ASoC: atmel-pcm: dma support based on pcm dmaengine

Specify overrun bit in interrupt mask
Add dmaengine specific routines

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[voice.shen@atmel.com: adapt to soc dmaengine framework]
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/atmel/Kconfig

@@ -10,6 +10,10 @@ config SND_ATMEL_SOC_PDC
 	tristate
 	depends on SND_ATMEL_SOC
 
+config SND_ATMEL_SOC_DMA
+	tristate
+	depends on SND_ATMEL_SOC
+
 config SND_ATMEL_SOC_SSC
 	tristate
 	depends on SND_ATMEL_SOC
@@ -31,6 +35,7 @@ config SND_AT91_SOC_SAM9G20_WM8731
 config SND_AT91_SOC_AFEB9260
 	tristate "SoC Audio support for AFEB9260 board"
 	depends on ATMEL_SSC && ARCH_AT91 && MACH_AFEB9260 && SND_ATMEL_SOC
+	select SND_ATMEL_SOC_PDC
 	select SND_ATMEL_SOC_SSC
 	select SND_SOC_TLV320AIC23
 	help

sound/soc/atmel/Makefile

@@ -1,10 +1,12 @@
 # AT91 Platform Support
 snd-soc-atmel-pcm-objs := atmel-pcm.o
 snd-soc-atmel-pcm-pdc-objs := atmel-pcm-pdc.o
+snd-soc-atmel-pcm-dma-objs := atmel-pcm-dma.o
 snd-soc-atmel_ssc_dai-objs := atmel_ssc_dai.o
 
 obj-$(CONFIG_SND_ATMEL_SOC) += snd-soc-atmel-pcm.o
 obj-$(CONFIG_SND_ATMEL_SOC_PDC) += snd-soc-atmel-pcm-pdc.o
+obj-$(CONFIG_SND_ATMEL_SOC_DMA) += snd-soc-atmel-pcm-dma.o
 obj-$(CONFIG_SND_ATMEL_SOC_SSC) += snd-soc-atmel_ssc_dai.o
 
 # AT91 Machine Support

sound/soc/atmel/atmel-pcm-dma.c

@@ -0,0 +1,240 @@
+/*
+ * 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");

sound/soc/atmel/atmel-pcm.h

@@ -52,6 +52,7 @@ struct atmel_pdc_regs {
 struct atmel_ssc_mask {
 	u32	ssc_enable;		/* SSC recv/trans enable */
 	u32	ssc_disable;		/* SSC recv/trans disable */
+	u32	ssc_error;		/* SSC error conditions */
 	u32	ssc_endx;		/* SSC ENDTX or ENDRX */
 	u32	ssc_endbuf;		/* SSC TXBUFE or RXBUFF */
 	u32	pdc_enable;		/* PDC recv/trans enable */
@@ -100,4 +101,17 @@ static inline void atmel_pcm_pdc_platform_unregister(struct device *dev)
 }
 #endif
 
+#ifdef CONFIG_SND_ATMEL_SOC_DMA
+int atmel_pcm_dma_platform_register(struct device *dev);
+void atmel_pcm_dma_platform_unregister(struct device *dev);
+#else
+static inline int atmel_pcm_dma_platform_register(struct device *dev)
+{
+	return 0;
+}
+static inline void atmel_pcm_dma_platform_unregister(struct device *dev)
+{
+}
+#endif
+
 #endif /* _ATMEL_PCM_H */

sound/soc/atmel/atmel_ssc_dai.c

@@ -721,6 +721,8 @@ static struct snd_soc_dai_driver atmel_ssc_dai = {
 
 static int asoc_ssc_init(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
+	struct ssc_device *ssc = platform_get_drvdata(pdev);
 	int ret;
 
 	ret = snd_soc_register_dai(dev, &atmel_ssc_dai);
@@ -729,7 +731,11 @@ static int asoc_ssc_init(struct device *dev)
 		goto err;
 	}
 
-	ret = atmel_pcm_pdc_platform_register(dev);
+	if (ssc->pdata->use_dma)
+		ret = atmel_pcm_dma_platform_register(dev);
+	else
+		ret = atmel_pcm_pdc_platform_register(dev);
+
 	if (ret) {
 		dev_err(dev, "Could not register PCM: %d\n", ret);
 		goto err_unregister_dai;
@@ -745,7 +751,14 @@ err:
 
 static void asoc_ssc_exit(struct device *dev)
 {
-	atmel_pcm_pdc_platform_unregister(dev);
+	struct platform_device *pdev = to_platform_device(dev);
+	struct ssc_device *ssc = platform_get_drvdata(pdev);
+
+	if (ssc->pdata->use_dma)
+		atmel_pcm_dma_platform_unregister(dev);
+	else
+		atmel_pcm_pdc_platform_unregister(dev);
+
 	snd_soc_unregister_dai(dev);
 }