diff options
| author | Nicolin Chen <b42378@freescale.com> | 2013-10-23 11:47:43 +0800 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-10-24 09:20:47 +0200 |
| commit | 055032142c42d2821c4aa617915292d6a08d56fc (patch) | |
| tree | ce10032a40379b482eda19f8b04f8924a1625195 /sound/core/pcm_native.c | |
| parent | 861e66d3418a90f57b31a50110fc70b23569c551 (diff) | |
| download | lwn-055032142c42d2821c4aa617915292d6a08d56fc.tar.gz lwn-055032142c42d2821c4aa617915292d6a08d56fc.zip | |
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.c | 6 |
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) |