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 int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data) 39 { 40 return regmap_bulk_read(wm8400->regmap, reg, data, count); 41 } 42 EXPORT_SYMBOL_GPL(wm8400_block_read); 43 44 static 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 */ 62 static 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, ®); 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, ®); 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 } 108 109 static 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 */ 123 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400) 124 { 125 regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config); 126 } 127 EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache); 128 129 #if IS_ENABLED(CONFIG_I2C) 130 static 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 } 148 149 static const struct i2c_device_id wm8400_i2c_id[] = { 150 { "wm8400", 0 }, 151 { } 152 }; 153 MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id); 154 155 static 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 163 164 static 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 } 176 subsys_initcall(wm8400_module_init); 177 178 static void __exit wm8400_module_exit(void) 179 { 180 #if IS_ENABLED(CONFIG_I2C) 181 i2c_del_driver(&wm8400_i2c_driver); 182 #endif 183 } 184 module_exit(wm8400_module_exit); 185 186 MODULE_LICENSE("GPL"); 187 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 188