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authorNicolin Chen <b42378@freescale.com>2013-10-23 11:47:43 +0800
committerTakashi Iwai <tiwai@suse.de>2013-10-24 09:20:47 +0200
commit055032142c42d2821c4aa617915292d6a08d56fc (patch)
treece10032a40379b482eda19f8b04f8924a1625195 /sound/core/pcm_native.c
parent861e66d3418a90f57b31a50110fc70b23569c551 (diff)
downloadlinux-055032142c42d2821c4aa617915292d6a08d56fc.tar.bz2
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/pcm_native.c')
-rw-r--r--sound/core/pcm_native.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index a68d4c6d702c..513f0954d92e 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3199,6 +3199,12 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *area)
{
area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+ if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_IRAM) {
+ area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+ return remap_pfn_range(area, area->vm_start,
+ substream->dma_buffer.addr >> PAGE_SHIFT,
+ area->vm_end - area->vm_start, area->vm_page_prot);
+ }
#ifdef ARCH_HAS_DMA_MMAP_COHERENT
if (!substream->ops->page &&
substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)