--- /dev/null
+/*
+ * 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,
+ .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 int atmel_pcm_close(struct snd_pcm_substream *substream)
+{
+ snd_dmaengine_pcm_close(substream);
+
+ return 0;
+}
+
+static struct snd_pcm_ops atmel_pcm_ops = {
+ .open = atmel_pcm_open,
+ .close = atmel_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 <voice.shen@atmel.com>");
+MODULE_DESCRIPTION("Atmel DMA based PCM module");
+MODULE_LICENSE("GPL");
projects / users / hch / configfs.git / commitdiff