linux-imx

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

/*

 * I2C multiplexer using GPIO API

 *

 * Peter Korsgaard <peter.korsgaard@barco.com>

 */

​

#include <linux/i2c.h>

#include <linux/i2c-mux.h>

#include <linux/platform_data/i2c-mux-gpio.h>

#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/gpio.h>

#include "../../gpio/gpiolib.h"

#include <linux/of_gpio.h>

​

struct gpiomux {

    struct i2c_mux_gpio_platform_data data;

    unsigned gpio_base;

    struct gpio_desc **gpios;

};

​

static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)

{

    DECLARE_BITMAP(values, BITS_PER_TYPE(val));

​

    values[0] = val;

​

    gpiod_set_array_value_cansleep(mux->data.n_gpios, mux->gpios, NULL,

                       values);

}

​

static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)

{

    struct gpiomux *mux = i2c_mux_priv(muxc);

​

    i2c_mux_gpio_set(mux, chan);

​

    return 0;

}

​

static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)

{

    struct gpiomux *mux = i2c_mux_priv(muxc);

​

    i2c_mux_gpio_set(mux, mux->data.idle);

​

    return 0;

}

​

static int match_gpio_chip_by_label(struct gpio_chip *chip,

                          void *data)

{

    return !strcmp(chip->label, data);

}

​

#ifdef CONFIG_OF

static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,

                    struct platform_device *pdev)

{

    struct device_node *np = pdev->dev.of_node;

    struct device_node *adapter_np, *child;

    struct i2c_adapter *adapter;

    unsigned *values, *gpios;

    int i = 0, ret;

​

    if (!np)

        return -ENODEV;

​

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

    if (!adapter_np) {

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

        return -ENODEV;

    }

    adapter = of_find_i2c_adapter_by_node(adapter_np);

    of_node_put(adapter_np);

    if (!adapter)

        return -EPROBE_DEFER;

​

    mux->data.parent = i2c_adapter_id(adapter);

    put_device(&adapter->dev);

​

    mux->data.n_values = of_get_child_count(np);

​

    values = devm_kcalloc(&pdev->dev,

                  mux->data.n_values, sizeof(*mux->data.values),

                  GFP_KERNEL);

    if (!values) {

        dev_err(&pdev->dev, "Cannot allocate values array");

        return -ENOMEM;

    }