| /* |
| * Industrial I/O driver for Microchip digital potentiometers |
| * |
| * Copyright (c) 2016 Slawomir Stepien |
| * Based on: Peter Rosin's code from mcp4531.c |
| * |
| * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22060b.pdf |
| * |
| * DEVID #Wipers #Positions Resistor Opts (kOhm) |
| * mcp4131 1 129 5, 10, 50, 100 |
| * mcp4132 1 129 5, 10, 50, 100 |
| * mcp4141 1 129 5, 10, 50, 100 |
| * mcp4142 1 129 5, 10, 50, 100 |
| * mcp4151 1 257 5, 10, 50, 100 |
| * mcp4152 1 257 5, 10, 50, 100 |
| * mcp4161 1 257 5, 10, 50, 100 |
| * mcp4162 1 257 5, 10, 50, 100 |
| * mcp4231 2 129 5, 10, 50, 100 |
| * mcp4232 2 129 5, 10, 50, 100 |
| * mcp4241 2 129 5, 10, 50, 100 |
| * mcp4242 2 129 5, 10, 50, 100 |
| * mcp4251 2 257 5, 10, 50, 100 |
| * mcp4252 2 257 5, 10, 50, 100 |
| * mcp4261 2 257 5, 10, 50, 100 |
| * mcp4262 2 257 5, 10, 50, 100 |
| * |
| * 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. |
| */ |
| |
| /* |
| * TODO: |
| * 1. Write wiper setting to EEPROM for EEPROM capable models. |
| */ |
| |
| #include <linux/cache.h> |
| #include <linux/err.h> |
| #include <linux/export.h> |
| #include <linux/iio/iio.h> |
| #include <linux/iio/types.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/spi/spi.h> |
| |
| #define MCP4131_WRITE (0x00 << 2) |
| #define MCP4131_READ (0x03 << 2) |
| |
| #define MCP4131_WIPER_SHIFT 4 |
| #define MCP4131_CMDERR(r) ((r[0]) & 0x02) |
| #define MCP4131_RAW(r) ((r[0]) == 0xff ? 0x100 : (r[1])) |
| |
| struct mcp4131_cfg { |
| int wipers; |
| int max_pos; |
| int kohms; |
| }; |
| |
| enum mcp4131_type { |
| MCP413x_502 = 0, |
| MCP413x_103, |
| MCP413x_503, |
| MCP413x_104, |
| MCP414x_502, |
| MCP414x_103, |
| MCP414x_503, |
| MCP414x_104, |
| MCP415x_502, |
| MCP415x_103, |
| MCP415x_503, |
| MCP415x_104, |
| MCP416x_502, |
| MCP416x_103, |
| MCP416x_503, |
| MCP416x_104, |
| MCP423x_502, |
| MCP423x_103, |
| MCP423x_503, |
| MCP423x_104, |
| MCP424x_502, |
| MCP424x_103, |
| MCP424x_503, |
| MCP424x_104, |
| MCP425x_502, |
| MCP425x_103, |
| MCP425x_503, |
| MCP425x_104, |
| MCP426x_502, |
| MCP426x_103, |
| MCP426x_503, |
| MCP426x_104, |
| }; |
| |
| static const struct mcp4131_cfg mcp4131_cfg[] = { |
| [MCP413x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, }, |
| [MCP413x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, }, |
| [MCP413x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, }, |
| [MCP413x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, }, |
| [MCP414x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, }, |
| [MCP414x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, }, |
| [MCP414x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, }, |
| [MCP414x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, }, |
| [MCP415x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, }, |
| [MCP415x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, }, |
| [MCP415x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, }, |
| [MCP415x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, }, |
| [MCP416x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, }, |
| [MCP416x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, }, |
| [MCP416x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, }, |
| [MCP416x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, }, |
| [MCP423x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, }, |
| [MCP423x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, }, |
| [MCP423x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, }, |
| [MCP423x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, }, |
| [MCP424x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, }, |
| [MCP424x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, }, |
| [MCP424x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, }, |
| [MCP424x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, }, |
| [MCP425x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, }, |
| [MCP425x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, }, |
| [MCP425x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, }, |
| [MCP425x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, }, |
| [MCP426x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, }, |
| [MCP426x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, }, |
| [MCP426x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, }, |
| [MCP426x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, }, |
| }; |
| |
| struct mcp4131_data { |
| struct spi_device *spi; |
| const struct mcp4131_cfg *cfg; |
| struct mutex lock; |
| u8 buf[2] ____cacheline_aligned; |
| }; |
| |
| #define MCP4131_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 mcp4131_channels[] = { |
| MCP4131_CHANNEL(0), |
| MCP4131_CHANNEL(1), |
| }; |
| |
| static int mcp4131_read(struct spi_device *spi, void *buf, size_t len) |
| { |
| struct spi_transfer t = { |
| .tx_buf = buf, /* We need to send addr, cmd and 12 bits */ |
| .rx_buf = buf, |
| .len = len, |
| }; |
| struct spi_message m; |
| |
| spi_message_init(&m); |
| spi_message_add_tail(&t, &m); |
| |
| return spi_sync(spi, &m); |
| } |
| |
| static int mcp4131_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| int err; |
| struct mcp4131_data *data = iio_priv(indio_dev); |
| int address = chan->channel; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| mutex_lock(&data->lock); |
| |
| data->buf[0] = (address << MCP4131_WIPER_SHIFT) | MCP4131_READ; |
| data->buf[1] = 0; |
| |
| err = mcp4131_read(data->spi, data->buf, 2); |
| if (err) { |
| mutex_unlock(&data->lock); |
| return err; |
| } |
| |
| /* Error, bad address/command combination */ |
| if (!MCP4131_CMDERR(data->buf)) { |
| mutex_unlock(&data->lock); |
| return -EIO; |
| } |
| |
| *val = MCP4131_RAW(data->buf); |
| mutex_unlock(&data->lock); |
| |
| 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 mcp4131_write_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int val, int val2, long mask) |
| { |
| int err; |
| struct mcp4131_data *data = iio_priv(indio_dev); |
| int address = chan->channel << MCP4131_WIPER_SHIFT; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| if (val > data->cfg->max_pos || val < 0) |
| return -EINVAL; |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| mutex_lock(&data->lock); |
| |
| data->buf[0] = address << MCP4131_WIPER_SHIFT; |
| data->buf[0] |= MCP4131_WRITE | (val >> 8); |
| data->buf[1] = val & 0xFF; /* 8 bits here */ |
| |
| err = spi_write(data->spi, data->buf, 2); |
| mutex_unlock(&data->lock); |
| |
| return err; |
| } |
| |
| static const struct iio_info mcp4131_info = { |
| .read_raw = mcp4131_read_raw, |
| .write_raw = mcp4131_write_raw, |
| }; |
| |
| static int mcp4131_probe(struct spi_device *spi) |
| { |
| int err; |
| struct device *dev = &spi->dev; |
| unsigned long devid = spi_get_device_id(spi)->driver_data; |
| struct mcp4131_data *data; |
| struct iio_dev *indio_dev; |
| |
| indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| data = iio_priv(indio_dev); |
| spi_set_drvdata(spi, indio_dev); |
| data->spi = spi; |
| data->cfg = &mcp4131_cfg[devid]; |
| |
| mutex_init(&data->lock); |
| |
| indio_dev->dev.parent = dev; |
| indio_dev->info = &mcp4131_info; |
| indio_dev->channels = mcp4131_channels; |
| indio_dev->num_channels = data->cfg->wipers; |
| indio_dev->name = spi_get_device_id(spi)->name; |
| |
| err = devm_iio_device_register(dev, indio_dev); |
| if (err) { |
| dev_info(&spi->dev, "Unable to register %s\n", indio_dev->name); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| #if defined(CONFIG_OF) |
| static const struct of_device_id mcp4131_dt_ids[] = { |
| { .compatible = "microchip,mcp4131-502", |
| .data = &mcp4131_cfg[MCP413x_502] }, |
| { .compatible = "microchip,mcp4131-103", |
| .data = &mcp4131_cfg[MCP413x_103] }, |
| { .compatible = "microchip,mcp4131-503", |
| .data = &mcp4131_cfg[MCP413x_503] }, |
| { .compatible = "microchip,mcp4131-104", |
| .data = &mcp4131_cfg[MCP413x_104] }, |
| { .compatible = "microchip,mcp4132-502", |
| .data = &mcp4131_cfg[MCP413x_502] }, |
| { .compatible = "microchip,mcp4132-103", |
| .data = &mcp4131_cfg[MCP413x_103] }, |
| { .compatible = "microchip,mcp4132-503", |
| .data = &mcp4131_cfg[MCP413x_503] }, |
| { .compatible = "microchip,mcp4132-104", |
| .data = &mcp4131_cfg[MCP413x_104] }, |
| { .compatible = "microchip,mcp4141-502", |
| .data = &mcp4131_cfg[MCP414x_502] }, |
| { .compatible = "microchip,mcp4141-103", |
| .data = &mcp4131_cfg[MCP414x_103] }, |
| { .compatible = "microchip,mcp4141-503", |
| .data = &mcp4131_cfg[MCP414x_503] }, |
| { .compatible = "microchip,mcp4141-104", |
| .data = &mcp4131_cfg[MCP414x_104] }, |
| { .compatible = "microchip,mcp4142-502", |
| .data = &mcp4131_cfg[MCP414x_502] }, |
| { .compatible = "microchip,mcp4142-103", |
| .data = &mcp4131_cfg[MCP414x_103] }, |
| { .compatible = "microchip,mcp4142-503", |
| .data = &mcp4131_cfg[MCP414x_503] }, |
| { .compatible = "microchip,mcp4142-104", |
| .data = &mcp4131_cfg[MCP414x_104] }, |
| { .compatible = "microchip,mcp4151-502", |
| .data = &mcp4131_cfg[MCP415x_502] }, |
| { .compatible = "microchip,mcp4151-103", |
| .data = &mcp4131_cfg[MCP415x_103] }, |
| { .compatible = "microchip,mcp4151-503", |
| .data = &mcp4131_cfg[MCP415x_503] }, |
| { .compatible = "microchip,mcp4151-104", |
| .data = &mcp4131_cfg[MCP415x_104] }, |
| { .compatible = "microchip,mcp4152-502", |
| .data = &mcp4131_cfg[MCP415x_502] }, |
| { .compatible = "microchip,mcp4152-103", |
| .data = &mcp4131_cfg[MCP415x_103] }, |
| { .compatible = "microchip,mcp4152-503", |
| .data = &mcp4131_cfg[MCP415x_503] }, |
| { .compatible = "microchip,mcp4152-104", |
| .data = &mcp4131_cfg[MCP415x_104] }, |
| { .compatible = "microchip,mcp4161-502", |
| .data = &mcp4131_cfg[MCP416x_502] }, |
| { .compatible = "microchip,mcp4161-103", |
| .data = &mcp4131_cfg[MCP416x_103] }, |
| { .compatible = "microchip,mcp4161-503", |
| .data = &mcp4131_cfg[MCP416x_503] }, |
| { .compatible = "microchip,mcp4161-104", |
| .data = &mcp4131_cfg[MCP416x_104] }, |
| { .compatible = "microchip,mcp4162-502", |
| .data = &mcp4131_cfg[MCP416x_502] }, |
| { .compatible = "microchip,mcp4162-103", |
| .data = &mcp4131_cfg[MCP416x_103] }, |
| { .compatible = "microchip,mcp4162-503", |
| .data = &mcp4131_cfg[MCP416x_503] }, |
| { .compatible = "microchip,mcp4162-104", |
| .data = &mcp4131_cfg[MCP416x_104] }, |
| { .compatible = "microchip,mcp4231-502", |
| .data = &mcp4131_cfg[MCP423x_502] }, |
| { .compatible = "microchip,mcp4231-103", |
| .data = &mcp4131_cfg[MCP423x_103] }, |
| { .compatible = "microchip,mcp4231-503", |
| .data = &mcp4131_cfg[MCP423x_503] }, |
| { .compatible = "microchip,mcp4231-104", |
| .data = &mcp4131_cfg[MCP423x_104] }, |
| { .compatible = "microchip,mcp4232-502", |
| .data = &mcp4131_cfg[MCP423x_502] }, |
| { .compatible = "microchip,mcp4232-103", |
| .data = &mcp4131_cfg[MCP423x_103] }, |
| { .compatible = "microchip,mcp4232-503", |
| .data = &mcp4131_cfg[MCP423x_503] }, |
| { .compatible = "microchip,mcp4232-104", |
| .data = &mcp4131_cfg[MCP423x_104] }, |
| { .compatible = "microchip,mcp4241-502", |
| .data = &mcp4131_cfg[MCP424x_502] }, |
| { .compatible = "microchip,mcp4241-103", |
| .data = &mcp4131_cfg[MCP424x_103] }, |
| { .compatible = "microchip,mcp4241-503", |
| .data = &mcp4131_cfg[MCP424x_503] }, |
| { .compatible = "microchip,mcp4241-104", |
| .data = &mcp4131_cfg[MCP424x_104] }, |
| { .compatible = "microchip,mcp4242-502", |
| .data = &mcp4131_cfg[MCP424x_502] }, |
| { .compatible = "microchip,mcp4242-103", |
| .data = &mcp4131_cfg[MCP424x_103] }, |
| { .compatible = "microchip,mcp4242-503", |
| .data = &mcp4131_cfg[MCP424x_503] }, |
| { .compatible = "microchip,mcp4242-104", |
| .data = &mcp4131_cfg[MCP424x_104] }, |
| { .compatible = "microchip,mcp4251-502", |
| .data = &mcp4131_cfg[MCP425x_502] }, |
| { .compatible = "microchip,mcp4251-103", |
| .data = &mcp4131_cfg[MCP425x_103] }, |
| { .compatible = "microchip,mcp4251-503", |
| .data = &mcp4131_cfg[MCP425x_503] }, |
| { .compatible = "microchip,mcp4251-104", |
| .data = &mcp4131_cfg[MCP425x_104] }, |
| { .compatible = "microchip,mcp4252-502", |
| .data = &mcp4131_cfg[MCP425x_502] }, |
| { .compatible = "microchip,mcp4252-103", |
| .data = &mcp4131_cfg[MCP425x_103] }, |
| { .compatible = "microchip,mcp4252-503", |
| .data = &mcp4131_cfg[MCP425x_503] }, |
| { .compatible = "microchip,mcp4252-104", |
| .data = &mcp4131_cfg[MCP425x_104] }, |
| { .compatible = "microchip,mcp4261-502", |
| .data = &mcp4131_cfg[MCP426x_502] }, |
| { .compatible = "microchip,mcp4261-103", |
| .data = &mcp4131_cfg[MCP426x_103] }, |
| { .compatible = "microchip,mcp4261-503", |
| .data = &mcp4131_cfg[MCP426x_503] }, |
| { .compatible = "microchip,mcp4261-104", |
| .data = &mcp4131_cfg[MCP426x_104] }, |
| { .compatible = "microchip,mcp4262-502", |
| .data = &mcp4131_cfg[MCP426x_502] }, |
| { .compatible = "microchip,mcp4262-103", |
| .data = &mcp4131_cfg[MCP426x_103] }, |
| { .compatible = "microchip,mcp4262-503", |
| .data = &mcp4131_cfg[MCP426x_503] }, |
| { .compatible = "microchip,mcp4262-104", |
| .data = &mcp4131_cfg[MCP426x_104] }, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(of, mcp4131_dt_ids); |
| #endif /* CONFIG_OF */ |
| |
| static const struct spi_device_id mcp4131_id[] = { |
| { "mcp4131-502", MCP413x_502 }, |
| { "mcp4131-103", MCP413x_103 }, |
| { "mcp4131-503", MCP413x_503 }, |
| { "mcp4131-104", MCP413x_104 }, |
| { "mcp4132-502", MCP413x_502 }, |
| { "mcp4132-103", MCP413x_103 }, |
| { "mcp4132-503", MCP413x_503 }, |
| { "mcp4132-104", MCP413x_104 }, |
| { "mcp4141-502", MCP414x_502 }, |
| { "mcp4141-103", MCP414x_103 }, |
| { "mcp4141-503", MCP414x_503 }, |
| { "mcp4141-104", MCP414x_104 }, |
| { "mcp4142-502", MCP414x_502 }, |
| { "mcp4142-103", MCP414x_103 }, |
| { "mcp4142-503", MCP414x_503 }, |
| { "mcp4142-104", MCP414x_104 }, |
| { "mcp4151-502", MCP415x_502 }, |
| { "mcp4151-103", MCP415x_103 }, |
| { "mcp4151-503", MCP415x_503 }, |
| { "mcp4151-104", MCP415x_104 }, |
| { "mcp4152-502", MCP415x_502 }, |
| { "mcp4152-103", MCP415x_103 }, |
| { "mcp4152-503", MCP415x_503 }, |
| { "mcp4152-104", MCP415x_104 }, |
| { "mcp4161-502", MCP416x_502 }, |
| { "mcp4161-103", MCP416x_103 }, |
| { "mcp4161-503", MCP416x_503 }, |
| { "mcp4161-104", MCP416x_104 }, |
| { "mcp4162-502", MCP416x_502 }, |
| { "mcp4162-103", MCP416x_103 }, |
| { "mcp4162-503", MCP416x_503 }, |
| { "mcp4162-104", MCP416x_104 }, |
| { "mcp4231-502", MCP423x_502 }, |
| { "mcp4231-103", MCP423x_103 }, |
| { "mcp4231-503", MCP423x_503 }, |
| { "mcp4231-104", MCP423x_104 }, |
| { "mcp4232-502", MCP423x_502 }, |
| { "mcp4232-103", MCP423x_103 }, |
| { "mcp4232-503", MCP423x_503 }, |
| { "mcp4232-104", MCP423x_104 }, |
| { "mcp4241-502", MCP424x_502 }, |
| { "mcp4241-103", MCP424x_103 }, |
| { "mcp4241-503", MCP424x_503 }, |
| { "mcp4241-104", MCP424x_104 }, |
| { "mcp4242-502", MCP424x_502 }, |
| { "mcp4242-103", MCP424x_103 }, |
| { "mcp4242-503", MCP424x_503 }, |
| { "mcp4242-104", MCP424x_104 }, |
| { "mcp4251-502", MCP425x_502 }, |
| { "mcp4251-103", MCP425x_103 }, |
| { "mcp4251-503", MCP425x_503 }, |
| { "mcp4251-104", MCP425x_104 }, |
| { "mcp4252-502", MCP425x_502 }, |
| { "mcp4252-103", MCP425x_103 }, |
| { "mcp4252-503", MCP425x_503 }, |
| { "mcp4252-104", MCP425x_104 }, |
| { "mcp4261-502", MCP426x_502 }, |
| { "mcp4261-103", MCP426x_103 }, |
| { "mcp4261-503", MCP426x_503 }, |
| { "mcp4261-104", MCP426x_104 }, |
| { "mcp4262-502", MCP426x_502 }, |
| { "mcp4262-103", MCP426x_103 }, |
| { "mcp4262-503", MCP426x_503 }, |
| { "mcp4262-104", MCP426x_104 }, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(spi, mcp4131_id); |
| |
| static struct spi_driver mcp4131_driver = { |
| .driver = { |
| .name = "mcp4131", |
| .of_match_table = of_match_ptr(mcp4131_dt_ids), |
| }, |
| .probe = mcp4131_probe, |
| .id_table = mcp4131_id, |
| }; |
| |
| module_spi_driver(mcp4131_driver); |
| |
| MODULE_AUTHOR("Slawomir Stepien <sst@poczta.fm>"); |
| MODULE_DESCRIPTION("MCP4131 digital potentiometer"); |
| MODULE_LICENSE("GPL v2"); |