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Diffstat (limited to '')
| -rw-r--r-- | sound/soc/atmel/atmel-pcm-dma.c | 139 |
1 files changed, 139 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..dd57a9eac --- /dev/null +++ b/sound/soc/atmel/atmel-pcm-dma.c @@ -0,0 +1,139 @@ +/* + * 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 + * + * 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/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 <linux/platform_data/dma-atmel.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 = substream->private_data; + struct atmel_pcm_dma_params *prtd; + + prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, 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 = substream->private_data; + struct atmel_pcm_dma_params *prtd; + struct ssc_device *ssc; + int ret; + + prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, 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 snd_dmaengine_pcm_register(dev, &atmel_dmaengine_pcm_config, 0); +} +EXPORT_SYMBOL(atmel_pcm_dma_platform_register); + +void atmel_pcm_dma_platform_unregister(struct device *dev) +{ + snd_dmaengine_pcm_unregister(dev); +} +EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); + +MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); +MODULE_DESCRIPTION("Atmel DMA based PCM module"); +MODULE_LICENSE("GPL"); |