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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ADGS1408/ADGS1409 SPI MUX driver
*
* Copyright 2018 Analog Devices Inc.
*/
#include <linux/err.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mux/driver.h>
#include <linux/property.h>
#include <linux/spi/spi.h>
#define ADGS1408_SW_DATA (0x01)
#define ADGS1408_REG_READ(reg) ((reg) | 0x80)
#define ADGS1408_DISABLE (0x00)
#define ADGS1408_MUX(state) (((state) << 1) | 1)
enum adgs1408_chip_id {
ADGS1408 = 1,
ADGS1409,
};
static int adgs1408_spi_reg_write(struct spi_device *spi,
u8 reg_addr, u8 reg_data)
{
u8 tx_buf[2];
tx_buf[0] = reg_addr;
tx_buf[1] = reg_data;
return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0);
}
static int adgs1408_set(struct mux_control *mux, int state)
{
struct spi_device *spi = to_spi_device(mux->chip->dev.parent);
u8 reg;
if (state == MUX_IDLE_DISCONNECT)
reg = ADGS1408_DISABLE;
else
reg = ADGS1408_MUX(state);
return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg);
}
static const struct mux_control_ops adgs1408_ops = {
.set = adgs1408_set,
};
static int adgs1408_probe(struct spi_device *spi)
{
struct device *dev = &spi->dev;
enum adgs1408_chip_id chip_id;
struct mux_chip *mux_chip;
struct mux_control *mux;
s32 idle_state;
int ret;
chip_id = (kernel_ulong_t)spi_get_device_match_data(spi);
mux_chip = devm_mux_chip_alloc(dev, 1, 0);
if (IS_ERR(mux_chip))
return PTR_ERR(mux_chip);
mux_chip->ops = &adgs1408_ops;
ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE);
if (ret < 0)
return ret;
ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
if (ret < 0)
idle_state = MUX_IDLE_AS_IS;
mux = mux_chip->mux;
if (chip_id == ADGS1408)
mux->states = 8;
else
mux->states = 4;
switch (idle_state) {
case MUX_IDLE_DISCONNECT:
case MUX_IDLE_AS_IS:
case 0 ... 7:
/* adgs1409 supports only 4 states */
if (idle_state < mux->states) {
mux->idle_state = idle_state;
break;
}
fallthrough;
default:
dev_err(dev, "invalid idle-state %d\n", idle_state);
return -EINVAL;
}
return devm_mux_chip_register(dev, mux_chip);
}
static const struct spi_device_id adgs1408_spi_id[] = {
{ "adgs1408", ADGS1408 },
{ "adgs1409", ADGS1409 },
{ }
};
MODULE_DEVICE_TABLE(spi, adgs1408_spi_id);
static const struct of_device_id adgs1408_of_match[] = {
{ .compatible = "adi,adgs1408", .data = (void *)ADGS1408, },
{ .compatible = "adi,adgs1409", .data = (void *)ADGS1409, },
{ }
};
MODULE_DEVICE_TABLE(of, adgs1408_of_match);
static struct spi_driver adgs1408_driver = {
.driver = {
.name = "adgs1408",
.of_match_table = adgs1408_of_match,
},
.probe = adgs1408_probe,
.id_table = adgs1408_spi_id,
};
module_spi_driver(adgs1408_driver);
MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");
MODULE_LICENSE("GPL");
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