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	/* Check that this is actually a WM8400 */
58	ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);
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, &reg);
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
96static 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 */
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{
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
137static const struct i2c_device_id wm8400_i2c_id[] = {
138       { "wm8400", 0 },
139       { }
140};
141
142static 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
151static 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}
163subsys_initcall(wm8400_driver_init);
164