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(dev: wm8400->dev, id: -1, cells: &cell, n_devs: 1, NULL, irq_base: 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 | /* Check that this is actually a WM8400 */ |
58 | ret = regmap_read(map: wm8400->regmap, WM8400_RESET_ID, val: ®); |
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(map: wm8400->regmap, WM8400_ID, val: ®); |
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 | |
96 | static 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 | */ |
112 | void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400) |
113 | { |
114 | regmap_reinit_cache(map: wm8400->regmap, config: &wm8400_regmap_config); |
115 | } |
116 | EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache); |
117 | |
118 | #if IS_ENABLED(CONFIG_I2C) |
119 | static int wm8400_i2c_probe(struct i2c_client *i2c) |
120 | { |
121 | struct wm8400 *wm8400; |
122 | |
123 | wm8400 = devm_kzalloc(dev: &i2c->dev, size: 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(ptr: wm8400->regmap)) |
129 | return PTR_ERR(ptr: wm8400->regmap); |
130 | |
131 | wm8400->dev = &i2c->dev; |
132 | i2c_set_clientdata(client: i2c, data: wm8400); |
133 | |
134 | return wm8400_init(wm8400, pdata: dev_get_platdata(dev: &i2c->dev)); |
135 | } |
136 | |
137 | static const struct i2c_device_id wm8400_i2c_id[] = { |
138 | { "wm8400" , 0 }, |
139 | { } |
140 | }; |
141 | |
142 | static 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 | |
151 | static 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 | } |
163 | subsys_initcall(wm8400_driver_init); |
164 | |