alistair23-linux/drivers/iio/potentiometer/mcp4131.c
Jonathan Cameron a51a834997 iio:potentiometer:mcp4131: Drop of_match_ptr and use generic fw interfaces.
This change allows the use of the driver with ACPI via PRP0001
and remove an example of an anti pattern I'm trying to remove from IIO.
Also adjust includes to reflect this change.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Slawomir Stepien <sst@poczta.fm>
Link: https://lore.kernel.org/r/20200910173242.621168-8-jic23@kernel.org
2020-09-21 18:41:26 +01:00

493 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Industrial I/O driver for Microchip digital potentiometers
*
* Copyright (c) 2016 Slawomir Stepien
* Based on: Peter Rosin's code from mcp4531.c
*
* Datasheet: https://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
*/
/*
* 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/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/property.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;
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 = device_get_match_data(&spi->dev);
if (!data->cfg) {
devid = spi_get_device_id(spi)->driver_data;
data->cfg = &mcp4131_cfg[devid];
}
mutex_init(&data->lock);
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;
}
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);
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 = 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");