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185 lines
4.7 KiB
185 lines
4.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Industrial I/O driver for Microchip digital potentiometers |
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* Copyright (c) 2018 Axentia Technologies AB |
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* Author: Peter Rosin <[email protected]> |
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* |
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* Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf |
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* |
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* DEVID #Wipers #Positions Resistor Opts (kOhm) |
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* mcp4017 1 128 5, 10, 50, 100 |
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* mcp4018 1 128 5, 10, 50, 100 |
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* mcp4019 1 128 5, 10, 50, 100 |
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*/ |
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#include <linux/err.h> |
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#include <linux/i2c.h> |
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#include <linux/iio/iio.h> |
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#include <linux/module.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/property.h> |
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#define MCP4018_WIPER_MAX 127 |
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struct mcp4018_cfg { |
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int kohms; |
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}; |
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enum mcp4018_type { |
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MCP4018_502, |
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MCP4018_103, |
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MCP4018_503, |
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MCP4018_104, |
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}; |
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static const struct mcp4018_cfg mcp4018_cfg[] = { |
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[MCP4018_502] = { .kohms = 5, }, |
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[MCP4018_103] = { .kohms = 10, }, |
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[MCP4018_503] = { .kohms = 50, }, |
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[MCP4018_104] = { .kohms = 100, }, |
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}; |
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struct mcp4018_data { |
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struct i2c_client *client; |
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const struct mcp4018_cfg *cfg; |
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}; |
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static const struct iio_chan_spec mcp4018_channel = { |
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.type = IIO_RESISTANCE, |
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.indexed = 1, |
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.output = 1, |
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.channel = 0, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
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}; |
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static int mcp4018_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct mcp4018_data *data = iio_priv(indio_dev); |
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s32 ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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ret = i2c_smbus_read_byte(data->client); |
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if (ret < 0) |
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return ret; |
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*val = ret; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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*val = 1000 * data->cfg->kohms; |
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*val2 = MCP4018_WIPER_MAX; |
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return IIO_VAL_FRACTIONAL; |
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} |
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return -EINVAL; |
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} |
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static int mcp4018_write_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int val, int val2, long mask) |
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{ |
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struct mcp4018_data *data = iio_priv(indio_dev); |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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if (val > MCP4018_WIPER_MAX || val < 0) |
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return -EINVAL; |
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break; |
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default: |
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return -EINVAL; |
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} |
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return i2c_smbus_write_byte(data->client, val); |
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} |
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static const struct iio_info mcp4018_info = { |
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.read_raw = mcp4018_read_raw, |
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.write_raw = mcp4018_write_raw, |
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}; |
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static const struct i2c_device_id mcp4018_id[] = { |
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{ "mcp4017-502", MCP4018_502 }, |
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{ "mcp4017-103", MCP4018_103 }, |
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{ "mcp4017-503", MCP4018_503 }, |
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{ "mcp4017-104", MCP4018_104 }, |
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{ "mcp4018-502", MCP4018_502 }, |
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{ "mcp4018-103", MCP4018_103 }, |
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{ "mcp4018-503", MCP4018_503 }, |
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{ "mcp4018-104", MCP4018_104 }, |
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{ "mcp4019-502", MCP4018_502 }, |
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{ "mcp4019-103", MCP4018_103 }, |
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{ "mcp4019-503", MCP4018_503 }, |
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{ "mcp4019-104", MCP4018_104 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(i2c, mcp4018_id); |
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#define MCP4018_COMPATIBLE(of_compatible, cfg) { \ |
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.compatible = of_compatible, \ |
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.data = &mcp4018_cfg[cfg], \ |
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} |
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static const struct of_device_id mcp4018_of_match[] = { |
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MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502), |
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MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103), |
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MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503), |
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MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104), |
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MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502), |
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MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103), |
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MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503), |
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MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104), |
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MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502), |
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MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103), |
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MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503), |
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MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104), |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, mcp4018_of_match); |
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static int mcp4018_probe(struct i2c_client *client) |
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{ |
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struct device *dev = &client->dev; |
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struct mcp4018_data *data; |
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struct iio_dev *indio_dev; |
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if (!i2c_check_functionality(client->adapter, |
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I2C_FUNC_SMBUS_BYTE)) { |
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dev_err(dev, "SMBUS Byte transfers not supported\n"); |
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return -EOPNOTSUPP; |
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} |
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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i2c_set_clientdata(client, indio_dev); |
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data->client = client; |
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data->cfg = device_get_match_data(dev); |
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if (!data->cfg) |
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data->cfg = &mcp4018_cfg[i2c_match_id(mcp4018_id, client)->driver_data]; |
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indio_dev->info = &mcp4018_info; |
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indio_dev->channels = &mcp4018_channel; |
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indio_dev->num_channels = 1; |
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indio_dev->name = client->name; |
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return devm_iio_device_register(dev, indio_dev); |
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} |
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static struct i2c_driver mcp4018_driver = { |
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.driver = { |
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.name = "mcp4018", |
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.of_match_table = mcp4018_of_match, |
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}, |
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.probe_new = mcp4018_probe, |
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.id_table = mcp4018_id, |
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}; |
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module_i2c_driver(mcp4018_driver); |
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MODULE_AUTHOR("Peter Rosin <[email protected]>"); |
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MODULE_DESCRIPTION("MCP4018 digital potentiometer"); |
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MODULE_LICENSE("GPL v2");
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