This patch adds support for LZO compression when storing the register cache. The initial register defaults cache is marked as __devinitconst and the only change required for a driver to use LZO compression is to set the compress_type member in codec->driver to SND_SOC_LZO_COMPRESSION.
Signed-off-by: Dimitris Papastamos dp@opensource.wolfsonmicro.com --- sound/soc/soc-cache.c | 379 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 379 insertions(+), 0 deletions(-)
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index a8ec23a..ea9d80f 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -14,6 +14,8 @@ #include <linux/i2c.h> #include <linux/spi/spi.h> #include <sound/soc.h> +#include <linux/lzo.h> +#include <linux/bitmap.h>
static unsigned int snd_soc_4_12_read(struct snd_soc_codec *codec, unsigned int reg) @@ -764,6 +766,375 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec, } EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
+struct snd_soc_lzo_ctx { + void *wmem; + void *dst; + const void *src; + size_t src_len; + size_t dst_len; + size_t decompressed_size; + unsigned long *sync_bmp; + int sync_bmp_nbits; +}; + +#define LZO_BLOCK_NUM 8 +static int snd_soc_lzo_block_count(void) +{ + return LZO_BLOCK_NUM; +} + +static int snd_soc_lzo_prepare(struct snd_soc_lzo_ctx *lzo_ctx) +{ + lzo_ctx->wmem = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!lzo_ctx->wmem) + return -ENOMEM; + return 0; +} + +static int snd_soc_lzo_compress(struct snd_soc_lzo_ctx *lzo_ctx) +{ + size_t compress_size; + int ret; + + ret = lzo1x_1_compress(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &compress_size, lzo_ctx->wmem); + if (ret != LZO_E_OK || compress_size > lzo_ctx->dst_len) + return -EINVAL; + lzo_ctx->dst_len = compress_size; + return 0; +} + +static int snd_soc_lzo_decompress(struct snd_soc_lzo_ctx *lzo_ctx) +{ + size_t dst_len; + int ret; + + dst_len = lzo_ctx->dst_len; + ret = lzo1x_decompress_safe(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &dst_len); + if (ret != LZO_E_OK || dst_len != lzo_ctx->dst_len) + return -EINVAL; + return 0; +} + +static int snd_soc_compress_cache_block(struct snd_soc_codec *codec, + struct snd_soc_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo1x_worst_compress(PAGE_SIZE); + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = snd_soc_lzo_compress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static int snd_soc_decompress_cache_block(struct snd_soc_codec *codec, + struct snd_soc_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo_ctx->decompressed_size; + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = snd_soc_lzo_decompress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static inline int snd_soc_get_lzo_blkindex(struct snd_soc_codec *codec, + unsigned int reg) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return (reg * codec_drv->reg_word_size) / + DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()); +} + +static inline int snd_soc_get_lzo_blkpos(struct snd_soc_codec *codec, + unsigned int reg) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return reg % (DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()) / + codec_drv->reg_word_size); +} + +static inline int snd_soc_get_lzo_blksize(struct snd_soc_codec *codec) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()); +} + +static int snd_soc_cache_lzo_sync(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + unsigned int val; + int n; + + lzo_blocks = codec->reg_cache; + for_each_set_bit(n, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) { + snd_soc_cache_read(codec, n, &val); + snd_soc_write(codec, n, val); + } + + return 0; +} + +static int snd_soc_cache_lzo_write(struct snd_soc_codec *codec, + unsigned int reg, unsigned int value) +{ + struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks; + u8 *cache; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + /* index of the compressed lzo block */ + blkindex = snd_soc_get_lzo_blkindex(codec, reg); + /* register index within the decompressed block */ + blkpos = snd_soc_get_lzo_blkpos(codec, reg); + blkpos *= codec->driver->reg_word_size; + /* size of the compressed block */ + blksize = snd_soc_get_lzo_blksize(codec); + lzo_blocks = codec->reg_cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = snd_soc_decompress_cache_block(codec, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + goto out; + } + + cache = lzo_block->dst; + /* bail out early, no change in value */ + if (!memcmp(&cache[blkpos], &value, + codec->driver->reg_word_size)) { + kfree(lzo_block->dst); + goto out; + } + /* set the new register value */ + memcpy(&cache[blkpos], &value, codec->driver->reg_word_size); + + /* prepare the source to be the decompressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* compress the block */ + ret = snd_soc_compress_cache_block(codec, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + kfree(lzo_block->src); + goto out; + } + + /* set the bit so we know we have to sync this register */ + set_bit(reg, lzo_block->sync_bmp); + kfree(tmp_dst); + kfree(lzo_block->src); + return 0; +out: + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + return ret; +} + +static int snd_soc_cache_lzo_read(struct snd_soc_codec *codec, + unsigned int reg, unsigned int *value) +{ + struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks; + u8 *cache; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + *value = 0; + /* index of the compressed lzo block */ + blkindex = snd_soc_get_lzo_blkindex(codec, reg); + /* register index within the decompressed block */ + blkpos = snd_soc_get_lzo_blkpos(codec, reg); + blkpos *= codec->driver->reg_word_size; + /* size of the compressed block */ + blksize = snd_soc_get_lzo_blksize(codec); + lzo_blocks = codec->reg_cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = snd_soc_decompress_cache_block(codec, lzo_block); + if (ret >= 0) { + cache = lzo_block->dst; + memcpy(value, &cache[blkpos], + codec->driver->reg_word_size); + } + + kfree(lzo_block->dst); + /* restore the pointer and length of the compressed block */ + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + return 0; +} + +static int snd_soc_cache_lzo_deinit(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + int i, blkcount; + + lzo_blocks = codec->reg_cache; + if (!lzo_blocks) + return -EINVAL; + + blkcount = snd_soc_lzo_block_count(); + if (lzo_blocks[0]) + kfree(lzo_blocks[0]->sync_bmp); + for (i = 0; i < blkcount; ++i) { + if (lzo_blocks[i]) { + kfree(lzo_blocks[i]->wmem); + kfree(lzo_blocks[i]->dst); + } + kfree(lzo_blocks[i]); + lzo_blocks[i] = NULL; + } + kfree(lzo_blocks); + codec->reg_cache = NULL; + return 0; +} + +static int snd_soc_cache_lzo_init(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + size_t reg_size; + struct snd_soc_codec_driver *codec_drv; + int ret, tofree, i, blksize, blkcount; + const char *p, *end; + unsigned long *sync_bmp; + + ret = 0; + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + + /* + * If we have not been given a default register cache + * then allocate a dummy zero-ed out region, compress it + * and remember to free it afterwards. + */ + tofree = 0; + if (!codec_drv->reg_cache_default) + tofree = 1; + + if (!codec_drv->reg_cache_default) { + codec_drv->reg_cache_default = kzalloc(reg_size, + GFP_KERNEL); + if (!codec_drv->reg_cache_default) + return -ENOMEM; + } + + blkcount = snd_soc_lzo_block_count(); + codec->reg_cache = kzalloc(blkcount * sizeof(*lzo_blocks), + GFP_KERNEL); + if (!codec->reg_cache) { + ret = -ENOMEM; + goto err_tofree; + } + lzo_blocks = codec->reg_cache; + + /* + * allocate a bitmap to be used when syncing the cache with + * the hardware. Each time a register is modified, the corresponding + * bit is set in the bitmap, so we know that we have to sync + * that register. + */ + sync_bmp = kmalloc(BITS_TO_LONGS(reg_size) * sizeof(unsigned long), + GFP_KERNEL); + if (!sync_bmp) { + ret = -ENOMEM; + goto err; + } + bitmap_zero(sync_bmp, reg_size); + + /* allocate the lzo blocks and initialize them */ + for (i = 0; i < blkcount; ++i) { + lzo_blocks[i] = kzalloc(sizeof **lzo_blocks, + GFP_KERNEL); + if (!lzo_blocks[i]) { + kfree(sync_bmp); + ret = -ENOMEM; + goto err; + } + lzo_blocks[i]->sync_bmp = sync_bmp; + lzo_blocks[i]->sync_bmp_nbits = reg_size; + /* alloc the working space for the compressed block */ + ret = snd_soc_lzo_prepare(lzo_blocks[i]); + if (ret < 0) + goto err; + } + + blksize = snd_soc_get_lzo_blksize(codec); + p = codec_drv->reg_cache_default; + end = codec_drv->reg_cache_default + reg_size; + /* compress the register map and fill the lzo blocks */ + for (i = 0; i < blkcount; ++i, p += blksize) { + lzo_blocks[i]->src = p; + if (p + blksize > end) + lzo_blocks[i]->src_len = end - p; + else + lzo_blocks[i]->src_len = blksize; + ret = snd_soc_compress_cache_block(codec, + lzo_blocks[i]); + if (ret < 0) + goto err; + lzo_blocks[i]->decompressed_size = + lzo_blocks[i]->src_len; + } + + if (tofree) + kfree(codec_drv->reg_cache_default); + return 0; +err: + snd_soc_cache_deinit(codec); +err_tofree: + if (tofree) + kfree(codec_drv->reg_cache_default); + return ret; +} + static int snd_soc_cache_default_sync(struct snd_soc_codec *codec) { const u8 *cache; @@ -842,6 +1213,14 @@ static const struct snd_soc_cache_ops cache_types[] = { .read = snd_soc_cache_default_read, .write = snd_soc_cache_default_write, .sync = snd_soc_cache_default_sync + }, + { + .id = SND_SOC_LZO_COMPRESSION, + .init = snd_soc_cache_lzo_init, + .deinit = snd_soc_cache_lzo_deinit, + .read = snd_soc_cache_lzo_read, + .write = snd_soc_cache_lzo_write, + .sync = snd_soc_cache_lzo_sync } };