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iio: mcp4531: Driver for Microchip digital potentiometers 

Add support for Microchip digital potentiometers and rheostats
	MCP4531, MCP4532, MCP4551, MCP4552
	MCP4631, MCP4632, MCP4651, MCP4652

DEVICE   Wipers  Steps  Resistor Opts (kOhm)  i2c address
MCP4531  1       129    5, 10, 50, 100        010111x
MCP4532  1       129    5, 10, 50, 100        01011xx
MCP4551  1       257    5, 10, 50, 100        010111x
MCP4552  1       257    5, 10, 50, 100        01011xx
MCP4631  2       129    5, 10, 50, 100        0101xxx
MCP4632  2       129    5, 10, 50, 100        01011xx
MCP4651  2       257    5, 10, 50, 100        0101xxx
MCP4652  2       257    5, 10, 50, 100        01011xx

Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Peter Rosin 2015-09-23 16:26:23 +02:00 committed by Jonathan Cameron
parent b15aef8d5b
commit c05dc2cce7
6 changed files with 265 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
MAINTAINERS
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@ -6682,6 +6682,12 @@ W: http://linuxtv.org
S: Maintained
F: drivers/media/radio/radio-maxiradio*
MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVER
M: Peter Rosin <peda@axentia.se>
L: linux-iio@vger.kernel.org
S: Maintained
F: drivers/iio/potentiometer/mcp4531.c
MEDIA DRIVERS FOR RENESAS - VSP1
M: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
L: linux-media@vger.kernel.org

1
drivers/iio/Kconfig
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@ -60,6 +60,7 @@ source "drivers/iio/orientation/Kconfig"
if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER
source "drivers/iio/potentiometer/Kconfig"
source "drivers/iio/pressure/Kconfig"
source "drivers/iio/proximity/Kconfig"
source "drivers/iio/temperature/Kconfig"

1
drivers/iio/Makefile
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@ -23,6 +23,7 @@ obj-y += imu/
obj-y += light/
obj-y += magnetometer/
obj-y += orientation/
obj-y += potentiometer/
obj-y += pressure/
obj-y += proximity/
obj-y += temperature/

20
drivers/iio/potentiometer/Kconfig Normal file
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@ -0,0 +1,20 @@
#
# Potentiometer drivers
#
# When adding new entries keep the list in alphabetical order
menu "Digital potentiometers"
config MCP4531
tristate "Microchip MCP45xx/MCP46xx Digital Potentiometer driver"
depends on I2C
help
Say yes here to build support for the Microchip
MCP4531, MCP4532, MCP4551, MCP4552,
MCP4631, MCP4632, MCP4651, MCP4652
digital potentiomenter chips.
To compile this driver as a module, choose M here: the
module will be called mcp4531.
endmenu

6
drivers/iio/potentiometer/Makefile Normal file
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@ -0,0 +1,6 @@
#
# Makefile for industrial I/O potentiometer drivers
#
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_MCP4531) += mcp4531.o

231
drivers/iio/potentiometer/mcp4531.c Normal file
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@ -0,0 +1,231 @@
/*
* Industrial I/O driver for Microchip digital potentiometers
* Copyright (c) 2015 Axentia Technologies AB
* Author: Peter Rosin <peda@axentia.se>
*
* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
*
* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
* mcp4531 1 129 5, 10, 50, 100 010111x
* mcp4532 1 129 5, 10, 50, 100 01011xx
* mcp4551 1 257 5, 10, 50, 100 010111x
* mcp4552 1 257 5, 10, 50, 100 01011xx
* mcp4631 2 129 5, 10, 50, 100 0101xxx
* mcp4632 2 129 5, 10, 50, 100 01011xx
* mcp4651 2 257 5, 10, 50, 100 0101xxx
* mcp4652 2 257 5, 10, 50, 100 01011xx
*
* 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/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
struct mcp4531_cfg {
int wipers;
int max_pos;
int kohms;
};
enum mcp4531_type {
MCP453x_502,
MCP453x_103,
MCP453x_503,
MCP453x_104,
MCP455x_502,
MCP455x_103,
MCP455x_503,
MCP455x_104,
MCP463x_502,
MCP463x_103,
MCP463x_503,
MCP463x_104,
MCP465x_502,
MCP465x_103,
MCP465x_503,
MCP465x_104,
};
static const struct mcp4531_cfg mcp4531_cfg[] = {
[MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, },
[MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
[MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, },
[MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
[MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, },
[MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, },
[MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
[MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
[MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, },
[MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, },
[MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, },
[MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
[MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, },
[MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, },
[MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, },
[MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
};
#define MCP4531_WRITE (0 << 2)
#define MCP4531_INCR (1 << 2)
#define MCP4531_DECR (2 << 2)
#define MCP4531_READ (3 << 2)
#define MCP4531_WIPER_SHIFT (4)
struct mcp4531_data {
struct i2c_client *client;
unsigned long devid;
};
#define MCP4531_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 mcp4531_channels[] = {
MCP4531_CHANNEL(0),
MCP4531_CHANNEL(1),
};
static int mcp4531_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mcp4531_data *data = iio_priv(indio_dev);
int address = chan->channel << MCP4531_WIPER_SHIFT;
s32 ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_word_swapped(data->client,
MCP4531_READ | address);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 1000 * mcp4531_cfg[data->devid].kohms;
*val2 = mcp4531_cfg[data->devid].max_pos;
return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
}
static int mcp4531_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct mcp4531_data *data = iio_priv(indio_dev);
int address = chan->channel << MCP4531_WIPER_SHIFT;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > mcp4531_cfg[data->devid].max_pos || val < 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
return i2c_smbus_write_byte_data(data->client,
MCP4531_WRITE | address | (val >> 8),
val & 0xff);
}
static const struct iio_info mcp4531_info = {
.read_raw = mcp4531_read_raw,
.write_raw = mcp4531_write_raw,
.driver_module = THIS_MODULE,
};
static int mcp4531_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
unsigned long devid = id->driver_data;
struct mcp4531_data *data;
struct iio_dev *indio_dev;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_err(dev, "SMBUS Word Data not supported\n");
return -EIO;
}
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;
data->devid = devid;
indio_dev->dev.parent = dev;
indio_dev->info = &mcp4531_info;
indio_dev->channels = mcp4531_channels;
indio_dev->num_channels = mcp4531_cfg[devid].wipers;
indio_dev->name = client->name;
return devm_iio_device_register(dev, indio_dev);
}
static const struct i2c_device_id mcp4531_id[] = {
{ "mcp4531-502", MCP453x_502 },
{ "mcp4531-103", MCP453x_103 },
{ "mcp4531-503", MCP453x_503 },
{ "mcp4531-104", MCP453x_104 },
{ "mcp4532-502", MCP453x_502 },
{ "mcp4532-103", MCP453x_103 },
{ "mcp4532-503", MCP453x_503 },
{ "mcp4532-104", MCP453x_104 },
{ "mcp4551-502", MCP455x_502 },
{ "mcp4551-103", MCP455x_103 },
{ "mcp4551-503", MCP455x_503 },
{ "mcp4551-104", MCP455x_104 },
{ "mcp4552-502", MCP455x_502 },
{ "mcp4552-103", MCP455x_103 },
{ "mcp4552-503", MCP455x_503 },
{ "mcp4552-104", MCP455x_104 },
{ "mcp4631-502", MCP463x_502 },
{ "mcp4631-103", MCP463x_103 },
{ "mcp4631-503", MCP463x_503 },
{ "mcp4631-104", MCP463x_104 },
{ "mcp4632-502", MCP463x_502 },
{ "mcp4632-103", MCP463x_103 },
{ "mcp4632-503", MCP463x_503 },
{ "mcp4632-104", MCP463x_104 },
{ "mcp4651-502", MCP465x_502 },
{ "mcp4651-103", MCP465x_103 },
{ "mcp4651-503", MCP465x_503 },
{ "mcp4651-104", MCP465x_104 },
{ "mcp4652-502", MCP465x_502 },
{ "mcp4652-103", MCP465x_103 },
{ "mcp4652-503", MCP465x_503 },
{ "mcp4652-104", MCP465x_104 },
{}
};
MODULE_DEVICE_TABLE(i2c, mcp4531_id);
static struct i2c_driver mcp4531_driver = {
.driver = {
.name = "mcp4531",
},
.probe = mcp4531_probe,
.id_table = mcp4531_id,
};
module_i2c_driver(mcp4531_driver);
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
MODULE_DESCRIPTION("MCP4531 digital potentiometer");
MODULE_LICENSE("GPL");