1 /*
2 * soc-io.c -- ASoC register I/O helpers
3 *
4 * Copyright 2009-2011 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 modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14 #include <linux/i2c.h>
15 #include <linux/spi/spi.h>
16 #include <linux/regmap.h>
17 #include <linux/export.h>
18 #include <sound/soc.h>
19
20 #include <trace/events/asoc.h>
21
22 #ifdef CONFIG_REGMAP
hw_write(struct snd_soc_codec * codec,unsigned int reg,unsigned int value)23 static int hw_write(struct snd_soc_codec *codec, unsigned int reg,
24 unsigned int value)
25 {
26 int ret;
27
28 if (!snd_soc_codec_volatile_register(codec, reg) &&
29 reg < codec->driver->reg_cache_size &&
30 !codec->cache_bypass) {
31 ret = snd_soc_cache_write(codec, reg, value);
32 if (ret < 0)
33 return -1;
34 }
35
36 if (codec->cache_only) {
37 codec->cache_sync = 1;
38 return 0;
39 }
40
41 return regmap_write(codec->control_data, reg, value);
42 }
43
hw_read(struct snd_soc_codec * codec,unsigned int reg)44 static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
45 {
46 int ret;
47 unsigned int val;
48
49 if (reg >= codec->driver->reg_cache_size ||
50 snd_soc_codec_volatile_register(codec, reg) ||
51 codec->cache_bypass) {
52 if (codec->cache_only)
53 return -1;
54
55 ret = regmap_read(codec->control_data, reg, &val);
56 if (ret == 0)
57 return val;
58 else
59 return -1;
60 }
61
62 ret = snd_soc_cache_read(codec, reg, &val);
63 if (ret < 0)
64 return -1;
65 return val;
66 }
67
68 /* Primitive bulk write support for soc-cache. The data pointed to by
69 * `data' needs to already be in the form the hardware expects. Any
70 * data written through this function will not go through the cache as
71 * it only handles writing to volatile or out of bounds registers.
72 *
73 * This is currently only supported for devices using the regmap API
74 * wrappers.
75 */
snd_soc_hw_bulk_write_raw(struct snd_soc_codec * codec,unsigned int reg,const void * data,size_t len)76 static int snd_soc_hw_bulk_write_raw(struct snd_soc_codec *codec,
77 unsigned int reg,
78 const void *data, size_t len)
79 {
80 /* To ensure that we don't get out of sync with the cache, check
81 * whether the base register is volatile or if we've directly asked
82 * to bypass the cache. Out of bounds registers are considered
83 * volatile.
84 */
85 if (!codec->cache_bypass
86 && !snd_soc_codec_volatile_register(codec, reg)
87 && reg < codec->driver->reg_cache_size)
88 return -EINVAL;
89
90 return regmap_raw_write(codec->control_data, reg, data, len);
91 }
92
93 /**
94 * snd_soc_codec_set_cache_io: Set up standard I/O functions.
95 *
96 * @codec: CODEC to configure.
97 * @addr_bits: Number of bits of register address data.
98 * @data_bits: Number of bits of data per register.
99 * @control: Control bus used.
100 *
101 * Register formats are frequently shared between many I2C and SPI
102 * devices. In order to promote code reuse the ASoC core provides
103 * some standard implementations of CODEC read and write operations
104 * which can be set up using this function.
105 *
106 * The caller is responsible for allocating and initialising the
107 * actual cache.
108 *
109 * Note that at present this code cannot be used by CODECs with
110 * volatile registers.
111 */
snd_soc_codec_set_cache_io(struct snd_soc_codec * codec,int addr_bits,int data_bits,enum snd_soc_control_type control)112 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
113 int addr_bits, int data_bits,
114 enum snd_soc_control_type control)
115 {
116 struct regmap_config config;
117 int ret;
118
119 memset(&config, 0, sizeof(config));
120 codec->write = hw_write;
121 codec->read = hw_read;
122 codec->bulk_write_raw = snd_soc_hw_bulk_write_raw;
123
124 config.reg_bits = addr_bits;
125 config.val_bits = data_bits;
126
127 switch (control) {
128 #if defined(CONFIG_REGMAP_I2C) || defined(CONFIG_REGMAP_I2C_MODULE)
129 case SND_SOC_I2C:
130 codec->control_data = regmap_init_i2c(to_i2c_client(codec->dev),
131 &config);
132 break;
133 #endif
134
135 #if defined(CONFIG_REGMAP_SPI) || defined(CONFIG_REGMAP_SPI_MODULE)
136 case SND_SOC_SPI:
137 codec->control_data = regmap_init_spi(to_spi_device(codec->dev),
138 &config);
139 break;
140 #endif
141
142 case SND_SOC_REGMAP:
143 /* Device has made its own regmap arrangements */
144 codec->using_regmap = true;
145 if (!codec->control_data)
146 codec->control_data = dev_get_regmap(codec->dev, NULL);
147
148 if (codec->control_data) {
149 ret = regmap_get_val_bytes(codec->control_data);
150 /* Errors are legitimate for non-integer byte
151 * multiples */
152 if (ret > 0)
153 codec->val_bytes = ret;
154 }
155 break;
156
157 default:
158 return -EINVAL;
159 }
160
161 return PTR_RET(codec->control_data);
162 }
163 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
164 #else
snd_soc_codec_set_cache_io(struct snd_soc_codec * codec,int addr_bits,int data_bits,enum snd_soc_control_type control)165 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
166 int addr_bits, int data_bits,
167 enum snd_soc_control_type control)
168 {
169 return -ENOTSUPP;
170 }
171 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
172 #endif
173