sound/soc/sh/siu_pcm.c - kernel/msm-4.9 - Gitiles

 /*
  * siu_pcm.c - ALSA driver for Renesas SH7343, SH7722 SIU peripheral.
  *
  * Copyright (C) 2009-2010 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
  * Copyright (C) 2006 Carlos Munoz <carlos@kenati.com>
  *
  * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>

 #include <sound/control.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>

 #include <asm/siu.h>

 #include "siu.h"

 #define GET_MAX_PERIODS(buf_bytes, period_bytes) \
 				((buf_bytes) / (period_bytes))
 #define PERIOD_OFFSET(buf_addr, period_num, period_bytes) \
 				((buf_addr) + ((period_num) * (period_bytes)))

 #define RWF_STM_RD		0x01		/* Read in progress */
 #define RWF_STM_WT		0x02		/* Write in progress */

 struct siu_port *siu_ports[SIU_PORT_NUM];

 /* transfersize is number of u32 dma transfers per period */
 static int siu_pcm_stmwrite_stop(struct siu_port *port_info)
 {
 	struct siu_info *info = siu_i2s_data;
 	u32 __iomem *base = info->reg;
 	struct siu_stream *siu_stream = &port_info->playback;
 	u32 stfifo;

 	if (!siu_stream->rw_flg)
 		return -EPERM;

 	/* output FIFO disable */
 	stfifo = siu_read32(base + SIU_STFIFO);
 	siu_write32(base + SIU_STFIFO, stfifo & ~0x0c180c18);
 	pr_debug("%s: STFIFO %x -> %x\n", __func__,
 		 stfifo, stfifo & ~0x0c180c18);

 	/* during stmwrite clear */
 	siu_stream->rw_flg = 0;

 	return 0;
 }

 static int siu_pcm_stmwrite_start(struct siu_port *port_info)
 {
 	struct siu_stream *siu_stream = &port_info->playback;

 	if (siu_stream->rw_flg)
 		return -EPERM;

 	/* Current period in buffer */
 	port_info->playback.cur_period = 0;

 	/* during stmwrite flag set */
 	siu_stream->rw_flg = RWF_STM_WT;

 	/* DMA transfer start */
 	tasklet_schedule(&siu_stream->tasklet);

 	return 0;
 }

 static void siu_dma_tx_complete(void *arg)
 {
 	struct siu_stream *siu_stream = arg;

 	if (!siu_stream->rw_flg)
 		return;

 	/* Update completed period count */
 	if (++siu_stream->cur_period >=
 	    GET_MAX_PERIODS(siu_stream->buf_bytes,
 			    siu_stream->period_bytes))
 		siu_stream->cur_period = 0;

 	pr_debug("%s: done period #%d (%u/%u bytes), cookie %d\n",
 		__func__, siu_stream->cur_period,
 		siu_stream->cur_period * siu_stream->period_bytes,
 		siu_stream->buf_bytes, siu_stream->cookie);

 	tasklet_schedule(&siu_stream->tasklet);

 	/* Notify alsa: a period is done */
 	snd_pcm_period_elapsed(siu_stream->substream);
 }

 static int siu_pcm_wr_set(struct siu_port *port_info,
 			  dma_addr_t buff, u32 size)
 {
 	struct siu_info *info = siu_i2s_data;
 	u32 __iomem *base = info->reg;
 	struct siu_stream *siu_stream = &port_info->playback;
 	struct snd_pcm_substream *substream = siu_stream->substream;
 	struct device *dev = substream->pcm->card->dev;
 	struct dma_async_tx_descriptor *desc;
 	dma_cookie_t cookie;
 	struct scatterlist sg;
 	u32 stfifo;

 	sg_init_table(&sg, 1);
 	sg_set_page(&sg, pfn_to_page(PFN_DOWN(buff)),
 		    size, offset_in_page(buff));
 	sg_dma_len(&sg) = size;
 	sg_dma_address(&sg) = buff;

 	desc = dmaengine_prep_slave_sg(siu_stream->chan,
 		&sg, 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		dev_err(dev, "Failed to allocate a dma descriptor\n");
 		return -ENOMEM;
 	}

 	desc->callback = siu_dma_tx_complete;
 	desc->callback_param = siu_stream;
 	cookie = dmaengine_submit(desc);
 	if (cookie < 0) {
 		dev_err(dev, "Failed to submit a dma transfer\n");
 		return cookie;
 	}

 	siu_stream->tx_desc = desc;
 	siu_stream->cookie = cookie;

 	dma_async_issue_pending(siu_stream->chan);

 	/* only output FIFO enable */
 	stfifo = siu_read32(base + SIU_STFIFO);
 	siu_write32(base + SIU_STFIFO, stfifo | (port_info->stfifo & 0x0c180c18));
 	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
 		stfifo, stfifo | (port_info->stfifo & 0x0c180c18));

 	return 0;
 }

 static int siu_pcm_rd_set(struct siu_port *port_info,
 			  dma_addr_t buff, size_t size)
 {
 	struct siu_info *info = siu_i2s_data;
 	u32 __iomem *base = info->reg;
 	struct siu_stream *siu_stream = &port_info->capture;
 	struct snd_pcm_substream *substream = siu_stream->substream;
 	struct device *dev = substream->pcm->card->dev;
 	struct dma_async_tx_descriptor *desc;
 	dma_cookie_t cookie;
 	struct scatterlist sg;
 	u32 stfifo;

 	dev_dbg(dev, "%s: %u@%llx\n", __func__, size, (unsigned long long)buff);

 	sg_init_table(&sg, 1);
 	sg_set_page(&sg, pfn_to_page(PFN_DOWN(buff)),
 		    size, offset_in_page(buff));
 	sg_dma_len(&sg) = size;
 	sg_dma_address(&sg) = buff;

 	desc = dmaengine_prep_slave_sg(siu_stream->chan,
 		&sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		dev_err(dev, "Failed to allocate dma descriptor\n");
 		return -ENOMEM;
 	}

 	desc->callback = siu_dma_tx_complete;
 	desc->callback_param = siu_stream;
 	cookie = dmaengine_submit(desc);
 	if (cookie < 0) {
 		dev_err(dev, "Failed to submit dma descriptor\n");
 		return cookie;
 	}

 	siu_stream->tx_desc = desc;
 	siu_stream->cookie = cookie;

 	dma_async_issue_pending(siu_stream->chan);

 	/* only input FIFO enable */
 	stfifo = siu_read32(base + SIU_STFIFO);
 	siu_write32(base + SIU_STFIFO, siu_read32(base + SIU_STFIFO) |
 		    (port_info->stfifo & 0x13071307));
 	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
 		stfifo, stfifo | (port_info->stfifo & 0x13071307));

 	return 0;
 }

 static void siu_io_tasklet(unsigned long data)
 {
 	struct siu_stream *siu_stream = (struct siu_stream *)data;
 	struct snd_pcm_substream *substream = siu_stream->substream;
 	struct device *dev = substream->pcm->card->dev;
 	struct snd_pcm_runtime *rt = substream->runtime;
 	struct siu_port *port_info = siu_port_info(substream);

 	dev_dbg(dev, "%s: flags %x\n", __func__, siu_stream->rw_flg);

 	if (!siu_stream->rw_flg) {
 		dev_dbg(dev, "%s: stream inactive\n", __func__);
 		return;
 	}

 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 		dma_addr_t buff;
 		size_t count;
 		u8 *virt;

 		buff = (dma_addr_t)PERIOD_OFFSET(rt->dma_addr,
 						siu_stream->cur_period,
 						siu_stream->period_bytes);
 		virt = PERIOD_OFFSET(rt->dma_area,
 				     siu_stream->cur_period,
 				     siu_stream->period_bytes);
 		count = siu_stream->period_bytes;

 		/* DMA transfer start */
 		siu_pcm_rd_set(port_info, buff, count);
 	} else {
 		siu_pcm_wr_set(port_info,
 			       (dma_addr_t)PERIOD_OFFSET(rt->dma_addr,
 						siu_stream->cur_period,
 						siu_stream->period_bytes),
 			       siu_stream->period_bytes);
 	}
 }

 /* Capture */
 static int siu_pcm_stmread_start(struct siu_port *port_info)
 {
 	struct siu_stream *siu_stream = &port_info->capture;

 	if (siu_stream->xfer_cnt > 0x1000000)
 		return -EINVAL;
 	if (siu_stream->rw_flg)
 		return -EPERM;

 	/* Current period in buffer */
 	siu_stream->cur_period = 0;

 	/* during stmread flag set */
 	siu_stream->rw_flg = RWF_STM_RD;

 	tasklet_schedule(&siu_stream->tasklet);

 	return 0;
 }

 static int siu_pcm_stmread_stop(struct siu_port *port_info)
 {
 	struct siu_info *info = siu_i2s_data;
 	u32 __iomem *base = info->reg;
 	struct siu_stream *siu_stream = &port_info->capture;
 	struct device *dev = siu_stream->substream->pcm->card->dev;
 	u32 stfifo;

 	if (!siu_stream->rw_flg)
 		return -EPERM;

 	/* input FIFO disable */
 	stfifo = siu_read32(base + SIU_STFIFO);
 	siu_write32(base + SIU_STFIFO, stfifo & ~0x13071307);
 	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
 		stfifo, stfifo & ~0x13071307);

 	/* during stmread flag clear */
 	siu_stream->rw_flg = 0;

 	return 0;
 }

 static int siu_pcm_hw_params(struct snd_pcm_substream *ss,
 			     struct snd_pcm_hw_params *hw_params)
 {
 	struct siu_info *info = siu_i2s_data;
 	struct device *dev = ss->pcm->card->dev;
 	int ret;

 	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

 	ret = snd_pcm_lib_malloc_pages(ss, params_buffer_bytes(hw_params));
 	if (ret < 0)
 		dev_err(dev, "snd_pcm_lib_malloc_pages() failed\n");

 	return ret;
 }

 static int siu_pcm_hw_free(struct snd_pcm_substream *ss)
 {
 	struct siu_info *info = siu_i2s_data;
 	struct siu_port	*port_info = siu_port_info(ss);
 	struct device *dev = ss->pcm->card->dev;
 	struct siu_stream *siu_stream;

 	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		siu_stream = &port_info->playback;
 	else
 		siu_stream = &port_info->capture;

 	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

 	return snd_pcm_lib_free_pages(ss);
 }

 static bool filter(struct dma_chan *chan, void *slave)
 {
 	struct sh_dmae_slave *param = slave;

 	pr_debug("%s: slave ID %d\n", __func__, param->shdma_slave.slave_id);

 	chan->private = &param->shdma_slave;
 	return true;
 }

 static int siu_pcm_open(struct snd_pcm_substream *ss)
 {
 	/* Playback / Capture */
 	struct snd_soc_pcm_runtime *rtd = ss->private_data;
 	struct siu_platform *pdata = rtd->platform->dev->platform_data;
 	struct siu_info *info = siu_i2s_data;
 	struct siu_port *port_info = siu_port_info(ss);
 	struct siu_stream *siu_stream;
 	u32 port = info->port_id;
 	struct device *dev = ss->pcm->card->dev;
 	dma_cap_mask_t mask;
 	struct sh_dmae_slave *param;

 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);

 	dev_dbg(dev, "%s, port=%d@%p\n", __func__, port, port_info);

 	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		siu_stream = &port_info->playback;
 		param = &siu_stream->param;
 		param->shdma_slave.slave_id = port ? pdata->dma_slave_tx_b :
 			pdata->dma_slave_tx_a;
 	} else {
 		siu_stream = &port_info->capture;
 		param = &siu_stream->param;
 		param->shdma_slave.slave_id = port ? pdata->dma_slave_rx_b :
 			pdata->dma_slave_rx_a;
 	}

 	/* Get DMA channel */
 	siu_stream->chan = dma_request_channel(mask, filter, param);
 	if (!siu_stream->chan) {
 		dev_err(dev, "DMA channel allocation failed!\n");
 		return -EBUSY;
 	}

 	siu_stream->substream = ss;

 	return 0;
 }

 static int siu_pcm_close(struct snd_pcm_substream *ss)
 {
 	struct siu_info *info = siu_i2s_data;
 	struct device *dev = ss->pcm->card->dev;
 	struct siu_port *port_info = siu_port_info(ss);
 	struct siu_stream *siu_stream;

 	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

 	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		siu_stream = &port_info->playback;
 	else
 		siu_stream = &port_info->capture;

 	dma_release_channel(siu_stream->chan);
 	siu_stream->chan = NULL;

 	siu_stream->substream = NULL;

 	return 0;
 }

 static int siu_pcm_prepare(struct snd_pcm_substream *ss)
 {
 	struct siu_info *info = siu_i2s_data;
 	struct siu_port *port_info = siu_port_info(ss);
 	struct device *dev = ss->pcm->card->dev;
 	struct snd_pcm_runtime 	*rt = ss->runtime;
 	struct siu_stream *siu_stream;
 	snd_pcm_sframes_t xfer_cnt;

 	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		siu_stream = &port_info->playback;
 	else
 		siu_stream = &port_info->capture;

 	rt = siu_stream->substream->runtime;

 	siu_stream->buf_bytes = snd_pcm_lib_buffer_bytes(ss);
 	siu_stream->period_bytes = snd_pcm_lib_period_bytes(ss);

 	dev_dbg(dev, "%s: port=%d, %d channels, period=%u bytes\n", __func__,
 		info->port_id, rt->channels, siu_stream->period_bytes);

 	/* We only support buffers that are multiples of the period */
 	if (siu_stream->buf_bytes % siu_stream->period_bytes) {
 		dev_err(dev, "%s() - buffer=%d not multiple of period=%d\n",
 		       __func__, siu_stream->buf_bytes,
 		       siu_stream->period_bytes);
 		return -EINVAL;
 	}

 	xfer_cnt = bytes_to_frames(rt, siu_stream->period_bytes);
 	if (!xfer_cnt || xfer_cnt > 0x1000000)
 		return -EINVAL;

 	siu_stream->format = rt->format;
 	siu_stream->xfer_cnt = xfer_cnt;

 	dev_dbg(dev, "port=%d buf=%lx buf_bytes=%d period_bytes=%d "
 		"format=%d channels=%d xfer_cnt=%d\n", info->port_id,
 		(unsigned long)rt->dma_addr, siu_stream->buf_bytes,
 		siu_stream->period_bytes,
 		siu_stream->format, rt->channels, (int)xfer_cnt);

 	return 0;
 }

 static int siu_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
 {
 	struct siu_info *info = siu_i2s_data;
 	struct device *dev = ss->pcm->card->dev;
 	struct siu_port *port_info = siu_port_info(ss);
 	int ret;

 	dev_dbg(dev, "%s: port=%d@%p, cmd=%d\n", __func__,
 		info->port_id, port_info, cmd);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			ret = siu_pcm_stmwrite_start(port_info);
 		else
 			ret = siu_pcm_stmread_start(port_info);

 		if (ret < 0)
 			dev_warn(dev, "%s: start failed on port=%d\n",
 				 __func__, info->port_id);

 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			siu_pcm_stmwrite_stop(port_info);
 		else
 			siu_pcm_stmread_stop(port_info);
 		ret = 0;

 		break;
 	default:
 		dev_err(dev, "%s() unsupported cmd=%d\n", __func__, cmd);
 		ret = -EINVAL;
 	}

 	return ret;
 }

 /*
  * So far only resolution of one period is supported, subject to extending the
  * dmangine API
  */
 static snd_pcm_uframes_t siu_pcm_pointer_dma(struct snd_pcm_substream *ss)
 {
 	struct device *dev = ss->pcm->card->dev;
 	struct siu_info *info = siu_i2s_data;
 	u32 __iomem *base = info->reg;
 	struct siu_port *port_info = siu_port_info(ss);
 	struct snd_pcm_runtime *rt = ss->runtime;
 	size_t ptr;
 	struct siu_stream *siu_stream;

 	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		siu_stream = &port_info->playback;
 	else
 		siu_stream = &port_info->capture;

 	/*
 	 * ptr is the offset into the buffer where the dma is currently at. We
 	 * check if the dma buffer has just wrapped.
 	 */
 	ptr = PERIOD_OFFSET(rt->dma_addr,
 			    siu_stream->cur_period,
 			    siu_stream->period_bytes) - rt->dma_addr;

 	dev_dbg(dev,
 		"%s: port=%d, events %x, FSTS %x, xferred %u/%u, cookie %d\n",
 		__func__, info->port_id, siu_read32(base + SIU_EVNTC),
 		siu_read32(base + SIU_SBFSTS), ptr, siu_stream->buf_bytes,
 		siu_stream->cookie);

 	if (ptr >= siu_stream->buf_bytes)
 		ptr = 0;

 	return bytes_to_frames(ss->runtime, ptr);
 }

 static int siu_pcm_new(struct snd_soc_pcm_runtime *rtd)
 {
 	/* card->dev == socdev->dev, see snd_soc_new_pcms() */
 	struct snd_card *card = rtd->card->snd_card;
 	struct snd_pcm *pcm = rtd->pcm;
 	struct siu_info *info = siu_i2s_data;
 	struct platform_device *pdev = to_platform_device(card->dev);
 	int ret;
 	int i;

 	/* pdev->id selects between SIUA and SIUB */
 	if (pdev->id < 0 || pdev->id >= SIU_PORT_NUM)
 		return -EINVAL;

 	info->port_id = pdev->id;

 	/*
 	 * While the siu has 2 ports, only one port can be on at a time (only 1
 	 * SPB). So far all the boards using the siu had only one of the ports
 	 * wired to a codec. To simplify things, we only register one port with
 	 * alsa. In case both ports are needed, it should be changed here
 	 */
 	for (i = pdev->id; i < pdev->id + 1; i++) {
 		struct siu_port **port_info = &siu_ports[i];

 		ret = siu_init_port(i, port_info, card);
 		if (ret < 0)
 			return ret;

 		ret = snd_pcm_lib_preallocate_pages_for_all(pcm,
 				SNDRV_DMA_TYPE_DEV, NULL,
 				SIU_BUFFER_BYTES_MAX, SIU_BUFFER_BYTES_MAX);
 		if (ret < 0) {
 			dev_err(card->dev,
 			       "snd_pcm_lib_preallocate_pages_for_all() err=%d",
 				ret);
 			goto fail;
 		}

 		(*port_info)->pcm = pcm;

 		/* IO tasklets */
 		tasklet_init(&(*port_info)->playback.tasklet, siu_io_tasklet,
 			     (unsigned long)&(*port_info)->playback);
 		tasklet_init(&(*port_info)->capture.tasklet, siu_io_tasklet,
 			     (unsigned long)&(*port_info)->capture);
 	}

 	dev_info(card->dev, "SuperH SIU driver initialized.\n");
 	return 0;

 fail:
 	siu_free_port(siu_ports[pdev->id]);
 	dev_err(card->dev, "SIU: failed to initialize.\n");
 	return ret;
 }

 static void siu_pcm_free(struct snd_pcm *pcm)
 {
 	struct platform_device *pdev = to_platform_device(pcm->card->dev);
 	struct siu_port *port_info = siu_ports[pdev->id];

 	tasklet_kill(&port_info->capture.tasklet);
 	tasklet_kill(&port_info->playback.tasklet);

 	siu_free_port(port_info);
 	snd_pcm_lib_preallocate_free_for_all(pcm);

 	dev_dbg(pcm->card->dev, "%s\n", __func__);
 }

 static struct snd_pcm_ops siu_pcm_ops = {
 	.open		= siu_pcm_open,
 	.close		= siu_pcm_close,
 	.ioctl		= snd_pcm_lib_ioctl,
 	.hw_params	= siu_pcm_hw_params,
 	.hw_free	= siu_pcm_hw_free,
 	.prepare	= siu_pcm_prepare,
 	.trigger	= siu_pcm_trigger,
 	.pointer	= siu_pcm_pointer_dma,
 };

 struct snd_soc_platform_driver siu_platform = {
 	.ops			= &siu_pcm_ops,
 	.pcm_new	= siu_pcm_new,
 	.pcm_free	= siu_pcm_free,
 };
 EXPORT_SYMBOL_GPL(siu_platform);
	/*
	* siu_pcm.c - ALSA driver for Renesas SH7343, SH7722 SIU peripheral.
	*
	* Copyright (C) 2009-2010 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
	* Copyright (C) 2006 Carlos Munoz <carlos@kenati.com>
	*
	* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/
	#include <linux/delay.h>
	#include <linux/dma-mapping.h>
	#include <linux/dmaengine.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>

	#include <sound/control.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>

	#include <asm/siu.h>

	#include "siu.h"

	#define GET_MAX_PERIODS(buf_bytes, period_bytes) \
	((buf_bytes) / (period_bytes))
	#define PERIOD_OFFSET(buf_addr, period_num, period_bytes) \
	((buf_addr) + ((period_num) * (period_bytes)))

	#define RWF_STM_RD 0x01 /* Read in progress */
	#define RWF_STM_WT 0x02 /* Write in progress */

	struct siu_port *siu_ports[SIU_PORT_NUM];

	/* transfersize is number of u32 dma transfers per period */
	static int siu_pcm_stmwrite_stop(struct siu_port *port_info)
	{
	struct siu_info *info = siu_i2s_data;
	u32 __iomem *base = info->reg;
	struct siu_stream *siu_stream = &port_info->playback;
	u32 stfifo;

	if (!siu_stream->rw_flg)
	return -EPERM;

	/* output FIFO disable */
	stfifo = siu_read32(base + SIU_STFIFO);
	siu_write32(base + SIU_STFIFO, stfifo & ~0x0c180c18);
	pr_debug("%s: STFIFO %x -> %x\n", __func__,
	stfifo, stfifo & ~0x0c180c18);

	/* during stmwrite clear */
	siu_stream->rw_flg = 0;

	return 0;
	}

	static int siu_pcm_stmwrite_start(struct siu_port *port_info)
	{
	struct siu_stream *siu_stream = &port_info->playback;

	if (siu_stream->rw_flg)
	return -EPERM;

	/* Current period in buffer */
	port_info->playback.cur_period = 0;

	/* during stmwrite flag set */
	siu_stream->rw_flg = RWF_STM_WT;

	/* DMA transfer start */
	tasklet_schedule(&siu_stream->tasklet);

	return 0;
	}

	static void siu_dma_tx_complete(void *arg)
	{
	struct siu_stream *siu_stream = arg;

	if (!siu_stream->rw_flg)
	return;

	/* Update completed period count */
	if (++siu_stream->cur_period >=
	GET_MAX_PERIODS(siu_stream->buf_bytes,
	siu_stream->period_bytes))
	siu_stream->cur_period = 0;

	pr_debug("%s: done period #%d (%u/%u bytes), cookie %d\n",
	__func__, siu_stream->cur_period,
	siu_stream->cur_period * siu_stream->period_bytes,
	siu_stream->buf_bytes, siu_stream->cookie);

	tasklet_schedule(&siu_stream->tasklet);

	/* Notify alsa: a period is done */
	snd_pcm_period_elapsed(siu_stream->substream);
	}

	static int siu_pcm_wr_set(struct siu_port *port_info,
	dma_addr_t buff, u32 size)
	{
	struct siu_info *info = siu_i2s_data;
	u32 __iomem *base = info->reg;
	struct siu_stream *siu_stream = &port_info->playback;
	struct snd_pcm_substream *substream = siu_stream->substream;
	struct device *dev = substream->pcm->card->dev;
	struct dma_async_tx_descriptor *desc;
	dma_cookie_t cookie;
	struct scatterlist sg;
	u32 stfifo;

	sg_init_table(&sg, 1);
	sg_set_page(&sg, pfn_to_page(PFN_DOWN(buff)),
	size, offset_in_page(buff));
	sg_dma_len(&sg) = size;
	sg_dma_address(&sg) = buff;

	desc = dmaengine_prep_slave_sg(siu_stream->chan,
	&sg, 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT \| DMA_CTRL_ACK);
	if (!desc) {
	dev_err(dev, "Failed to allocate a dma descriptor\n");
	return -ENOMEM;
	}

	desc->callback = siu_dma_tx_complete;
	desc->callback_param = siu_stream;
	cookie = dmaengine_submit(desc);
	if (cookie < 0) {
	dev_err(dev, "Failed to submit a dma transfer\n");
	return cookie;
	}

	siu_stream->tx_desc = desc;
	siu_stream->cookie = cookie;

	dma_async_issue_pending(siu_stream->chan);

	/* only output FIFO enable */
	stfifo = siu_read32(base + SIU_STFIFO);
	siu_write32(base + SIU_STFIFO, stfifo \| (port_info->stfifo & 0x0c180c18));
	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
	stfifo, stfifo \| (port_info->stfifo & 0x0c180c18));

	return 0;
	}

	static int siu_pcm_rd_set(struct siu_port *port_info,
	dma_addr_t buff, size_t size)
	{
	struct siu_info *info = siu_i2s_data;
	u32 __iomem *base = info->reg;
	struct siu_stream *siu_stream = &port_info->capture;
	struct snd_pcm_substream *substream = siu_stream->substream;
	struct device *dev = substream->pcm->card->dev;
	struct dma_async_tx_descriptor *desc;
	dma_cookie_t cookie;
	struct scatterlist sg;
	u32 stfifo;

	dev_dbg(dev, "%s: %u@%llx\n", __func__, size, (unsigned long long)buff);

	sg_init_table(&sg, 1);
	sg_set_page(&sg, pfn_to_page(PFN_DOWN(buff)),
	size, offset_in_page(buff));
	sg_dma_len(&sg) = size;
	sg_dma_address(&sg) = buff;

	desc = dmaengine_prep_slave_sg(siu_stream->chan,
	&sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT \| DMA_CTRL_ACK);
	if (!desc) {
	dev_err(dev, "Failed to allocate dma descriptor\n");
	return -ENOMEM;
	}

	desc->callback = siu_dma_tx_complete;
	desc->callback_param = siu_stream;
	cookie = dmaengine_submit(desc);
	if (cookie < 0) {
	dev_err(dev, "Failed to submit dma descriptor\n");
	return cookie;
	}

	siu_stream->tx_desc = desc;
	siu_stream->cookie = cookie;

	dma_async_issue_pending(siu_stream->chan);

	/* only input FIFO enable */
	stfifo = siu_read32(base + SIU_STFIFO);
	siu_write32(base + SIU_STFIFO, siu_read32(base + SIU_STFIFO) \|
	(port_info->stfifo & 0x13071307));
	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
	stfifo, stfifo \| (port_info->stfifo & 0x13071307));

	return 0;
	}

	static void siu_io_tasklet(unsigned long data)
	{
	struct siu_stream siu_stream = (struct siu_stream )data;
	struct snd_pcm_substream *substream = siu_stream->substream;
	struct device *dev = substream->pcm->card->dev;
	struct snd_pcm_runtime *rt = substream->runtime;
	struct siu_port *port_info = siu_port_info(substream);

	dev_dbg(dev, "%s: flags %x\n", __func__, siu_stream->rw_flg);

	if (!siu_stream->rw_flg) {
	dev_dbg(dev, "%s: stream inactive\n", __func__);
	return;
	}

	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
	dma_addr_t buff;
	size_t count;
	u8 *virt;

	buff = (dma_addr_t)PERIOD_OFFSET(rt->dma_addr,
	siu_stream->cur_period,
	siu_stream->period_bytes);
	virt = PERIOD_OFFSET(rt->dma_area,
	siu_stream->cur_period,
	siu_stream->period_bytes);
	count = siu_stream->period_bytes;

	/* DMA transfer start */
	siu_pcm_rd_set(port_info, buff, count);
	} else {
	siu_pcm_wr_set(port_info,
	(dma_addr_t)PERIOD_OFFSET(rt->dma_addr,
	siu_stream->cur_period,
	siu_stream->period_bytes),
	siu_stream->period_bytes);
	}
	}

	/* Capture */
	static int siu_pcm_stmread_start(struct siu_port *port_info)
	{
	struct siu_stream *siu_stream = &port_info->capture;

	if (siu_stream->xfer_cnt > 0x1000000)
	return -EINVAL;
	if (siu_stream->rw_flg)
	return -EPERM;

	/* Current period in buffer */
	siu_stream->cur_period = 0;

	/* during stmread flag set */
	siu_stream->rw_flg = RWF_STM_RD;

	tasklet_schedule(&siu_stream->tasklet);

	return 0;
	}

	static int siu_pcm_stmread_stop(struct siu_port *port_info)
	{
	struct siu_info *info = siu_i2s_data;
	u32 __iomem *base = info->reg;
	struct siu_stream *siu_stream = &port_info->capture;
	struct device *dev = siu_stream->substream->pcm->card->dev;
	u32 stfifo;

	if (!siu_stream->rw_flg)
	return -EPERM;

	/* input FIFO disable */
	stfifo = siu_read32(base + SIU_STFIFO);
	siu_write32(base + SIU_STFIFO, stfifo & ~0x13071307);
	dev_dbg(dev, "%s: STFIFO %x -> %x\n", __func__,
	stfifo, stfifo & ~0x13071307);

	/* during stmread flag clear */
	siu_stream->rw_flg = 0;

	return 0;
	}

	static int siu_pcm_hw_params(struct snd_pcm_substream *ss,
	struct snd_pcm_hw_params *hw_params)
	{
	struct siu_info *info = siu_i2s_data;
	struct device *dev = ss->pcm->card->dev;
	int ret;

	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

	ret = snd_pcm_lib_malloc_pages(ss, params_buffer_bytes(hw_params));
	if (ret < 0)
	dev_err(dev, "snd_pcm_lib_malloc_pages() failed\n");

	return ret;
	}

	static int siu_pcm_hw_free(struct snd_pcm_substream *ss)
	{
	struct siu_info *info = siu_i2s_data;
	struct siu_port *port_info = siu_port_info(ss);
	struct device *dev = ss->pcm->card->dev;
	struct siu_stream *siu_stream;

	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	siu_stream = &port_info->playback;
	else
	siu_stream = &port_info->capture;

	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

	return snd_pcm_lib_free_pages(ss);
	}

	static bool filter(struct dma_chan chan, void slave)
	{
	struct sh_dmae_slave *param = slave;

	pr_debug("%s: slave ID %d\n", __func__, param->shdma_slave.slave_id);

	chan->private = &param->shdma_slave;
	return true;
	}

	static int siu_pcm_open(struct snd_pcm_substream *ss)
	{
	/* Playback / Capture */
	struct snd_soc_pcm_runtime *rtd = ss->private_data;
	struct siu_platform *pdata = rtd->platform->dev->platform_data;
	struct siu_info *info = siu_i2s_data;
	struct siu_port *port_info = siu_port_info(ss);
	struct siu_stream *siu_stream;
	u32 port = info->port_id;
	struct device *dev = ss->pcm->card->dev;
	dma_cap_mask_t mask;
	struct sh_dmae_slave *param;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	dev_dbg(dev, "%s, port=%d@%p\n", __func__, port, port_info);

	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	siu_stream = &port_info->playback;
	param = &siu_stream->param;
	param->shdma_slave.slave_id = port ? pdata->dma_slave_tx_b :
	pdata->dma_slave_tx_a;
	} else {
	siu_stream = &port_info->capture;
	param = &siu_stream->param;
	param->shdma_slave.slave_id = port ? pdata->dma_slave_rx_b :
	pdata->dma_slave_rx_a;
	}

	/* Get DMA channel */
	siu_stream->chan = dma_request_channel(mask, filter, param);
	if (!siu_stream->chan) {
	dev_err(dev, "DMA channel allocation failed!\n");
	return -EBUSY;
	}

	siu_stream->substream = ss;

	return 0;
	}

	static int siu_pcm_close(struct snd_pcm_substream *ss)
	{
	struct siu_info *info = siu_i2s_data;
	struct device *dev = ss->pcm->card->dev;
	struct siu_port *port_info = siu_port_info(ss);
	struct siu_stream *siu_stream;

	dev_dbg(dev, "%s: port=%d\n", __func__, info->port_id);

	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	siu_stream = &port_info->playback;
	else
	siu_stream = &port_info->capture;

	dma_release_channel(siu_stream->chan);
	siu_stream->chan = NULL;

	siu_stream->substream = NULL;

	return 0;
	}

	static int siu_pcm_prepare(struct snd_pcm_substream *ss)
	{
	struct siu_info *info = siu_i2s_data;
	struct siu_port *port_info = siu_port_info(ss);
	struct device *dev = ss->pcm->card->dev;
	struct snd_pcm_runtime *rt = ss->runtime;
	struct siu_stream *siu_stream;
	snd_pcm_sframes_t xfer_cnt;

	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	siu_stream = &port_info->playback;
	else
	siu_stream = &port_info->capture;

	rt = siu_stream->substream->runtime;

	siu_stream->buf_bytes = snd_pcm_lib_buffer_bytes(ss);
	siu_stream->period_bytes = snd_pcm_lib_period_bytes(ss);

	dev_dbg(dev, "%s: port=%d, %d channels, period=%u bytes\n", __func__,
	info->port_id, rt->channels, siu_stream->period_bytes);

	/* We only support buffers that are multiples of the period */
	if (siu_stream->buf_bytes % siu_stream->period_bytes) {
	dev_err(dev, "%s() - buffer=%d not multiple of period=%d\n",
	__func__, siu_stream->buf_bytes,
	siu_stream->period_bytes);
	return -EINVAL;
	}

	xfer_cnt = bytes_to_frames(rt, siu_stream->period_bytes);
	if (!xfer_cnt \|\| xfer_cnt > 0x1000000)
	return -EINVAL;

	siu_stream->format = rt->format;
	siu_stream->xfer_cnt = xfer_cnt;

	dev_dbg(dev, "port=%d buf=%lx buf_bytes=%d period_bytes=%d "
	"format=%d channels=%d xfer_cnt=%d\n", info->port_id,
	(unsigned long)rt->dma_addr, siu_stream->buf_bytes,
	siu_stream->period_bytes,
	siu_stream->format, rt->channels, (int)xfer_cnt);

	return 0;
	}

	static int siu_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
	{
	struct siu_info *info = siu_i2s_data;
	struct device *dev = ss->pcm->card->dev;
	struct siu_port *port_info = siu_port_info(ss);
	int ret;

	dev_dbg(dev, "%s: port=%d@%p, cmd=%d\n", __func__,
	info->port_id, port_info, cmd);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	ret = siu_pcm_stmwrite_start(port_info);
	else
	ret = siu_pcm_stmread_start(port_info);

	if (ret < 0)
	dev_warn(dev, "%s: start failed on port=%d\n",
	__func__, info->port_id);

	break;
	case SNDRV_PCM_TRIGGER_STOP:
	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	siu_pcm_stmwrite_stop(port_info);
	else
	siu_pcm_stmread_stop(port_info);
	ret = 0;

	break;
	default:
	dev_err(dev, "%s() unsupported cmd=%d\n", __func__, cmd);
	ret = -EINVAL;
	}

	return ret;
	}

	/*
	* So far only resolution of one period is supported, subject to extending the
	* dmangine API
	*/
	static snd_pcm_uframes_t siu_pcm_pointer_dma(struct snd_pcm_substream *ss)
	{
	struct device *dev = ss->pcm->card->dev;
	struct siu_info *info = siu_i2s_data;
	u32 __iomem *base = info->reg;
	struct siu_port *port_info = siu_port_info(ss);
	struct snd_pcm_runtime *rt = ss->runtime;
	size_t ptr;
	struct siu_stream *siu_stream;

	if (ss->stream == SNDRV_PCM_STREAM_PLAYBACK)
	siu_stream = &port_info->playback;
	else
	siu_stream = &port_info->capture;

	/*
	* ptr is the offset into the buffer where the dma is currently at. We
	* check if the dma buffer has just wrapped.
	*/
	ptr = PERIOD_OFFSET(rt->dma_addr,
	siu_stream->cur_period,
	siu_stream->period_bytes) - rt->dma_addr;

	dev_dbg(dev,
	"%s: port=%d, events %x, FSTS %x, xferred %u/%u, cookie %d\n",
	__func__, info->port_id, siu_read32(base + SIU_EVNTC),
	siu_read32(base + SIU_SBFSTS), ptr, siu_stream->buf_bytes,
	siu_stream->cookie);

	if (ptr >= siu_stream->buf_bytes)
	ptr = 0;

	return bytes_to_frames(ss->runtime, ptr);
	}

	static int siu_pcm_new(struct snd_soc_pcm_runtime *rtd)
	{
	/* card->dev == socdev->dev, see snd_soc_new_pcms() */
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	struct siu_info *info = siu_i2s_data;
	struct platform_device *pdev = to_platform_device(card->dev);
	int ret;
	int i;

	/* pdev->id selects between SIUA and SIUB */
	if (pdev->id < 0 \|\| pdev->id >= SIU_PORT_NUM)
	return -EINVAL;

	info->port_id = pdev->id;

	/*
	* While the siu has 2 ports, only one port can be on at a time (only 1
	* SPB). So far all the boards using the siu had only one of the ports
	* wired to a codec. To simplify things, we only register one port with
	* alsa. In case both ports are needed, it should be changed here
	*/
	for (i = pdev->id; i < pdev->id + 1; i++) {
	struct siu_port **port_info = &siu_ports[i];

	ret = siu_init_port(i, port_info, card);
	if (ret < 0)
	return ret;

	ret = snd_pcm_lib_preallocate_pages_for_all(pcm,
	SNDRV_DMA_TYPE_DEV, NULL,
	SIU_BUFFER_BYTES_MAX, SIU_BUFFER_BYTES_MAX);
	if (ret < 0) {
	dev_err(card->dev,
	"snd_pcm_lib_preallocate_pages_for_all() err=%d",
	ret);
	goto fail;
	}

	(*port_info)->pcm = pcm;

	/* IO tasklets */
	tasklet_init(&(*port_info)->playback.tasklet, siu_io_tasklet,
	(unsigned long)&(*port_info)->playback);
	tasklet_init(&(*port_info)->capture.tasklet, siu_io_tasklet,
	(unsigned long)&(*port_info)->capture);
	}

	dev_info(card->dev, "SuperH SIU driver initialized.\n");
	return 0;

	fail:
	siu_free_port(siu_ports[pdev->id]);
	dev_err(card->dev, "SIU: failed to initialize.\n");
	return ret;
	}

	static void siu_pcm_free(struct snd_pcm *pcm)
	{
	struct platform_device *pdev = to_platform_device(pcm->card->dev);
	struct siu_port *port_info = siu_ports[pdev->id];

	tasklet_kill(&port_info->capture.tasklet);
	tasklet_kill(&port_info->playback.tasklet);

	siu_free_port(port_info);
	snd_pcm_lib_preallocate_free_for_all(pcm);

	dev_dbg(pcm->card->dev, "%s\n", __func__);
	}

	static struct snd_pcm_ops siu_pcm_ops = {
	.open = siu_pcm_open,
	.close = siu_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = siu_pcm_hw_params,
	.hw_free = siu_pcm_hw_free,
	.prepare = siu_pcm_prepare,
	.trigger = siu_pcm_trigger,
	.pointer = siu_pcm_pointer_dma,
	};

	struct snd_soc_platform_driver siu_platform = {
	.ops = &siu_pcm_ops,
	.pcm_new = siu_pcm_new,
	.pcm_free = siu_pcm_free,
	};
	EXPORT_SYMBOL_GPL(siu_platform);