linux-imx

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * ADGS1408/ADGS1409 SPI MUX driver

 *

 * Copyright 2018 Analog Devices Inc.

 */

​

#include <linux/err.h>

#include <linux/module.h>

#include <linux/mux/driver.h>

#include <linux/of_platform.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 = (enum adgs1408_chip_id)of_device_get_match_data(dev);

    if (!chip_id)

        chip_id = spi_get_device_id(spi)->driver_data;

​

    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) {