LXR linux/drivers/mfd/wm8400-core.c

   1/*
   2 * Core driver for WM8400.
   3 *
   4 * Copyright 2008 Wolfson Microelectronics PLC.
   5 *
   6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of the
  11 * License, or (at your option) any later version.
  12 *
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/bug.h>
  17#include <linux/err.h>
  18#include <linux/i2c.h>
  19#include <linux/kernel.h>
  20#include <linux/mfd/core.h>
  21#include <linux/mfd/wm8400-private.h>
  22#include <linux/mfd/wm8400-audio.h>
  23#include <linux/regmap.h>
  24#include <linux/slab.h>
  25
  26static bool wm8400_volatile(struct device *dev, unsigned int reg)
  27{
  28        switch (reg) {
  29        case WM8400_INTERRUPT_STATUS_1:
  30        case WM8400_INTERRUPT_LEVELS:
  31        case WM8400_SHUTDOWN_REASON:
  32                return true;
  33        default:
  34                return false;
  35        }
  36}
  37
  38int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data)
  39{
  40        return regmap_bulk_read(wm8400->regmap, reg, data, count);
  41}
  42EXPORT_SYMBOL_GPL(wm8400_block_read);
  43
  44static int wm8400_register_codec(struct wm8400 *wm8400)
  45{
  46        const struct mfd_cell cell = {
  47                .name = "wm8400-codec",
  48                .platform_data = wm8400,
  49                .pdata_size = sizeof(*wm8400),
  50        };
  51
  52        return devm_mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL);
  53}
  54
  55/*
  56 * wm8400_init - Generic initialisation
  57 *
  58 * The WM8400 can be configured as either an I2C or SPI device.  Probe
  59 * functions for each bus set up the accessors then call into this to
  60 * set up the device itself.
  61 */
  62static int wm8400_init(struct wm8400 *wm8400,
  63                       struct wm8400_platform_data *pdata)
  64{
  65        unsigned int reg;
  66        int ret;
  67
  68        dev_set_drvdata(wm8400->dev, wm8400);
  69
  70        /* Check that this is actually a WM8400 */
  71        ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);
  72        if (ret != 0) {
  73                dev_err(wm8400->dev, "Chip ID register read failed\n");
  74                return -EIO;
  75        }
  76        if (reg != 0x6172) {
  77                dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
  78                        reg);
  79                return -ENODEV;
  80        }
  81
  82        ret = regmap_read(wm8400->regmap, WM8400_ID, &reg);
  83        if (ret != 0) {
  84                dev_err(wm8400->dev, "ID register read failed: %d\n", ret);
  85                return ret;
  86        }
  87        reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
  88        dev_info(wm8400->dev, "WM8400 revision %x\n", reg);
  89
  90        ret = wm8400_register_codec(wm8400);
  91        if (ret != 0) {
  92                dev_err(wm8400->dev, "Failed to register codec\n");
  93                return ret;
  94        }
  95
  96        if (pdata && pdata->platform_init) {
  97                ret = pdata->platform_init(wm8400->dev);
  98                if (ret != 0) {
  99                        dev_err(wm8400->dev, "Platform init failed: %d\n",
 100                                ret);
 101                        return ret;
 102                }
 103        } else
 104                dev_warn(wm8400->dev, "No platform initialisation supplied\n");
 105
 106        return 0;
 107}
 108
 109static const struct regmap_config wm8400_regmap_config = {
 110        .reg_bits = 8,
 111        .val_bits = 16,
 112        .max_register = WM8400_REGISTER_COUNT - 1,
 113
 114        .volatile_reg = wm8400_volatile,
 115
 116        .cache_type = REGCACHE_RBTREE,
 117};
 118
 119/**
 120 * wm8400_reset_codec_reg_cache - Reset cached codec registers to
 121 * their default values.
 122 */
 123void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
 124{
 125        regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
 126}
 127EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
 128
 129#if IS_ENABLED(CONFIG_I2C)
 130static int wm8400_i2c_probe(struct i2c_client *i2c,
 131                            const struct i2c_device_id *id)
 132{
 133        struct wm8400 *wm8400;
 134
 135        wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);
 136        if (!wm8400)
 137                return -ENOMEM;
 138
 139        wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);
 140        if (IS_ERR(wm8400->regmap))
 141                return PTR_ERR(wm8400->regmap);
 142
 143        wm8400->dev = &i2c->dev;
 144        i2c_set_clientdata(i2c, wm8400);
 145
 146        return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));
 147}
 148
 149static const struct i2c_device_id wm8400_i2c_id[] = {
 150       { "wm8400", 0 },
 151       { }
 152};
 153MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id);
 154
 155static struct i2c_driver wm8400_i2c_driver = {
 156        .driver = {
 157                .name = "WM8400",
 158        },
 159        .probe    = wm8400_i2c_probe,
 160        .id_table = wm8400_i2c_id,
 161};
 162#endif
 163
 164static int __init wm8400_module_init(void)
 165{
 166        int ret = -ENODEV;
 167
 168#if IS_ENABLED(CONFIG_I2C)
 169        ret = i2c_add_driver(&wm8400_i2c_driver);
 170        if (ret != 0)
 171                pr_err("Failed to register I2C driver: %d\n", ret);
 172#endif
 173
 174        return ret;
 175}
 176subsys_initcall(wm8400_module_init);
 177
 178static void __exit wm8400_module_exit(void)
 179{
 180#if IS_ENABLED(CONFIG_I2C)
 181        i2c_del_driver(&wm8400_i2c_driver);
 182#endif
 183}
 184module_exit(wm8400_module_exit);
 185
 186MODULE_LICENSE("GPL");
 187MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 188