linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * General Purpose I2C multiplexer

 *

 * Copyright (C) 2017 Axentia Technologies AB

 *

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

 */

​

#include <linux/i2c.h>

#include <linux/i2c-mux.h>

#include <linux/module.h>

#include <linux/mux/consumer.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

​

struct mux {

    struct mux_control *control;

​

    bool do_not_deselect;

};

​

static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)

{

    struct mux *mux = i2c_mux_priv(muxc);

    int ret;

​

    ret = mux_control_select(mux->control, chan);

    mux->do_not_deselect = ret < 0;

​

    return ret;

}

​

static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)

{

    struct mux *mux = i2c_mux_priv(muxc);

​

    if (mux->do_not_deselect)

        return 0;

​

    return mux_control_deselect(mux->control);

}

​

static struct i2c_adapter *mux_parent_adapter(struct device *dev)

{

    struct device_node *np = dev->of_node;

    struct device_node *parent_np;

    struct i2c_adapter *parent;

​

    parent_np = of_parse_phandle(np, "i2c-parent", 0);

    if (!parent_np) {

        dev_err(dev, "Cannot parse i2c-parent\n");

        return ERR_PTR(-ENODEV);

    }

    parent = of_find_i2c_adapter_by_node(parent_np);

    of_node_put(parent_np);

    if (!parent)

        return ERR_PTR(-EPROBE_DEFER);

​

    return parent;

}

​

static const struct of_device_id i2c_mux_of_match[] = {