ASoC: soc-cache: Add support for LZO register caching
[pandora-kernel.git] / sound / soc / soc-cache.c
index cbf9694..4581bf1 100644 (file)
@@ -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)
@@ -758,6 +760,409 @@ 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_lzo_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_lzo_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_lzo_get_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_lzo_get_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_lzo_get_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_lzo_cache_sync(struct snd_soc_codec *codec)
+{
+       struct snd_soc_lzo_ctx **lzo_blocks;
+       unsigned int val;
+       int i;
+
+       lzo_blocks = codec->reg_cache;
+       for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) {
+               snd_soc_cache_read(codec, i, &val);
+               snd_soc_write(codec, i, val);
+               dev_dbg(codec->dev, "Synced register %#x, value = %#x\n",
+                       i, val);
+       }
+
+       return 0;
+}
+
+static int snd_soc_lzo_cache_write(struct snd_soc_codec *codec,
+                                  unsigned int reg, unsigned int value)
+{
+       struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks;
+       int ret, blkindex, blkpos;
+       size_t blksize, tmp_dst_len;
+       void *tmp_dst;
+
+       /* index of the compressed lzo block */
+       blkindex = snd_soc_lzo_get_blkindex(codec, reg);
+       /* register index within the decompressed block */
+       blkpos = snd_soc_lzo_get_blkpos(codec, reg);
+       /* size of the compressed block */
+       blksize = snd_soc_lzo_get_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_lzo_decompress_cache_block(codec, lzo_block);
+       if (ret < 0) {
+               kfree(lzo_block->dst);
+               goto out;
+       }
+
+       /* write the new value to the cache */
+       switch (codec->driver->reg_word_size) {
+       case 1: {
+               u8 *cache;
+               cache = lzo_block->dst;
+               if (cache[blkpos] == value) {
+                       kfree(lzo_block->dst);
+                       goto out;
+               }
+               cache[blkpos] = value;
+       }
+       break;
+       case 2: {
+               u16 *cache;
+               cache = lzo_block->dst;
+               if (cache[blkpos] == value) {
+                       kfree(lzo_block->dst);
+                       goto out;
+               }
+               cache[blkpos] = value;
+       }
+       break;
+       default:
+               BUG();
+       }
+
+       /* 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_lzo_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_lzo_cache_read(struct snd_soc_codec *codec,
+                                 unsigned int reg, unsigned int *value)
+{
+       struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks;
+       int ret, blkindex, blkpos;
+       size_t blksize, tmp_dst_len;
+       void *tmp_dst;
+
+       *value = 0;
+       /* index of the compressed lzo block */
+       blkindex = snd_soc_lzo_get_blkindex(codec, reg);
+       /* register index within the decompressed block */
+       blkpos = snd_soc_lzo_get_blkpos(codec, reg);
+       /* size of the compressed block */
+       blksize = snd_soc_lzo_get_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_lzo_decompress_cache_block(codec, lzo_block);
+       if (ret >= 0) {
+               /* fetch the value from the cache */
+               switch (codec->driver->reg_word_size) {
+               case 1: {
+                       u8 *cache;
+                       cache = lzo_block->dst;
+                       *value = cache[blkpos];
+               }
+               break;
+               case 2: {
+                       u16 *cache;
+                       cache = lzo_block->dst;
+                       *value = cache[blkpos];
+               }
+               break;
+               default:
+                       BUG();
+               }
+       }
+
+       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_lzo_cache_exit(struct snd_soc_codec *codec)
+{
+       struct snd_soc_lzo_ctx **lzo_blocks;
+       int i, blkcount;
+
+       lzo_blocks = codec->reg_cache;
+       if (!lzo_blocks)
+               return 0;
+
+       blkcount = snd_soc_lzo_block_count();
+       /*
+        * the pointer to the bitmap used for syncing the cache
+        * is shared amongst all lzo_blocks.  Ensure it is freed
+        * only once.
+        */
+       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);
+               }
+               /* each lzo_block is a pointer returned by kmalloc or NULL */
+               kfree(lzo_blocks[i]);
+       }
+       kfree(lzo_blocks);
+       codec->reg_cache = NULL;
+       return 0;
+}
+
+static int snd_soc_lzo_cache_init(struct snd_soc_codec *codec)
+{
+       struct snd_soc_lzo_ctx **lzo_blocks;
+       size_t reg_size, bmp_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.
+        */
+       bmp_size = codec_drv->reg_cache_size;
+       sync_bmp = kmalloc(BITS_TO_LONGS(bmp_size) * sizeof (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_lzo_get_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_lzo_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_exit(codec);
+err_tofree:
+       if (tofree)
+               kfree(codec_drv->reg_cache_default);
+       return ret;
+}
+
 static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec)
 {
        int i;
@@ -883,6 +1288,14 @@ static const struct snd_soc_cache_ops cache_types[] = {
                .read = snd_soc_flat_cache_read,
                .write = snd_soc_flat_cache_write,
                .sync = snd_soc_flat_cache_sync
+       },
+       {
+               .id = SND_SOC_LZO_COMPRESSION,
+               .init = snd_soc_lzo_cache_init,
+               .exit = snd_soc_lzo_cache_exit,
+               .read = snd_soc_lzo_cache_read,
+               .write = snd_soc_lzo_cache_write,
+               .sync = snd_soc_lzo_cache_sync
        }
 };