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 26 static 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 38 /** 39 * wm8400_reg_read - Single register read 40 * 41 * @wm8400: Pointer to wm8400 control structure 42 * @reg: Register to read 43 * 44 * @return Read value 45 */ 46 u16 wm8400_reg_read(struct wm8400 *wm8400, u8 reg) 47 { 48 unsigned int val; 49 int ret; 50 51 ret = regmap_read(wm8400->regmap, reg, &val); 52 if (ret < 0) 53 return ret; 54 55 return val; 56 } 57 EXPORT_SYMBOL_GPL(wm8400_reg_read); 58 59 int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data) 60 { 61 return regmap_bulk_read(wm8400->regmap, reg, data, count); 62 } 63 EXPORT_SYMBOL_GPL(wm8400_block_read); 64 65 static int wm8400_register_codec(struct wm8400 *wm8400) 66 { 67 const struct mfd_cell cell = { 68 .name = "wm8400-codec", 69 .platform_data = wm8400, 70 .pdata_size = sizeof(*wm8400), 71 }; 72 73 return mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL); 74 } 75 76 /* 77 * wm8400_init - Generic initialisation 78 * 79 * The WM8400 can be configured as either an I2C or SPI device. Probe 80 * functions for each bus set up the accessors then call into this to 81 * set up the device itself. 82 */ 83 static int wm8400_init(struct wm8400 *wm8400, 84 struct wm8400_platform_data *pdata) 85 { 86 unsigned int reg; 87 int ret; 88 89 dev_set_drvdata(wm8400->dev, wm8400); 90 91 /* Check that this is actually a WM8400 */ 92 ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, ®); 93 if (ret != 0) { 94 dev_err(wm8400->dev, "Chip ID register read failed\n"); 95 return -EIO; 96 } 97 if (reg != 0x6172) { 98 dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n", 99 reg); 100 return -ENODEV; 101 } 102 103 ret = regmap_read(wm8400->regmap, WM8400_ID, ®); 104 if (ret != 0) { 105 dev_err(wm8400->dev, "ID register read failed: %d\n", ret); 106 return ret; 107 } 108 reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT; 109 dev_info(wm8400->dev, "WM8400 revision %x\n", reg); 110 111 ret = wm8400_register_codec(wm8400); 112 if (ret != 0) { 113 dev_err(wm8400->dev, "Failed to register codec\n"); 114 goto err_children; 115 } 116 117 if (pdata && pdata->platform_init) { 118 ret = pdata->platform_init(wm8400->dev); 119 if (ret != 0) { 120 dev_err(wm8400->dev, "Platform init failed: %d\n", 121 ret); 122 goto err_children; 123 } 124 } else 125 dev_warn(wm8400->dev, "No platform initialisation supplied\n"); 126 127 return 0; 128 129 err_children: 130 mfd_remove_devices(wm8400->dev); 131 return ret; 132 } 133 134 static void wm8400_release(struct wm8400 *wm8400) 135 { 136 mfd_remove_devices(wm8400->dev); 137 } 138 139 static const struct regmap_config wm8400_regmap_config = { 140 .reg_bits = 8, 141 .val_bits = 16, 142 .max_register = WM8400_REGISTER_COUNT - 1, 143 144 .volatile_reg = wm8400_volatile, 145 146 .cache_type = REGCACHE_RBTREE, 147 }; 148 149 /** 150 * wm8400_reset_codec_reg_cache - Reset cached codec registers to 151 * their default values. 152 */ 153 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400) 154 { 155 regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config); 156 } 157 EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache); 158 159 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 160 static int wm8400_i2c_probe(struct i2c_client *i2c, 161 const struct i2c_device_id *id) 162 { 163 struct wm8400 *wm8400; 164 165 wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL); 166 if (!wm8400) 167 return -ENOMEM; 168 169 wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config); 170 if (IS_ERR(wm8400->regmap)) 171 return PTR_ERR(wm8400->regmap); 172 173 wm8400->dev = &i2c->dev; 174 i2c_set_clientdata(i2c, wm8400); 175 176 return wm8400_init(wm8400, dev_get_platdata(&i2c->dev)); 177 } 178 179 static int wm8400_i2c_remove(struct i2c_client *i2c) 180 { 181 struct wm8400 *wm8400 = i2c_get_clientdata(i2c); 182 183 wm8400_release(wm8400); 184 185 return 0; 186 } 187 188 static const struct i2c_device_id wm8400_i2c_id[] = { 189 { "wm8400", 0 }, 190 { } 191 }; 192 MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id); 193 194 static struct i2c_driver wm8400_i2c_driver = { 195 .driver = { 196 .name = "WM8400", 197 }, 198 .probe = wm8400_i2c_probe, 199 .remove = wm8400_i2c_remove, 200 .id_table = wm8400_i2c_id, 201 }; 202 #endif 203 204 static int __init wm8400_module_init(void) 205 { 206 int ret = -ENODEV; 207 208 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 209 ret = i2c_add_driver(&wm8400_i2c_driver); 210 if (ret != 0) 211 pr_err("Failed to register I2C driver: %d\n", ret); 212 #endif 213 214 return ret; 215 } 216 subsys_initcall(wm8400_module_init); 217 218 static void __exit wm8400_module_exit(void) 219 { 220 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 221 i2c_del_driver(&wm8400_i2c_driver); 222 #endif 223 } 224 module_exit(wm8400_module_exit); 225 226 MODULE_LICENSE("GPL"); 227 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 228