From: Peter Rosin <peda@xxxxxxxxxx> Add support for Microchip digital potentiometers and rheostats MCP4531, MCP4532, MCP4551, MCP4552 MCP4631, MCP4632, MCP4651, MCP4652 These are either single (45xx) or dual (46xx) wipers with either 129 (4x3x) or 257 (4x5x) steps, and configured either as potentiometers (4xx1) or rheostats (4xx2). Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> --- MAINTAINERS | 6 ++ drivers/iio/Kconfig | 1 + drivers/iio/Makefile | 1 + drivers/iio/potentiometer/Kconfig | 20 ++++ drivers/iio/potentiometer/Makefile | 6 ++ drivers/iio/potentiometer/mcp4531.c | 200 +++++++++++++++++++++++++++++++++++ 6 files changed, 234 insertions(+) create mode 100644 drivers/iio/potentiometer/Kconfig create mode 100644 drivers/iio/potentiometer/Makefile create mode 100644 drivers/iio/potentiometer/mcp4531.c diff --git a/MAINTAINERS b/MAINTAINERS index b60e2b2369d2..27862156c7a7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6600,6 +6600,12 @@ W: http://linuxtv.org S: Maintained F: drivers/media/radio/radio-maxiradio* +MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVER +M: Peter Rosin <peda@xxxxxxxxxx> +L: linux-iio@xxxxxxxxxxxxxxx +S: Maintained +F: drivers/iio/potentiometer/mcp4531.c + MEDIA DRIVERS FOR RENESAS - VSP1 M: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> L: linux-media@xxxxxxxxxxxxxxx diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 4011effe4c05..7cc87f322655 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -73,6 +73,7 @@ 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" diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index 698afc2d17ce..121c814e366b 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -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/ diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig new file mode 100644 index 000000000000..fd75db73e582 --- /dev/null +++ b/drivers/iio/potentiometer/Kconfig @@ -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 diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile new file mode 100644 index 000000000000..8afe49227012 --- /dev/null +++ b/drivers/iio/potentiometer/Makefile @@ -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 diff --git a/drivers/iio/potentiometer/mcp4531.c b/drivers/iio/potentiometer/mcp4531.c new file mode 100644 index 000000000000..11039b215080 --- /dev/null +++ b/drivers/iio/potentiometer/mcp4531.c @@ -0,0 +1,200 @@ +/* + * Industrial I/O driver for Microchip digital potentiometers + * Copyright (c) 2015 Axentia Technologies AB + * Author: Peter Rosin <peda@xxxxxxxxxx> + * + * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf + * + * DEVID #Wipers #Positions Resistor Options (kOhm) + * mcp4531 1 129 5, 10, 50, 100 + * mcp4532 1 129 5, 10, 50, 100 + * mcp4551 1 257 5, 10, 50, 100 + * mcp4552 1 257 5, 10, 50, 100 + * mcp4631 2 129 5, 10, 50, 100 + * mcp4632 2 129 5, 10, 50, 100 + * mcp4651 2 257 5, 10, 50, 100 + * mcp4652 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. + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/err.h> + +#include <linux/iio/iio.h> + + +#define MCP4531_CONF(wipers, max_pos, uid) \ + ((((wipers) & 0xf) << 10) | \ + (((max_pos) & 0xf) << 6) | \ + ((uid) & 0x3f)) + +#define MCP4531_UID(conf) ((conf) & 0x3f) +#define MCP4531_MAX_POS(conf) (((conf) >> 6) & 0xf) +#define MCP4531_WIPERS(conf) (((conf) >> 10) & 0xf) + +enum mcp4531_devid { + MCP4531_ID = MCP4531_CONF(1, 7, 0), + MCP4532_ID = MCP4531_CONF(1, 7, 1), + MCP4551_ID = MCP4531_CONF(1, 8, 2), + MCP4552_ID = MCP4531_CONF(1, 8, 3), + MCP4631_ID = MCP4531_CONF(2, 7, 4), + MCP4632_ID = MCP4531_CONF(2, 7, 5), + MCP4651_ID = MCP4531_CONF(2, 8, 6), + MCP4652_ID = MCP4531_CONF(2, 8, 7), +}; + +struct mcp4531_data { + struct i2c_client *client; + unsigned int max_pos; + unsigned long devid; +}; + +static const struct iio_chan_spec mcp4531_channels[] = { + { + .type = IIO_RESISTANCE, + .indexed = 1, + .output = 1, + .channel = 0, + .address = 0 << 4, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, { + .type = IIO_RESISTANCE, + .indexed = 1, + .output = 1, + .channel = 1, + .address = 1 << 4, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + } +}; + +static int mcp4531_get_value(struct iio_dev *indio_dev, + int address, int *val) +{ + struct mcp4531_data *data = iio_priv(indio_dev); + s32 value; + + value = i2c_smbus_read_word_data(data->client, address | 0xc); + if (value < 0) + return value; + *val = ((value >> 8) & 0xff) | ((value & 0xff) << 8); + return 0; +} + +static int mcp4531_set_value(struct iio_dev *indio_dev, + int address, int val) +{ + struct mcp4531_data *data = iio_priv(indio_dev); + + if (val >= data->max_pos || val < 0) + return -EINVAL; + + return i2c_smbus_write_byte_data(data->client, + address | (val >> 8), + val & 0xff); +} + +static int mcp4531_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int err; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + err = mcp4531_get_value(indio_dev, chan->address, val); + if (err < 0) + return err; + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static int mcp4531_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_RAW: + return mcp4531_set_value(indio_dev, chan->address, val); + } + + return -EINVAL; +} + +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(&client->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; + + data->max_pos = (1 << MCP4531_MAX_POS(devid)) + 1; + + indio_dev->dev.parent = dev; + indio_dev->info = &mcp4531_info; + indio_dev->channels = mcp4531_channels; + indio_dev->num_channels = MCP4531_WIPERS(devid); + indio_dev->name = client->name; + + return iio_device_register(indio_dev); +} + +static int mcp4531_remove(struct i2c_client *client) +{ + iio_device_unregister(i2c_get_clientdata(client)); + return 0; +} + +static const struct i2c_device_id mcp4531_id[] = { + { "mcp4531", MCP4531_ID }, + { "mcp4532", MCP4532_ID }, + { "mcp4551", MCP4551_ID }, + { "mcp4552", MCP4552_ID }, + { "mcp4631", MCP4631_ID }, + { "mcp4632", MCP4632_ID }, + { "mcp4651", MCP4651_ID }, + { "mcp4652", MCP4652_ID }, + {} +}; +MODULE_DEVICE_TABLE(i2c, mcp4531_id); + +static struct i2c_driver mcp4531_driver = { + .driver = { + .name = "mcp4531", + }, + .probe = mcp4531_probe, + .remove = mcp4531_remove, + .id_table = mcp4531_id, +}; + +module_i2c_driver(mcp4531_driver); + +MODULE_AUTHOR("Peter Rosin <peda@xxxxxxxxxx>"); +MODULE_DESCRIPTION("MCP4531 digital potentiometer"); +MODULE_LICENSE("GPL"); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
