Add support for Microchip digital potentiometers and rheostats MCP4017, MCP4018, MCP4019 They all have one wiper with 128 steps and come in 5, 10, 50 and 100 kOhm variations. Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> --- MAINTAINERS | 3 +- drivers/iio/potentiometer/Kconfig | 11 ++ drivers/iio/potentiometer/Makefile | 1 + drivers/iio/potentiometer/mcp4018.c | 194 ++++++++++++++++++++++++++++++++++++ 4 files changed, 208 insertions(+), 1 deletion(-) create mode 100644 drivers/iio/potentiometer/mcp4018.c diff --git a/MAINTAINERS b/MAINTAINERS index 4623caf8d72d..81527c75adee 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8589,11 +8589,12 @@ W: https://linuxtv.org S: Maintained F: drivers/media/radio/radio-maxiradio* -MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVER +MCP4018 AND MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVERS M: Peter Rosin <peda@xxxxxxxxxx> L: linux-iio@xxxxxxxxxxxxxxx S: Maintained F: Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531 +F: drivers/iio/potentiometer/mcp4018.c F: drivers/iio/potentiometer/mcp4531.c MEASUREMENT COMPUTING CIO-DAC IIO DRIVER diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig index 8bf282510be6..84bdbcd53114 100644 --- a/drivers/iio/potentiometer/Kconfig +++ b/drivers/iio/potentiometer/Kconfig @@ -37,6 +37,17 @@ config MAX5487 To compile this driver as a module, choose M here: the module will be called max5487. +config MCP4018 + tristate "Microchip MCP4017/18/19 Digital Potentiometer driver" + depends on I2C + help + Say yes here to build support for the Microchip + MCP4017, MCP4018, MCP4019 + digital potentiometer chips. + + To compile this driver as a module, choose M here: the + module will be called mcp4018. + config MCP4131 tristate "Microchip MCP413X/414X/415X/416X/423X/424X/425X/426X Digital Potentiometer driver" depends on SPI diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile index 1afd1e70f8cc..0cff8a2916d5 100644 --- a/drivers/iio/potentiometer/Makefile +++ b/drivers/iio/potentiometer/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_DS1803) += ds1803.o obj-$(CONFIG_MAX5481) += max5481.o obj-$(CONFIG_MAX5487) += max5487.o +obj-$(CONFIG_MCP4018) += mcp4018.o obj-$(CONFIG_MCP4131) += mcp4131.o obj-$(CONFIG_MCP4531) += mcp4531.o obj-$(CONFIG_TPL0102) += tpl0102.o diff --git a/drivers/iio/potentiometer/mcp4018.c b/drivers/iio/potentiometer/mcp4018.c new file mode 100644 index 000000000000..601b25d1f387 --- /dev/null +++ b/drivers/iio/potentiometer/mcp4018.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Industrial I/O driver for Microchip digital potentiometers + * Copyright (c) 2018 Axentia Technologies AB + * Author: Peter Rosin <peda@xxxxxxxxxx> + * + * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf + * + * DEVID #Wipers #Positions Resistor Opts (kOhm) + * mcp4017 1 128 5, 10, 50, 100 + * mcp4018 1 128 5, 10, 50, 100 + * mcp4019 1 128 5, 10, 50, 100 + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> + +#define MCP4018_WIPER_MAX 127 + +struct mcp4018_cfg { + int kohms; +}; + +enum mcp4018_type { + MCP4018_502, + MCP4018_103, + MCP4018_503, + MCP4018_104, +}; + +static const struct mcp4018_cfg mcp4018_cfg[] = { + [MCP4018_502] = { .kohms = 5, }, + [MCP4018_103] = { .kohms = 10, }, + [MCP4018_503] = { .kohms = 50, }, + [MCP4018_104] = { .kohms = 100, }, +}; + +struct mcp4018_data { + struct i2c_client *client; + const struct mcp4018_cfg *cfg; +}; + +static const struct iio_chan_spec mcp4018_channel = { + .type = IIO_RESISTANCE, + .indexed = 1, + .output = 1, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), +}; + +static int mcp4018_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mcp4018_data *data = iio_priv(indio_dev); + s32 ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = i2c_smbus_read_byte(data->client); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 1000 * data->cfg->kohms; + *val2 = MCP4018_WIPER_MAX; + return IIO_VAL_FRACTIONAL; + } + + return -EINVAL; +} + +static int mcp4018_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct mcp4018_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (val > MCP4018_WIPER_MAX || val < 0) + return -EINVAL; + break; + default: + return -EINVAL; + } + + return i2c_smbus_write_byte(data->client, val); +} + +static const struct iio_info mcp4018_info = { + .read_raw = mcp4018_read_raw, + .write_raw = mcp4018_write_raw, +}; + +#ifdef CONFIG_OF + +#define MCP4018_COMPATIBLE(of_compatible, cfg) { \ + .compatible = of_compatible, \ + .data = &mcp4018_cfg[cfg], \ +} + +static const struct of_device_id mcp4018_of_match[] = { + MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502), + MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103), + MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503), + MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104), + MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502), + MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103), + MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503), + MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104), + MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502), + MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103), + MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503), + MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104), + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mcp4018_of_match); + +#endif + +static int mcp4018_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct mcp4018_data *data; + struct iio_dev *indio_dev; + const struct of_device_id *match; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE)) { + dev_err(dev, "SMBUS Byte transfers not supported\n"); + return -EOPNOTSUPP; + } + + 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; + + match = of_match_device(of_match_ptr(mcp4018_of_match), dev); + if (match) + data->cfg = of_device_get_match_data(dev); + else + data->cfg = &mcp4018_cfg[id->driver_data]; + + indio_dev->dev.parent = dev; + indio_dev->info = &mcp4018_info; + indio_dev->channels = &mcp4018_channel; + indio_dev->num_channels = 1; + indio_dev->name = client->name; + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct i2c_device_id mcp4018_id[] = { + { "mcp4017-502", MCP4018_502 }, + { "mcp4017-103", MCP4018_103 }, + { "mcp4017-503", MCP4018_503 }, + { "mcp4017-104", MCP4018_104 }, + { "mcp4018-502", MCP4018_502 }, + { "mcp4018-103", MCP4018_103 }, + { "mcp4018-503", MCP4018_503 }, + { "mcp4018-104", MCP4018_104 }, + { "mcp4019-502", MCP4018_502 }, + { "mcp4019-103", MCP4018_103 }, + { "mcp4019-503", MCP4018_503 }, + { "mcp4019-104", MCP4018_104 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, mcp4018_id); + +static struct i2c_driver mcp4018_driver = { + .driver = { + .name = "mcp4018", + .of_match_table = of_match_ptr(mcp4018_of_match), + }, + .probe = mcp4018_probe, + .id_table = mcp4018_id, +}; + +module_i2c_driver(mcp4018_driver); + +MODULE_AUTHOR("Peter Rosin <peda@xxxxxxxxxx>"); +MODULE_DESCRIPTION("MCP4018 digital potentiometer"); +MODULE_LICENSE("GPL"); -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
