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, &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
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 *
112 * @wm8400: pointer to local driver data structure
113 */
114void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
115{
116	regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
117}
118EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
119
120#if IS_ENABLED(CONFIG_I2C)
121static 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
140static const struct i2c_device_id wm8400_i2c_id[] = {
141       { "wm8400", 0 },
142       { }
143};
144
145static 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
154static 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}
166subsys_initcall(wm8400_driver_init);
167