linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * MMIO register bitfield-controlled multiplexer driver

 *

 * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>

 */

​

#include <linux/bitops.h>

#include <linux/err.h>

#include <linux/mfd/syscon.h>

#include <linux/module.h>

#include <linux/mux/driver.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/property.h>

#include <linux/regmap.h>

​

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

{

    struct regmap_field **fields = mux_chip_priv(mux->chip);

​

    return regmap_field_write(fields[mux_control_get_index(mux)], state);

}

​

static const struct mux_control_ops mux_mmio_ops = {

    .set = mux_mmio_set,

};

​

static const struct of_device_id mux_mmio_dt_ids[] = {

    { .compatible = "mmio-mux", },

    { /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mux_mmio_dt_ids);

​

static int mux_mmio_probe(struct platform_device *pdev)

{

    struct device *dev = &pdev->dev;

    struct device_node *np = dev->of_node;

    struct regmap_field **fields;

    struct mux_chip *mux_chip;

    struct regmap *regmap;

    int num_fields;

    int ret;

    int i;

​

    regmap = syscon_node_to_regmap(np->parent);

    if (IS_ERR(regmap)) {

        ret = PTR_ERR(regmap);

        dev_err(dev, "failed to get regmap: %d\n", ret);

        return ret;

    }

​

    ret = of_property_count_u32_elems(np, "mux-reg-masks");

    if (ret == 0 || ret % 2)

        ret = -EINVAL;

    if (ret < 0) {

        dev_err(dev, "mux-reg-masks property missing or invalid: %d\n",

            ret);

        return ret;

    }

    num_fields = ret / 2;

​

    mux_chip = devm_mux_chip_alloc(dev, num_fields, num_fields *