diff options
Diffstat (limited to 'sound/soc/atmel/atmel-pcm-dma.c')
| -rw-r--r-- | sound/soc/atmel/atmel-pcm-dma.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/sound/soc/atmel/atmel-pcm-dma.c b/sound/soc/atmel/atmel-pcm-dma.c new file mode 100644 index 000000000..96a8c7dba --- /dev/null +++ b/sound/soc/atmel/atmel-pcm-dma.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC. + * + * Copyright (C) 2012 Atmel + * + * Author: Bo Shen <voice.shen@atmel.com> + * + * Based on atmel-pcm by: + * Sedji Gaouaou <sedji.gaouaou@atmel.com> + * Copyright 2008 Atmel + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/atmel-ssc.h> + +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/soc.h> +#include <sound/dmaengine_pcm.h> + +#include "atmel-pcm.h" + +/*--------------------------------------------------------------------------*\ + * Hardware definition +\*--------------------------------------------------------------------------*/ +static const struct snd_pcm_hardware atmel_pcm_dma_hardware = { + .info = SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_RESUME | + SNDRV_PCM_INFO_PAUSE, + .period_bytes_min = 256, /* lighting DMA overhead */ + .period_bytes_max = 2 * 0xffff, /* if 2 bytes format */ + .periods_min = 8, + .periods_max = 1024, /* no limit */ + .buffer_bytes_max = 512 * 1024, +}; + +/* + * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC + * + * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to + * check if any overrun occured. + */ +static void atmel_pcm_dma_irq(u32 ssc_sr, + struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); + struct atmel_pcm_dma_params *prtd; + + prtd = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); + + if (ssc_sr & prtd->mask->ssc_error) { + if (snd_pcm_running(substream)) + pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n", + substream->stream == SNDRV_PCM_STREAM_PLAYBACK + ? "underrun" : "overrun", prtd->name, + ssc_sr); + + /* stop RX and capture: will be enabled again at restart */ + ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable); + snd_pcm_stop_xrun(substream); + + /* now drain RHR and read status to remove xrun condition */ + ssc_readx(prtd->ssc->regs, SSC_RHR); + ssc_readx(prtd->ssc->regs, SSC_SR); + } +} + +static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) +{ + struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); + struct atmel_pcm_dma_params *prtd; + struct ssc_device *ssc; + int ret; + + prtd = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); + ssc = prtd->ssc; + + ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); + if (ret) { + pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); + return ret; + } + + slave_config->dst_addr = ssc->phybase + SSC_THR; + slave_config->dst_maxburst = 1; + + slave_config->src_addr = ssc->phybase + SSC_RHR; + slave_config->src_maxburst = 1; + + prtd->dma_intr_handler = atmel_pcm_dma_irq; + + return 0; +} + +static const struct snd_dmaengine_pcm_config atmel_dmaengine_pcm_config = { + .prepare_slave_config = atmel_pcm_configure_dma, + .pcm_hardware = &atmel_pcm_dma_hardware, + .prealloc_buffer_size = 64 * 1024, +}; + +int atmel_pcm_dma_platform_register(struct device *dev) +{ + return devm_snd_dmaengine_pcm_register(dev, + &atmel_dmaengine_pcm_config, 0); +} +EXPORT_SYMBOL(atmel_pcm_dma_platform_register); + +MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); +MODULE_DESCRIPTION("Atmel DMA based PCM module"); +MODULE_LICENSE("GPL"); |