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authorNicolin Chen <b42378@freescale.com>2013-10-23 07:47:43 +0400
committerTakashi Iwai <tiwai@suse.de>2013-10-24 11:20:47 +0400
commit055032142c42d2821c4aa617915292d6a08d56fc (patch)
treece10032a40379b482eda19f8b04f8924a1625195 /sound/core/memalloc.c
parent861e66d3418a90f57b31a50110fc70b23569c551 (diff)
downloadlinux-055032142c42d2821c4aa617915292d6a08d56fc.tar.xz
ALSA: Add SoC on-chip internal ram support for DMA buffer allocation
Now it's quite common that an SoC contains its on-chip internal RAM. By using this RAM space for DMA buffer during audio playback/record, we can shutdown the voltage for external RAM to save power. So add new DEV type with iram malloc()/free() and accordingly modify current default mmap() for the iram circumstance. Signed-off-by: Nicolin Chen <b42378@freescale.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/memalloc.c')
-rw-r--r--sound/core/memalloc.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index bdf826f4fe0c..18c1d4759ccb 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -30,6 +30,7 @@
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include <linux/dma-mapping.h>
+#include <linux/genalloc.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <sound/memalloc.h>
@@ -157,6 +158,46 @@ static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dec_snd_pages(pg);
dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
}
+
+/**
+ * snd_malloc_dev_iram - allocate memory from on-chip internal ram
+ * @dmab: buffer allocation record to store the allocated data
+ * @size: number of bytes to allocate from the iram
+ *
+ * This function requires iram phandle provided via of_node
+ */
+void snd_malloc_dev_iram(struct snd_dma_buffer *dmab, size_t size)
+{
+ struct device *dev = dmab->dev.dev;
+ struct gen_pool *pool = NULL;
+
+ if (dev->of_node)
+ pool = of_get_named_gen_pool(dev->of_node, "iram", 0);
+
+ if (!pool)
+ return;
+
+ /* Assign the pool into private_data field */
+ dmab->private_data = pool;
+
+ dmab->area = (void *)gen_pool_alloc(pool, size);
+ if (!dmab->area)
+ return;
+
+ dmab->addr = gen_pool_virt_to_phys(pool, (unsigned long)dmab->area);
+}
+
+/**
+ * snd_free_dev_iram - free allocated specific memory from on-chip internal ram
+ * @dmab: buffer allocation record to store the allocated data
+ */
+void snd_free_dev_iram(struct snd_dma_buffer *dmab)
+{
+ struct gen_pool *pool = dmab->private_data;
+
+ if (pool && dmab->area)
+ gen_pool_free(pool, (unsigned long)dmab->area, dmab->bytes);
+}
#endif /* CONFIG_HAS_DMA */
/*
@@ -197,6 +238,14 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
dmab->addr = 0;
break;
#ifdef CONFIG_HAS_DMA
+ case SNDRV_DMA_TYPE_DEV_IRAM:
+ snd_malloc_dev_iram(dmab, size);
+ if (dmab->area)
+ break;
+ /* Internal memory might have limited size and no enough space,
+ * so if we fail to malloc, try to fetch memory traditionally.
+ */
+ dmab->dev.type = SNDRV_DMA_TYPE_DEV;
case SNDRV_DMA_TYPE_DEV:
dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
break;
@@ -269,6 +318,9 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab)
snd_free_pages(dmab->area, dmab->bytes);
break;
#ifdef CONFIG_HAS_DMA
+ case SNDRV_DMA_TYPE_DEV_IRAM:
+ snd_free_dev_iram(dmab);
+ break;
case SNDRV_DMA_TYPE_DEV:
snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
break;