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
wm8400_volatile(struct device * dev,unsigned int reg)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
wm8400_register_codec(struct wm8400 * wm8400)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 */
wm8400_init(struct wm8400 * wm8400,struct wm8400_platform_data * pdata)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_RBTREE,
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 */
wm8400_reset_codec_reg_cache(struct wm8400 * wm8400)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)
wm8400_i2c_probe(struct i2c_client * 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
wm8400_driver_init(void)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