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// SPDX-License-Identifier: GPL-2.0
/*
*
* x9250.c -- Renesas X9250 potentiometers IIO driver
*
* Copyright 2023 CS GROUP France
*
* Author: Herve Codina <herve.codina@bootlin.com>
*/
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
struct x9250_cfg {
const char *name;
int kohms;
};
struct x9250 {
struct spi_device *spi;
const struct x9250_cfg *cfg;
struct gpio_desc *wp_gpio;
};
#define X9250_ID 0x50
#define X9250_CMD_RD_WCR(_p) (0x90 | (_p))
#define X9250_CMD_WR_WCR(_p) (0xa0 | (_p))
static int x9250_write8(struct x9250 *x9250, u8 cmd, u8 val)
{
u8 txbuf[3];
txbuf[0] = X9250_ID;
txbuf[1] = cmd;
txbuf[2] = val;
return spi_write_then_read(x9250->spi, txbuf, ARRAY_SIZE(txbuf), NULL, 0);
}
static int x9250_read8(struct x9250 *x9250, u8 cmd, u8 *val)
{
u8 txbuf[2];
txbuf[0] = X9250_ID;
txbuf[1] = cmd;
return spi_write_then_read(x9250->spi, txbuf, ARRAY_SIZE(txbuf), val, 1);
}
#define X9250_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), \
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
}
static const struct iio_chan_spec x9250_channels[] = {
X9250_CHANNEL(0),
X9250_CHANNEL(1),
X9250_CHANNEL(2),
X9250_CHANNEL(3),
};
static int x9250_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct x9250 *x9250 = iio_priv(indio_dev);
int ch = chan->channel;
int ret;
u8 v;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = x9250_read8(x9250, X9250_CMD_RD_WCR(ch), &v);
if (ret)
return ret;
*val = v;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 1000 * x9250->cfg->kohms;
*val2 = U8_MAX;
return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
}
static int x9250_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
const int **vals, int *type, int *length, long mask)
{
static const int range[] = {0, 1, 255}; /* min, step, max */
switch (mask) {
case IIO_CHAN_INFO_RAW:
*length = ARRAY_SIZE(range);
*vals = range;
*type = IIO_VAL_INT;
return IIO_AVAIL_RANGE;
}
return -EINVAL;
}
static int x9250_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct x9250 *x9250 = iio_priv(indio_dev);
int ch = chan->channel;
int ret;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
if (val > U8_MAX || val < 0)
return -EINVAL;
gpiod_set_value_cansleep(x9250->wp_gpio, 0);
ret = x9250_write8(x9250, X9250_CMD_WR_WCR(ch), val);
gpiod_set_value_cansleep(x9250->wp_gpio, 1);
return ret;
}
static const struct iio_info x9250_info = {
.read_raw = x9250_read_raw,
.read_avail = x9250_read_avail,
.write_raw = x9250_write_raw,
};
enum x9250_type {
X9250T,
X9250U,
};
static const struct x9250_cfg x9250_cfg[] = {
[X9250T] = { .name = "x9250t", .kohms = 100, },
[X9250U] = { .name = "x9250u", .kohms = 50, },
};
static const char *const x9250_regulator_names[] = {
"vcc",
"avp",
"avn",
};
static int x9250_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct x9250 *x9250;
int ret;
ret = devm_regulator_bulk_get_enable(&spi->dev, ARRAY_SIZE(x9250_regulator_names),
x9250_regulator_names);
if (ret)
return dev_err_probe(&spi->dev, ret, "Failed to get regulators\n");
/*
* The x9250 needs a 5ms maximum delay after the power-supplies are set
* before performing the first write (1ms for the first read).
*/
usleep_range(5000, 6000);
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*x9250));
if (!indio_dev)
return -ENOMEM;
x9250 = iio_priv(indio_dev);
x9250->spi = spi;
x9250->cfg = spi_get_device_match_data(spi);
x9250->wp_gpio = devm_gpiod_get_optional(&spi->dev, "wp", GPIOD_OUT_LOW);
if (IS_ERR(x9250->wp_gpio))
return dev_err_probe(&spi->dev, PTR_ERR(x9250->wp_gpio),
"failed to get wp gpio\n");
indio_dev->info = &x9250_info;
indio_dev->channels = x9250_channels;
indio_dev->num_channels = ARRAY_SIZE(x9250_channels);
indio_dev->name = x9250->cfg->name;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct of_device_id x9250_of_match[] = {
{ .compatible = "renesas,x9250t", .data = &x9250_cfg[X9250T]},
{ .compatible = "renesas,x9250u", .data = &x9250_cfg[X9250U]},
{ }
};
MODULE_DEVICE_TABLE(of, x9250_of_match);
static const struct spi_device_id x9250_id_table[] = {
{ "x9250t", (kernel_ulong_t)&x9250_cfg[X9250T] },
{ "x9250u", (kernel_ulong_t)&x9250_cfg[X9250U] },
{ }
};
MODULE_DEVICE_TABLE(spi, x9250_id_table);
static struct spi_driver x9250_spi_driver = {
.driver = {
.name = "x9250",
.of_match_table = x9250_of_match,
},
.id_table = x9250_id_table,
.probe = x9250_probe,
};
module_spi_driver(x9250_spi_driver);
MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
MODULE_DESCRIPTION("X9250 ALSA SoC driver");
MODULE_LICENSE("GPL");
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