1 files changed, 357 insertions, 0 deletions
diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
new file mode 100644
index 0000000..6237020
--- /dev/null
+++ b/sound/soc/omap/omap-pcm.c
@@ -0,0 +1,357 @@
+/*
+ * omap-pcm.c  --  ALSA PCM interface for the OMAP SoC
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <asm/arch/dma.h>
+#include "omap-pcm.h"
+
+static const struct snd_pcm_hardware omap_pcm_hardware = {
+	.info			= SNDRV_PCM_INFO_MMAP |
+				  SNDRV_PCM_INFO_MMAP_VALID |
+				  SNDRV_PCM_INFO_INTERLEAVED |
+				  SNDRV_PCM_INFO_PAUSE |
+				  SNDRV_PCM_INFO_RESUME,
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
+	.period_bytes_min	= 32,
+	.period_bytes_max	= 64 * 1024,
+	.periods_min		= 2,
+	.periods_max		= 255,
+	.buffer_bytes_max	= 128 * 1024,
+};
+
+struct omap_runtime_data {
+	spinlock_t			lock;
+	struct omap_pcm_dma_data	*dma_data;
+	int				dma_ch;
+	int				period_index;
+};
+
+static void omap_pcm_dma_irq(int ch, u16 stat, void *data)
+{
+	struct snd_pcm_substream *substream = data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd = runtime->private_data;
+	unsigned long flags;
+
+	if (cpu_is_omap1510()) {
+		/*
+		 * OMAP1510 doesn't support DMA chaining so have to restart
+		 * the transfer after all periods are transferred
+		 */
+		spin_lock_irqsave(&prtd->lock, flags);
+		if (prtd->period_index >= 0) {
+			if (++prtd->period_index == runtime->periods) {
+				prtd->period_index = 0;
+				omap_start_dma(prtd->dma_ch);
+			}
+		}
+		spin_unlock_irqrestore(&prtd->lock, flags);
+	}
+
+	snd_pcm_period_elapsed(substream);
+}
+
+/* this may get called several times by oss emulation */
+static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct omap_runtime_data *prtd = runtime->private_data;
+	struct omap_pcm_dma_data *dma_data = rtd->dai->cpu_dai->dma_data;
+	int err = 0;
+
+	if (!dma_data)
+		return -ENODEV;
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	runtime->dma_bytes = params_buffer_bytes(params);
+
+	if (prtd->dma_data)
+		return 0;
+	prtd->dma_data = dma_data;
+	err = omap_request_dma(dma_data->dma_req, dma_data->name,
+			       omap_pcm_dma_irq, substream, &prtd->dma_ch);
+	if (!cpu_is_omap1510()) {
+		/*
+		 * Link channel with itself so DMA doesn't need any
+		 * reprogramming while looping the buffer
+		 */
+		omap_dma_link_lch(prtd->dma_ch, prtd->dma_ch);
+	}
+
+	return err;
+}
+
+static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd = runtime->private_data;
+
+	if (prtd->dma_data == NULL)
+		return 0;
+
+	if (!cpu_is_omap1510())
+		omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
+	omap_free_dma(prtd->dma_ch);
+	prtd->dma_data = NULL;
+
+	snd_pcm_set_runtime_buffer(substream, NULL);
+
+	return 0;
+}
+
+static int omap_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd = runtime->private_data;
+	struct omap_pcm_dma_data *dma_data = prtd->dma_data;
+	struct omap_dma_channel_params dma_params;
+
+	memset(&dma_params, 0, sizeof(dma_params));
+	/*
+	 * Note: Regardless of interface data formats supported by OMAP McBSP
+	 * or EAC blocks, internal representation is always fixed 16-bit/sample
+	 */
+	dma_params.data_type			= OMAP_DMA_DATA_TYPE_S16;
+	dma_params.trigger			= dma_data->dma_req;
+	dma_params.sync_mode			= OMAP_DMA_SYNC_ELEMENT;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		dma_params.src_amode		= OMAP_DMA_AMODE_POST_INC;
+		dma_params.dst_amode		= OMAP_DMA_AMODE_CONSTANT;
+		dma_params.src_or_dst_synch	= OMAP_DMA_DST_SYNC;
+		dma_params.src_start		= runtime->dma_addr;
+		dma_params.dst_start		= dma_data->port_addr;
+	} else {
+		dma_params.src_amode		= OMAP_DMA_AMODE_CONSTANT;
+		dma_params.dst_amode		= OMAP_DMA_AMODE_POST_INC;
+		dma_params.src_or_dst_synch	= OMAP_DMA_SRC_SYNC;
+		dma_params.src_start		= dma_data->port_addr;
+		dma_params.dst_start		= runtime->dma_addr;
+	}
+	/*
+	 * Set DMA transfer frame size equal to ALSA period size and frame
+	 * count as no. of ALSA periods. Then with DMA frame interrupt enabled,
+	 * we can transfer the whole ALSA buffer with single DMA transfer but
+	 * still can get an interrupt at each period bounary
+	 */
+	dma_params.elem_count	= snd_pcm_lib_period_bytes(substream) / 2;
+	dma_params.frame_count	= runtime->periods;
+	omap_set_dma_params(prtd->dma_ch, &dma_params);
+
+	omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ);
+
+	return 0;
+}
+
+static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd = runtime->private_data;
+	int ret = 0;
+
+	spin_lock_irq(&prtd->lock);
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		prtd->period_index = 0;
+		omap_start_dma(prtd->dma_ch);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		prtd->period_index = -1;
+		omap_stop_dma(prtd->dma_ch);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	spin_unlock_irq(&prtd->lock);
+
+	return ret;
+}
+
+static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd = runtime->private_data;
+	dma_addr_t ptr;
+	snd_pcm_uframes_t offset;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		ptr = omap_get_dma_src_pos(prtd->dma_ch);
+	else
+		ptr = omap_get_dma_dst_pos(prtd->dma_ch);
+
+	offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
+	if (offset >= runtime->buffer_size)
+		offset = 0;
+
+	return offset;
+}
+
+static int omap_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct omap_runtime_data *prtd;
+	int ret;
+
+	snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);
+
+	/* Ensure that buffer size is a multiple of period size */
+	ret = snd_pcm_hw_constraint_integer(runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		goto out;
+
+	prtd = kzalloc(sizeof(prtd), GFP_KERNEL);
+	if (prtd == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	spin_lock_init(&prtd->lock);
+	runtime->private_data = prtd;
+
+out:
+	return ret;
+}
+
+static int omap_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	kfree(runtime->private_data);
+	return 0;
+}
+
+static int omap_pcm_mmap(struct snd_pcm_substream *substream,
+	struct vm_area_struct *vma)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
+				     runtime->dma_area,
+				     runtime->dma_addr,
+				     runtime->dma_bytes);
+}
+
+struct snd_pcm_ops omap_pcm_ops = {
+	.open		= omap_pcm_open,
+	.close		= omap_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= omap_pcm_hw_params,
+	.hw_free	= omap_pcm_hw_free,
+	.prepare	= omap_pcm_prepare,
+	.trigger	= omap_pcm_trigger,
+	.pointer	= omap_pcm_pointer,
+	.mmap		= omap_pcm_mmap,
+};
+
+static u64 omap_pcm_dmamask = DMA_BIT_MASK(32);
+
+static int omap_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
+	int stream)
+{
+	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
+	struct snd_dma_buffer *buf = &substream->dma_buffer;
+	size_t size = omap_pcm_hardware.buffer_bytes_max;
+
+	buf->dev.type = SNDRV_DMA_TYPE_DEV;
+	buf->dev.dev = pcm->card->dev;
+	buf->private_data = NULL;
+	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
+					   &buf->addr, GFP_KERNEL);
+	if (!buf->area)
+		return -ENOMEM;
+
+	buf->bytes = size;
+	return 0;
+}
+
+static void omap_pcm_free_dma_buffers(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_dma_buffer *buf;
+	int stream;
+
+	for (stream = 0; stream < 2; stream++) {
+		substream = pcm->streams[stream].substream;
+		if (!substream)
+			continue;
+
+		buf = &substream->dma_buffer;
+		if (!buf->area)
+			continue;
+
+		dma_free_writecombine(pcm->card->dev, buf->bytes,
+				      buf->area, buf->addr);
+		buf->area = NULL;
+	}
+}
+
+int omap_pcm_new(struct snd_card *card, struct snd_soc_codec_dai *dai,
+		 struct snd_pcm *pcm)
+{
+	int ret = 0;
+
+	if (!card->dev->dma_mask)
+		card->dev->dma_mask = &omap_pcm_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = DMA_32BIT_MASK;
+
+	if (dai->playback.channels_min) {
+		ret = omap_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			goto out;
+	}
+
+	if (dai->capture.channels_min) {
+		ret = omap_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_CAPTURE);
+		if (ret)
+			goto out;
+	}
+
+out:
+	return ret;
+}
+
+struct snd_soc_platform omap_soc_platform = {
+	.name		= "omap-pcm-audio",
+	.pcm_ops 	= &omap_pcm_ops,
+	.pcm_new	= omap_pcm_new,
+	.pcm_free	= omap_pcm_free_dma_buffers,
+};
+EXPORT_SYMBOL_GPL(omap_soc_platform);
+
+MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@nokia.com>");
+MODULE_DESCRIPTION("OMAP PCM DMA module");
+MODULE_LICENSE("GPL");