|  | /* | 
|  | * 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 | 
|  | * mcp4541	1	129		5, 10, 50, 100          010111x | 
|  | * mcp4542	1	129		5, 10, 50, 100          01011xx | 
|  | * mcp4551	1	257		5, 10, 50, 100          010111x | 
|  | * mcp4552	1	257		5, 10, 50, 100          01011xx | 
|  | * mcp4561	1	257		5, 10, 50, 100          010111x | 
|  | * mcp4562	1	257		5, 10, 50, 100          01011xx | 
|  | * mcp4631	2	129		5, 10, 50, 100          0101xxx | 
|  | * mcp4632	2	129		5, 10, 50, 100          01011xx | 
|  | * mcp4641	2	129		5, 10, 50, 100          0101xxx | 
|  | * mcp4642	2	129		5, 10, 50, 100          01011xx | 
|  | * mcp4651	2	257		5, 10, 50, 100          0101xxx | 
|  | * mcp4652	2	257		5, 10, 50, 100          01011xx | 
|  | * mcp4661	2	257		5, 10, 50, 100          0101xxx | 
|  | * mcp4662	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/of.h> | 
|  | #include <linux/of_device.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, | 
|  | MCP454x_502, | 
|  | MCP454x_103, | 
|  | MCP454x_503, | 
|  | MCP454x_104, | 
|  | MCP455x_502, | 
|  | MCP455x_103, | 
|  | MCP455x_503, | 
|  | MCP455x_104, | 
|  | MCP456x_502, | 
|  | MCP456x_103, | 
|  | MCP456x_503, | 
|  | MCP456x_104, | 
|  | MCP463x_502, | 
|  | MCP463x_103, | 
|  | MCP463x_503, | 
|  | MCP463x_104, | 
|  | MCP464x_502, | 
|  | MCP464x_103, | 
|  | MCP464x_503, | 
|  | MCP464x_104, | 
|  | MCP465x_502, | 
|  | MCP465x_103, | 
|  | MCP465x_503, | 
|  | MCP465x_104, | 
|  | MCP466x_502, | 
|  | MCP466x_103, | 
|  | MCP466x_503, | 
|  | MCP466x_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, }, | 
|  | [MCP454x_502] = { .wipers = 1, .max_pos = 128, .kohms =   5, }, | 
|  | [MCP454x_103] = { .wipers = 1, .max_pos = 128, .kohms =  10, }, | 
|  | [MCP454x_503] = { .wipers = 1, .max_pos = 128, .kohms =  50, }, | 
|  | [MCP454x_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, }, | 
|  | [MCP456x_502] = { .wipers = 1, .max_pos = 256, .kohms =   5, }, | 
|  | [MCP456x_103] = { .wipers = 1, .max_pos = 256, .kohms =  10, }, | 
|  | [MCP456x_503] = { .wipers = 1, .max_pos = 256, .kohms =  50, }, | 
|  | [MCP456x_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, }, | 
|  | [MCP464x_502] = { .wipers = 2, .max_pos = 128, .kohms =   5, }, | 
|  | [MCP464x_103] = { .wipers = 2, .max_pos = 128, .kohms =  10, }, | 
|  | [MCP464x_503] = { .wipers = 2, .max_pos = 128, .kohms =  50, }, | 
|  | [MCP464x_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, }, | 
|  | [MCP466x_502] = { .wipers = 2, .max_pos = 256, .kohms =   5, }, | 
|  | [MCP466x_103] = { .wipers = 2, .max_pos = 256, .kohms =  10, }, | 
|  | [MCP466x_503] = { .wipers = 2, .max_pos = 256, .kohms =  50, }, | 
|  | [MCP466x_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; | 
|  | const struct mcp4531_cfg *cfg; | 
|  | }; | 
|  |  | 
|  | #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 * data->cfg->kohms; | 
|  | *val2 = data->cfg->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 > data->cfg->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, | 
|  | }; | 
|  |  | 
|  | #ifdef CONFIG_OF | 
|  |  | 
|  | #define MCP4531_COMPATIBLE(of_compatible, cfg) {	\ | 
|  | .compatible = of_compatible,	\ | 
|  | .data = &mcp4531_cfg[cfg],	\ | 
|  | } | 
|  |  | 
|  | static const struct of_device_id mcp4531_of_match[] = { | 
|  | MCP4531_COMPATIBLE("microchip,mcp4531-502", MCP453x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4531-103", MCP453x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4531-503", MCP453x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4531-104", MCP453x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4532-502", MCP453x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4532-103", MCP453x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4532-503", MCP453x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4532-104", MCP453x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4541-502", MCP454x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4541-103", MCP454x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4541-503", MCP454x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4541-104", MCP454x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4542-502", MCP454x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4542-103", MCP454x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4542-503", MCP454x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4542-104", MCP454x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4551-502", MCP455x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4551-103", MCP455x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4551-503", MCP455x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4551-104", MCP455x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4552-502", MCP455x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4552-103", MCP455x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4552-503", MCP455x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4552-104", MCP455x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4561-502", MCP456x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4561-103", MCP456x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4561-503", MCP456x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4561-104", MCP456x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4562-502", MCP456x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4562-103", MCP456x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4562-503", MCP456x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4562-104", MCP456x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4631-502", MCP463x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4631-103", MCP463x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4631-503", MCP463x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4631-104", MCP463x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4632-502", MCP463x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4632-103", MCP463x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4632-503", MCP463x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4632-104", MCP463x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4641-502", MCP464x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4641-103", MCP464x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4641-503", MCP464x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4641-104", MCP464x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4642-502", MCP464x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4642-103", MCP464x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4642-503", MCP464x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4642-104", MCP464x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4651-502", MCP465x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4651-103", MCP465x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4651-503", MCP465x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4651-104", MCP465x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4652-502", MCP465x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4652-103", MCP465x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4652-503", MCP465x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4652-104", MCP465x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4661-502", MCP466x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4661-103", MCP466x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4661-503", MCP466x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4661-104", MCP466x_104), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4662-502", MCP466x_502), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4662-103", MCP466x_103), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4662-503", MCP466x_503), | 
|  | MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104), | 
|  | { /* sentinel */ } | 
|  | }; | 
|  | #endif | 
|  |  | 
|  | static int mcp4531_probe(struct i2c_client *client, | 
|  | const struct i2c_device_id *id) | 
|  | { | 
|  | struct device *dev = &client->dev; | 
|  | struct mcp4531_data *data; | 
|  | struct iio_dev *indio_dev; | 
|  | const struct of_device_id *match; | 
|  |  | 
|  | 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; | 
|  |  | 
|  | match = of_match_device(of_match_ptr(mcp4531_of_match), dev); | 
|  | if (match) | 
|  | data->cfg = of_device_get_match_data(dev); | 
|  | else | 
|  | data->cfg = &mcp4531_cfg[id->driver_data]; | 
|  |  | 
|  | indio_dev->dev.parent = dev; | 
|  | indio_dev->info = &mcp4531_info; | 
|  | indio_dev->channels = mcp4531_channels; | 
|  | indio_dev->num_channels = data->cfg->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 }, | 
|  | { "mcp4541-502", MCP454x_502 }, | 
|  | { "mcp4541-103", MCP454x_103 }, | 
|  | { "mcp4541-503", MCP454x_503 }, | 
|  | { "mcp4541-104", MCP454x_104 }, | 
|  | { "mcp4542-502", MCP454x_502 }, | 
|  | { "mcp4542-103", MCP454x_103 }, | 
|  | { "mcp4542-503", MCP454x_503 }, | 
|  | { "mcp4542-104", MCP454x_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 }, | 
|  | { "mcp4561-502", MCP456x_502 }, | 
|  | { "mcp4561-103", MCP456x_103 }, | 
|  | { "mcp4561-503", MCP456x_503 }, | 
|  | { "mcp4561-104", MCP456x_104 }, | 
|  | { "mcp4562-502", MCP456x_502 }, | 
|  | { "mcp4562-103", MCP456x_103 }, | 
|  | { "mcp4562-503", MCP456x_503 }, | 
|  | { "mcp4562-104", MCP456x_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 }, | 
|  | { "mcp4641-502", MCP464x_502 }, | 
|  | { "mcp4641-103", MCP464x_103 }, | 
|  | { "mcp4641-503", MCP464x_503 }, | 
|  | { "mcp4641-104", MCP464x_104 }, | 
|  | { "mcp4642-502", MCP464x_502 }, | 
|  | { "mcp4642-103", MCP464x_103 }, | 
|  | { "mcp4642-503", MCP464x_503 }, | 
|  | { "mcp4642-104", MCP464x_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 }, | 
|  | { "mcp4661-502", MCP466x_502 }, | 
|  | { "mcp4661-103", MCP466x_103 }, | 
|  | { "mcp4661-503", MCP466x_503 }, | 
|  | { "mcp4661-104", MCP466x_104 }, | 
|  | { "mcp4662-502", MCP466x_502 }, | 
|  | { "mcp4662-103", MCP466x_103 }, | 
|  | { "mcp4662-503", MCP466x_503 }, | 
|  | { "mcp4662-104", MCP466x_104 }, | 
|  | {} | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(i2c, mcp4531_id); | 
|  |  | 
|  | static struct i2c_driver mcp4531_driver = { | 
|  | .driver = { | 
|  | .name	= "mcp4531", | 
|  | .of_match_table = of_match_ptr(mcp4531_of_match), | 
|  | }, | 
|  | .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"); |