![Lars-Peter Clausen](/assets/img/avatar_default.png)
The ASoC core assumes that the PCM component of the ASoC card transparently moves data around and does not impose any restrictions on the memory layout or the transfer speed. It ignores all fields from the snd_pcm_hardware struct for the PCM driver that are related to this. Setting these fields in the PCM driver might suggest otherwise though, so rather not set them. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@linaro.org>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/*
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* linux/sound/arm/ep93xx-pcm.c - EP93xx ALSA PCM interface
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*
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* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
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* Copyright (C) 2006 Applied Data Systems
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*
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* Rewritten for the SoC audio subsystem (Based on PXA2xx code):
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* Copyright (c) 2008 Ryan Mallon
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/dmaengine.h>
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#include <sound/pcm.h>
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#include <sound/soc.h>
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#include <sound/dmaengine_pcm.h>
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#include <linux/platform_data/dma-ep93xx.h>
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#include "ep93xx-pcm.h"
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static const struct snd_pcm_hardware ep93xx_pcm_hardware = {
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.info = (SNDRV_PCM_INFO_MMAP |
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SNDRV_PCM_INFO_MMAP_VALID |
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SNDRV_PCM_INFO_INTERLEAVED |
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SNDRV_PCM_INFO_BLOCK_TRANSFER),
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.buffer_bytes_max = 131072,
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.period_bytes_min = 32,
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.period_bytes_max = 32768,
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.periods_min = 1,
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.periods_max = 32,
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.fifo_size = 32,
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};
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static bool ep93xx_pcm_dma_filter(struct dma_chan *chan, void *filter_param)
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{
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struct ep93xx_dma_data *data = filter_param;
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if (data->direction == ep93xx_dma_chan_direction(chan)) {
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chan->private = data;
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return true;
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}
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return false;
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}
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static const struct snd_dmaengine_pcm_config ep93xx_dmaengine_pcm_config = {
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.pcm_hardware = &ep93xx_pcm_hardware,
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.compat_filter_fn = ep93xx_pcm_dma_filter,
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.prealloc_buffer_size = 131072,
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};
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int devm_ep93xx_pcm_platform_register(struct device *dev)
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{
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return devm_snd_dmaengine_pcm_register(dev,
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&ep93xx_dmaengine_pcm_config,
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SND_DMAENGINE_PCM_FLAG_NO_RESIDUE |
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SND_DMAENGINE_PCM_FLAG_NO_DT |
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SND_DMAENGINE_PCM_FLAG_COMPAT);
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}
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EXPORT_SYMBOL_GPL(devm_ep93xx_pcm_platform_register);
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MODULE_AUTHOR("Ryan Mallon");
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MODULE_DESCRIPTION("EP93xx ALSA PCM interface");
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MODULE_LICENSE("GPL");
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