| Mark Brown | 17a52fd | 2009-07-05 17:24:50 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * soc-cache.c -- ASoC register cache helpers |
| 3 | * |
| 4 | * Copyright 2009 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 <sound/soc.h> |
| 15 | |
| 16 | static unsigned int snd_soc_7_9_read(struct snd_soc_codec *codec, |
| 17 | unsigned int reg) |
| 18 | { |
| 19 | u16 *cache = codec->reg_cache; |
| 20 | if (reg >= codec->reg_cache_size) |
| 21 | return -1; |
| 22 | return cache[reg]; |
| 23 | } |
| 24 | |
| 25 | static int snd_soc_7_9_write(struct snd_soc_codec *codec, unsigned int reg, |
| 26 | unsigned int value) |
| 27 | { |
| 28 | u16 *cache = codec->reg_cache; |
| 29 | u8 data[2]; |
| 30 | int ret; |
| 31 | |
| 32 | BUG_ON(codec->volatile_register); |
| 33 | |
| 34 | data[0] = (reg << 1) | ((value >> 8) & 0x0001); |
| 35 | data[1] = value & 0x00ff; |
| 36 | |
| 37 | if (reg < codec->reg_cache_size) |
| 38 | cache[reg] = value; |
| 39 | ret = codec->hw_write(codec->control_data, data, 2); |
| 40 | if (ret == 2) |
| 41 | return 0; |
| 42 | if (ret < 0) |
| 43 | return ret; |
| 44 | else |
| 45 | return -EIO; |
| 46 | } |
| 47 | |
| 48 | |
| 49 | static struct { |
| 50 | int addr_bits; |
| 51 | int data_bits; |
| 52 | int (*write)(struct snd_soc_codec *, unsigned int, unsigned int); |
| 53 | unsigned int (*read)(struct snd_soc_codec *, unsigned int); |
| 54 | } io_types[] = { |
| 55 | { 7, 9, snd_soc_7_9_write, snd_soc_7_9_read }, |
| 56 | }; |
| 57 | |
| 58 | /** |
| 59 | * snd_soc_codec_set_cache_io: Set up standard I/O functions. |
| 60 | * |
| 61 | * @codec: CODEC to configure. |
| 62 | * @type: Type of cache. |
| 63 | * @addr_bits: Number of bits of register address data. |
| 64 | * @data_bits: Number of bits of data per register. |
| 65 | * |
| 66 | * Register formats are frequently shared between many I2C and SPI |
| 67 | * devices. In order to promote code reuse the ASoC core provides |
| 68 | * some standard implementations of CODEC read and write operations |
| 69 | * which can be set up using this function. |
| 70 | * |
| 71 | * The caller is responsible for allocating and initialising the |
| 72 | * actual cache. |
| 73 | * |
| 74 | * Note that at present this code cannot be used by CODECs with |
| 75 | * volatile registers. |
| 76 | */ |
| 77 | int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec, |
| 78 | int addr_bits, int data_bits) |
| 79 | { |
| 80 | int i; |
| 81 | |
| 82 | /* We don't support volatile registers yet - refactoring of |
| 83 | * the hw_read operation will be required to do so. */ |
| 84 | if (codec->volatile_register) { |
| 85 | printk(KERN_ERR "Volatile registers not yet supported\n"); |
| 86 | return -EINVAL; |
| 87 | } |
| 88 | |
| 89 | for (i = 0; i < ARRAY_SIZE(io_types); i++) |
| 90 | if (io_types[i].addr_bits == addr_bits && |
| 91 | io_types[i].data_bits == data_bits) |
| 92 | break; |
| 93 | if (i == ARRAY_SIZE(io_types)) { |
| 94 | printk(KERN_ERR |
| 95 | "No I/O functions for %d bit address %d bit data\n", |
| 96 | addr_bits, data_bits); |
| 97 | return -EINVAL; |
| 98 | } |
| 99 | |
| 100 | codec->write = io_types[i].write; |
| 101 | codec->read = io_types[i].read; |
| 102 | |
| 103 | return 0; |
| 104 | } |
| 105 | EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io); |