root/drivers/mfd/twl4030-audio.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * MFD driver for twl4030 audio submodule, which contains an audio codec, and
 * the vibra control.
 *
 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 *
 * Copyright:   (C) 2009 Nokia Corporation
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/mfd/twl.h>
#include <linux/mfd/core.h>
#include <linux/mfd/twl4030-audio.h>

#define TWL4030_AUDIO_CELLS     2

static struct platform_device *twl4030_audio_dev;

struct twl4030_audio_resource {
        int request_count;
        u8 reg;
        u8 mask;
};

struct twl4030_audio {
        unsigned int audio_mclk;
        struct mutex mutex;
        struct twl4030_audio_resource resource[TWL4030_AUDIO_RES_MAX];
        struct mfd_cell cells[TWL4030_AUDIO_CELLS];
};

/*
 * Modify the resource, the function returns the content of the register
 * after the modification.
 */
static int twl4030_audio_set_resource(enum twl4030_audio_res id, int enable)
{
        struct twl4030_audio *audio = platform_get_drvdata(twl4030_audio_dev);
        u8 val;

        twl_i2c_read_u8(TWL4030_MODULE_AUDIO_VOICE, &val,
                        audio->resource[id].reg);

        if (enable)
                val |= audio->resource[id].mask;
        else
                val &= ~audio->resource[id].mask;

        twl_i2c_write_u8(TWL4030_MODULE_AUDIO_VOICE,
                                        val, audio->resource[id].reg);

        return val;
}

static inline int twl4030_audio_get_resource(enum twl4030_audio_res id)
{
        struct twl4030_audio *audio = platform_get_drvdata(twl4030_audio_dev);
        u8 val;

        twl_i2c_read_u8(TWL4030_MODULE_AUDIO_VOICE, &val,
                        audio->resource[id].reg);

        return val;
}

/*
 * Enable the resource.
 * The function returns with error or the content of the register
 */
int twl4030_audio_enable_resource(enum twl4030_audio_res id)
{
        struct twl4030_audio *audio = platform_get_drvdata(twl4030_audio_dev);
        int val;

        if (id >= TWL4030_AUDIO_RES_MAX) {
                dev_err(&twl4030_audio_dev->dev,
                                "Invalid resource ID (%u)\n", id);
                return -EINVAL;
        }

        mutex_lock(&audio->mutex);
        if (!audio->resource[id].request_count)
                /* Resource was disabled, enable it */
                val = twl4030_audio_set_resource(id, 1);
        else
                val = twl4030_audio_get_resource(id);

        audio->resource[id].request_count++;
        mutex_unlock(&audio->mutex);

        return val;
}
EXPORT_SYMBOL_GPL(twl4030_audio_enable_resource);

/*
 * Disable the resource.
 * The function returns with error or the content of the register
 */
int twl4030_audio_disable_resource(enum twl4030_audio_res id)
{
        struct twl4030_audio *audio = platform_get_drvdata(twl4030_audio_dev);
        int val;

        if (id >= TWL4030_AUDIO_RES_MAX) {
                dev_err(&twl4030_audio_dev->dev,
                                "Invalid resource ID (%u)\n", id);
                return -EINVAL;
        }

        mutex_lock(&audio->mutex);
        if (!audio->resource[id].request_count) {
                dev_err(&twl4030_audio_dev->dev,
                        "Resource has been disabled already (%u)\n", id);
                mutex_unlock(&audio->mutex);
                return -EPERM;
        }
        audio->resource[id].request_count--;

        if (!audio->resource[id].request_count)
                /* Resource can be disabled now */
                val = twl4030_audio_set_resource(id, 0);
        else
                val = twl4030_audio_get_resource(id);

        mutex_unlock(&audio->mutex);

        return val;
}
EXPORT_SYMBOL_GPL(twl4030_audio_disable_resource);

unsigned int twl4030_audio_get_mclk(void)
{
        struct twl4030_audio *audio = platform_get_drvdata(twl4030_audio_dev);

        return audio->audio_mclk;
}
EXPORT_SYMBOL_GPL(twl4030_audio_get_mclk);

static bool twl4030_audio_has_codec(struct twl4030_audio_data *pdata,
                              struct device_node *parent)
{
        struct device_node *node;

        if (pdata && pdata->codec)
                return true;

        node = of_get_child_by_name(parent, "codec");
        if (node) {
                of_node_put(node);
                return true;
        }

        return false;
}

static bool twl4030_audio_has_vibra(struct twl4030_audio_data *pdata,
                              struct device_node *node)
{
        int vibra;

        if (pdata && pdata->vibra)
                return true;

        if (!of_property_read_u32(node, "ti,enable-vibra", &vibra) && vibra)
                return true;

        return false;
}

static int twl4030_audio_probe(struct platform_device *pdev)
{
        struct twl4030_audio *audio;
        struct twl4030_audio_data *pdata = dev_get_platdata(&pdev->dev);
        struct device_node *node = pdev->dev.of_node;
        struct mfd_cell *cell = NULL;
        int ret, childs = 0;
        u8 val;

        if (!pdata && !node) {
                dev_err(&pdev->dev, "Platform data is missing\n");
                return -EINVAL;
        }

        audio = devm_kzalloc(&pdev->dev, sizeof(struct twl4030_audio),
                             GFP_KERNEL);
        if (!audio)
                return -ENOMEM;

        mutex_init(&audio->mutex);
        audio->audio_mclk = twl_get_hfclk_rate();

        /* Configure APLL_INFREQ and disable APLL if enabled */
        switch (audio->audio_mclk) {
        case 19200000:
                val = TWL4030_APLL_INFREQ_19200KHZ;
                break;
        case 26000000:
                val = TWL4030_APLL_INFREQ_26000KHZ;
                break;
        case 38400000:
                val = TWL4030_APLL_INFREQ_38400KHZ;
                break;
        default:
                dev_err(&pdev->dev, "Invalid audio_mclk\n");
                return -EINVAL;
        }
        twl_i2c_write_u8(TWL4030_MODULE_AUDIO_VOICE, val, TWL4030_REG_APLL_CTL);

        /* Codec power */
        audio->resource[TWL4030_AUDIO_RES_POWER].reg = TWL4030_REG_CODEC_MODE;
        audio->resource[TWL4030_AUDIO_RES_POWER].mask = TWL4030_CODECPDZ;

        /* PLL */
        audio->resource[TWL4030_AUDIO_RES_APLL].reg = TWL4030_REG_APLL_CTL;
        audio->resource[TWL4030_AUDIO_RES_APLL].mask = TWL4030_APLL_EN;

        if (twl4030_audio_has_codec(pdata, node)) {
                cell = &audio->cells[childs];
                cell->name = "twl4030-codec";
                if (pdata) {
                        cell->platform_data = pdata->codec;
                        cell->pdata_size = sizeof(*pdata->codec);
                }
                childs++;
        }
        if (twl4030_audio_has_vibra(pdata, node)) {
                cell = &audio->cells[childs];
                cell->name = "twl4030-vibra";
                if (pdata) {
                        cell->platform_data = pdata->vibra;
                        cell->pdata_size = sizeof(*pdata->vibra);
                }
                childs++;
        }

        platform_set_drvdata(pdev, audio);
        twl4030_audio_dev = pdev;

        if (childs)
                ret = mfd_add_devices(&pdev->dev, pdev->id, audio->cells,
                                      childs, NULL, 0, NULL);
        else {
                dev_err(&pdev->dev, "No platform data found for childs\n");
                ret = -ENODEV;
        }

        if (ret)
                twl4030_audio_dev = NULL;

        return ret;
}

static void twl4030_audio_remove(struct platform_device *pdev)
{
        mfd_remove_devices(&pdev->dev);
        twl4030_audio_dev = NULL;
}

static const struct of_device_id twl4030_audio_of_match[] = {
        {.compatible = "ti,twl4030-audio", },
        { },
};
MODULE_DEVICE_TABLE(of, twl4030_audio_of_match);

static struct platform_driver twl4030_audio_driver = {
        .driver         = {
                .name   = "twl4030-audio",
                .of_match_table = twl4030_audio_of_match,
        },
        .probe          = twl4030_audio_probe,
        .remove         = twl4030_audio_remove,
};

module_platform_driver(twl4030_audio_driver);

MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_DESCRIPTION("TWL4030 audio block MFD driver");
MODULE_ALIAS("platform:twl4030-audio");