path: root/drivers/media/video/s5p-tv/mixer_video.c

/*
 * Samsung TV Mixer driver
 *
 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
 *
 * Tomasz Stanislawski, <t.stanislaws@samsung.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
 */

#include "mixer.h"

#include <media/v4l2-ioctl.h>
#include <linux/videodev2.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/timer.h>
#include <media/videobuf2-dma-contig.h>

static int find_reg_callback(struct device *dev, void *p)
{
	struct v4l2_subdev **sd = p;

	*sd = dev_get_drvdata(dev);
	/* non-zero value stops iteration */
	return 1;
}

static struct v4l2_subdev *find_and_register_subdev(
	struct mxr_device *mdev, char *module_name)
{
	struct device_driver *drv;
	struct v4l2_subdev *sd = NULL;
	int ret;

	/* TODO: add waiting until probe is finished */
	drv = driver_find(module_name, &platform_bus_type);
	if (!drv) {
		mxr_warn(mdev, "module %s is missing\n", module_name);
		return NULL;
	}
	/* driver refcnt is increased, it is safe to iterate over devices */
	ret = driver_for_each_device(drv, NULL, &sd, find_reg_callback);
	/* ret == 0 means that find_reg_callback was never executed */
	if (sd == NULL) {
		mxr_warn(mdev, "module %s provides no subdev!\n", module_name);
		goto done;
	}
	/* v4l2_device_register_subdev detects if sd is NULL */
	ret = v4l2_device_register_subdev(&mdev->v4l2_dev, sd);
	if (ret) {
		mxr_warn(mdev, "failed to register subdev %s\n", sd->name);
		sd = NULL;
	}

done:
	put_driver(drv);
	return sd;
}

int __devinit mxr_acquire_video(struct mxr_device *mdev,
	struct mxr_output_conf *output_conf, int output_count)
{
	struct device *dev = mdev->dev;
	struct v4l2_device *v4l2_dev = &mdev->v4l2_dev;
	int i;
	int ret = 0;
	struct v4l2_subdev *sd;

	strlcpy(v4l2_dev->name, dev_name(mdev->dev), sizeof(v4l2_dev->name));
	/* prepare context for V4L2 device */
	ret = v4l2_device_register(dev, v4l2_dev);
	if (ret) {
		mxr_err(mdev, "could not register v4l2 device.\n");
		goto fail;
	}

	mdev->alloc_ctx = vb2_dma_contig_init_ctx(mdev->dev);
	if (IS_ERR_OR_NULL(mdev->alloc_ctx)) {
		mxr_err(mdev, "could not acquire vb2 allocator\n");
		goto fail_v4l2_dev;
	}

	/* registering outputs */
	mdev->output_cnt = 0;
	for (i = 0; i < output_count; ++i) {
		struct mxr_output_conf *conf = &output_conf[i];
		struct mxr_output *out;

		sd = find_and_register_subdev(mdev, conf->module_name);
		/* trying to register next output */
		if (sd == NULL)
			continue;
		out = kzalloc(sizeof *out, GFP_KERNEL);
		if (out == NULL) {
			mxr_err(mdev, "no memory for '%s'\n",
				conf->output_name);
			ret = -ENOMEM;
			/* registered subdevs are removed in fail_v4l2_dev */
			goto fail_output;
		}
		strlcpy(out->name, conf->output_name, sizeof(out->name));
		out->sd = sd;
		out->cookie = conf->cookie;
		mdev->output[mdev->output_cnt++] =