = len,
> +	};
> +	struct spi_message m;
> +
> +	spi_message_init(&m);
> +	spi_message_add_tail(&t, &m);
> +
> +	return spi_sync(spi, &m);
> +}
> +
> +static int mcp4131_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	int err;
> +	struct mcp4131_data *data = iio_priv(indio_dev);
> +	int address = chan->channel;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->lock);
> +
> +		data->buf[0] = (address << MCP4131_WIPER_SHIFT) | MCP4131_READ;
> +		data->buf[1] = 0;
> +
> +		err = mcp4131_read(data->spi, data->buf, 2);
> +		if (err) {
> +			mutex_unlock(&data->lock);
> +			return err;
> +		}
> +
> +		/* Error, bad address/command combination */
> +		if (!MCP4131_CMDERR(data->buf)) {
> +			mutex_unlock(&data->lock);
> +			return -EIO;
> +		}
> +
> +		*val = MCP4131_RAW(data->buf);
> +		mutex_unlock(&data->lock);
> +
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 1000 * data->cfg->kohms;
> +		*val2 = data->cfg->max_pos;
> +		return IIO_VAL_FRACTIONAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int mcp4131_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long mask)
> +{
> +	int err;
> +	struct mcp4131_data *data = iio_priv(indio_dev);
> +	int address = chan->channel << MCP4131_WIPER_SHIFT;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (val > data->cfg->max_pos || val < 0)
> +			return -EINVAL;
> +		break;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	mutex_lock(&data->lock);
> +
> +	data->buf[0] = address << MCP4131_WIPER_SHIFT;
> +	data->buf[0] |= MCP4131_WRITE | (val >> 8);
> +	data->buf[1] = val & 0xFF; /* 8 bits here */
> +
> +	err = spi_write(data->spi, data->buf, 2);
> +	mutex_unlock(&data->lock);
> +
> +	return err;
> +}
> +
> +static const struct iio_info mcp4131_info = {
> +	.read_raw = mcp4131_read_raw,
> +	.write_raw = mcp4131_write_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int mcp4131_probe(struct spi_device *spi)
> +{
> +	int err;
> +	struct device *dev = &spi->dev;
> +	unsigned long devid = spi_get_device_id(spi)->driver_data;
> +	struct mcp4131_data *data;
> +	struct iio_dev *indio_dev;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	spi_set_drvdata(spi, indio_dev);
> +	data->spi = spi;
> +	data->cfg = &mcp4131_cfg[devid];
> +
> +	mutex_init(&data->lock);
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->info = &mcp4131_info;
> +	indio_dev->channels = mcp4131_channels;
> +	indio_dev->num_channels = data->cfg->wipers;
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +
> +	err = devm_iio_device_register(dev, indio_dev);
> +	if (err) {
> +		dev_info(&spi->dev, "Unable to register %s\n", indio_dev->name);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +#if defined(CONFIG_OF)
> +static const struct of_device_id mcp4131_dt_ids[] = {
> +	{ .compatible = "microchip,mcp4131-502",
> +		.data = &mcp4131_cfg[MCP413x_502] },
> +	{ .compatible = "microchip,mcp4131-103",
> +		.data = &mcp4131_cfg[MCP413x_103] },
> +	{ .compatible = "microchip,mcp4131-503",
> +		.data = &mcp4131_cfg[MCP413x_503] },
> +	{ .compatible = "microchip,mcp4131-104",
> +		.data = &mcp4131_cfg[MCP413x_104] },
> +	{ .compatible = "microchip,mcp4132-502",
> +		.data = &mcp4131_cfg[MCP413x_502] },
> +	{ .compatible = "microchip,mcp4132-103",
> +		.data = &mcp4131_cfg[MCP413x_103] },
> +	{ .compatible = "microchip,mcp4132-503",
> +		.data = &mcp4131_cfg[MCP413x_503] },
> +	{ .compatible = "microchip,mcp4132-104",
> +		.data = &mcp4131_cfg[MCP413x_104] },
> +	{ .compatible = "microchip,mcp4141-502",
> +		.data = &mcp4131_cfg[MCP414x_502] },
> +	{ .compatible = "microchip,mcp4141-103",
> +		.data = &mcp4131_cfg[MCP414x_103] },
> +	{ .compatible = "microchip,mcp4141-503",
> +		.data = &mcp4131_cfg[MCP414x_503] },
> +	{ .compatible = "microchip,mcp4141-104",
> +		.data = &mcp4131_cfg[MCP414x_104] },
> +	{ .compatible = "microchip,mcp4142-502",
> +		.data = &mcp4131_cfg[MCP414x_502] },
> +	{ .compatible = "microchip,mcp4142-103",
> +		.data = &mcp4131_cfg[MCP414x_103] },
> +	{ .compatible = "microchip,mcp4142-503",
> +		.data = &mcp4131_cfg[MCP414x_503] },
> +	{ .compatible = "microchip,mcp4142-104",
> +		.data = &mcp4131_cfg[MCP414x_104] },
> +	{ .compatible = "microchip,mcp4151-502",
> +		.data = &mcp4131_cfg[MCP415x_502] },
> +	{ .compatible = "microchip,mcp4151-103",
> +		.data = &mcp4131_cfg[MCP415x_103] },
> +	{ .compatible = "microchip,mcp4151-503",
> +		.data = &mcp4131_cfg[MCP415x_503] },
> +	{ .compatible = "microchip,mcp4151-104",
> +		.data = &mcp4131_cfg[MCP415x_104] },
> +	{ .compatible = "microchip,mcp4152-502",
> +		.data = &mcp4131_cfg[MCP415x_502] },
> +	{ .compatible = "microchip,mcp4152-103",
> +		.data = &mcp4131_cfg[MCP415x_103] },
> +	{ .compatible = "microchip,mcp4152-503",
> +		.data = &mcp4131_cfg[MCP415x_503] },
> +	{ .compatible = "microchip,mcp4152-104",
> +		.data = &mcp4131_cfg[MCP415x_104] },
> +	{ .compatible = "microchip,mcp4161-502",
> +		.data = &mcp4131_cfg[MCP416x_502] },
> +	{ .compatible = "microchip,mcp4161-103",
> +		.data = &mcp4131_cfg[MCP416x_103] },
> +	{ .compatible = "microchip,mcp4161-503",
> +		.data = &mcp4131_cfg[MCP416x_503] },
> +	{ .compatible = "microchip,mcp4161-104",
> +		.data = &mcp4131_cfg[MCP416x_104] },
> +	{ .compatible = "microchip,mcp4162-502",
> +		.data = &mcp4131_cfg[MCP416x_502] },
> +	{ .compatible = "microchip,mcp4162-103",
> +		.data = &mcp4131_cfg[MCP416x_103] },
> +	{ .compatible = "microchip,mcp4162-503",
> +		.data = &mcp4131_cfg[MCP416x_503] },
> +	{ .compatible = "microchip,mcp4162-104",
> +		.data = &mcp4131_cfg[MCP416x_104] },
> +	{ .compatible = "microchip,mcp4231-502",
> +		.data = &mcp4131_cfg[MCP423x_502] },
> +	{ .compatible = "microchip,mcp4231-103",
> +		.data = &mcp4131_cfg[MCP423x_103] },
> +	{ .compatible = "microchip,mcp4231-503",
> +		.data = &mcp4131_cfg[MCP423x_503] },
> +	{ .compatible = "microchip,mcp4231-104",
> +		.data = &mcp4131_cfg[MCP423x_104] },
> +	{ .compatible = "microchip,mcp4232-502",
> +		.data = &mcp4131_cfg[MCP423x_502] },
> +	{ .compatible = "microchip,mcp4232-103",
> +		.data = &mcp4131_cfg[MCP423x_103] },
> +	{ .compatible = "microchip,mcp4232-503",
> +		.data = &mcp4131_cfg[MCP423x_503] },
> +	{ .compatible = "microchip,mcp4232-104",
> +		.data = &mcp4131_cfg[MCP423x_104] },
> +	{ .compatible = "microchip,mcp4241-502",
> +		.data = &mcp4131_cfg[MCP424x_502] },
> +	{ .compatible = "microchip,mcp4241-103",
> +		.data = &mcp4131_cfg[MCP424x_103] },
> +	{ .compatible = "microchip,mcp4241-503",
> +		.data = &mcp4131_cfg[MCP424x_503] },
> +	{ .compatible = "microchip,mcp4241-104",
> +		.data = &mcp4131_cfg[MCP424x_104] },
> +	{ .compatible = "microchip,mcp4242-502",
> +		.data = &mcp4131_cfg[MCP424x_502] },
> +	{ .compatible = "microchip,mcp4242-103",
> +		.data = &mcp4131_cfg[MCP424x_103] },
> +	{ .compatible = "microchip,mcp4242-503",
> +		.data = &mcp4131_cfg[MCP424x_503] },
> +	{ .compatible = "microchip,mcp4242-104",
> +		.data = &mcp4131_cfg[MCP424x_104] },
> +	{ .compatible = "microchip,mcp4251-502",
> +		.data = &mcp4131_cfg[MCP425x_502] },
> +	{ .compatible = "microchip,mcp4251-103",
> +		.data = &mcp4131_cfg[MCP425x_103] },
> +	{ .compatible = "microchip,mcp4251-503",
> +		.data = &mcp4131_cfg[MCP425x_503] },
> +	{ .compatible = "microchip,mcp4251-104",
> +		.data = &mcp4131_cfg[MCP425x_104] },
> +	{ .compatible = "microchip,mcp4252-502",
> +		.data = &mcp4131_cfg[MCP425x_502] },
> +	{ .compatible = "microchip,mcp4252-103",
> +		.data = &mcp4131_cfg[MCP425x_103] },
> +	{ .compatible = "microchip,mcp4252-503",
> +		.data = &mcp4131_cfg[MCP425x_503] },
> +	{ .compatible = "microchip,mcp4252-104",
> +		.data = &mcp4131_cfg[MCP425x_104] },
> +	{ .compatible = "microchip,mcp4261-502",
> +		.data = &mcp4131_cfg[MCP426x_502] },
> +	{ .compatible = "microchip,mcp4261-103",
> +		.data = &mcp4131_cfg[MCP426x_103] },
> +	{ .compatible = "microchip,mcp4261-503",
> +		.data = &mcp4131_cfg[MCP426x_503] },
> +	{ .compatible = "microchip,mcp4261-104",
> +		.data = &mcp4131_cfg[MCP426x_104] },
> +	{ .compatible = "microchip,mcp4262-502",
> +		.data = &mcp4131_cfg[MCP426x_502] },
> +	{ .compatible = "microchip,mcp4262-103",
> +		.data = &mcp4131_cfg[MCP426x_103] },
> +	{ .compatible = "microchip,mcp4262-503",
> +		.data = &mcp4131_cfg[MCP426x_503] },
> +	{ .compatible = "microchip,mcp4262-104",
> +		.data = &mcp4131_cfg[MCP426x_104] },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mcp4131_dt_ids);
> +#endif /* CONFIG_OF */
> +
> +static const struct spi_device_id mcp4131_id[] = {
> +	{ "mcp4131-502", MCP413x_502 },
> +	{ "mcp4131-103", MCP413x_103 },
> +	{ "mcp4131-503", MCP413x_503 },
> +	{ "mcp4131-104", MCP413x_104 },
> +	{ "mcp4132-502", MCP413x_502 },
> +	{ "mcp4132-103", MCP413x_103 },
> +	{ "mcp4132-503", MCP413x_503 },
> +	{ "mcp4132-104", MCP413x_104 },
> +	{ "mcp4141-502", MCP414x_502 },
> +	{ "mcp4141-103", MCP414x_103 },
> +	{ "mcp4141-503", MCP414x_503 },
> +	{ "mcp4141-104", MCP414x_104 },
> +	{ "mcp4142-502", MCP414x_502 },
> +	{ "mcp4142-103", MCP414x_103 },
> +	{ "mcp4142-503", MCP414x_503 },
> +	{ "mcp4142-104", MCP414x_104 },
> +	{ "mcp4151-502", MCP415x_502 },
> +	{ "mcp4151-103", MCP415x_103 },
> +	{ "mcp4151-503", MCP415x_503 },
> +	{ "mcp4151-104", MCP415x_104 },
> +	{ "mcp4152-502", MCP415x_502 },
> +	{ "mcp4152-103", MCP415x_103 },
> +	{ "mcp4152-503", MCP415x_503 },
> +	{ "mcp4152-104", MCP415x_104 },
> +	{ "mcp4161-502", MCP416x_502 },
> +	{ "mcp4161-103", MCP416x_103 },
> +	{ "mcp4161-503", MCP416x_503 },
> +	{ "mcp4161-104", MCP416x_104 },
> +	{ "mcp4162-502", MCP416x_502 },
> +	{ "mcp4162-103", MCP416x_103 },
> +	{ "mcp4162-503", MCP416x_503 },
> +	{ "mcp4162-104", MCP416x_104 },
> +	{ "mcp4231-502", MCP423x_502 },
> +	{ "mcp4231-103", MCP423x_103 },
> +	{ "mcp4231-503", MCP423x_503 },
> +	{ "mcp4231-104", MCP423x_104 },
> +	{ "mcp4232-502", MCP423x_502 },
> +	{ "mcp4232-103", MCP423x_103 },
> +	{ "mcp4232-503", MCP423x_503 },
> +	{ "mcp4232-104", MCP423x_104 },
> +	{ "mcp4241-502", MCP424x_502 },
> +	{ "mcp4241-103", MCP424x_103 },
> +	{ "mcp4241-503", MCP424x_503 },
> +	{ "mcp4241-104", MCP424x_104 },
> +	{ "mcp4242-502", MCP424x_502 },
> +	{ "mcp4242-103", MCP424x_103 },
> +	{ "mcp4242-503", MCP424x_503 },
> +	{ "mcp4242-104", MCP424x_104 },
> +	{ "mcp4251-502", MCP425x_502 },
> +	{ "mcp4251-103", MCP425x_103 },
> +	{ "mcp4251-503", MCP425x_503 },
> +	{ "mcp4251-104", MCP425x_104 },
> +	{ "mcp4252-502", MCP425x_502 },
> +	{ "mcp4252-103", MCP425x_103 },
> +	{ "mcp4252-503", MCP425x_503 },
> +	{ "mcp4252-104", MCP425x_104 },
> +	{ "mcp4261-502", MCP426x_502 },
> +	{ "mcp4261-103", MCP426x_103 },
> +	{ "mcp4261-503", MCP426x_503 },
> +	{ "mcp4261-104", MCP426x_104 },
> +	{ "mcp4262-502", MCP426x_502 },
> +	{ "mcp4262-103", MCP426x_103 },
> +	{ "mcp4262-503", MCP426x_503 },
> +	{ "mcp4262-104", MCP426x_104 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(spi, mcp4131_id);
> +
> +static struct spi_driver mcp4131_driver = {
> +	.driver = {
> +		.name	= "mcp4131",
> +		.of_match_table = of_match_ptr(mcp4131_dt_ids),
> +	},
> +	.probe		= mcp4131_probe,
> +	.id_table	= mcp4131_id,
> +};
> +
> +module_spi_driver(mcp4131_driver);
> +
> +MODULE_AUTHOR("Slawomir Stepien <sst@poczta.fm>");
> +MODULE_DESCRIPTION("MCP4131 digital potentiometer");
> +MODULE_LICENSE("GPL v2");
>