diff options
Diffstat (limited to 'drivers/iio/potentiometer/mcp4531.c')
| -rw-r--r-- | drivers/iio/potentiometer/mcp4531.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/iio/potentiometer/mcp4531.c b/drivers/iio/potentiometer/mcp4531.c new file mode 100644 index 000000000..a3f66874e --- /dev/null +++ b/drivers/iio/potentiometer/mcp4531.c @@ -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"); |