[RFC 4/5] compress: add the core file

[Vinod Koul <vinod.koul@linux.intel.com>]

This patch ads core.c, the file which implements the ioctls and
registers the devices

Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 sound/compress_offload/core.c |  632 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 632 insertions(+), 0 deletions(-)
 create mode 100644 sound/compress_offload/core.c

diff --git a/sound/compress_offload/core.c b/sound/compress_offload/core.c
new file mode 100644
index 0000000..1797dba
--- /dev/null
+++ b/sound/compress_offload/core.c
@@ -0,0 +1,632 @@
+/*
+ *  core.c - compress offload core
+ *
+ *  Copyright (C) 2011 Intel Corporation
+ *  Authors:	Vinod Koul <vinod.koul@linux.intel.com>
+ *		Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.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; version 2 of the License.
+ *
+ *  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/file.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/uio.h>
+#include <linux/uaccess.h>
+#include <sound/snd_compress_params.h>
+#include <sound/compress_offload.h>
+#include <sound/compress_driver.h>
+
+/* TODO:
+ * - Integrate with alsa, compressed devices should register as alsa devices
+ *	as /dev/snd_compr_xxx
+ * - Integrate with ASoC:
+ *	Opening compressed path should also start the codec dai
+ *   TBD how the cpu dai will be viewed and started.
+ *	ASoC should always be optional part
+ *	(we should be able to use this framework in non asoc systems
+ * - Multiple node representation
+ *	driver should be able to register multiple nodes
+ * - Version numbering for API
+ */
+
+static DEFINE_MUTEX(device_mutex);
+static LIST_HEAD(device_list);
+static LIST_HEAD(misc_list);
+
+/*
+ * currently we are using misc device for registration and exposing ioctls
+ * this is temporary and will be moved to snd
+ * the device should be registered as /dev/snd_compr.....
+ */
+
+struct snd_compr_misc {
+	struct miscdevice misc;
+	struct list_head list;
+	struct snd_compr *compr;
+};
+
+struct snd_ioctl_data {
+	struct snd_compr_misc *misc;
+	unsigned long caps;
+	unsigned int minor;
+	struct snd_compr_stream stream;
+};
+
+static struct snd_compr_misc *snd_compr_get_device(unsigned int minor)
+{
+	struct snd_compr_misc *misc;
+
+	list_for_each_entry(misc, &misc_list, list) {
+		if (minor == misc->misc.minor)
+			return misc;
+	}
+	return NULL;
+}
+
+static int snd_compr_open(struct inode *inode, struct file *f)
+{
+	unsigned int minor = iminor(inode);
+	struct snd_compr_misc *misc = snd_compr_get_device(minor);
+	struct snd_ioctl_data *data;
+	struct snd_compr_runtime *runtime;
+	unsigned int direction;
+	int ret;
+
+	mutex_lock(&device_mutex);
+	if (f->f_flags & O_WRONLY)
+		direction = SNDRV_PCM_STREAM_PLAYBACK;
+	else {
+		ret = -ENXIO;
+		goto out;
+	}
+	/* curently only encoded playback is supported, above needs to be removed
+	 * once we have recording support */
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	data->misc = misc;
+	data->minor = minor;
+	data->stream.ops = misc->compr->ops;
+	data->stream.direction = direction;
+	data->stream.private_data = misc->compr->private_data;
+	data->stream.device = misc->compr;
+	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
+	if (!runtime) {
+		ret = -ENOMEM;
+		kfree(data);
+		goto out;
+	}
+	ret = misc->compr->ops->open(&data->stream);
+	if (ret) {
+		kfree(runtime);
+		kfree(data);
+		goto out;
+	}
+	runtime->state = SNDRV_PCM_STATE_OPEN;
+	init_waitqueue_head(&runtime->sleep);
+	data->stream.runtime = runtime;
+	f->private_data = (void *)data;
+out:
+	mutex_unlock(&device_mutex);
+	return ret;
+}
+
+static int snd_compr_free(struct inode *inode, struct file *f)
+{
+	struct snd_ioctl_data *data = f->private_data;
+	mutex_lock(&device_mutex);
+	data->stream.ops->free(&data->stream);
+	kfree(data->stream.runtime->buffer);
+	kfree(data->stream.runtime);
+	kfree(data);
+	mutex_unlock(&device_mutex);
+	return 0;
+}
+
+static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
+		struct snd_compr_tstamp *tstamp)
+{
+	stream->ops->pointer(stream, tstamp);
+	stream->runtime->hw_pointer = tstamp->copied_bytes;
+}
+
+static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
+		struct snd_compr_avail *avail)
+{
+	size_t avail_calc;
+
+	snd_compr_update_tstamp(stream, &avail->tstamp);
+	avail_calc = stream->runtime->app_pointer -  stream->runtime->hw_pointer;
+	if (avail_calc < 0)
+		avail_calc = stream->runtime->buffer_size + avail_calc;
+	avail->avail = avail_calc;
+	return avail_calc;
+}
+
+static size_t snd_compr_get_avail(struct snd_compr_stream *stream)
+{
+	struct snd_compr_avail avail;
+
+	return snd_compr_calc_avail(stream, &avail);
+}
+
+static int
+snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_avail ioctl_avail;
+
+	snd_compr_calc_avail(stream, &ioctl_avail);
+
+	if (copy_to_user((unsigned long __user *)arg, &ioctl_avail, sizeof(ioctl_avail)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_compr_write_data(struct snd_compr_stream *stream,
+	       const char __user *buf, size_t count)
+{
+	void *dstn;
+	size_t copy;
+
+	dstn = stream->runtime->buffer + stream->runtime->app_pointer;
+	if (count <  stream->runtime->buffer_size - stream->runtime->app_pointer) {
+		if (copy_from_user(dstn, buf, count))
+			return -EFAULT;
+		stream->runtime->app_pointer += count;
+	} else {
+		copy = stream->runtime->buffer_size - stream->runtime->app_pointer;
+		if (copy_from_user(dstn, buf, copy))
+			return -EFAULT;
+		if (copy_from_user(stream->runtime->buffer, buf + copy, count - copy))
+			return -EFAULT;
+		stream->runtime->app_pointer = count - copy;
+	}
+	/* if DSP cares, let it know data has been written */
+	if (stream->ops->ack)
+		stream->ops->ack(stream);
+	return count;
+}
+
+static int snd_compr_write(struct file *f, const char __user *buf,
+		size_t count, loff_t *offset)
+{
+	struct snd_ioctl_data *data = f->private_data;
+	struct snd_compr_stream *stream;
+	size_t avail;
+	int retval;
+
+	BUG_ON(!data);
+	stream = &data->stream;
+	/* write is allowed when stream is running or has been steup */
+	if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
+			stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
+		return -EPERM;
+	mutex_lock(&stream->device->lock);
+
+	avail = snd_compr_get_avail(stream);
+	/* calculate how much we can write to buffer */
+	if (avail > count)
+		avail = count;
+
+	if (stream->ops->copy)
+		retval = stream->ops->copy(stream, buf, avail);
+	else
+		retval = snd_compr_write_data(stream, buf, avail);
+
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+
+static int snd_compr_read(struct file *f, char __user *buf,
+		size_t count, loff_t *offset)
+{
+	return -ENXIO;
+}
+
+static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
+{
+	return -ENXIO;
+}
+
+unsigned int snd_compr_poll(struct file *f, poll_table *wait)
+{
+	struct snd_ioctl_data *data = f->private_data;
+	struct snd_compr_stream *stream;
+
+	BUG_ON(!data);
+	stream = &data->stream;
+
+	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
+		return -ENXIO;
+	poll_wait(f, &stream->runtime->sleep, wait);
+
+	/* this would change after read is implemented, we would need to
+	 * check for direction here */
+	if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
+		return POLLOUT | POLLWRNORM;
+
+	return 0;
+}
+
+void snd_compr_period_elapsed(struct snd_compr_stream *stream)
+{
+	size_t avail;
+
+	avail = snd_compr_get_avail(stream);
+	if (avail >= stream->runtime->fragment_size)
+		wake_up(&stream->runtime->sleep);
+}
+EXPORT_SYMBOL_GPL(snd_compr_period_elapsed);
+
+static int snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
+{
+	int retval;
+	struct snd_compr_caps caps;
+
+	if (!stream->ops->get_caps)
+		return -ENXIO;
+
+	retval = stream->ops->get_caps(stream, &caps);
+	if (retval)
+		goto out;
+	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
+		retval = -EFAULT;
+out:
+	return retval;
+}
+
+static int snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
+{
+	int retval;
+	struct snd_compr_codec_caps *caps;
+
+	if (!stream->ops->get_codec_caps)
+		return -ENXIO;
+
+	caps = kmalloc(sizeof(*caps), GFP_KERNEL);
+	if (!caps)
+		return -ENOMEM;
+
+	retval = stream->ops->get_codec_caps(stream, caps);
+	if (retval)
+		goto out;
+	if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
+		retval = -EFAULT;
+
+out:
+	kfree(caps);
+	return retval;
+}
+
+/* revisit this with snd_pcm_preallocate_xxx */
+static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
+		struct snd_compr_params *params)
+{
+	unsigned int buffer_size;
+	void *buffer;
+
+	buffer_size = params->buffer.fragment_size * params->buffer.periods;
+	if (stream->ops->copy) {
+		buffer = NULL;
+		/* if copy is defined the driver will be required to copy
+		 * the data from core
+		 */
+	} else {
+		buffer = kmalloc(buffer_size, GFP_KERNEL);
+		if (!buffer)
+			return -ENOMEM;
+	}
+	stream->runtime->fragment_size = params->buffer.fragment_size;
+	stream->runtime->periods = params->buffer.periods;
+	stream->runtime->buffer = buffer;
+	stream->runtime->buffer_size = buffer_size;
+	return 0;
+}
+
+static int snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_params *params;
+	int retval;
+
+	if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
+		/*
+		 * we should allow parameter change only when stream has been
+		 * opened not in other cases
+		 */
+		params = kmalloc(sizeof(*params), GFP_KERNEL);
+		if (!params)
+			return -ENOMEM;
+		if (copy_from_user(&params, (void __user *)arg, sizeof(params)))
+			return -EFAULT;
+		retval = snd_compr_allocate_buffer(stream, params);
+		if (retval) {
+			kfree(params);
+			return -ENOMEM;
+		}
+		retval = stream->ops->set_params(stream, params);
+		if (retval)
+			goto out;
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+	} else
+		return -EPERM;
+out:
+	kfree(params);
+	return retval;
+}
+
+static int snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_params *params;
+	int retval;
+
+	if (!stream->ops->get_params)
+		return -ENXIO;
+
+	params = kmalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return -ENOMEM;
+	retval = stream->ops->get_params(stream, params);
+	if (retval)
+		goto out;
+	if (copy_to_user((char __user *)arg, params, sizeof(*params)))
+		retval = -EFAULT;
+
+out:
+	kfree(params);
+	return retval;
+}
+
+static int snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
+{
+	struct snd_compr_tstamp tstamp;
+
+	snd_compr_update_tstamp(stream, &tstamp);
+	if (copy_to_user((struct snd_compr_tstamp __user *)arg, &tstamp, sizeof(tstamp)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_compr_pause(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED)
+		return 0;
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
+	if (!retval) {
+		stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
+		wake_up(&stream->runtime->sleep);
+	}
+	return retval;
+}
+
+static int snd_compr_resume(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
+		return -EPERM;
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
+	if (!retval)
+		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
+	return retval;
+}
+
+static int snd_compr_start(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
+		return -EPERM;
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
+	if (!retval)
+		stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
+	return retval;
+}
+
+static int snd_compr_stop(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
+		return -EPERM;
+	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
+	if (!retval) {
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+		wake_up(&stream->runtime->sleep);
+	}
+	return retval;
+}
+
+static int snd_compr_drain(struct snd_compr_stream *stream)
+{
+	int retval;
+
+	if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED ||
+			stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
+		return -EPERM;
+	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
+	if (!retval) {
+		stream->runtime->state = SNDRV_PCM_STATE_SETUP;
+		wake_up(&stream->runtime->sleep);
+	}
+	return retval;
+}
+
+static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+	struct snd_ioctl_data *data = f->private_data;
+	struct snd_compr_stream *stream;
+	int retval = -ENOTTY;
+
+	BUG_ON(!data);
+	stream = &data->stream;
+	mutex_lock(&stream->device->lock);
+	switch (_IOC_NR(cmd)) {
+	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
+		retval = snd_compr_get_caps(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
+		retval = snd_compr_get_codec_caps(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
+		retval = snd_compr_set_params(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
+		retval = snd_compr_get_params(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
+		retval = snd_compr_tstamp(stream, arg);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_AVAIL):
+		retval = snd_compr_ioctl_avail(stream, arg);
+	case _IOC_NR(SNDRV_COMPRESS_PAUSE):
+		retval = snd_compr_pause(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_RESUME):
+		retval = snd_compr_resume(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_START):
+		retval = snd_compr_start(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_STOP):
+		retval = snd_compr_stop(stream);
+		break;
+	case _IOC_NR(SNDRV_COMPRESS_DRAIN):
+		cmd = SND_COMPR_TRIGGER_DRAIN;
+		retval = snd_compr_drain(stream);
+		break;
+	}
+	mutex_unlock(&stream->device->lock);
+	return retval;
+}
+
+static const struct file_operations snd_comp_file = {
+	.owner =	THIS_MODULE,
+	.open =		snd_compr_open,
+	.release =	snd_compr_free,
+	.read =		snd_compr_read,
+	.write =	snd_compr_write,
+	.unlocked_ioctl = snd_compr_ioctl,
+	.mmap =		snd_compr_mmap,
+	.poll =		snd_compr_poll,
+};
+
+static int snd_compress_add_device(struct snd_compr *device)
+{
+	int ret;
+
+	struct snd_compr_misc *misc = kzalloc(sizeof(*misc), GFP_KERNEL);
+
+	misc->misc.name = device->name;
+	misc->misc.fops = &snd_comp_file;
+	misc->misc.minor = MISC_DYNAMIC_MINOR;
+	misc->compr = device;
+	ret = misc_register(&misc->misc);
+	if (ret) {
+		pr_err("couldn't register misc device\n");
+		kfree(misc);
+	} else {
+		pr_debug("Got minor %d\n", misc->misc.minor);
+		list_add_tail(&misc->list, &misc_list);
+	}
+	return ret;
+}
+
+static int snd_compress_remove_device(struct snd_compr *device)
+{
+	struct snd_compr_misc *misc, *__misc;
+
+	list_for_each_entry_safe(misc, __misc, &misc_list, list) {
+		if (device == misc->compr) {
+			misc_deregister(&misc->misc);
+			list_del(&device->list);
+			kfree(misc);
+		}
+	}
+	return 0;
+}
+/**
+ * snd_compress_register - register compressed device
+ *
+ * @device: compressed device to register
+ */
+int snd_compress_register(struct snd_compr *device)
+{
+	int retval;
+
+	if (device->name == NULL || device->dev == NULL || device->ops == NULL)
+		return -EINVAL;
+	BUG_ON(!device->ops->open);
+	BUG_ON(!device->ops->free);
+	BUG_ON(!device->ops->set_params);
+	BUG_ON(!device->ops->get_params);
+	BUG_ON(!device->ops->trigger);
+	BUG_ON(!device->ops->pointer);
+	BUG_ON(!device->ops->get_caps);
+	BUG_ON(!device->ops->get_codec_caps);
+
+	INIT_LIST_HEAD(&device->list);
+	/* todo register the compressed streams */
+	/* todo integrate with asoc */
+
+	/* register a compressed card  TBD if this needs change */
+
+	pr_debug("Registering compressed device %s\n", device->name);
+	mutex_lock(&device_mutex);
+	/*  register a msic device for now */
+	retval = snd_compress_add_device(device);
+	if (!retval)
+		list_add_tail(&device->list, &device_list);
+	mutex_unlock(&device_mutex);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(snd_compress_register);
+
+int snd_compress_deregister(struct snd_compr *device)
+{
+	pr_debug("Removing compressed device %s\n", device->name);
+	mutex_lock(&device_mutex);
+	snd_compress_remove_device(device);
+	list_del(&device->list);
+	mutex_unlock(&device_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_compress_deregister);
+
+static int __init snd_compress_init(void)
+{
+	return 0;
+}
+
+static void __exit snd_compress_exit(void)
+{
+}
+
+module_init(snd_compress_init);
+module_exit(snd_compress_exit);
-- 
1.7.0.4