[ALSA] ASoC Samsung S3C24xx audio DMA

This patch by Ben Dooks from Simtec Electronics adds ASoC audio DMA
support for the Samsung S3C24xx CPU.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

2 files changed, 494 insertions, 0 deletions

diff --git a/sound/soc/s3c24xx/s3c24xx-pcm.c b/sound/soc/s3c24xx/s3c24xx-pcm.c
new file mode 100644
index 0000000..f1c0b9f
--- /dev/null
+++ b/sound/soc/s3c24xx/s3c24xx-pcm.c
@@ -0,0 +1,462 @@
+/*
+ * s3c24xx-pcm.c  --  ALSA Soc Audio Layer
+ *
+ * (c) 2006 Wolfson Microelectronics PLC.
+ * Graeme Gregory graeme.gregory@wolfsonmicro.com or linux@wolfsonmicro.com
+ *
+ * (c) 2004-2005 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ *  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.
+ *
+ *  Revision history
+ *    11th Dec 2006   Merged with Simtec driver
+ *    10th Nov 2006   Initial version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <asm/dma.h>
+#include <asm/io.h>
+#include <asm/hardware.h>
+#include <asm/arch/dma.h>
+#include <asm/arch/audio.h>
+
+#include "s3c24xx-pcm.h"
+
+#define S3C24XX_PCM_DEBUG 0
+#if S3C24XX_PCM_DEBUG
+#define DBG(x...) printk(KERN_DEBUG x)
+#else
+#define DBG(x...)
+#endif
+
+static const struct snd_pcm_hardware s3c24xx_pcm_hardware = {
+	.info			= SNDRV_PCM_INFO_INTERLEAVED |
+				    SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				    SNDRV_PCM_INFO_MMAP |
+				    SNDRV_PCM_INFO_MMAP_VALID,
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE |
+				    SNDRV_PCM_FMTBIT_U16_LE |
+				    SNDRV_PCM_FMTBIT_U8 |
+				    SNDRV_PCM_FMTBIT_S8,
+	.channels_min		= 2,
+	.channels_max		= 2,
+	.buffer_bytes_max	= 128*1024,
+	.period_bytes_min	= PAGE_SIZE,
+	.period_bytes_max	= PAGE_SIZE*2,
+	.periods_min		= 2,
+	.periods_max		= 128,
+	.fifo_size		= 32,
+};
+
+struct s3c24xx_runtime_data {
+	spinlock_t lock;
+	int state;
+	unsigned int dma_loaded;
+	unsigned int dma_limit;
+	unsigned int dma_period;
+	dma_addr_t dma_start;
+	dma_addr_t dma_pos;
+	dma_addr_t dma_end;
+	struct s3c24xx_pcm_dma_params *params;
+};
+
+/* s3c24xx_pcm_enqueue
+ *
+ * place a dma buffer onto the queue for the dma system
+ * to handle.
+*/
+static void s3c24xx_pcm_enqueue(struct snd_pcm_substream *substream)
+{
+	struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
+	dma_addr_t pos = prtd->dma_pos;
+	int ret;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	while ( prtd->dma_loaded < prtd->dma_limit) {
+		unsigned long len = prtd->dma_period;
+
+		DBG("dma_loaded: %d\n",prtd->dma_loaded);
+
+		if ((pos + len) > prtd->dma_end) {
+			len  = prtd->dma_end - pos;
+			DBG(KERN_DEBUG "%s: corrected dma len %ld\n",
+			       __FUNCTION__, len);
+		}
+
+		ret = s3c2410_dma_enqueue(prtd->params->channel, substream, pos, len);
+
+		if (ret == 0) {
+			prtd->dma_loaded++;
+			pos += prtd->dma_period;
+			if (pos >= prtd->dma_end)
+				pos = prtd->dma_start;
+		} else
+			break;
+	}
+
+	prtd->dma_pos = pos;
+}
+
+static void s3c24xx_audio_buffdone(struct s3c2410_dma_chan *channel,
+							void *dev_id, int size,
+							enum s3c2410_dma_buffresult result)
+{
+	struct snd_pcm_substream *substream = dev_id;
+	struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	if (result == S3C2410_RES_ABORT || result == S3C2410_RES_ERR)
+		return;
+
+	if (substream)
+		snd_pcm_period_elapsed(substream);
+
+	spin_lock(&prtd->lock);
+	if (prtd->state & ST_RUNNING) {
+		prtd->dma_loaded--;
+		s3c24xx_pcm_enqueue(substream);
+	}
+
+	spin_unlock(&prtd->lock);
+}
+
+static int s3c24xx_pcm_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s3c24xx_runtime_data *prtd = runtime->private_data;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct s3c24xx_pcm_dma_params *dma = rtd->dai->cpu_dai->dma_data;
+	unsigned long totbytes = params_buffer_bytes(params);
+	int ret=0;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	/* return if this is a bufferless transfer e.g.
+	 * codec <--> BT codec or GSM modem -- lg FIXME */
+	if (!dma)
+		return 0;
+
+	/* prepare DMA */
+	prtd->params = dma;
+
+	DBG("params %p, client %p, channel %d\n", prtd->params,
+		prtd->params->client, prtd->params->channel);
+
+	ret = s3c2410_dma_request(prtd->params->channel,
+				  prtd->params->client, NULL);
+
+	if (ret) {
+		DBG(KERN_ERR "failed to get dma channel\n");
+		return ret;
+	}
+
+	/* channel needs configuring for mem=>device, increment memory addr,
+	 * sync to pclk, half-word transfers to the IIS-FIFO. */
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		s3c2410_dma_devconfig(prtd->params->channel,
+						S3C2410_DMASRC_MEM, S3C2410_DISRCC_INC |
+						S3C2410_DISRCC_APB, prtd->params->dma_addr);
+
+		s3c2410_dma_config(prtd->params->channel,
+						2, S3C2410_DCON_SYNC_PCLK | S3C2410_DCON_HANDSHAKE);
+	} else {
+		s3c2410_dma_config(prtd->params->channel,
+						2, S3C2410_DCON_HANDSHAKE | S3C2410_DCON_SYNC_PCLK);
+
+		s3c2410_dma_devconfig(prtd->params->channel,
+						S3C2410_DMASRC_HW, 0x3,
+						prtd->params->dma_addr);
+	}
+
+	s3c2410_dma_set_buffdone_fn(prtd->params->channel,
+				    s3c24xx_audio_buffdone);
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+
+	runtime->dma_bytes = totbytes;
+
+	spin_lock_irq(&prtd->lock);
+	prtd->dma_loaded = 0;
+	prtd->dma_limit = runtime->hw.periods_min;
+	prtd->dma_period = params_period_bytes(params);
+	prtd->dma_start = runtime->dma_addr;
+	prtd->dma_pos = prtd->dma_start;
+	prtd->dma_end = prtd->dma_start + totbytes;
+	spin_unlock_irq(&prtd->lock);
+
+	return 0;
+}
+
+static int s3c24xx_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	/* TODO - do we need to ensure DMA flushed */
+	snd_pcm_set_runtime_buffer(substream, NULL);
+
+	if(prtd->params) {
+		s3c2410_dma_free(prtd->params->channel, prtd->params->client);
+		prtd->params = NULL;
+	}
+
+	return 0;
+}
+
+static int s3c24xx_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
+	int ret = 0;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	/* return if this is a bufferless transfer e.g.
+	 * codec <--> BT codec or GSM modem -- lg FIXME */
+	if (!prtd->params)
+	 	return 0;
+
+	/* flush the DMA channel */
+	s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_FLUSH);
+	prtd->dma_loaded = 0;
+	prtd->dma_pos = prtd->dma_start;
+
+	/* enqueue dma buffers */
+	s3c24xx_pcm_enqueue(substream);
+
+	return ret;
+}
+
+static int s3c24xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
+	int ret = 0;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	spin_lock(&prtd->lock);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		prtd->state |= ST_RUNNING;
+		s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_START);
+		s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STARTED);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		prtd->state &= ~ST_RUNNING;
+		s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STOP);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock(&prtd->lock);
+
+	return ret;
+}
+
+static snd_pcm_uframes_t s3c24xx_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s3c24xx_runtime_data *prtd = runtime->private_data;
+	unsigned long res;
+	dma_addr_t src, dst;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	spin_lock(&prtd->lock);
+	s3c2410_dma_getposition(prtd->params->channel, &src, &dst);
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		res = dst - prtd->dma_start;
+	else
+		res = src - prtd->dma_start;
+
+	spin_unlock(&prtd->lock);
+
+	DBG("Pointer %x %x\n",src,dst);
+
+	/* we seem to be getting the odd error from the pcm library due
+	 * to out-of-bounds pointers. this is maybe due to the dma engine
+	 * not having loaded the new values for the channel before being
+	 * callled... (todo - fix )
+	 */
+
+	if (res >= snd_pcm_lib_buffer_bytes(substream)) {
+		if (res == snd_pcm_lib_buffer_bytes(substream))
+			res = 0;
+	}
+
+	return bytes_to_frames(substream->runtime, res);
+}
+
+static int s3c24xx_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s3c24xx_runtime_data *prtd;
+
+	int ret;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	snd_soc_set_runtime_hwparams(substream, &s3c24xx_pcm_hardware);
+
+	prtd = kzalloc(sizeof(struct s3c24xx_runtime_data), GFP_KERNEL);
+	if (prtd == NULL)
+		return -ENOMEM;
+
+	runtime->private_data = prtd;
+	return 0;
+}
+
+static int s3c24xx_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s3c24xx_runtime_data *prtd = runtime->private_data;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	if(prtd)
+		kfree(prtd);
+	else
+		DBG("s3c24xx_pcm_close called with prtd == NULL\n");
+
+	return 0;
+}
+
+static int s3c24xx_pcm_mmap(struct snd_pcm_substream *substream,
+	struct vm_area_struct *vma)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
+                                     runtime->dma_area,
+                                     runtime->dma_addr,
+                                     runtime->dma_bytes);
+}
+
+static struct snd_pcm_ops s3c24xx_pcm_ops = {
+	.open		= s3c24xx_pcm_open,
+	.close		= s3c24xx_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= s3c24xx_pcm_hw_params,
+	.hw_free	= s3c24xx_pcm_hw_free,
+	.prepare	= s3c24xx_pcm_prepare,
+	.trigger	= s3c24xx_pcm_trigger,
+	.pointer	= s3c24xx_pcm_pointer,
+	.mmap		= s3c24xx_pcm_mmap,
+};
+
+static int s3c24xx_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 = s3c24xx_pcm_hardware.buffer_bytes_max;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	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 s3c24xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_dma_buffer *buf;
+	int stream;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	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;
+	}
+}
+
+static u64 s3c24xx_pcm_dmamask = DMA_32BIT_MASK;
+
+static int s3c24xx_pcm_new(struct snd_card *card, struct snd_soc_codec_dai *dai,
+	struct snd_pcm *pcm)
+{
+	int ret = 0;
+
+	DBG("Entered %s\n", __FUNCTION__);
+
+	if (!card->dev->dma_mask)
+		card->dev->dma_mask = &s3c24xx_pcm_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = 0xffffffff;
+
+	if (dai->playback.channels_min) {
+		ret = s3c24xx_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			goto out;
+	}
+
+	if (dai->capture.channels_min) {
+		ret = s3c24xx_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_CAPTURE);
+		if (ret)
+			goto out;
+	}
+ out:
+	return ret;
+}
+
+struct snd_soc_platform s3c24xx_soc_platform = {
+	.name		= "s3c24xx-audio",
+	.pcm_ops 	= &s3c24xx_pcm_ops,
+	.pcm_new	= s3c24xx_pcm_new,
+	.pcm_free	= s3c24xx_pcm_free_dma_buffers,
+};
+
+EXPORT_SYMBOL_GPL(s3c24xx_soc_platform);
+
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_DESCRIPTION("Samsung S3C24XX PCM DMA module");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/s3c24xx/s3c24xx-pcm.h b/sound/soc/s3c24xx/s3c24xx-pcm.h
new file mode 100644
index 0000000..5dced4a
--- /dev/null
+++ b/sound/soc/s3c24xx/s3c24xx-pcm.h
@@ -0,0 +1,32 @@
+/*
+ *  s3c24xx-pcm.h --
+ *
+ *  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.
+ *
+ *  ALSA PCM interface for the Samsung S3C24xx CPU
+ */
+
+#ifndef _S3C24XX_PCM_H
+#define _S3C24XX_PCM_H
+
+#define ST_RUNNING		(1<<0)
+#define ST_OPENED		(1<<1)
+
+struct s3c24xx_pcm_dma_params {
+	struct s3c2410_dma_client *client;			/* stream identifier */
+	int channel;						/* Channel ID */
+	dma_addr_t dma_addr;
+};
+
+#define S3C24XX_DAI_I2S			0
+
+extern struct snd_soc_cpu_dai s3c24xx_i2s_dai;
+
+/* platform data */
+extern struct snd_soc_platform s3c24xx_soc_platform;
+extern struct snd_ac97_bus_ops s3c24xx_ac97_ops;
+
+#endif