3 files changed, 417 insertions, 1 deletions

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 275e41133468..10f5932d3d07 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -256,7 +256,8 @@ enum snd_soc_control_type {
 };
 
 enum snd_soc_compress_type {
-        SND_SOC_NO_COMPRESSION
+        SND_SOC_NO_COMPRESSION,
+        SND_SOC_LZO_COMPRESSION
 };
 
 int snd_soc_register_platform(struct device *dev,
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 3e598e756e54..4562c898a7ef 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -4,6 +4,8 @@
 
 menuconfig SND_SOC
         tristate "ALSA for SoC audio support"
+        select LZO_COMPRESS
+        select LZO_DECOMPRESS
         select SND_PCM
         select AC97_BUS if SND_SOC_AC97_BUS
         select SND_JACK if INPUT=y || INPUT=SND
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index cbf9694097b2..4581bf100222 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)
@@ -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
         }
 };