linux/sound/soc/cirrus/ep93xx-pcm.c
Lars-Peter Clausen acde50a7bf ASoC: dmaengine_pcm: Make FLAG_NO_RESIDUE internal
Whether residue can be reported or not is not a property of the audio
controller but of the DMA controller. The FLAG_NO_RESIDUE was initially
added when the DMAengine framework had no support for describing the residue
reporting capabilities of the controller. Support for this was added quite a
while ago and recently the DMAengine framework started to complain if a
driver does not describe its capabilities and a lot of patches have been
merged that add support for this where it was missing. So it should be safe
to assume that driver on actively used platforms properly implement the DMA
capabilities API.

This patch makes the FLAG_NO_RESIDUE internal and no longer allows audio
controller drivers to manually set the flag. If a DMA driver against
expectations does not support reporting its capabilities for now the generic
DMAengine PCM driver will now emit a warning and simply assume that residue
reporting is not supported. In the future this might be changed to aborting
with an error.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-04-27 19:26:07 +01:00

70 lines
1.9 KiB
C

/*
* linux/sound/arm/ep93xx-pcm.c - EP93xx ALSA PCM interface
*
* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
* Copyright (C) 2006 Applied Data Systems
*
* Rewritten for the SoC audio subsystem (Based on PXA2xx code):
* Copyright (c) 2008 Ryan Mallon
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include <linux/platform_data/dma-ep93xx.h>
#include "ep93xx-pcm.h"
static const struct snd_pcm_hardware ep93xx_pcm_hardware = {
.info = (SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_BLOCK_TRANSFER),
.buffer_bytes_max = 131072,
.period_bytes_min = 32,
.period_bytes_max = 32768,
.periods_min = 1,
.periods_max = 32,
.fifo_size = 32,
};
static bool ep93xx_pcm_dma_filter(struct dma_chan *chan, void *filter_param)
{
struct ep93xx_dma_data *data = filter_param;
if (data->direction == ep93xx_dma_chan_direction(chan)) {
chan->private = data;
return true;
}
return false;
}
static const struct snd_dmaengine_pcm_config ep93xx_dmaengine_pcm_config = {
.pcm_hardware = &ep93xx_pcm_hardware,
.compat_filter_fn = ep93xx_pcm_dma_filter,
.prealloc_buffer_size = 131072,
};
int devm_ep93xx_pcm_platform_register(struct device *dev)
{
return devm_snd_dmaengine_pcm_register(dev,
&ep93xx_dmaengine_pcm_config,
SND_DMAENGINE_PCM_FLAG_NO_DT |
SND_DMAENGINE_PCM_FLAG_COMPAT);
}
EXPORT_SYMBOL_GPL(devm_ep93xx_pcm_platform_register);
MODULE_AUTHOR("Ryan Mallon");
MODULE_DESCRIPTION("EP93xx ALSA PCM interface");
MODULE_LICENSE("GPL");