ALSA: move dmaengine implementation from ASoC to ALSA core

For the PXA DMA rework, we need the generic dmaengine implementation
that currently lives in sound/soc for standalone (non-ASoC) AC'97
support.

Move it to sound/core, and rename the Kconfig symbol.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

3 files changed, 373 insertions, 0 deletions

diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index c0c2f57a0d6..94ce1c44ff8 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -6,6 +6,9 @@ config SND_PCM
 	tristate
 	select SND_TIMER
 
+config SND_DMAENGINE_PCM
+	bool
+
 config SND_HWDEP
 	tristate
 
diff --git a/sound/core/Makefile b/sound/core/Makefile
index 43d4117428a..5e890cfed42 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -13,6 +13,8 @@ snd-$(CONFIG_SND_JACK)	  += jack.o
 snd-pcm-objs := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \
 		pcm_memory.o
 
+snd-pcm-dmaengine-objs := pcm_dmaengine.o
+
 snd-page-alloc-y := memalloc.o
 snd-page-alloc-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o
 
@@ -30,6 +32,7 @@ obj-$(CONFIG_SND_TIMER)		+= snd-timer.o
 obj-$(CONFIG_SND_HRTIMER)	+= snd-hrtimer.o
 obj-$(CONFIG_SND_RTCTIMER)	+= snd-rtctimer.o
 obj-$(CONFIG_SND_PCM)		+= snd-pcm.o snd-page-alloc.o
+obj-$(CONFIG_SND_DMAENGINE_PCM)	+= snd-pcm-dmaengine.o
 obj-$(CONFIG_SND_RAWMIDI)	+= snd-rawmidi.o
 
 obj-$(CONFIG_SND_OSSEMUL)	+= oss/
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
new file mode 100644
index 00000000000..aa924d9b798
--- /dev/null
+++ b/sound/core/pcm_dmaengine.c
@@ -0,0 +1,367 @@
+/*
+ *  Copyright (C) 2012, Analog Devices Inc.
+ *	Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  Based on:
+ *	imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
+ *	mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
+ *	ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *		      Copyright (C) 2006 Applied Data Systems
+ *
+ *  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.
+ *
+ *  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/module.h>
+#include <linux/init.h>
+#include <linux/dmaengine.h>
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <sound/dmaengine_pcm.h>
+
+struct dmaengine_pcm_runtime_data {
+	struct dma_chan *dma_chan;
+	dma_cookie_t cookie;
+
+	unsigned int pos;
+};
+
+static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
+	const struct snd_pcm_substream *substream)
+{
+	return substream->runtime->private_data;
+}
+
+struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	return prtd->dma_chan;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
+
+/**
+ * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
+ * @substream: PCM substream
+ * @params: hw_params
+ * @slave_config: DMA slave config
+ *
+ * This function can be used to initialize a dma_slave_config from a substream
+ * and hw_params in a dmaengine based PCM driver implementation.
+ */
+int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
+	const struct snd_pcm_hw_params *params,
+	struct dma_slave_config *slave_config)
+{
+	enum dma_slave_buswidth buswidth;
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S8:
+		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		break;
+	case SNDRV_PCM_FORMAT_S16_LE:
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		break;
+	case SNDRV_PCM_FORMAT_S18_3LE:
+	case SNDRV_PCM_FORMAT_S20_3LE:
+	case SNDRV_PCM_FORMAT_S24_LE:
+	case SNDRV_PCM_FORMAT_S32_LE:
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		slave_config->direction = DMA_MEM_TO_DEV;
+		slave_config->dst_addr_width = buswidth;
+	} else {
+		slave_config->direction = DMA_DEV_TO_MEM;
+		slave_config->src_addr_width = buswidth;
+	}
+
+	slave_config->device_fc = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
+
+/**
+ * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
+ *  using DAI DMA data.
+ * @substream: PCM substream
+ * @dma_data: DAI DMA data
+ * @slave_config: DMA slave configuration
+ *
+ * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
+ * slave_id fields of the DMA slave config from the same fields of the DAI DMA
+ * data struct. The src and dst fields will be initialized depending on the
+ * direction of the substream. If the substream is a playback stream the dst
+ * fields will be initialized, if it is a capture stream the src fields will be
+ * initialized. The {dst,src}_addr_width field will only be initialized if the
+ * addr_width field of the DAI DMA data struct is not equal to
+ * DMA_SLAVE_BUSWIDTH_UNDEFINED.
+ */
+void snd_dmaengine_pcm_set_config_from_dai_data(
+	const struct snd_pcm_substream *substream,
+	const struct snd_dmaengine_dai_dma_data *dma_data,
+	struct dma_slave_config *slave_config)
+{
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		slave_config->dst_addr = dma_data->addr;
+		slave_config->dst_maxburst = dma_data->maxburst;
+		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
+			slave_config->dst_addr_width = dma_data->addr_width;
+	} else {
+		slave_config->src_addr = dma_data->addr;
+		slave_config->src_maxburst = dma_data->maxburst;
+		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
+			slave_config->src_addr_width = dma_data->addr_width;
+	}
+
+	slave_config->slave_id = dma_data->slave_id;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
+
+static void dmaengine_pcm_dma_complete(void *arg)
+{
+	struct snd_pcm_substream *substream = arg;
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	prtd->pos += snd_pcm_lib_period_bytes(substream);
+	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
+		prtd->pos = 0;
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_chan *chan = prtd->dma_chan;
+	struct dma_async_tx_descriptor *desc;
+	enum dma_transfer_direction direction;
+	unsigned long flags = DMA_CTRL_ACK;
+
+	direction = snd_pcm_substream_to_dma_direction(substream);
+
+	if (!substream->runtime->no_period_wakeup)
+		flags |= DMA_PREP_INTERRUPT;
+
+	prtd->pos = 0;
+	desc = dmaengine_prep_dma_cyclic(chan,
+		substream->runtime->dma_addr,
+		snd_pcm_lib_buffer_bytes(substream),
+		snd_pcm_lib_period_bytes(substream), direction, flags);
+
+	if (!desc)
+		return -ENOMEM;
+
+	desc->callback = dmaengine_pcm_dma_complete;
+	desc->callback_param = substream;
+	prtd->cookie = dmaengine_submit(desc);
+
+	return 0;
+}
+
+/**
+ * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
+ * @substream: PCM substream
+ * @cmd: Trigger command
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ *
+ * This function can be used as the PCM trigger callback for dmaengine based PCM
+ * driver implementations.
+ */
+int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	int ret;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		ret = dmaengine_pcm_prepare_and_submit(substream);
+		if (ret)
+			return ret;
+		dma_async_issue_pending(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		dmaengine_resume(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		dmaengine_pause(prtd->dma_chan);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		dmaengine_terminate_all(prtd->dma_chan);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
+
+/**
+ * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
+ * @substream: PCM substream
+ *
+ * This function is deprecated and should not be used by new drivers, as its
+ * results may be unreliable.
+ */
+snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	return bytes_to_frames(substream->runtime, prtd->pos);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
+
+/**
+ * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
+ * @substream: PCM substream
+ *
+ * This function can be used as the PCM pointer callback for dmaengine based PCM
+ * driver implementations.
+ */
+snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_tx_state state;
+	enum dma_status status;
+	unsigned int buf_size;
+	unsigned int pos = 0;
+
+	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
+	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
+		buf_size = snd_pcm_lib_buffer_bytes(substream);
+		if (state.residue > 0 && state.residue <= buf_size)
+			pos = buf_size - state.residue;
+	}
+
+	return bytes_to_frames(substream->runtime, pos);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
+
+/**
+ * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
+ * @filter_fn: Filter function used to request the DMA channel
+ * @filter_data: Data passed to the DMA filter function
+ *
+ * Returns NULL or the requested DMA channel.
+ *
+ * This function request a DMA channel for usage with dmaengine PCM.
+ */
+struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
+	void *filter_data)
+{
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_CYCLIC, mask);
+
+	return dma_request_channel(mask, filter_fn, filter_data);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
+
+/**
+ * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
+ * @substream: PCM substream
+ * @chan: DMA channel to use for data transfers
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ *
+ * The function should usually be called from the pcm open callback. Note that
+ * this function will use private_data field of the substream's runtime. So it
+ * is not availabe to your pcm driver implementation.
+ */
+int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
+	struct dma_chan *chan)
+{
+	struct dmaengine_pcm_runtime_data *prtd;
+	int ret;
+
+	if (!chan)
+		return -ENXIO;
+
+	ret = snd_pcm_hw_constraint_integer(substream->runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
+	if (!prtd)
+		return -ENOMEM;
+
+	prtd->dma_chan = chan;
+
+	substream->runtime->private_data = prtd;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
+
+/**
+ * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
+ * @substream: PCM substream
+ * @filter_fn: Filter function used to request the DMA channel
+ * @filter_data: Data passed to the DMA filter function
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ *
+ * This function will request a DMA channel using the passed filter function and
+ * data. The function should usually be called from the pcm open callback. Note
+ * that this function will use private_data field of the substream's runtime. So
+ * it is not availabe to your pcm driver implementation.
+ */
+int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
+	dma_filter_fn filter_fn, void *filter_data)
+{
+	return snd_dmaengine_pcm_open(substream,
+		    snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
+
+/**
+ * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
+ * @substream: PCM substream
+ */
+int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	kfree(prtd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
+
+/**
+ * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
+ * @substream: PCM substream
+ *
+ * Releases the DMA channel associated with the PCM substream.
+ */
+int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+	dma_release_channel(prtd->dma_chan);
+
+	return snd_dmaengine_pcm_close(substream);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
+
+MODULE_LICENSE("GPL");