tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
21static 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
33static 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 */
51static 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, ®);
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, ®);
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
98static 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 */
112void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
113{
114 regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
115}
116EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
117
118#if IS_ENABLED(CONFIG_I2C)
119static int wm8400_i2c_probe(struct i2c_client *i2c,
120 const struct i2c_device_id *id)
121{
122 struct wm8400 *wm8400;
123
124 wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);
125 if (!wm8400)
126 return -ENOMEM;
127
128 wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);
129 if (IS_ERR(wm8400->regmap))
130 return PTR_ERR(wm8400->regmap);
131
132 wm8400->dev = &i2c->dev;
133 i2c_set_clientdata(i2c, wm8400);
134
135 return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));
136}
137
138static const struct i2c_device_id wm8400_i2c_id[] = {
139 { "wm8400", 0 },
140 { }
141};
142
143static struct i2c_driver wm8400_i2c_driver = {
144 .driver = {
145 .name = "WM8400",
146 },
147 .probe = wm8400_i2c_probe,
148 .id_table = wm8400_i2c_id,
149};
150#endif
151
152static int __init wm8400_driver_init(void)
153{
154 int ret = -ENODEV;
155
156#if IS_ENABLED(CONFIG_I2C)
157 ret = i2c_add_driver(&wm8400_i2c_driver);
158 if (ret != 0)
159 pr_err("Failed to register I2C driver: %d\n", ret);
160#endif
161
162 return ret;
163}
164subsys_initcall(wm8400_driver_init);