linux/sound/soc/atmel/atmel-pcm.c
Linus Torvalds 8ceafbfa91 Merge branch 'for-linus-dma-masks' of git://git.linaro.org/people/rmk/linux-arm
Pull DMA mask updates from Russell King:
 "This series cleans up the handling of DMA masks in a lot of drivers,
  fixing some bugs as we go.

  Some of the more serious errors include:
   - drivers which only set their coherent DMA mask if the attempt to
     set the streaming mask fails.
   - drivers which test for a NULL dma mask pointer, and then set the
     dma mask pointer to a location in their module .data section -
     which will cause problems if the module is reloaded.

  To counter these, I have introduced two helper functions:
   - dma_set_mask_and_coherent() takes care of setting both the
     streaming and coherent masks at the same time, with the correct
     error handling as specified by the API.
   - dma_coerce_mask_and_coherent() which resolves the problem of
     drivers forcefully setting DMA masks.  This is more a marker for
     future work to further clean these locations up - the code which
     creates the devices really should be initialising these, but to fix
     that in one go along with this change could potentially be very
     disruptive.

  The last thing this series does is prise away some of Linux's addition
  to "DMA addresses are physical addresses and RAM always starts at
  zero".  We have ARM LPAE systems where all system memory is above 4GB
  physical, hence having DMA masks interpreted by (eg) the block layers
  as describing physical addresses in the range 0..DMAMASK fails on
  these platforms.  Santosh Shilimkar addresses this in this series; the
  patches were copied to the appropriate people multiple times but were
  ignored.

  Fixing this also gets rid of some ARM weirdness in the setup of the
  max*pfn variables, and brings ARM into line with every other Linux
  architecture as far as those go"

* 'for-linus-dma-masks' of git://git.linaro.org/people/rmk/linux-arm: (52 commits)
  ARM: 7805/1: mm: change max*pfn to include the physical offset of memory
  ARM: 7797/1: mmc: Use dma_max_pfn(dev) helper for bounce_limit calculations
  ARM: 7796/1: scsi: Use dma_max_pfn(dev) helper for bounce_limit calculations
  ARM: 7795/1: mm: dma-mapping: Add dma_max_pfn(dev) helper function
  ARM: 7794/1: block: Rename parameter dma_mask to max_addr for blk_queue_bounce_limit()
  ARM: DMA-API: better handing of DMA masks for coherent allocations
  ARM: 7857/1: dma: imx-sdma: setup dma mask
  DMA-API: firmware/google/gsmi.c: avoid direct access to DMA masks
  DMA-API: dcdbas: update DMA mask handing
  DMA-API: dma: edma.c: no need to explicitly initialize DMA masks
  DMA-API: usb: musb: use platform_device_register_full() to avoid directly messing with dma masks
  DMA-API: crypto: remove last references to 'static struct device *dev'
  DMA-API: crypto: fix ixp4xx crypto platform device support
  DMA-API: others: use dma_set_coherent_mask()
  DMA-API: staging: use dma_set_coherent_mask()
  DMA-API: usb: use new dma_coerce_mask_and_coherent()
  DMA-API: usb: use dma_set_coherent_mask()
  DMA-API: parport: parport_pc.c: use dma_coerce_mask_and_coherent()
  DMA-API: net: octeon: use dma_coerce_mask_and_coherent()
  DMA-API: net: nxp/lpc_eth: use dma_coerce_mask_and_coherent()
  ...
2013-11-14 07:55:21 +09:00

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C

/*
* atmel-pcm.c -- ALSA PCM interface for the Atmel atmel SoC.
*
* Copyright (C) 2005 SAN People
* Copyright (C) 2008 Atmel
*
* Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
*
* Based on at91-pcm. by:
* Frank Mandarino <fmandarino@endrelia.com>
* Copyright 2006 Endrelia Technologies Inc.
*
* Based on pxa2xx-pcm.c by:
*
* Author: Nicolas Pitre
* Created: Nov 30, 2004
* Copyright: (C) 2004 MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include "atmel-pcm.h"
static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
size_t size = ATMEL_SSC_DMABUF_SIZE;
buf->dev.type = SNDRV_DMA_TYPE_DEV;
buf->dev.dev = pcm->card->dev;
buf->private_data = NULL;
buf->area = dma_alloc_coherent(pcm->card->dev, size,
&buf->addr, GFP_KERNEL);
pr_debug("atmel-pcm: alloc dma buffer: area=%p, addr=%p, size=%zu\n",
(void *)buf->area, (void *)(long)buf->addr, size);
if (!buf->area)
return -ENOMEM;
buf->bytes = size;
return 0;
}
int atmel_pcm_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
{
return remap_pfn_range(vma, vma->vm_start,
substream->dma_buffer.addr >> PAGE_SHIFT,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
}
EXPORT_SYMBOL_GPL(atmel_pcm_mmap);
int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
struct snd_card *card = rtd->card->snd_card;
struct snd_pcm *pcm = rtd->pcm;
int ret;
ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
if (ret)
return ret;
if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
ret = atmel_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
if (ret)
goto out;
}
if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
ret = atmel_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_CAPTURE);
if (ret)
goto out;
}
out:
return ret;
}
EXPORT_SYMBOL_GPL(atmel_pcm_new);
void atmel_pcm_free(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
int stream;
for (stream = 0; stream < 2; stream++) {
substream = pcm->streams[stream].substream;
if (!substream)
continue;
buf = &substream->dma_buffer;
if (!buf->area)
continue;
dma_free_coherent(pcm->card->dev, buf->bytes,
buf->area, buf->addr);
buf->area = NULL;
}
}
EXPORT_SYMBOL_GPL(atmel_pcm_free);