[alsa-devel] [PATCH 4/7] ASoC: Add files to manage the pcm interface for all atmel boards.

Sedji Gaouaou sedji.gaouaou at atmel.com
Fri Oct 3 16:58:49 CEST 2008


Add files to manage the pcm interface for all atmel boards(merge between 
sound/soc/at91 sound/soc/at32).
As well as the atmel_ssc_dai file, it will use the common atmel_ssc API.
This file is based on at32-pcm. and at91-pcm.c.

Signed-off-by: Sedji Gaouaou <sedji.gaouaou at atmel.com>

---
 sound/soc/atmel/atmel-pcm.c |  484 +++++++++++++++++++++++++++++++++++++++++++
 sound/soc/atmel/atmel-pcm.h |   86 ++++++++
 2 files changed, 570 insertions(+), 0 deletions(-)
 create mode 100644 sound/soc/atmel/atmel-pcm.c
 create mode 100644 sound/soc/atmel/atmel-pcm.h

diff --git a/sound/soc/atmel/atmel-pcm.c b/sound/soc/atmel/atmel-pcm.c
new file mode 100644
index 0000000..6d317d2
--- /dev/null
+++ b/sound/soc/atmel/atmel-pcm.c
@@ -0,0 +1,484 @@
+/*
+ * atmel-pcm.c  --  ALSA PCM interface for the Atmel atmel SoC.
+ *
+ *  Copyright (C) 2005 SAN People
+ *  Copyright (C) 2008 Atmel
+ *
+ * Authors: Sedji Gaouaou <sedji.gaouaou at atmel.com>
+ *
+ * Based on at91-pcm. by:
+ * Frank Mandarino <fmandarino at endrelia.com>
+ * Copyright 2006 Endrelia Technologies Inc.
+ *
+ * Based on pxa2xx-pcm.c by:
+ *
+ * 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 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/atmel_pdc.h>
+#include <linux/atmel-ssc.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <mach/hardware.h>
+
+#include "atmel-pcm.h"
+
+
+/*--------------------------------------------------------------------------*\
+ * Hardware definition
+\*--------------------------------------------------------------------------*/
+/* TODO: These values were taken from the AT91 platform driver, check
+ *	 them against real values for AT32
+ */
+static const struct snd_pcm_hardware atmel_pcm_hardware = {
+	.info			= SNDRV_PCM_INFO_MMAP |
+				  SNDRV_PCM_INFO_MMAP_VALID |
+				  SNDRV_PCM_INFO_INTERLEAVED |
+				  SNDRV_PCM_INFO_PAUSE,
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
+	.period_bytes_min	= 32,
+	.period_bytes_max	= 8192,
+	.periods_min		= 2,
+	.periods_max		= 1024,
+	.buffer_bytes_max	= 32 * 1024,
+};
+
+
+/*--------------------------------------------------------------------------*\
+ * Data types
+\*--------------------------------------------------------------------------*/
+struct atmel_runtime_data {
+	struct atmel_pcm_dma_params *params;
+	dma_addr_t dma_buffer;		/* physical address of dma buffer */
+	dma_addr_t dma_buffer_end;	/* first address beyond DMA buffer */
+	size_t period_size;
+
+	dma_addr_t period_ptr;		/* physical address of next period */
+	int periods;			/* period index of period_ptr */
+
+	/* PDC register save */
+	u32 pdc_xpr_save;
+	u32 pdc_xcr_save;
+	u32 pdc_xnpr_save;
+	u32 pdc_xncr_save;
+};
+
+
+/*--------------------------------------------------------------------------*\
+ * Helper functions
+\*--------------------------------------------------------------------------*/
+static int atmel_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 = atmel_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_coherent(pcm->card->dev, size,
+					  &buf->addr, GFP_KERNEL);
+	pr_debug("atmel-pcm:"
+		"preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
+		(void *) buf->area,
+		(void *) buf->addr,
+		size);
+
+	if (!buf->area)
+		return -ENOMEM;
+
+	buf->bytes = size;
+	return 0;
+}
+/*--------------------------------------------------------------------------*\
+ * ISR
+\*--------------------------------------------------------------------------*/
+static void atmel_pcm_dma_irq(u32 ssc_sr,
+	struct snd_pcm_substream *substream)
+{
+	struct atmel_runtime_data *prtd = substream->runtime->private_data;
+	struct atmel_pcm_dma_params *params = prtd->params;
+	static int count = 0;
+
+	count++;
+
+	if (ssc_sr & params->mask->ssc_endbuf) {
+		pr_warning("atmel-pcm: buffer %s on %s"
+				" (SSC_SR=%#x, count=%d)\n",
+				substream->stream == SNDRV_PCM_STREAM_PLAYBACK
+				? "underrun" : "overrun",
+				params->name, ssc_sr, count);
+
+		/* re-start the PDC */
+		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
+			   params->mask->pdc_disable);
+		prtd->period_ptr += prtd->period_size;
+		if (prtd->period_ptr >= prtd->dma_buffer_end)
+			prtd->period_ptr = prtd->dma_buffer;
+
+		ssc_writex(params->ssc->regs, params->pdc->xpr,
+			   prtd->period_ptr);
+		ssc_writex(params->ssc->regs, params->pdc->xcr,
+			   prtd->period_size / params->pdc_xfer_size);
+		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
+			   params->mask->pdc_enable);
+	}
+
+	if (ssc_sr & params->mask->ssc_endx) {
+		/* Load the PDC next pointer and counter registers */
+		prtd->period_ptr += prtd->period_size;
+		if (prtd->period_ptr >= prtd->dma_buffer_end)
+			prtd->period_ptr = prtd->dma_buffer;
+
+		ssc_writex(params->ssc->regs, params->pdc->xnpr,
+			   prtd->period_ptr);
+		ssc_writex(params->ssc->regs, params->pdc->xncr,
+			   prtd->period_size / params->pdc_xfer_size);
+	}
+
+	snd_pcm_period_elapsed(substream);
+}
+
+
+/*--------------------------------------------------------------------------*\
+ * PCM operations
+\*--------------------------------------------------------------------------*/
+static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct atmel_runtime_data *prtd = runtime->private_data;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+
+	/* this may get called several times by oss emulation
+	 * with different params */
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	runtime->dma_bytes = params_buffer_bytes(params);
+
+	prtd->params = rtd->dai->cpu_dai->dma_data;
+	prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
+
+	prtd->dma_buffer = runtime->dma_addr;
+	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
+	prtd->period_size = params_period_bytes(params);
+
+	pr_debug("atmel-pcm: "
+		"hw_params: DMA for %s initialized "
+		"(dma_bytes=%u, period_size=%u)\n",
+		prtd->params->name,
+		runtime->dma_bytes,
+		prtd->period_size);
+	return 0;
+}
+
+static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct atmel_runtime_data *prtd = substream->runtime->private_data;
+	struct atmel_pcm_dma_params *params = prtd->params;
+
+	if (params != NULL) {
+		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
+			   params->mask->pdc_disable);
+		prtd->params->dma_intr_handler = NULL;
+	}
+
+	return 0;
+}
+
+static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct atmel_runtime_data *prtd = substream->runtime->private_data;
+	struct atmel_pcm_dma_params *params = prtd->params;
+
+	ssc_writex(params->ssc->regs, SSC_IDR,
+		   params->mask->ssc_endx | params->mask->ssc_endbuf);
+	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
+		   params->mask->pdc_disable);
+	return 0;
+}
+
+static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
+	int cmd)
+{
+	struct snd_pcm_runtime *rtd = substream->runtime;
+	struct atmel_runtime_data *prtd = rtd->private_data;
+	struct atmel_pcm_dma_params *params = prtd->params;
+	int ret = 0;
+
+	pr_debug("atmel-pcm:buffer_size = %ld,"
+		"dma_area = %p, dma_bytes = %u\n",
+		rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		prtd->period_ptr = prtd->dma_buffer;
+
+		ssc_writex(params->ssc->regs, params->pdc->xpr,
+			   prtd->period_ptr);
+		ssc_writex(params->ssc->regs, params->pdc->xcr,
+			   prtd->period_size / params->pdc_xfer_size);
+
+		prtd->period_ptr += prtd->period_size;
+		ssc_writex(params->ssc->regs, params->pdc->xnpr,
+			   prtd->period_ptr);
+		ssc_writex(params->ssc->regs, params->pdc->xncr,
+			   prtd->period_size / params->pdc_xfer_size);
+
+		pr_debug("atmel-pcm: trigger: "
+			"period_ptr=%lx, xpr=%u, "
+			"xcr=%u, xnpr=%u, xncr=%u\n",
+			(unsigned long)prtd->period_ptr,
+			ssc_readx(params->ssc->regs, params->pdc->xpr),
+			ssc_readx(params->ssc->regs, params->pdc->xcr),
+			ssc_readx(params->ssc->regs, params->pdc->xnpr),
+			ssc_readx(params->ssc->regs, params->pdc->xncr));
+
+		ssc_writex(params->ssc->regs, SSC_IER,
+			   params->mask->ssc_endx | params->mask->ssc_endbuf);
+		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
+			   params->mask->pdc_enable);
+
+		pr_debug("sr=%u imr=%u\n",
+			ssc_readx(params->ssc->regs, SSC_SR),
+			ssc_readx(params->ssc->regs, SSC_IER));
+		break;		/* SNDRV_PCM_TRIGGER_START */
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
+			   params->mask->pdc_disable);
+		break;
+
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
+			   params->mask->pdc_enable);
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static snd_pcm_uframes_t atmel_pcm_pointer(
+	struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct atmel_runtime_data *prtd = runtime->private_data;
+	struct atmel_pcm_dma_params *params = prtd->params;
+	dma_addr_t ptr;
+	snd_pcm_uframes_t x;
+
+	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
+	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
+
+	if (x == runtime->buffer_size)
+		x = 0;
+
+	return x;
+}
+
+static int atmel_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct atmel_runtime_data *prtd;
+	int ret = 0;
+
+	snd_soc_set_runtime_hwparams(substream, &atmel_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(struct atmel_runtime_data), GFP_KERNEL);
+	if (prtd == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	runtime->private_data = prtd;
+
+ out:
+	return ret;
+}
+
+static int atmel_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct atmel_runtime_data *prtd = substream->runtime->private_data;
+
+	kfree(prtd);
+	return 0;
+}
+
+static int atmel_pcm_mmap(struct snd_pcm_substream *substream,
+	struct vm_area_struct *vma)
+{
+	return remap_pfn_range(vma, vma->vm_start,
+		       substream->dma_buffer.addr >> PAGE_SHIFT,
+		       vma->vm_end - vma->vm_start, vma->vm_page_prot);
+}
+
+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,
+	.hw_free	= atmel_pcm_hw_free,
+	.prepare	= atmel_pcm_prepare,
+	.trigger	= atmel_pcm_trigger,
+	.pointer	= atmel_pcm_pointer,
+	.mmap		= atmel_pcm_mmap,
+};
+
+
+/*--------------------------------------------------------------------------*\
+ * ASoC platform driver
+\*--------------------------------------------------------------------------*/
+static u64 atmel_pcm_dmamask = 0xffffffff;
+
+static int atmel_pcm_new(struct snd_card *card,
+	struct snd_soc_dai *dai, struct snd_pcm *pcm)
+{
+	int ret = 0;
+
+	if (!card->dev->dma_mask)
+		card->dev->dma_mask = &atmel_pcm_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = 0xffffffff;
+
+	if (dai->playback.channels_min) {
+		ret = atmel_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			goto out;
+	}
+
+	if (dai->capture.channels_min) {
+		pr_debug("at32-pcm:"
+				"Allocating PCM capture DMA buffer\n");
+		ret = atmel_pcm_preallocate_dma_buffer(pcm,
+			SNDRV_PCM_STREAM_CAPTURE);
+		if (ret)
+			goto out;
+	}
+ out:
+	return ret;
+}
+
+static void atmel_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_coherent(pcm->card->dev, buf->bytes,
+				  buf->area, buf->addr);
+		buf->area = NULL;
+	}
+}
+
+#ifdef CONFIG_PM
+static int atmel_pcm_suspend(struct platform_device *pdev,
+	struct snd_soc_dai *dai)
+{
+	struct snd_pcm_runtime *runtime = dai->runtime;
+	struct atmel_runtime_data *prtd;
+	struct atmel_pcm_dma_params *params;
+
+	if (!runtime)
+		return 0;
+
+	prtd = runtime->private_data;
+	params = prtd->params;
+
+	/* disable the PDC and save the PDC registers */
+
+	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_disable);
+
+	prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr);
+	prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr);
+	prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr);
+	prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr);
+
+	return 0;
+}
+
+static int atmel_pcm_resume(struct platform_device *pdev,
+	struct snd_soc_dai *dai)
+{
+	struct snd_pcm_runtime *runtime = dai->runtime;
+	struct atmel_runtime_data *prtd;
+	struct atmel_pcm_dma_params *params;
+
+	if (!runtime)
+		return 0;
+
+	prtd = runtime->private_data;
+	params = prtd->params;
+
+	/* restore the PDC registers and enable the PDC */
+	ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save);
+	ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save);
+	ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save);
+	ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save);
+
+	ssc_writel(params->ssc->regs, PDC_PTCR, params->mask->pdc_enable);
+	return 0;
+}
+#else
+#define atmel_pcm_suspend	NULL
+#define atmel_pcm_resume	NULL
+#endif
+
+struct snd_soc_platform atmel_soc_platform = {
+	.name		= "atmel-audio",
+	.pcm_ops 	= &atmel_pcm_ops,
+	.pcm_new	= atmel_pcm_new,
+	.pcm_free	= atmel_pcm_free_dma_buffers,
+	.suspend	= atmel_pcm_suspend,
+	.resume		= atmel_pcm_resume,
+};
+EXPORT_SYMBOL_GPL(atmel_soc_platform);
+
+MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou at atmel.com>");
+MODULE_DESCRIPTION("Atmel PCM module");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/atmel/atmel-pcm.h b/sound/soc/atmel/atmel-pcm.h
new file mode 100644
index 0000000..ec9b282
--- /dev/null
+++ b/sound/soc/atmel/atmel-pcm.h
@@ -0,0 +1,86 @@
+/*
+ * at91-pcm.h - ALSA PCM interface for the Atmel AT91 SoC.
+ *
+ *  Copyright (C) 2005 SAN People
+ *  Copyright (C) 2008 Atmel
+ *
+ * Authors: Sedji Gaouaou <sedji.gaouaou at atmel.com>
+ *
+ * Based on at91-pcm. by:
+ * Frank Mandarino <fmandarino at endrelia.com>
+ * Copyright 2006 Endrelia Technologies Inc.
+ *
+ * Based on pxa2xx-pcm.c by:
+ *
+ * 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 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
+ */
+
+#ifndef _ATMEL_PCM_H
+#define _ATMEL_PCM_H
+
+#include <linux/atmel-ssc.h>
+
+/*
+ * Registers and status bits that are required by the PCM driver.
+ */
+struct atmel_pdc_regs {
+	unsigned int	xpr;		/* PDC recv/trans pointer */
+	unsigned int	xcr;		/* PDC recv/trans counter */
+	unsigned int	xnpr;		/* PDC next recv/trans pointer */
+	unsigned int	xncr;		/* PDC next recv/trans counter */
+	unsigned int	ptcr;		/* PDC transfer control */
+};
+
+struct atmel_ssc_mask {
+	u32	ssc_enable;		/* SSC recv/trans enable */
+	u32	ssc_disable;		/* SSC recv/trans disable */
+	u32	ssc_endx;		/* SSC ENDTX or ENDRX */
+	u32	ssc_endbuf;		/* SSC TXBUFE or RXBUFF */
+	u32	pdc_enable;		/* PDC recv/trans enable */
+	u32	pdc_disable;		/* PDC recv/trans disable */
+};
+
+/*
+ * This structure, shared between the PCM driver and the interface,
+ * contains all information required by the PCM driver to perform the
+ * PDC DMA operation.  All fields except dma_intr_handler() are initialized
+ * by the interface.  The dms_intr_handler() pointer is set by the PCM
+ * driver and called by the interface SSC interrupt handler if it is
+ * non-NULL.
+ */
+struct atmel_pcm_dma_params {
+	char *name;			/* stream identifier */
+	int pdc_xfer_size;		/* PDC counter increment in bytes */
+	struct ssc_device *ssc;		/* SSC device for stream */
+	struct atmel_pdc_regs *pdc;	/* PDC receive or transmit registers */
+	struct atmel_ssc_mask *mask;	/* SSC & PDC status bits */
+	struct snd_pcm_substream *substream;
+	void (*dma_intr_handler)(u32, struct snd_pcm_substream *);
+};
+
+extern struct snd_soc_platform atmel_soc_platform;
+
+
+/*
+ * SSC register access (since ssc_writel() / ssc_readl() require literal name)
+ */
+#define ssc_readx(base, reg)            (__raw_readl((base) + (reg)))
+#define ssc_writex(base, reg, value)    __raw_writel((value), (base) + (reg))
+
+#endif /* _ATMEL_PCM_H */
-- 
1.5.3.7

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