1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 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 21 static 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 33 static 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 initialisation 46 * 47 * The WM8400 can be configured as either an I2C or SPI device. Probe 48 * functions for each bus set up the accessors then call into this to 49 * set up the device itself. 50 */ 51 static 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 } else 91 dev_warn(wm8400->dev, "No platform initialisation supplied\n"); 92 93 return 0; 94 } 95 96 static 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 to 108 * their default values. 109 * 110 * @wm8400: pointer to local driver data structure 111 */ 112 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400) 113 { 114 regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config); 115 } 116 EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache); 117 118 #if IS_ENABLED(CONFIG_I2C) 119 static 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 } 136 137 static const struct i2c_device_id wm8400_i2c_id[] = { 138 { "wm8400", 0 }, 139 { } 140 }; 141 142 static 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 #endif 150 151 static 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 #endif 160 161 return ret; 162 } 163 subsys_initcall(wm8400_driver_init); 164