ASoC: Add driver for s6000 I2S interface

This patch adds a driver for the I2S interface found on Stretch s6000
family processors.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 497 insertions, 0 deletions

diff --git a/sound/soc/s6000/s6000-pcm.c b/sound/soc/s6000/s6000-pcm.c
new file mode 100644
index 00000000000..83b8028e209
--- /dev/null
+++ b/sound/soc/s6000/s6000-pcm.c
@@ -0,0 +1,497 @@
+/*
+ * ALSA PCM interface for the Stetch s6000 family
+ *
+ * Author:      Daniel Gloeckner, <dg@emlix.com>
+ * Copyright:   (C) 2009 emlix GmbH <info@emlix.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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <asm/dma.h>
+#include <variant/dmac.h>
+
+#include "s6000-pcm.h"
+
+#define S6_PCM_PREALLOCATE_SIZE (96 * 1024)
+#define S6_PCM_PREALLOCATE_MAX  (2048 * 1024)
+
+static struct snd_pcm_hardware s6000_pcm_hardware = {
+	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
+		 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_JOINT_DUPLEX),
+	.formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE),
+	.rates = (SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_5512 | \
+		  SNDRV_PCM_RATE_8000_192000),
+	.rate_min = 0,
+	.rate_max = 1562500,
+	.channels_min = 2,
+	.channels_max = 8,
+	.buffer_bytes_max = 0x7ffffff0,
+	.period_bytes_min = 16,
+	.period_bytes_max = 0xfffff0,
+	.periods_min = 2,
+	.periods_max = 1024, /* no limit */
+	.fifo_size = 0,
+};
+
+struct s6000_runtime_data {
+	spinlock_t lock;
+	int period;		/* current DMA period */
+};
+
+static void s6000_pcm_enqueue_dma(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s6000_runtime_data *prtd = runtime->private_data;
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	int channel;
+	unsigned int period_size;
+	unsigned int dma_offset;
+	dma_addr_t dma_pos;
+	dma_addr_t src, dst;
+
+	period_size = snd_pcm_lib_period_bytes(substream);
+	dma_offset = prtd->period * period_size;
+	dma_pos = runtime->dma_addr + dma_offset;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		src = dma_pos;
+		dst = par->sif_out;
+		channel = par->dma_out;
+	} else {
+		src = par->sif_in;
+		dst = dma_pos;
+		channel = par->dma_in;
+	}
+
+	if (!s6dmac_channel_enabled(DMA_MASK_DMAC(channel),
+				    DMA_INDEX_CHNL(channel)))
+		return;
+
+	if (s6dmac_fifo_full(DMA_MASK_DMAC(channel), DMA_INDEX_CHNL(channel))) {
+		printk(KERN_ERR "s6000-pcm: fifo full\n");
+		return;
+	}
+
+	BUG_ON(period_size & 15);
+	s6dmac_put_fifo(DMA_MASK_DMAC(channel), DMA_INDEX_CHNL(channel),
+			src, dst, period_size);
+
+	prtd->period++;
+	if (unlikely(prtd->period >= runtime->periods))
+		prtd->period = 0;
+}
+
+static irqreturn_t s6000_pcm_irq(int irq, void *data)
+{
+	struct snd_pcm *pcm = data;
+	struct snd_soc_pcm_runtime *runtime = pcm->private_data;
+	struct s6000_pcm_dma_params *params = runtime->dai->cpu_dai->dma_data;
+	struct s6000_runtime_data *prtd;
+	unsigned int has_xrun;
+	int i, ret = IRQ_NONE;
+	u32 channel[2] = {
+		[SNDRV_PCM_STREAM_PLAYBACK] = params->dma_out,
+		[SNDRV_PCM_STREAM_CAPTURE] = params->dma_in
+	};
+
+	has_xrun = params->check_xrun(runtime->dai->cpu_dai);
+
+	for (i = 0; i < ARRAY_SIZE(channel); ++i) {
+		struct snd_pcm_substream *substream = pcm->streams[i].substream;
+		unsigned int pending;
+
+		if (!channel[i])
+			continue;
+
+		if (unlikely(has_xrun & (1 << i)) &&
+		    substream->runtime &&
+		    snd_pcm_running(substream)) {
+			dev_dbg(pcm->dev, "xrun\n");
+			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+			ret = IRQ_HANDLED;
+		}
+
+		pending = s6dmac_int_sources(DMA_MASK_DMAC(channel[i]),
+					     DMA_INDEX_CHNL(channel[i]));
+
+		if (pending & 1) {
+			ret = IRQ_HANDLED;
+			if (likely(substream->runtime &&
+				   snd_pcm_running(substream))) {
+				snd_pcm_period_elapsed(substream);
+				dev_dbg(pcm->dev, "period elapsed %x %x\n",
+				       s6dmac_cur_src(DMA_MASK_DMAC(channel[i]),
+						   DMA_INDEX_CHNL(channel[i])),
+				       s6dmac_cur_dst(DMA_MASK_DMAC(channel[i]),
+						   DMA_INDEX_CHNL(channel[i])));
+				prtd = substream->runtime->private_data;
+				spin_lock(&prtd->lock);
+				s6000_pcm_enqueue_dma(substream);
+				spin_unlock(&prtd->lock);
+			}
+		}
+
+		if (unlikely(pending & ~7)) {
+			if (pending & (1 << 3))
+				printk(KERN_WARNING
+				       "s6000-pcm: DMA %x Underflow\n",
+				       channel[i]);
+			if (pending & (1 << 4))
+				printk(KERN_WARNING
+				       "s6000-pcm: DMA %x Overflow\n",
+				       channel[i]);
+			if (pending & 0x1e0)
+				printk(KERN_WARNING
+				       "s6000-pcm: DMA %x Master Error "
+				       "(mask %x)\n",
+				       channel[i], pending >> 5);
+
+		}
+	}
+
+	return ret;
+}
+
+static int s6000_pcm_start(struct snd_pcm_substream *substream)
+{
+	struct s6000_runtime_data *prtd = substream->runtime->private_data;
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	unsigned long flags;
+	int srcinc;
+	u32 dma;
+
+	spin_lock_irqsave(&prtd->lock, flags);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		srcinc = 1;
+		dma = par->dma_out;
+	} else {
+		srcinc = 0;
+		dma = par->dma_in;
+	}
+	s6dmac_enable_chan(DMA_MASK_DMAC(dma), DMA_INDEX_CHNL(dma),
+			   1 /* priority 1 (0 is max) */,
+			   0 /* peripheral requests w/o xfer length mode */,
+			   srcinc /* source address increment */,
+			   srcinc^1 /* destination address increment */,
+			   0 /* chunksize 0 (skip impossible on this dma) */,
+			   0 /* source skip after chunk (impossible) */,
+			   0 /* destination skip after chunk (impossible) */,
+			   4 /* 16 byte burst size */,
+			   -1 /* don't conserve bandwidth */,
+			   0 /* low watermark irq descriptor theshold */,
+			   0 /* disable hardware timestamps */,
+			   1 /* enable channel */);
+
+	s6000_pcm_enqueue_dma(substream);
+	s6000_pcm_enqueue_dma(substream);
+
+	spin_unlock_irqrestore(&prtd->lock, flags);
+
+	return 0;
+}
+
+static int s6000_pcm_stop(struct snd_pcm_substream *substream)
+{
+	struct s6000_runtime_data *prtd = substream->runtime->private_data;
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	unsigned long flags;
+	u32 channel;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		channel = par->dma_out;
+	else
+		channel = par->dma_in;
+
+	s6dmac_set_terminal_count(DMA_MASK_DMAC(channel),
+				  DMA_INDEX_CHNL(channel), 0);
+
+	spin_lock_irqsave(&prtd->lock, flags);
+
+	s6dmac_disable_chan(DMA_MASK_DMAC(channel), DMA_INDEX_CHNL(channel));
+
+	spin_unlock_irqrestore(&prtd->lock, flags);
+
+	return 0;
+}
+
+static int s6000_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	int ret;
+
+	ret = par->trigger(substream, cmd, 0);
+	if (ret < 0)
+		return ret;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		ret = s6000_pcm_start(substream);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		ret = s6000_pcm_stop(substream);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	if (ret < 0)
+		return ret;
+
+	return par->trigger(substream, cmd, 1);
+}
+
+static int s6000_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct s6000_runtime_data *prtd = substream->runtime->private_data;
+
+	prtd->period = 0;
+
+	return 0;
+}
+
+static snd_pcm_uframes_t s6000_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s6000_runtime_data *prtd = runtime->private_data;
+	unsigned long flags;
+	unsigned int offset;
+	dma_addr_t count;
+
+	spin_lock_irqsave(&prtd->lock, flags);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		count = s6dmac_cur_src(DMA_MASK_DMAC(par->dma_out),
+				       DMA_INDEX_CHNL(par->dma_out));
+	else
+		count = s6dmac_cur_dst(DMA_MASK_DMAC(par->dma_in),
+				       DMA_INDEX_CHNL(par->dma_in));
+
+	count -= runtime->dma_addr;
+
+	spin_unlock_irqrestore(&prtd->lock, flags);
+
+	offset = bytes_to_frames(runtime, count);
+	if (unlikely(offset >= runtime->buffer_size))
+		offset = 0;
+
+	return offset;
+}
+
+static int s6000_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s6000_runtime_data *prtd;
+	int ret;
+
+	snd_soc_set_runtime_hwparams(substream, &s6000_pcm_hardware);
+
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 16);
+	if (ret < 0)
+		return ret;
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 16);
+	if (ret < 0)
+		return ret;
+	ret = snd_pcm_hw_constraint_integer(runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	if (par->same_rate) {
+		int rate;
+		spin_lock(&par->lock); /* needed? */
+		rate = par->rate;
+		spin_unlock(&par->lock);
+		if (rate != -1) {
+			ret = snd_pcm_hw_constraint_minmax(runtime,
+							SNDRV_PCM_HW_PARAM_RATE,
+							rate, rate);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	prtd = kzalloc(sizeof(struct s6000_runtime_data), GFP_KERNEL);
+	if (prtd == NULL)
+		return -ENOMEM;
+
+	spin_lock_init(&prtd->lock);
+
+	runtime->private_data = prtd;
+
+	return 0;
+}
+
+static int s6000_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct s6000_runtime_data *prtd = runtime->private_data;
+
+	kfree(prtd);
+
+	return 0;
+}
+
+static int s6000_pcm_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *hw_params)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+	int ret;
+	ret = snd_pcm_lib_malloc_pages(substream,
+				       params_buffer_bytes(hw_params));
+	if (ret < 0) {
+		printk(KERN_WARNING "s6000-pcm: allocation of memory failed\n");
+		return ret;
+	}
+
+	if (par->same_rate) {
+		spin_lock(&par->lock);
+		if (par->rate == -1 ||
+		    !(par->in_use & ~(1 << substream->stream))) {
+			par->rate = params_rate(hw_params);
+			par->in_use |= 1 << substream->stream;
+		} else if (params_rate(hw_params) != par->rate) {
+			snd_pcm_lib_free_pages(substream);
+			par->in_use &= ~(1 << substream->stream);
+			ret = -EBUSY;
+		}
+		spin_unlock(&par->lock);
+	}
+	return ret;
+}
+
+static int s6000_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+	struct s6000_pcm_dma_params *par = soc_runtime->dai->cpu_dai->dma_data;
+
+	spin_lock(&par->lock);
+	par->in_use &= ~(1 << substream->stream);
+	if (!par->in_use)
+		par->rate = -1;
+	spin_unlock(&par->lock);
+
+	return snd_pcm_lib_free_pages(substream);
+}
+
+static struct snd_pcm_ops s6000_pcm_ops = {
+	.open = 	s6000_pcm_open,
+	.close = 	s6000_pcm_close,
+	.ioctl = 	snd_pcm_lib_ioctl,
+	.hw_params = 	s6000_pcm_hw_params,
+	.hw_free = 	s6000_pcm_hw_free,
+	.trigger =	s6000_pcm_trigger,
+	.prepare = 	s6000_pcm_prepare,
+	.pointer = 	s6000_pcm_pointer,
+};
+
+static void s6000_pcm_free(struct snd_pcm *pcm)
+{
+	struct snd_soc_pcm_runtime *runtime = pcm->private_data;
+	struct s6000_pcm_dma_params *params = runtime->dai->cpu_dai->dma_data;
+
+	free_irq(params->irq, pcm);
+	snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+static u64 s6000_pcm_dmamask = DMA_32BIT_MASK;
+
+static int s6000_pcm_new(struct snd_card *card,
+			 struct snd_soc_dai *dai, struct snd_pcm *pcm)
+{
+	struct snd_soc_pcm_runtime *runtime = pcm->private_data;
+	struct s6000_pcm_dma_params *params = runtime->dai->cpu_dai->dma_data;
+	int res;
+
+	if (!card->dev->dma_mask)
+		card->dev->dma_mask = &s6000_pcm_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = DMA_32BIT_MASK;
+
+	if (params->dma_in) {
+		s6dmac_disable_chan(DMA_MASK_DMAC(params->dma_in),
+				    DMA_INDEX_CHNL(params->dma_in));
+		s6dmac_int_sources(DMA_MASK_DMAC(params->dma_in),
+				   DMA_INDEX_CHNL(params->dma_in));
+	}
+
+	if (params->dma_out) {
+		s6dmac_disable_chan(DMA_MASK_DMAC(params->dma_out),
+				    DMA_INDEX_CHNL(params->dma_out));
+		s6dmac_int_sources(DMA_MASK_DMAC(params->dma_out),
+				   DMA_INDEX_CHNL(params->dma_out));
+	}
+
+	res = request_irq(params->irq, s6000_pcm_irq, IRQF_SHARED,
+			  s6000_soc_platform.name, pcm);
+	if (res) {
+		printk(KERN_ERR "s6000-pcm couldn't get IRQ\n");
+		return res;
+	}
+
+	res = snd_pcm_lib_preallocate_pages_for_all(pcm,
+						    SNDRV_DMA_TYPE_DEV,
+						    card->dev,
+						    S6_PCM_PREALLOCATE_SIZE,
+						    S6_PCM_PREALLOCATE_MAX);
+	if (res)
+		printk(KERN_WARNING "s6000-pcm: preallocation failed\n");
+
+	spin_lock_init(&params->lock);
+	params->in_use = 0;
+	params->rate = -1;
+	return 0;
+}
+
+struct snd_soc_platform s6000_soc_platform = {
+	.name = 	"s6000-audio",
+	.pcm_ops = 	&s6000_pcm_ops,
+	.pcm_new = 	s6000_pcm_new,
+	.pcm_free = 	s6000_pcm_free,
+};
+EXPORT_SYMBOL_GPL(s6000_soc_platform);
+
+static int __init s6000_pcm_init(void)
+{
+	return snd_soc_register_platform(&s6000_soc_platform);
+}
+module_init(s6000_pcm_init);
+
+static void __exit s6000_pcm_exit(void)
+{
+	snd_soc_unregister_platform(&s6000_soc_platform);
+}
+module_exit(s6000_pcm_exit);
+
+MODULE_AUTHOR("Daniel Gloeckner");
+MODULE_DESCRIPTION("Stretch s6000 family PCM DMA module");
+MODULE_LICENSE("GPL");