/* * Industrial I/O driver for Microchip digital potentiometers * Copyright (c) 2015 Axentia Technologies AB * Author: Peter Rosin * * 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 #include #include #include 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 "); MODULE_DESCRIPTION("MCP4531 digital potentiometer"); MODULE_LICENSE("GPL");