| /* |
| * 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 -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; |
| 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"); |