/* * atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC. * * Copyright (C) 2012 Atmel * * Author: Bo Shen * * Based on atmel-pcm by: * Sedji Gaouaou * 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 #include #include #include #include #include #include #include #include #include #include #include #include #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, .formats = SNDRV_PCM_FMTBIT_S16_LE, .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 = ATMEL_SSC_DMABUF_SIZE, }; /** * 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 atmel_pcm_dma_params *prtd; prtd = snd_dmaengine_pcm_get_data(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(substream, SNDRV_PCM_STATE_XRUN); /* now drain RHR and read status to remove xrun condition */ ssc_readx(prtd->ssc->regs, SSC_RHR); ssc_readx(prtd->ssc->regs, SSC_SR); } } /*--------------------------------------------------------------------------*\ * DMAENGINE operations \*--------------------------------------------------------------------------*/ static bool filter(struct dma_chan *chan, void *slave) { struct at_dma_slave *sl = slave; if (sl->dma_dev == chan->device->dev) { chan->private = sl; return true; } else { return false; } } static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { struct atmel_pcm_dma_params *prtd; struct ssc_device *ssc; struct dma_chan *dma_chan; struct dma_slave_config slave_config; int ret; prtd = snd_dmaengine_pcm_get_data(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; } if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR; slave_config.dst_maxburst = 1; } else { slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR; slave_config.src_maxburst = 1; } slave_config.device_fc = false; dma_chan = snd_dmaengine_pcm_get_chan(substream); if (dmaengine_slave_config(dma_chan, &slave_config)) { pr_err("atmel-pcm: failed to configure dma channel\n"); ret = -EBUSY; return ret; } return 0; } static int atmel_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct atmel_pcm_dma_params *prtd; struct ssc_device *ssc; struct at_dma_slave *sdata = NULL; int ret; snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer); prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); ssc = prtd->ssc; if (ssc->pdev) sdata = ssc->pdev->dev.platform_data; ret = snd_dmaengine_pcm_open(substream, filter, sdata); if (ret) { pr_err("atmel-pcm: dmaengine pcm open failed\n"); return -EINVAL; } snd_dmaengine_pcm_set_data(substream, prtd); ret = atmel_pcm_configure_dma(substream, params); if (ret) { pr_err("atmel-pcm: failed to configure dmai\n"); goto err; } prtd->dma_intr_handler = atmel_pcm_dma_irq; return 0; err: snd_dmaengine_pcm_close(substream); return ret; } static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream) { struct atmel_pcm_dma_params *prtd; prtd = snd_dmaengine_pcm_get_data(substream); ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error); ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable); return 0; } static int atmel_pcm_open(struct snd_pcm_substream *substream) { snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware); return 0; } static struct snd_pcm_ops atmel_pcm_ops = { .open = atmel_pcm_open, .close = snd_dmaengine_pcm_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = atmel_pcm_hw_params, .prepare = atmel_pcm_dma_prepare, .trigger = snd_dmaengine_pcm_trigger, .pointer = snd_dmaengine_pcm_pointer_no_residue, .mmap = atmel_pcm_mmap, }; static struct snd_soc_platform_driver atmel_soc_platform = { .ops = &atmel_pcm_ops, .pcm_new = atmel_pcm_new, .pcm_free = atmel_pcm_free, }; int atmel_pcm_dma_platform_register(struct device *dev) { return snd_soc_register_platform(dev, &atmel_soc_platform); } EXPORT_SYMBOL(atmel_pcm_dma_platform_register); void atmel_pcm_dma_platform_unregister(struct device *dev) { snd_soc_unregister_platform(dev); } EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); MODULE_AUTHOR("Bo Shen "); MODULE_DESCRIPTION("Atmel DMA based PCM module"); MODULE_LICENSE("GPL");