GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / mfd / wm8400-core.c
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         dev_set_drvdata(wm8400->dev, wm8400);
58
59         /* Check that this is actually a WM8400 */
60         ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);
61         if (ret != 0) {
62                 dev_err(wm8400->dev, "Chip ID register read failed\n");
63                 return -EIO;
64         }
65         if (reg != 0x6172) {
66                 dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
67                         reg);
68                 return -ENODEV;
69         }
70
71         ret = regmap_read(wm8400->regmap, WM8400_ID, &reg);
72         if (ret != 0) {
73                 dev_err(wm8400->dev, "ID register read failed: %d\n", ret);
74                 return ret;
75         }
76         reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
77         dev_info(wm8400->dev, "WM8400 revision %x\n", reg);
78
79         ret = wm8400_register_codec(wm8400);
80         if (ret != 0) {
81                 dev_err(wm8400->dev, "Failed to register codec\n");
82                 return ret;
83         }
84
85         if (pdata && pdata->platform_init) {
86                 ret = pdata->platform_init(wm8400->dev);
87                 if (ret != 0) {
88                         dev_err(wm8400->dev, "Platform init failed: %d\n",
89                                 ret);
90                         return ret;
91                 }
92         } else
93                 dev_warn(wm8400->dev, "No platform initialisation supplied\n");
94
95         return 0;
96 }
97
98 static const struct regmap_config wm8400_regmap_config = {
99         .reg_bits = 8,
100         .val_bits = 16,
101         .max_register = WM8400_REGISTER_COUNT - 1,
102
103         .volatile_reg = wm8400_volatile,
104
105         .cache_type = REGCACHE_RBTREE,
106 };
107
108 /**
109  * wm8400_reset_codec_reg_cache - Reset cached codec registers to
110  * their default values.
111  *
112  * @wm8400: pointer to local driver data structure
113  */
114 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
115 {
116         regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
117 }
118 EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
119
120 #if IS_ENABLED(CONFIG_I2C)
121 static int wm8400_i2c_probe(struct i2c_client *i2c,
122                             const struct i2c_device_id *id)
123 {
124         struct wm8400 *wm8400;
125
126         wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);
127         if (!wm8400)
128                 return -ENOMEM;
129
130         wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);
131         if (IS_ERR(wm8400->regmap))
132                 return PTR_ERR(wm8400->regmap);
133
134         wm8400->dev = &i2c->dev;
135         i2c_set_clientdata(i2c, wm8400);
136
137         return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));
138 }
139
140 static const struct i2c_device_id wm8400_i2c_id[] = {
141        { "wm8400", 0 },
142        { }
143 };
144
145 static struct i2c_driver wm8400_i2c_driver = {
146         .driver = {
147                 .name = "WM8400",
148         },
149         .probe    = wm8400_i2c_probe,
150         .id_table = wm8400_i2c_id,
151 };
152 #endif
153
154 static int __init wm8400_driver_init(void)
155 {
156         int ret = -ENODEV;
157
158 #if IS_ENABLED(CONFIG_I2C)
159         ret = i2c_add_driver(&wm8400_i2c_driver);
160         if (ret != 0)
161                 pr_err("Failed to register I2C driver: %d\n", ret);
162 #endif
163
164         return ret;
165 }
166 subsys_initcall(wm8400_driver_init);