1/*
2 * Core driver for WM8400.
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/bug.h>
17#include <linux/err.h>
18#include <linux/i2c.h>
19#include <linux/kernel.h>
20#include <linux/mfd/core.h>
21#include <linux/mfd/wm8400-private.h>
22#include <linux/mfd/wm8400-audio.h>
23#include <linux/regmap.h>
24#include <linux/slab.h>
25
26static bool wm8400_volatile(struct device *dev, unsigned int reg)
27{
28	switch (reg) {
29	case WM8400_INTERRUPT_STATUS_1:
30	case WM8400_INTERRUPT_LEVELS:
31	case WM8400_SHUTDOWN_REASON:
32		return true;
33	default:
34		return false;
35	}
36}
37
38/**
39 * wm8400_reg_read - Single register read
40 *
41 * @wm8400: Pointer to wm8400 control structure
42 * @reg:    Register to read
43 *
44 * @return  Read value
45 */
46u16 wm8400_reg_read(struct wm8400 *wm8400, u8 reg)
47{
48	unsigned int val;
49	int ret;
50
51	ret = regmap_read(wm8400->regmap, reg, &val);
52	if (ret < 0)
53		return ret;
54
55	return val;
56}
57EXPORT_SYMBOL_GPL(wm8400_reg_read);
58
59int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data)
60{
61	return regmap_bulk_read(wm8400->regmap, reg, data, count);
62}
63EXPORT_SYMBOL_GPL(wm8400_block_read);
64
65static int wm8400_register_codec(struct wm8400 *wm8400)
66{
67	const struct mfd_cell cell = {
68		.name = "wm8400-codec",
69		.platform_data = wm8400,
70		.pdata_size = sizeof(*wm8400),
71	};
72
73	return mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL);
74}
75
76/*
77 * wm8400_init - Generic initialisation
78 *
79 * The WM8400 can be configured as either an I2C or SPI device.  Probe
80 * functions for each bus set up the accessors then call into this to
81 * set up the device itself.
82 */
83static int wm8400_init(struct wm8400 *wm8400,
84		       struct wm8400_platform_data *pdata)
85{
86	unsigned int reg;
87	int ret;
88
89	dev_set_drvdata(wm8400->dev, wm8400);
90
91	/* Check that this is actually a WM8400 */
92	ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &reg);
93	if (ret != 0) {
94		dev_err(wm8400->dev, "Chip ID register read failed\n");
95		return -EIO;
96	}
97	if (reg != 0x6172) {
98		dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
99			reg);
100		return -ENODEV;
101	}
102
103	ret = regmap_read(wm8400->regmap, WM8400_ID, &reg);
104	if (ret != 0) {
105		dev_err(wm8400->dev, "ID register read failed: %d\n", ret);
106		return ret;
107	}
108	reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
109	dev_info(wm8400->dev, "WM8400 revision %x\n", reg);
110
111	ret = wm8400_register_codec(wm8400);
112	if (ret != 0) {
113		dev_err(wm8400->dev, "Failed to register codec\n");
114		goto err_children;
115	}
116
117	if (pdata && pdata->platform_init) {
118		ret = pdata->platform_init(wm8400->dev);
119		if (ret != 0) {
120			dev_err(wm8400->dev, "Platform init failed: %d\n",
121				ret);
122			goto err_children;
123		}
124	} else
125		dev_warn(wm8400->dev, "No platform initialisation supplied\n");
126
127	return 0;
128
129err_children:
130	mfd_remove_devices(wm8400->dev);
131	return ret;
132}
133
134static void wm8400_release(struct wm8400 *wm8400)
135{
136	mfd_remove_devices(wm8400->dev);
137}
138
139static const struct regmap_config wm8400_regmap_config = {
140	.reg_bits = 8,
141	.val_bits = 16,
142	.max_register = WM8400_REGISTER_COUNT - 1,
143
144	.volatile_reg = wm8400_volatile,
145
146	.cache_type = REGCACHE_RBTREE,
147};
148
149/**
150 * wm8400_reset_codec_reg_cache - Reset cached codec registers to
151 * their default values.
152 */
153void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
154{
155	regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config);
156}
157EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
158
159#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
160static int wm8400_i2c_probe(struct i2c_client *i2c,
161			    const struct i2c_device_id *id)
162{
163	struct wm8400 *wm8400;
164
165	wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL);
166	if (!wm8400)
167		return -ENOMEM;
168
169	wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config);
170	if (IS_ERR(wm8400->regmap))
171		return PTR_ERR(wm8400->regmap);
172
173	wm8400->dev = &i2c->dev;
174	i2c_set_clientdata(i2c, wm8400);
175
176	return wm8400_init(wm8400, dev_get_platdata(&i2c->dev));
177}
178
179static int wm8400_i2c_remove(struct i2c_client *i2c)
180{
181	struct wm8400 *wm8400 = i2c_get_clientdata(i2c);
182
183	wm8400_release(wm8400);
184
185	return 0;
186}
187
188static const struct i2c_device_id wm8400_i2c_id[] = {
189       { "wm8400", 0 },
190       { }
191};
192MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id);
193
194static struct i2c_driver wm8400_i2c_driver = {
195	.driver = {
196		.name = "WM8400",
197		.owner = THIS_MODULE,
198	},
199	.probe    = wm8400_i2c_probe,
200	.remove   = wm8400_i2c_remove,
201	.id_table = wm8400_i2c_id,
202};
203#endif
204
205static int __init wm8400_module_init(void)
206{
207	int ret = -ENODEV;
208
209#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
210	ret = i2c_add_driver(&wm8400_i2c_driver);
211	if (ret != 0)
212		pr_err("Failed to register I2C driver: %d\n", ret);
213#endif
214
215	return ret;
216}
217subsys_initcall(wm8400_module_init);
218
219static void __exit wm8400_module_exit(void)
220{
221#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
222	i2c_del_driver(&wm8400_i2c_driver);
223#endif
224}
225module_exit(wm8400_module_exit);
226
227MODULE_LICENSE("GPL");
228MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
229