linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux

 *

 * Copyright (C) 2017 Axentia Technologies AB

 *

 * Author: Peter Rosin <peda@axentia.se>

 */

​

#include <linux/err.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/mux/driver.h>

#include <linux/property.h>

​

#define ADG792A_LDSW        BIT(0)

#define ADG792A_RESETB      BIT(1)

#define ADG792A_DISABLE(mux)    (0x50 | (mux))

#define ADG792A_DISABLE_ALL (0x5f)

#define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state))

#define ADG792A_MUX_ALL(state)  (0xc0 | (state))

​

static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset)

{

    u8 data = ADG792A_RESETB | ADG792A_LDSW;

​

    /* ADG792A_RESETB is active low, the chip resets when it is zero. */

    if (reset)

        data &= ~ADG792A_RESETB;

​

    return i2c_smbus_write_byte_data(i2c, cmd, data);

}

​

static int adg792a_set(struct mux_control *mux, int state)

{

    struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent);

    u8 cmd;

​

    if (mux->chip->controllers == 1) {

        /* parallel mux controller operation */

        if (state == MUX_IDLE_DISCONNECT)

            cmd = ADG792A_DISABLE_ALL;

        else

            cmd = ADG792A_MUX_ALL(state);

    } else {

        unsigned int controller = mux_control_get_index(mux);

​

        if (state == MUX_IDLE_DISCONNECT)

            cmd = ADG792A_DISABLE(controller);

        else

            cmd = ADG792A_MUX(controller, state);

    }

​

    return adg792a_write_cmd(i2c, cmd, 0);

}

​

static const struct mux_control_ops adg792a_ops = {

    .set = adg792a_set,

};

​

static int adg792a_probe(struct i2c_client *i2c)

{

    struct device *dev = &i2c->dev;