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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Core driver for WM8400.4 *5 * Copyright 2008 Wolfson Microelectronics PLC.6 *7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>8 */9 10#include <linux/init.h>11#include <linux/bug.h>12#include <linux/err.h>13#include <linux/i2c.h>14#include <linux/kernel.h>15#include <linux/mfd/core.h>16#include <linux/mfd/wm8400-private.h>17#include <linux/mfd/wm8400-audio.h>18#include <linux/regmap.h>19#include <linux/slab.h>20 21static bool wm8400_volatile(struct device *dev, unsigned int reg)22{23 switch (reg) {24 case WM8400_INTERRUPT_STATUS_1:25 case WM8400_INTERRUPT_LEVELS:26 case WM8400_SHUTDOWN_REASON:27 return true;28 default:29 return false;30 }31}32 33static int wm8400_register_codec(struct wm8400 *wm8400)34{35 const struct mfd_cell cell = {36 .name = "wm8400-codec",37 .platform_data = wm8400,38 .pdata_size = sizeof(*wm8400),39 };40 41 return devm_mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL);42}43 44/*45 * wm8400_init - Generic initialisation46 *47 * The WM8400 can be configured as either an I2C or SPI device. Probe48 * functions for each bus set up the accessors then call into this to49 * set up the device itself.50 */51static int wm8400_init(struct wm8400 *wm8400,52 struct wm8400_platform_data *pdata)53{54 unsigned int reg;55 int ret;56 57 /* Check that this is actually a WM8400 */58 ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, ®);59 if (ret != 0) {60 dev_err(wm8400->dev, "Chip ID register read failed\n");61 return -EIO;62 }63 if (reg != 0x6172) {64 dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",65 reg);66 return -ENODEV;67 }68 69 ret = regmap_read(wm8400->regmap, WM8400_ID, ®);70 if (ret != 0) {71 dev_err(wm8400->dev, "ID register read failed: %d\n", ret);72 return ret;73 }74 reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;75 dev_info(wm8400->dev, "WM8400 revision %x\n", reg);76 77 ret = wm8400_register_codec(wm8400);78 if (ret != 0) {79 dev_err(wm8400->dev, "Failed to register codec\n");80 return ret;81 }82 83 if (pdata && pdata->platform_init) {84 ret = pdata->platform_init(wm8400->dev);85 if (ret != 0) {86 dev_err(wm8400->dev, "Platform init failed: %d\n",87 ret);88 return ret;89 }90 } else91 dev_warn(wm8400->dev, "No platform initialisation supplied\n");92 93 return 0;94}95 96static const struct regmap_config wm8400_regmap_config = {97 .reg_bits = 8,98 .val_bits = 16,99 .max_register = WM8400_REGISTER_COUNT - 1,100 101 .volatile_reg = wm8400_volatile,102 103 .cache_type = REGCACHE_MAPLE,104};105 106/**107 * wm8400_reset_codec_reg_cache - Reset cached codec registers to108 * their default values.109 *110 * @wm8400: pointer to local driver data structure111 */112void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)113{114 regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);115}116EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);117 118#if IS_ENABLED(CONFIG_I2C)119static int wm8400_i2c_probe(struct i2c_client *i2c)120{121 struct wm8400 *wm8400;122 123 wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);124 if (!wm8400)125 return -ENOMEM;126 127 wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);128 if (IS_ERR(wm8400->regmap))129 return PTR_ERR(wm8400->regmap);130 131 wm8400->dev = &i2c->dev;132 i2c_set_clientdata(i2c, wm8400);133 134 return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));135}136 137static const struct i2c_device_id wm8400_i2c_id[] = {138 { "wm8400" },139 { }140};141 142static struct i2c_driver wm8400_i2c_driver = {143 .driver = {144 .name = "WM8400",145 },146 .probe = wm8400_i2c_probe,147 .id_table = wm8400_i2c_id,148};149#endif150 151static int __init wm8400_driver_init(void)152{153 int ret = -ENODEV;154 155#if IS_ENABLED(CONFIG_I2C)156 ret = i2c_add_driver(&wm8400_i2c_driver);157 if (ret != 0)158 pr_err("Failed to register I2C driver: %d\n", ret);159#endif160 161 return ret;162}163subsys_initcall(wm8400_driver_init);164