linux-imx

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

/*

 * Pinctrl based I2C DeMultiplexer

 *

 * Copyright (C) 2015-16 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>

 * Copyright (C) 2015-16 by Renesas Electronics Corporation

 *

 * See the bindings doc for DTS setup and the sysfs doc for usage information.

 * (look for filenames containing 'i2c-demux-pinctrl' in Documentation/)

 */

​

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/pinctrl/consumer.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/slab.h>

#include <linux/sysfs.h>

​

struct i2c_demux_pinctrl_chan {

    struct device_node *parent_np;

    struct i2c_adapter *parent_adap;

    struct of_changeset chgset;

};

​

struct i2c_demux_pinctrl_priv {

    int cur_chan;

    int num_chan;

    struct device *dev;

    const char *bus_name;

    struct i2c_adapter cur_adap;

    struct i2c_algorithm algo;

    struct i2c_demux_pinctrl_chan chan[];

};

​

static int i2c_demux_master_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

{

    struct i2c_demux_pinctrl_priv *priv = adap->algo_data;

    struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;

​

    return __i2c_transfer(parent, msgs, num);

}

​

static u32 i2c_demux_functionality(struct i2c_adapter *adap)

{

    struct i2c_demux_pinctrl_priv *priv = adap->algo_data;

    struct i2c_adapter *parent = priv->chan[priv->cur_chan].parent_adap;

​

    return parent->algo->functionality(parent);

}

​

static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 new_chan)

{

    struct i2c_adapter *adap;

    struct pinctrl *p;

    int ret;

​

    ret = of_changeset_apply(&priv->chan[new_chan].chgset);

    if (ret)

        goto err;

​