diff options
Diffstat (limited to 'sound/soc/soc-cache.c')
| -rw-r--r-- | sound/soc/soc-cache.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c new file mode 100644 index 000000000000..c8ceddc2a26c --- /dev/null +++ b/sound/soc/soc-cache.c @@ -0,0 +1,218 @@ +/* + * soc-cache.c -- ASoC register cache helpers + * + * Copyright 2009 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/i2c.h> +#include <linux/spi/spi.h> +#include <sound/soc.h> + +static unsigned int snd_soc_7_9_read(struct snd_soc_codec *codec, + unsigned int reg) +{ + u16 *cache = codec->reg_cache; + if (reg >= codec->reg_cache_size) + return -1; + return cache[reg]; +} + +static int snd_soc_7_9_write(struct snd_soc_codec *codec, unsigned int reg, + unsigned int value) +{ + u16 *cache = codec->reg_cache; + u8 data[2]; + int ret; + + BUG_ON(codec->volatile_register); + + data[0] = (reg << 1) | ((value >> 8) & 0x0001); + data[1] = value & 0x00ff; + + if (reg < codec->reg_cache_size) + cache[reg] = value; + ret = codec->hw_write(codec->control_data, data, 2); + if (ret == 2) + return 0; + if (ret < 0) + return ret; + else + return -EIO; +} + +#if defined(CONFIG_SPI_MASTER) +static int snd_soc_7_9_spi_write(void *control_data, const char *data, + int len) +{ + struct spi_device *spi = control_data; + struct spi_transfer t; + struct spi_message m; + u8 msg[2]; + + if (len <= 0) + return 0; + + msg[0] = data[0]; + msg[1] = data[1]; + + spi_message_init(&m); + memset(&t, 0, (sizeof t)); + + t.tx_buf = &msg[0]; + t.len = len; + + spi_message_add_tail(&t, &m); + spi_sync(spi, &m); + + return len; +} +#else +#define snd_soc_7_9_spi_write NULL +#endif + +static int snd_soc_8_16_write(struct snd_soc_codec *codec, unsigned int reg, + unsigned int value) +{ + u16 *reg_cache = codec->reg_cache; + u8 data[3]; + + data[0] = reg; + data[1] = (value >> 8) & 0xff; + data[2] = value & 0xff; + + if (!snd_soc_codec_volatile_register(codec, reg)) + reg_cache[reg] = value; + + if (codec->hw_write(codec->control_data, data, 3) == 3) + return 0; + else + return -EIO; +} + +static unsigned int snd_soc_8_16_read(struct snd_soc_codec *codec, + unsigned int reg) +{ + u16 *cache = codec->reg_cache; + + if (reg >= codec->reg_cache_size || + snd_soc_codec_volatile_register(codec, reg)) + return codec->hw_read(codec, reg); + else + return cache[reg]; +} + +#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE)) +static unsigned int snd_soc_8_16_read_i2c(struct snd_soc_codec *codec, + unsigned int r) +{ + struct i2c_msg xfer[2]; + u8 reg = r; + u16 data; + int ret; + struct i2c_client *client = codec->control_data; + + /* Write register */ + xfer[0].addr = client->addr; + xfer[0].flags = 0; + xfer[0].len = 1; + xfer[0].buf = ® + + /* Read data */ + xfer[1].addr = client->addr; + xfer[1].flags = I2C_M_RD; + xfer[1].len = 2; + xfer[1].buf = (u8 *)&data; + + ret = i2c_transfer(client->adapter, xfer, 2); + if (ret != 2) { + dev_err(&client->dev, "i2c_transfer() returned %d\n", ret); + return 0; + } + + return (data >> 8) | ((data & 0xff) << 8); +} +#else +#define snd_soc_8_16_read_i2c NULL +#endif + +static struct { + int addr_bits; + int data_bits; + int (*write)(struct snd_soc_codec *codec, unsigned int, unsigned int); + int (*spi_write)(void *, const char *, int); + unsigned int (*read)(struct snd_soc_codec *, unsigned int); + unsigned int (*i2c_read)(struct snd_soc_codec *, unsigned int); +} io_types[] = { + { 7, 9, snd_soc_7_9_write, snd_soc_7_9_spi_write, snd_soc_7_9_read }, + { 8, 16, snd_soc_8_16_write, NULL, snd_soc_8_16_read, + snd_soc_8_16_read_i2c }, +}; + +/** + * snd_soc_codec_set_cache_io: Set up standard I/O functions. + * + * @codec: CODEC to configure. + * @type: Type of cache. + * @addr_bits: Number of bits of register address data. + * @data_bits: Number of bits of data per register. + * @control: Control bus used. + * + * Register formats are frequently shared between many I2C and SPI + * devices. In order to promote code reuse the ASoC core provides + * some standard implementations of CODEC read and write operations + * which can be set up using this function. + * + * The caller is responsible for allocating and initialising the + * actual cache. + * + * Note that at present this code cannot be used by CODECs with + * volatile registers. + */ +int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec, + int addr_bits, int data_bits, + enum snd_soc_control_type control) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(io_types); i++) + if (io_types[i].addr_bits == addr_bits && + io_types[i].data_bits == data_bits) + break; + if (i == ARRAY_SIZE(io_types)) { + printk(KERN_ERR + "No I/O functions for %d bit address %d bit data\n", + addr_bits, data_bits); + return -EINVAL; + } + + codec->write = io_types[i].write; + codec->read = io_types[i].read; + + switch (control) { + case SND_SOC_CUSTOM: + break; + + case SND_SOC_I2C: +#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE)) + codec->hw_write = (hw_write_t)i2c_master_send; +#endif + if (io_types[i].i2c_read) + codec->hw_read = io_types[i].i2c_read; + break; + + case SND_SOC_SPI: + if (io_types[i].spi_write) + codec->hw_write = io_types[i].spi_write; + break; + } + + return 0; +} +EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io); |