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120 lines
3.5 KiB
120 lines
3.5 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC. |
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* |
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* Copyright (C) 2012 Atmel |
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* |
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* Author: Bo Shen <[email protected]> |
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* |
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* Based on atmel-pcm by: |
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* Sedji Gaouaou <[email protected]> |
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* Copyright 2008 Atmel |
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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/slab.h> |
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#include <linux/dma-mapping.h> |
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#include <linux/dmaengine.h> |
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#include <linux/atmel-ssc.h> |
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#include <sound/core.h> |
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#include <sound/pcm.h> |
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#include <sound/pcm_params.h> |
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#include <sound/soc.h> |
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#include <sound/dmaengine_pcm.h> |
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#include "atmel-pcm.h" |
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/*--------------------------------------------------------------------------*\ |
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* Hardware definition |
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\*--------------------------------------------------------------------------*/ |
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static const struct snd_pcm_hardware atmel_pcm_dma_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_RESUME | |
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SNDRV_PCM_INFO_PAUSE, |
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.period_bytes_min = 256, /* lighting DMA overhead */ |
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.period_bytes_max = 2 * 0xffff, /* if 2 bytes format */ |
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.periods_min = 8, |
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.periods_max = 1024, /* no limit */ |
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.buffer_bytes_max = 512 * 1024, |
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}; |
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/* |
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* atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC |
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* |
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* We use DMAENGINE to send/receive data to/from SSC so this ISR is only to |
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* check if any overrun occured. |
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*/ |
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static void atmel_pcm_dma_irq(u32 ssc_sr, |
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struct snd_pcm_substream *substream) |
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{ |
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struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); |
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struct atmel_pcm_dma_params *prtd; |
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prtd = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); |
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if (ssc_sr & prtd->mask->ssc_error) { |
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if (snd_pcm_running(substream)) |
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pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n", |
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substream->stream == SNDRV_PCM_STREAM_PLAYBACK |
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? "underrun" : "overrun", prtd->name, |
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ssc_sr); |
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/* stop RX and capture: will be enabled again at restart */ |
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ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable); |
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snd_pcm_stop_xrun(substream); |
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/* now drain RHR and read status to remove xrun condition */ |
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ssc_readx(prtd->ssc->regs, SSC_RHR); |
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ssc_readx(prtd->ssc->regs, SSC_SR); |
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} |
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} |
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static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, |
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struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) |
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{ |
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struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); |
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struct atmel_pcm_dma_params *prtd; |
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struct ssc_device *ssc; |
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int ret; |
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prtd = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); |
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ssc = prtd->ssc; |
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ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); |
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if (ret) { |
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pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); |
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return ret; |
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} |
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slave_config->dst_addr = ssc->phybase + SSC_THR; |
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slave_config->dst_maxburst = 1; |
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slave_config->src_addr = ssc->phybase + SSC_RHR; |
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slave_config->src_maxburst = 1; |
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prtd->dma_intr_handler = atmel_pcm_dma_irq; |
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return 0; |
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} |
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static const struct snd_dmaengine_pcm_config atmel_dmaengine_pcm_config = { |
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.prepare_slave_config = atmel_pcm_configure_dma, |
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.pcm_hardware = &atmel_pcm_dma_hardware, |
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.prealloc_buffer_size = 64 * 1024, |
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}; |
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int atmel_pcm_dma_platform_register(struct device *dev) |
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{ |
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return devm_snd_dmaengine_pcm_register(dev, |
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&atmel_dmaengine_pcm_config, 0); |
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} |
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EXPORT_SYMBOL(atmel_pcm_dma_platform_register); |
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MODULE_AUTHOR("Bo Shen <[email protected]>"); |
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MODULE_DESCRIPTION("Atmel DMA based PCM module"); |
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MODULE_LICENSE("GPL");
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