ASoC: tegra: Add tegra-pcm driver

This provides an ASoC platform driver that manages Tegra's APB DMA
controller.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/tegra/tegra_pcm.c

+/*
+ * tegra_pcm.c - Tegra PCM driver
+ *
+ * Author: Stephen Warren <swarren@nvidia.com>
+ * Copyright (C) 2010 - NVIDIA, Inc.
+ *
+ * Based on code copyright/by:
+ *
+ * Copyright (c) 2009-2010, NVIDIA Corporation.
+ * Scott Peterson <speterson@nvidia.com>
+ * Vijay Mali <vmali@nvidia.com>
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Iliyan Malchev <malchev@google.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.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include "tegra_pcm.h"
+
+static const struct snd_pcm_hardware tegra_pcm_hardware = {
+	.info			= SNDRV_PCM_INFO_MMAP |
+				  SNDRV_PCM_INFO_MMAP_VALID |
+				  SNDRV_PCM_INFO_PAUSE |
+				  SNDRV_PCM_INFO_RESUME |
+				  SNDRV_PCM_INFO_INTERLEAVED,
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
+	.channels_min		= 2,
+	.channels_max		= 2,
+	.period_bytes_min	= 1024,
+	.period_bytes_max	= PAGE_SIZE,
+	.periods_min		= 2,
+	.periods_max		= 8,
+	.buffer_bytes_max	= PAGE_SIZE * 8,
+	.fifo_size		= 4,
+};
+
+static void tegra_pcm_queue_dma(struct tegra_runtime_data *prtd)
+{
+	struct snd_pcm_substream *substream = prtd->substream;
+	struct snd_dma_buffer *buf = &substream->dma_buffer;
+	struct tegra_dma_req *dma_req;
+	unsigned long addr;
+
+	dma_req = &prtd->dma_req[prtd->dma_req_idx];
+	prtd->dma_req_idx = 1 - prtd->dma_req_idx;
+
+	addr = buf->addr + prtd->dma_pos;
+	prtd->dma_pos += dma_req->size;
+	if (prtd->dma_pos >= prtd->dma_pos_end)
+		prtd->dma_pos = 0;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		dma_req->source_addr = addr;
+	else
+		dma_req->dest_addr = addr;
+
+	tegra_dma_enqueue_req(prtd->dma_chan, dma_req);
+}
+
+static void dma_complete_callback(struct tegra_dma_req *req)
+{
+	struct tegra_runtime_data *prtd = (struct tegra_runtime_data *)req->dev;
+	struct snd_pcm_substream *substream = prtd->substream;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	spin_lock(&prtd->lock);
+
+	if (!prtd->running) {
+		spin_unlock(&prtd->lock);
+		return;
+	}
+
+	if (++prtd->period_index >= runtime->periods)
+		prtd->period_index = 0;
+
+	tegra_pcm_queue_dma(prtd);
+
+	spin_unlock(&prtd->lock);
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static void setup_dma_tx_request(struct tegra_dma_req *req,
+					struct tegra_pcm_dma_params * dmap)
+{
+	req->complete = dma_complete_callback;
+	req->to_memory = false;
+	req->dest_addr = dmap->addr;
+	req->dest_wrap = dmap->wrap;
+	req->source_bus_width = 32;
+	req->source_wrap = 0;
+	req->dest_bus_width = dmap->width;
+	req->req_sel = dmap->req_sel;
+}
+
+static void setup_dma_rx_request(struct tegra_dma_req *req,
+					struct tegra_pcm_dma_params * dmap)
+{
+	req->complete = dma_complete_callback;
+	req->to_memory = true;
+	req->source_addr = dmap->addr;
+	req->dest_wrap = 0;
+	req->source_bus_width = dmap->width;
+	req->source_wrap = dmap->wrap;
+	req->dest_bus_width = 32;
+	req->req_sel = dmap->req_sel;
+}
+
+static int tegra_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct tegra_runtime_data *prtd;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct tegra_pcm_dma_params * dmap;
+	int ret = 0;
+
+	prtd = kzalloc(sizeof(struct tegra_runtime_data), GFP_KERNEL);
+	if (prtd == NULL)
+		return -ENOMEM;
+
+	runtime->private_data = prtd;
+	prtd->substream = substream;
+
+	spin_lock_init(&prtd->lock);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		dmap = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+		setup_dma_tx_request(&prtd->dma_req[0], dmap);
+		setup_dma_tx_request(&prtd->dma_req[1], dmap);
+	} else {
+		dmap = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+		setup_dma_rx_request(&prtd->dma_req[0], dmap);
+		setup_dma_rx_request(&prtd->dma_req[1], dmap);
+	}
+
+	prtd->dma_req[0].dev = prtd;
+	prtd->dma_req[1].dev = prtd;
+
+	prtd->dma_chan = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT);
+	if (IS_ERR(prtd->dma_chan)) {
+		ret = PTR_ERR(prtd->dma_chan);
+		goto err;
+	}
+
+	/* Set HW params now that initialization is complete */
+	snd_soc_set_runtime_hwparams(substream, &tegra_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 err;
+
+	return 0;
+
+err:
+	if (prtd->dma_chan) {
+		tegra_dma_free_channel(prtd->dma_chan);
+	}
+
+	kfree(prtd);
+
+	return ret;
+}
+
+static int tegra_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct tegra_runtime_data *prtd = runtime->private_data;
+
+	tegra_dma_free_channel(prtd->dma_chan);
+
+	kfree(prtd);
+
+	return 0;
+}
+
+static int tegra_pcm_hw_params(struct snd_pcm_substream *substream,
+				struct snd_pcm_hw_params *params)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct tegra_runtime_data *prtd = runtime->private_data;
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+
+	prtd->dma_req[0].size = params_period_bytes(params);
+	prtd->dma_req[1].size = prtd->dma_req[0].size;
+
+	return 0;
+}
+
+static int tegra_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	snd_pcm_set_runtime_buffer(substream, NULL);
+
+	return 0;
+}
+
+static int tegra_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct tegra_runtime_data *prtd = runtime->private_data;
+	unsigned long flags;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		prtd->dma_pos = 0;
+		prtd->dma_pos_end = frames_to_bytes(runtime, runtime->periods * runtime->period_size);
+		prtd->period_index = 0;
+		prtd->dma_req_idx = 0;
+		/* Fall-through */
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		spin_lock_irqsave(&prtd->lock, flags);
+		prtd->running = 1;
+		spin_unlock_irqrestore(&prtd->lock, flags);
+		tegra_pcm_queue_dma(prtd);
+		tegra_pcm_queue_dma(prtd);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		spin_lock_irqsave(&prtd->lock, flags);
+		prtd->running = 0;
+		spin_unlock_irqrestore(&prtd->lock, flags);
+		tegra_dma_dequeue_req(prtd->dma_chan, &prtd->dma_req[0]);
+		tegra_dma_dequeue_req(prtd->dma_chan, &prtd->dma_req[1]);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static snd_pcm_uframes_t tegra_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct tegra_runtime_data *prtd = runtime->private_data;
+
+	return prtd->period_index * runtime->period_size;
+}
+
+
+static int tegra_pcm_mmap(struct snd_pcm_substream *substream,
+				struct vm_area_struct *vma)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
+					runtime->dma_area,
+					runtime->dma_addr,
+					runtime->dma_bytes);
+}
+
+static struct snd_pcm_ops tegra_pcm_ops = {
+	.open		= tegra_pcm_open,
+	.close		= tegra_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= tegra_pcm_hw_params,
+	.hw_free	= tegra_pcm_hw_free,
+	.trigger	= tegra_pcm_trigger,
+	.pointer	= tegra_pcm_pointer,
+	.mmap		= tegra_pcm_mmap,
+};
+
+static int tegra_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 = tegra_pcm_hardware.buffer_bytes_max;
+
+	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
+						&buf->addr, GFP_KERNEL);
+	if (!buf->area)
+		return -ENOMEM;
+
+	buf->dev.type = SNDRV_DMA_TYPE_DEV;
+	buf->dev.dev = pcm->card->dev;
+	buf->private_data = NULL;
+	buf->bytes = size;
+
+	return 0;
+}
+
+static void tegra_pcm_deallocate_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;
+
+	if (!buf->area)
+		return;
+
+	dma_free_writecombine(pcm->card->dev, buf->bytes,
+				buf->area, buf->addr);
+	buf->area = NULL;
+}
+
+static u64 tegra_dma_mask = DMA_BIT_MASK(32);
+
+static int tegra_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 = &tegra_dma_mask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = 0xffffffff;
+
+	if (dai->driver->playback.channels_min) {
+		ret = tegra_pcm_preallocate_dma_buffer(pcm,
+						SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			goto err;
+	}
+
+	if (dai->driver->capture.channels_min) {
+		ret = tegra_pcm_preallocate_dma_buffer(pcm,
+						SNDRV_PCM_STREAM_CAPTURE);
+		if (ret)
+			goto err_free_play;
+	}
+
+	return 0;
+
+err_free_play:
+	tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
+err:
+	return ret;
+}
+
+static void tegra_pcm_free(struct snd_pcm *pcm)
+{
+	tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_CAPTURE);
+	tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
+}
+
+struct snd_soc_platform_driver tegra_pcm_platform = {
+	.ops		= &tegra_pcm_ops,
+	.pcm_new	= tegra_pcm_new,
+	.pcm_free	= tegra_pcm_free,
+};
+
+static int __devinit tegra_pcm_platform_probe(struct platform_device *pdev)
+{
+	return snd_soc_register_platform(&pdev->dev, &tegra_pcm_platform);
+}
+
+static int __devexit tegra_pcm_platform_remove(struct platform_device *pdev)
+{
+	snd_soc_unregister_platform(&pdev->dev);
+	return 0;
+}
+
+static struct platform_driver tegra_pcm_driver = {
+	.driver = {
+		.name = "tegra-pcm-audio",
+		.owner = THIS_MODULE,
+	},
+	.probe = tegra_pcm_platform_probe,
+	.remove = __devexit_p(tegra_pcm_platform_remove),
+};
+
+static int __init snd_tegra_pcm_init(void)
+{
+	return platform_driver_register(&tegra_pcm_driver);
+}
+module_init(snd_tegra_pcm_init);
+
+static void __exit snd_tegra_pcm_exit(void)
+{
+	platform_driver_unregister(&tegra_pcm_driver);
+}
+module_exit(snd_tegra_pcm_exit);
+
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_DESCRIPTION("Tegra PCM ASoC driver");
+MODULE_LICENSE("GPL");

sound/soc/tegra/tegra_pcm.h

+/*
+ * tegra_pcm.h - Definitions for Tegra PCM driver
+ *
+ * Author: Stephen Warren <swarren@nvidia.com>
+ * Copyright (C) 2010 - NVIDIA, Inc.
+ *
+ * Based on code copyright/by:
+ *
+ * Copyright (c) 2009-2010, NVIDIA Corporation.
+ * Scott Peterson <speterson@nvidia.com>
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Iliyan Malchev <malchev@google.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.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef __TEGRA_PCM_H__
+#define __TEGRA_PCM_H__
+
+#include <mach/dma.h>
+
+struct tegra_pcm_dma_params {
+	unsigned long addr;
+	unsigned long wrap;
+	unsigned long width;
+	unsigned long req_sel;
+};
+
+struct tegra_runtime_data {
+	struct snd_pcm_substream *substream;
+	spinlock_t lock;
+	int running;
+	int dma_pos;
+	int dma_pos_end;
+	int period_index;
+	int dma_req_idx;
+	struct tegra_dma_req dma_req[2];
+	struct tegra_dma_channel *dma_chan;
+};
+
+#endif