[ALSA] ASoC pxa2xx DMA support

This patch adds pxa2xx ASoC DMA audio support. It's based on
sound/arm/pxa-pcm.c by Nicolas Pitre with the following differences.
o Modified driver structure to use ASoC core PCM callbacks and data
structures.
o Registration with ASoC core.
From: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 363 insertions, 0 deletions

diff --git a/sound/soc/pxa/pxa2xx-pcm.c b/sound/soc/pxa/pxa2xx-pcm.c
new file mode 100644
index 00000000000..ff32f892287
--- /dev/null
+++ b/sound/soc/pxa/pxa2xx-pcm.c
@@ -0,0 +1,363 @@
+/*
+ * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
+ *
+ * Author:	Nicolas Pitre
+ * Created:	Nov 30, 2004
+ * Copyright:	(C) 2004 MontaVista Software, Inc.
+ *
+ * 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.
+ */
+
+#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/hardware.h>
+#include <asm/arch/pxa-regs.h>
+#include <asm/arch/audio.h>
+
+#include "pxa2xx-pcm.h"
+
+static const struct snd_pcm_hardware pxa2xx_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 |
+					SNDRV_PCM_FMTBIT_S24_LE |
+					SNDRV_PCM_FMTBIT_S32_LE,
+	.period_bytes_min	= 32,
+	.period_bytes_max	= 8192 - 32,
+	.periods_min		= 1,
+	.periods_max		= PAGE_SIZE/sizeof(pxa_dma_desc),
+	.buffer_bytes_max	= 128 * 1024,
+	.fifo_size		= 32,
+};
+
+struct pxa2xx_runtime_data {
+	int dma_ch;
+	struct pxa2xx_pcm_dma_params *params;
+	pxa_dma_desc *dma_desc_array;
+	dma_addr_t dma_desc_array_phys;
+};
+
+static void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
+{
+	struct snd_pcm_substream *substream = dev_id;
+	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+	int dcsr;
+
+	dcsr = DCSR(dma_ch);
+	DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
+
+	if (dcsr & DCSR_ENDINTR) {
+		snd_pcm_period_elapsed(substream);
+	} else {
+		printk( KERN_ERR "%s: DMA error on channel %d (DCSR=%#x)\n",
+			prtd->params->name, dma_ch, dcsr );
+	}
+}
+
+static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct pxa2xx_runtime_data *prtd = runtime->private_data;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct pxa2xx_pcm_dma_params *dma = rtd->cpu_dai->dma_data;
+	size_t totsize = params_buffer_bytes(params);
+	size_t period = params_period_bytes(params);
+	pxa_dma_desc *dma_desc;
+	dma_addr_t dma_buff_phys, next_desc_phys;
+	int ret;
+
+	/* this may get called several times by oss emulation
+	 * with different params */
+	if (prtd->params == NULL) {
+		prtd->params = dma;
+		ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
+			      pxa2xx_pcm_dma_irq, substream);
+		if (ret < 0)
+			return ret;
+		prtd->dma_ch = ret;
+	} else if (prtd->params != dma) {
+		pxa_free_dma(prtd->dma_ch);
+		prtd->params = dma;
+		ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
+			      pxa2xx_pcm_dma_irq, substream);
+		if (ret < 0)
+			return ret;
+		prtd->dma_ch = ret;
+	}
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	runtime->dma_bytes = totsize;
+
+	dma_desc = prtd->dma_desc_array;
+	next_desc_phys = prtd->dma_desc_array_phys;
+	dma_buff_phys = runtime->dma_addr;
+	do {
+		next_desc_phys += sizeof(pxa_dma_desc);
+		dma_desc->ddadr = next_desc_phys;
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			dma_desc->dsadr = dma_buff_phys;
+			dma_desc->dtadr = prtd->params->dev_addr;
+		} else {
+			dma_desc->dsadr = prtd->params->dev_addr;
+			dma_desc->dtadr = dma_buff_phys;
+		}
+		if (period > totsize)
+			period = totsize;
+		dma_desc->dcmd = prtd->params->dcmd | period | DCMD_ENDIRQEN;
+		dma_desc++;
+		dma_buff_phys += period;
+	} while (totsize -= period);
+	dma_desc[-1].ddadr = prtd->dma_desc_array_phys;
+
+	return 0;
+}
+
+static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+
+	if (prtd && prtd->params)
+		*prtd->params->drcmr = 0;
+
+	if (prtd->dma_ch) {
+		snd_pcm_set_runtime_buffer(substream, NULL);
+		pxa_free_dma(prtd->dma_ch);
+		prtd->dma_ch = 0;
+	}
+
+	return 0;
+}
+
+static int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+
+	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
+	DCSR(prtd->dma_ch) = 0;
+	DCMD(prtd->dma_ch) = 0;
+	*prtd->params->drcmr = prtd->dma_ch | DRCMR_MAPVLD;
+
+	return 0;
+}
+
+static int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
+		DCSR(prtd->dma_ch) = DCSR_RUN;
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		DCSR(prtd->dma_ch) &= ~DCSR_RUN;
+		break;
+
+	case SNDRV_PCM_TRIGGER_RESUME:
+		DCSR(prtd->dma_ch) |= DCSR_RUN;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
+		DCSR(prtd->dma_ch) |= DCSR_RUN;
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static snd_pcm_uframes_t
+pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct pxa2xx_runtime_data *prtd = runtime->private_data;
+
+	dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
+			 DSADR(prtd->dma_ch) : DTADR(prtd->dma_ch);
+	snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
+
+	if (x == runtime->buffer_size)
+		x = 0;
+	return x;
+}
+
+static int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct pxa2xx_runtime_data *prtd;
+	int ret;
+
+	snd_soc_set_runtime_hwparams(substream, &pxa2xx_pcm_hardware);
+
+	/*
+	 * For mysterious reasons (and despite what the manual says)
+	 * playback samples are lost if the DMA count is not a multiple
+	 * of the DMA burst size.  Let's add a rule to enforce that.
+	 */
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
+	if (ret)
+		goto out;
+
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
+	if (ret)
+		goto out;
+
+	prtd = kzalloc(sizeof(struct pxa2xx_runtime_data), GFP_KERNEL);
+	if (prtd == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	prtd->dma_desc_array =
+		dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
+				       &prtd->dma_desc_array_phys, GFP_KERNEL);
+	if (!prtd->dma_desc_array) {
+		ret = -ENOMEM;
+		goto err1;
+	}
+
+	runtime->private_data = prtd;
+	return 0;
+
+ err1:
+	kfree(prtd);
+ out:
+	return ret;
+}
+
+static int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct pxa2xx_runtime_data *prtd = runtime->private_data;
+
+	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
+			      prtd->dma_desc_array, prtd->dma_desc_array_phys);
+	kfree(prtd);
+	return 0;
+}
+
+static int pxa2xx_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 pxa2xx_pcm_ops = {
+	.open		= pxa2xx_pcm_open,
+	.close		= pxa2xx_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= pxa2xx_pcm_hw_params,
+	.hw_free	= pxa2xx_pcm_hw_free,
+	.prepare	= pxa2xx_pcm_prepare,
+	.trigger	= pxa2xx_pcm_trigger,
+	.pointer	= pxa2xx_pcm_pointer,
+	.mmap		= pxa2xx_pcm_mmap,
+};
+
+static int pxa2xx_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 = pxa2xx_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 pxa2xx_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;
+	}
+}
+
+static u64 pxa2xx_pcm_dmamask = DMA_32BIT_MASK;
+
+int pxa2xx_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 = &pxa2xx_pcm_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = DMA_32BIT_MASK;
+
+	if (dai->playback.channels_min) {
+		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			goto out;
+	}
+
+	if (dai->capture.channels_min) {
+		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_CAPTURE);
+		if (ret)
+			goto out;
+	}
+ out:
+	return ret;
+}
+
+struct snd_soc_platform pxa2xx_soc_platform = {
+	.name		= "pxa2xx-audio",
+	.pcm_ops 	= &pxa2xx_pcm_ops,
+	.pcm_new	= pxa2xx_pcm_new,
+	.pcm_free	= pxa2xx_pcm_free_dma_buffers,
+};
+
+EXPORT_SYMBOL_GPL(pxa2xx_soc_platform);
+
+MODULE_AUTHOR("Nicolas Pitre");
+MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
+MODULE_LICENSE("GPL");