wm8400-core.c

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/*
 * Core driver for WM8400.
 *
 * Copyright 2008 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/bug.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/mfd/core.h>
#include <linux/mfd/wm8400-private.h>
#include <linux/mfd/wm8400-audio.h>
#include <linux/regmap.h>
#include <linux/slab.h>

static bool wm8400_volatile(struct device *dev, unsigned int reg)
{
    switch (reg) {
    case WM8400_INTERRUPT_STATUS_1:
    case WM8400_INTERRUPT_LEVELS:
    case WM8400_SHUTDOWN_REASON:
        return true;
    default:
        return false;
    }
}

u16 wm8400_reg_read(struct wm8400 *wm8400, u8 reg)
{
    unsigned int val;
    int ret;

    ret = regmap_read(wm8400->regmap, reg, &val);
    if (ret < 0)
        return ret;

    return val;
}
EXPORT_SYMBOL_GPL(wm8400_reg_read);

int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data)
{
    return regmap_bulk_read(wm8400->regmap, reg, data, count);
}
EXPORT_SYMBOL_GPL(wm8400_block_read);

static int wm8400_register_codec(struct wm8400 *wm8400)
{
    struct mfd_cell cell = {
        .name = "wm8400-codec",
        .platform_data = wm8400,
        .pdata_size = sizeof(*wm8400),
    };

    return mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL);
}

/*
 * wm8400_init - Generic initialisation
 *
 * The WM8400 can be configured as either an I2C or SPI device.  Probe
 * functions for each bus set up the accessors then call into this to
 * set up the device itself.
 */
static int wm8400_init(struct wm8400 *wm8400,
               struct wm8400_platform_data *pdata)
{
    unsigned int reg;
    int ret;

    dev_set_drvdata(wm8400->dev, wm8400);

    /* Check that this is actually a WM8400 */
    ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);
    if (ret != 0) {
        dev_err(wm8400->dev, "Chip ID register read failed\n");
        return -EIO;
    }
    if (reg != 0x6172) {
        dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
            reg);
        return -ENODEV;
    }

    ret = regmap_read(wm8400->regmap, WM8400_ID, &reg);
    if (ret != 0) {
        dev_err(wm8400->dev, "ID register read failed: %d\n", ret);
        return ret;
    }
    reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
    dev_info(wm8400->dev, "WM8400 revision %x\n", reg);

    ret = wm8400_register_codec(wm8400);
    if (ret != 0) {
        dev_err(wm8400->dev, "Failed to register codec\n");
        goto err_children;
    }

    if (pdata && pdata->platform_init) {
        ret = pdata->platform_init(wm8400->dev);
        if (ret != 0) {
            dev_err(wm8400->dev, "Platform init failed: %d\n",
                ret);
            goto err_children;
        }
    } else
        dev_warn(wm8400->dev, "No platform initialisation supplied\n");

    return 0;

err_children:
    mfd_remove_devices(wm8400->dev);
    return ret;
}

static void wm8400_release(struct wm8400 *wm8400)
{
    mfd_remove_devices(wm8400->dev);
}

static const struct regmap_config wm8400_regmap_config = {
    .reg_bits = 8,
    .val_bits = 16,
    .max_register = WM8400_REGISTER_COUNT - 1,

    .volatile_reg = wm8400_volatile,

    .cache_type = REGCACHE_RBTREE,
};

void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
{
    regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
}
EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);

#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
static int wm8400_i2c_probe(struct i2c_client *i2c,
                const struct i2c_device_id *id)
{
    struct wm8400 *wm8400;
    int ret;

    wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);
    if (wm8400 == NULL) {
        ret = -ENOMEM;
        goto err;
    }

    wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);
    if (IS_ERR(wm8400->regmap)) {
        ret = PTR_ERR(wm8400->regmap);
        goto err;
    }

    wm8400->dev = &i2c->dev;
    i2c_set_clientdata(i2c, wm8400);

    ret = wm8400_init(wm8400, i2c->dev.platform_data);
    if (ret != 0)
        goto err;

    return 0;

err:
    return ret;
}

static int wm8400_i2c_remove(struct i2c_client *i2c)
{
    struct wm8400 *wm8400 = i2c_get_clientdata(i2c);

    wm8400_release(wm8400);

    return 0;
}

static const struct i2c_device_id wm8400_i2c_id[] = {
       { "wm8400", 0 },
       { }
};
MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id);

static struct i2c_driver wm8400_i2c_driver = {
    .driver = {
        .name = "WM8400",
        .owner = THIS_MODULE,
    },
    .probe    = wm8400_i2c_probe,
    .remove   = wm8400_i2c_remove,
    .id_table = wm8400_i2c_id,
};
#endif

static int __init wm8400_module_init(void)
{
    int ret = -ENODEV;

#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
    ret = i2c_add_driver(&wm8400_i2c_driver);
    if (ret != 0)
        pr_err("Failed to register I2C driver: %d\n", ret);
#endif

    return ret;
}
subsys_initcall(wm8400_module_init);

static void __exit wm8400_module_exit(void)
{
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
    i2c_del_driver(&wm8400_i2c_driver);
#endif
}
module_exit(wm8400_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mark Brown <[email protected]>");