[media] s5p-fimc: Add the media device driver

Add a top level media device driver aggregating FIMC video devnodes,
MIPI-CSIS and sensor subdevs. This driver gathers all media entities
and creates the possible links between them during initialization. By
default some links will be activated to enable access to all available
sensors in the system. For example if there are sensors S0, S1 listed
in the media device platform data definition they will be by default
assigned to FIMC0, FIMC1 respectively, which in turn will corresponds
to separate /dev/video?.
There is enough FIMC H/W entities to cover all available physical camera
interfaces in the system.

The fimc media device driver is bound to the "s5p-fimc-md" platform device.
Such platform device should be created by board initialization code
and camera sensors description array need to be specified as its
platform data.

The media device driver also implements various video pipeline operations,
for enabling subdevs power, streaming, etc., which will be used by the
capture video node driver.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/s5p-fimc/fimc-mdevice.c b/drivers/media/video/s5p-fimc/fimc-mdevice.c
new file mode 100644
index 0000000..50f3fca
--- /dev/null
+++ b/drivers/media/video/s5p-fimc/fimc-mdevice.c
@@ -0,0 +1,829 @@
+/*
+ * S5P/EXYNOS4 SoC series camera host interface media device driver
+ *
+ * Copyright (C) 2011 Samsung Electronics Co., Ltd.
+ * Contact: Sylwester Nawrocki, <s.nawrocki@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 <linux/bug.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+#include <media/media-device.h>
+
+#include "fimc-core.h"
+#include "fimc-mdevice.h"
+#include "mipi-csis.h"
+
+static int __fimc_md_set_camclk(struct fimc_md *fmd,
+				struct fimc_sensor_info *s_info,
+				bool on);
+/**
+ * fimc_pipeline_prepare - update pipeline information with subdevice pointers
+ * @fimc: fimc device terminating the pipeline
+ *
+ * Caller holds the graph mutex.
+ */
+void fimc_pipeline_prepare(struct fimc_dev *fimc, struct media_entity *me)
+{
+	struct media_entity_graph graph;
+	struct v4l2_subdev *sd;
+
+	media_entity_graph_walk_start(&graph, me);
+
+	while ((me = media_entity_graph_walk_next(&graph))) {
+		if (media_entity_type(me) != MEDIA_ENT_T_V4L2_SUBDEV)
+			continue;
+		sd = media_entity_to_v4l2_subdev(me);
+
+		if (sd->grp_id == SENSOR_GROUP_ID)
+			fimc->pipeline.sensor = sd;
+		else if (sd->grp_id == CSIS_GROUP_ID)
+			fimc->pipeline.csis = sd;
+	}
+}
+
+/**
+ * __subdev_set_power - change power state of a single subdev
+ * @sd: subdevice to change power state for
+ * @on: 1 to enable power or 0 to disable
+ *
+ * Return result of s_power subdev operation or -ENXIO if sd argument
+ * is NULL. Return 0 if the subdevice does not implement s_power.
+ */
+static int __subdev_set_power(struct v4l2_subdev *sd, int on)
+{
+	int *use_count;
+	int ret;
+
+	if (sd == NULL)
+		return -ENXIO;
+
+	use_count = &sd->entity.use_count;
+	if (on && (*use_count)++ > 0)
+		return 0;
+	else if (!on && (*use_count == 0 || --(*use_count) > 0))
+		return 0;
+	ret = v4l2_subdev_call(sd, core, s_power, on);
+
+	return ret != -ENOIOCTLCMD ? ret : 0;
+}
+
+/**
+ * fimc_pipeline_s_power - change power state of all pipeline subdevs
+ * @fimc: fimc device terminating the pipeline
+ * @state: 1 to enable power or 0 for power down
+ *
+ * Need to be called with the graph mutex held.
+ */
+int fimc_pipeline_s_power(struct fimc_dev *fimc, int state)
+{
+	int ret = 0;
+
+	if (fimc->pipeline.sensor == NULL)
+		return -ENXIO;
+
+	if (state) {
+		ret = __subdev_set_power(fimc->pipeline.csis, 1);
+		if (ret && ret != -ENXIO)
+			return ret;
+		return __subdev_set_power(fimc->pipeline.sensor, 1);
+	}
+
+	ret = __subdev_set_power(fimc->pipeline.sensor, 0);
+	if (ret)
+		return ret;
+	ret = __subdev_set_power(fimc->pipeline.csis, 0);
+
+	return ret == -ENXIO ? 0 : ret;
+}
+
+/**
+ * __fimc_pipeline_initialize - update the pipeline information, enable power
+ *                              of all pipeline subdevs and the sensor clock
+ * @me: media entity to start graph walk with
+ * @prep: true to acquire sensor (and csis) subdevs
+ *
+ * This function must be called with the graph mutex held.
+ */
+static int __fimc_pipeline_initialize(struct fimc_dev *fimc,
+				      struct media_entity *me, bool prep)
+{
+	int ret;
+
+	if (prep)
+		fimc_pipeline_prepare(fimc, me);
+	if (fimc->pipeline.sensor == NULL)
+		return -EINVAL;
+	ret = fimc_md_set_camclk(fimc->pipeline.sensor, true);
+	if (ret)
+		return ret;
+	return fimc_pipeline_s_power(fimc, 1);
+}
+
+int fimc_pipeline_initialize(struct fimc_dev *fimc, struct media_entity *me,
+			     bool prep)
+{
+	int ret;
+
+	mutex_lock(&me->parent->graph_mutex);
+	ret =  __fimc_pipeline_initialize(fimc, me, prep);
+	mutex_unlock(&me->parent->graph_mutex);
+
+	return ret;
+}
+
+/**
+ * __fimc_pipeline_shutdown - disable the sensor clock and pipeline power
+ * @fimc: fimc device terminating the pipeline
+ *
+ * Disable power of all subdevs in the pipeline and turn off the external
+ * sensor clock.
+ * Called with the graph mutex held.
+ */
+int __fimc_pipeline_shutdown(struct fimc_dev *fimc)
+{
+	int ret = 0;
+
+	if (fimc->pipeline.sensor) {
+		ret = fimc_pipeline_s_power(fimc, 0);
+		fimc_md_set_camclk(fimc->pipeline.sensor, false);
+	}
+	return ret == -ENXIO ? 0 : ret;
+}
+
+int fimc_pipeline_shutdown(struct fimc_dev *fimc)
+{
+	struct media_entity *me = &fimc->vid_cap.vfd->entity;
+	int ret;
+
+	mutex_lock(&me->parent->graph_mutex);
+	ret = __fimc_pipeline_shutdown(fimc);
+	mutex_unlock(&me->parent->graph_mutex);
+
+	return ret;
+}
+
+/**
+ * fimc_pipeline_s_stream - invoke s_stream on pipeline subdevs
+ * @fimc: fimc device terminating the pipeline
+ * @on: passed as the s_stream call argument
+ */
+int fimc_pipeline_s_stream(struct fimc_dev *fimc, int on)
+{
+	struct fimc_pipeline *p = &fimc->pipeline;
+	int ret = 0;
+
+	if (p->sensor == NULL)
+		return -ENODEV;
+
+	if ((on && p->csis) || !on)
+		ret = v4l2_subdev_call(on ? p->csis : p->sensor,
+				       video, s_stream, on);
+	if (ret && ret != -ENOIOCTLCMD)
+		return ret;
+	if ((!on && p->csis) || on)
+		ret = v4l2_subdev_call(on ? p->sensor : p->csis,
+				       video, s_stream, on);
+	return ret == -ENOIOCTLCMD ? 0 : ret;
+}
+
+/*
+ * Sensor subdevice helper functions
+ */
+static struct v4l2_subdev *fimc_md_register_sensor(struct fimc_md *fmd,
+				   struct fimc_sensor_info *s_info)
+{
+	struct i2c_adapter *adapter;
+	struct v4l2_subdev *sd = NULL;
+
+	if (!s_info || !fmd)
+		return NULL;
+
+	adapter = i2c_get_adapter(s_info->pdata->i2c_bus_num);
+	if (!adapter)
+		return NULL;
+	sd = v4l2_i2c_new_subdev_board(&fmd->v4l2_dev, adapter,
+				       s_info->pdata->board_info, NULL);
+	if (IS_ERR_OR_NULL(sd)) {
+		v4l2_err(&fmd->v4l2_dev, "Failed to acquire subdev\n");
+		return NULL;
+	}
+	v4l2_set_subdev_hostdata(sd, s_info);
+	sd->grp_id = SENSOR_GROUP_ID;
+
+	v4l2_info(&fmd->v4l2_dev, "Registered sensor subdevice %s\n",
+		  s_info->pdata->board_info->type);
+	return sd;
+}
+
+static void fimc_md_unregister_sensor(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	if (!client)
+		return;
+	v4l2_device_unregister_subdev(sd);
+	i2c_unregister_device(client);
+	i2c_put_adapter(client->adapter);
+}
+
+static int fimc_md_register_sensor_entities(struct fimc_md *fmd)
+{
+	struct s5p_platform_fimc *pdata = fmd->pdev->dev.platform_data;
+	struct fimc_dev *fd = NULL;
+	int num_clients, ret, i;
+
+	/*
+	 * Runtime resume one of the FIMC entities to make sure
+	 * the sclk_cam clocks are not globally disabled.
+	 */
+	for (i = 0; !fd && i < ARRAY_SIZE(fmd->fimc); i++)
+		if (fmd->fimc[i])
+			fd = fmd->fimc[i];
+	if (!fd)
+		return -ENXIO;
+	ret = pm_runtime_get_sync(&fd->pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	WARN_ON(pdata->num_clients > ARRAY_SIZE(fmd->sensor));
+	num_clients = min_t(u32, pdata->num_clients, ARRAY_SIZE(fmd->sensor));
+
+	fmd->num_sensors = num_clients;
+	for (i = 0; i < num_clients; i++) {
+		fmd->sensor[i].pdata = &pdata->isp_info[i];
+		ret = __fimc_md_set_camclk(fmd, &fmd->sensor[i], true);
+		if (ret)
+			break;
+		fmd->sensor[i].subdev =
+			fimc_md_register_sensor(fmd, &fmd->sensor[i]);
+		ret = __fimc_md_set_camclk(fmd, &fmd->sensor[i], false);
+		if (ret)
+			break;
+	}
+	pm_runtime_put(&fd->pdev->dev);
+	return ret;
+}
+
+/*
+ * MIPI CSIS and FIMC platform devices registration.
+ */
+static int fimc_register_callback(struct device *dev, void *p)
+{
+	struct fimc_dev *fimc = dev_get_drvdata(dev);
+	struct fimc_md *fmd = p;
+	int ret;
+
+	if (!fimc || !fimc->pdev)
+		return 0;
+	if (fimc->pdev->id < 0 || fimc->pdev->id >= FIMC_MAX_DEVS)
+		return 0;
+
+	fmd->fimc[fimc->pdev->id] = fimc;
+	ret = fimc_register_m2m_device(fimc, &fmd->v4l2_dev);
+	if (ret)
+		return ret;
+	ret = fimc_register_capture_device(fimc, &fmd->v4l2_dev);
+	if (!ret)
+		fimc->vid_cap.user_subdev_api = fmd->user_subdev_api;
+	return ret;
+}
+
+static int csis_register_callback(struct device *dev, void *p)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct platform_device *pdev;
+	struct fimc_md *fmd = p;
+	int id, ret;
+
+	if (!sd)
+		return 0;
+	pdev = v4l2_get_subdevdata(sd);
+	if (!pdev || pdev->id < 0 || pdev->id >= CSIS_MAX_ENTITIES)
+		return 0;
+	v4l2_info(sd, "csis%d sd: %s\n", pdev->id, sd->name);
+
+	id = pdev->id < 0 ? 0 : pdev->id;
+	fmd->csis[id].sd = sd;
+	sd->grp_id = CSIS_GROUP_ID;
+	ret = v4l2_device_register_subdev(&fmd->v4l2_dev, sd);
+	if (ret)
+		v4l2_err(&fmd->v4l2_dev,
+			 "Failed to register CSIS subdevice: %d\n", ret);
+	return ret;
+}
+
+/**
+ * fimc_md_register_platform_entities - register FIMC and CSIS media entities
+ */
+static int fimc_md_register_platform_entities(struct fimc_md *fmd)
+{
+	struct device_driver *driver;
+	int ret;
+
+	driver = driver_find(FIMC_MODULE_NAME, &platform_bus_type);
+	if (!driver)
+		return -ENODEV;
+	ret = driver_for_each_device(driver, NULL, fmd,
+				     fimc_register_callback);
+	put_driver(driver);
+	if (ret)
+		return ret;
+
+	driver = driver_find(CSIS_DRIVER_NAME, &platform_bus_type);
+	if (driver) {
+		ret = driver_for_each_device(driver, NULL, fmd,
+					     csis_register_callback);
+		put_driver(driver);
+	}
+	return ret;
+}
+
+static void fimc_md_unregister_entities(struct fimc_md *fmd)
+{
+	int i;
+
+	for (i = 0; i < FIMC_MAX_DEVS; i++) {
+		if (fmd->fimc[i] == NULL)
+			continue;
+		fimc_unregister_m2m_device(fmd->fimc[i]);
+		fimc_unregister_capture_device(fmd->fimc[i]);
+		fmd->fimc[i] = NULL;
+	}
+	for (i = 0; i < CSIS_MAX_ENTITIES; i++) {
+		if (fmd->csis[i].sd == NULL)
+			continue;
+		v4l2_device_unregister_subdev(fmd->csis[i].sd);
+		fmd->csis[i].sd = NULL;
+	}
+	for (i = 0; i < fmd->num_sensors; i++) {
+		if (fmd->sensor[i].subdev == NULL)
+			continue;
+		fimc_md_unregister_sensor(fmd->sensor[i].subdev);
+		fmd->sensor[i].subdev = NULL;
+	}
+}
+
+static int fimc_md_register_video_nodes(struct fimc_md *fmd)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < FIMC_MAX_DEVS && !ret; i++) {
+		if (!fmd->fimc[i])
+			continue;
+
+		if (fmd->fimc[i]->m2m.vfd)
+			ret = video_register_device(fmd->fimc[i]->m2m.vfd,
+						    VFL_TYPE_GRABBER, -1);
+		if (ret)
+			break;
+		if (fmd->fimc[i]->vid_cap.vfd)
+			ret = video_register_device(fmd->fimc[i]->vid_cap.vfd,
+						    VFL_TYPE_GRABBER, -1);
+	}
+
+	return ret;
+}
+
+/**
+ * __fimc_md_create_fimc_links - create links to all FIMC entities
+ * @fmd: fimc media device
+ * @source: the source entity to create links to all fimc entities from
+ * @sensor: sensor subdev linked to FIMC[fimc_id] entity, may be null
+ * @pad: the source entity pad index
+ * @fimc_id: index of the fimc device for which link should be enabled
+ */
+static int __fimc_md_create_fimc_links(struct fimc_md *fmd,
+				       struct media_entity *source,
+				       struct v4l2_subdev *sensor,
+				       int pad, int fimc_id)
+{
+	struct fimc_sensor_info *s_info;
+	struct media_entity *sink;
+	unsigned int flags;
+	int ret, i, src_pad;
+
+	for (i = 0; i < FIMC_MAX_DEVS; i++) {
+		if (!fmd->fimc[i])
+			break;
+		/*
+		 * Some FIMC variants are not fitted with camera capture
+		 * interface. Skip creating a link from sensor for those.
+		 */
+		if (sensor && sensor->grp_id == SENSOR_GROUP_ID &&
+		    !fmd->fimc[i]->variant->has_cam_if)
+			continue;
+
+		flags = (i == fimc_id) ? MEDIA_LNK_FL_ENABLED : 0;
+		sink = &fmd->fimc[i]->vid_cap.vfd->entity;
+		ret = media_entity_create_link(source, 0, sink, 0, flags);
+		if (ret)
+			return ret;
+
+		v4l2_info(&fmd->v4l2_dev, "created link [%s] %c> [%s]",
+			  source->name, flags ? '=' : '-', sink->name);
+
+		if (flags == 0 || sensor == NULL)
+			continue;
+		s_info = v4l2_get_subdev_hostdata(sensor);
+		if (!WARN_ON(s_info == NULL)) {
+			unsigned long irq_flags;
+			spin_lock_irqsave(&fmd->slock, irq_flags);
+			s_info->host = fmd->fimc[i];
+			spin_unlock_irqrestore(&fmd->slock, irq_flags);
+		}
+	}
+	return 0;
+}
+
+/**
+ * fimc_md_create_links - create default links between registered entities
+ *
+ * Parallel interface sensor entities are connected directly to FIMC capture
+ * entities. The sensors using MIPI CSIS bus are connected through immutable
+ * link with CSI receiver entity specified by mux_id. Any registered CSIS
+ * entity has a link to each registered FIMC capture entity. Enabled links
+ * are created by default between each subsequent registered sensor and
+ * subsequent FIMC capture entity. The number of default active links is
+ * determined by the number of available sensors or FIMC entities,
+ * whichever is less.
+ */
+static int fimc_md_create_links(struct fimc_md *fmd)
+{
+	struct v4l2_subdev *sensor, *csis;
+	struct s5p_fimc_isp_info *pdata;
+	struct fimc_sensor_info *s_info;
+	struct media_entity *source;
+	int fimc_id = 0;
+	int i, pad;
+	int ret = 0;
+
+	for (i = 0; i < fmd->num_sensors; i++) {
+		if (fmd->sensor[i].subdev == NULL)
+			continue;
+
+		sensor = fmd->sensor[i].subdev;
+		s_info = v4l2_get_subdev_hostdata(sensor);
+		if (!s_info || !s_info->pdata)
+			continue;
+
+		source = NULL;
+		pdata = s_info->pdata;
+
+		switch (pdata->bus_type) {
+		case FIMC_MIPI_CSI2:
+			if (WARN(pdata->mux_id >= CSIS_MAX_ENTITIES,
+				"Wrong CSI channel id: %d\n", pdata->mux_id))
+				return -EINVAL;
+
+			csis = fmd->csis[pdata->mux_id].sd;
+			if (WARN(csis == NULL,
+				 "MIPI-CSI interface specified "
+				 "but s5p-csis module is not loaded!\n"))
+				continue;
+
+			ret = media_entity_create_link(&sensor->entity, 0,
+					      &csis->entity, CSIS_PAD_SINK,
+					      MEDIA_LNK_FL_IMMUTABLE |
+					      MEDIA_LNK_FL_ENABLED);
+			if (ret)
+				return ret;
+
+			v4l2_info(&fmd->v4l2_dev, "created link [%s] => [%s]",
+				  sensor->entity.name, csis->entity.name);
+
+			sensor = NULL;
+			source = &csis->entity;
+			pad = CSIS_PAD_SOURCE;
+			break;
+
+		case FIMC_ITU_601...FIMC_ITU_656:
+			source = &sensor->entity;
+			pad = 0;
+			break;
+
+		default:
+			v4l2_err(&fmd->v4l2_dev, "Wrong bus_type: %x\n",
+				 pdata->bus_type);
+			return -EINVAL;
+		}
+		if (source == NULL)
+			continue;
+
+		ret = __fimc_md_create_fimc_links(fmd, source, sensor, pad,
+						 fimc_id++);
+	}
+	return ret;
+}
+
+/*
+ * The peripheral sensor clock management.
+ */
+static int fimc_md_get_clocks(struct fimc_md *fmd)
+{
+	char clk_name[32];
+	struct clk *clock;
+	int i;
+
+	for (i = 0; i < FIMC_MAX_CAMCLKS; i++) {
+		snprintf(clk_name, sizeof(clk_name), "sclk_cam%u", i);
+		clock = clk_get(NULL, clk_name);
+		if (IS_ERR_OR_NULL(clock)) {
+			v4l2_err(&fmd->v4l2_dev, "Failed to get clock: %s",
+				  clk_name);
+			return -ENXIO;
+		}
+		fmd->camclk[i].clock = clock;
+	}
+	return 0;
+}
+
+static void fimc_md_put_clocks(struct fimc_md *fmd)
+{
+	int i = FIMC_MAX_CAMCLKS;
+
+	while (--i >= 0) {
+		if (IS_ERR_OR_NULL(fmd->camclk[i].clock))
+			continue;
+		clk_put(fmd->camclk[i].clock);
+		fmd->camclk[i].clock = NULL;
+	}
+}
+
+static int __fimc_md_set_camclk(struct fimc_md *fmd,
+					 struct fimc_sensor_info *s_info,
+					 bool on)
+{
+	struct s5p_fimc_isp_info *pdata = s_info->pdata;
+	struct fimc_camclk_info *camclk;
+	int ret = 0;
+
+	if (WARN_ON(pdata->clk_id >= FIMC_MAX_CAMCLKS) || fmd == NULL)
+		return -EINVAL;
+
+	if (s_info->clk_on == on)
+		return 0;
+	camclk = &fmd->camclk[pdata->clk_id];
+
+	dbg("camclk %d, f: %lu, clk: %p, on: %d",
+	    pdata->clk_id, pdata->clk_frequency, camclk, on);
+
+	if (on) {
+		if (camclk->use_count > 0 &&
+		    camclk->frequency != pdata->clk_frequency)
+			return -EINVAL;
+
+		if (camclk->use_count++ == 0) {
+			clk_set_rate(camclk->clock, pdata->clk_frequency);
+			camclk->frequency = pdata->clk_frequency;
+			ret = clk_enable(camclk->clock);
+		}
+		s_info->clk_on = 1;
+		dbg("Enabled camclk %d: f: %lu", pdata->clk_id,
+		    clk_get_rate(camclk->clock));
+
+		return ret;
+	}
+
+	if (WARN_ON(camclk->use_count == 0))
+		return 0;
+
+	if (--camclk->use_count == 0) {
+		clk_disable(camclk->clock);
+		s_info->clk_on = 0;
+		dbg("Disabled camclk %d", pdata->clk_id);
+	}
+	return ret;
+}
+
+/**
+ * fimc_md_set_camclk - peripheral sensor clock setup
+ * @sd: sensor subdev to configure sclk_cam clock for
+ * @on: 1 to enable or 0 to disable the clock
+ *
+ * There are 2 separate clock outputs available in the SoC for external
+ * image processors. These clocks are shared between all registered FIMC
+ * devices to which sensors can be attached, either directly or through
+ * the MIPI CSI receiver. The clock is allowed here to be used by
+ * multiple sensors concurrently if they use same frequency.
+ * The per sensor subdev clk_on attribute helps to synchronize accesses
+ * to the sclk_cam clocks from the video and media device nodes.
+ * This function should only be called when the graph mutex is held.
+ */
+int fimc_md_set_camclk(struct v4l2_subdev *sd, bool on)
+{
+	struct fimc_sensor_info *s_info = v4l2_get_subdev_hostdata(sd);
+	struct fimc_md *fmd = entity_to_fimc_mdev(&sd->entity);
+
+	return __fimc_md_set_camclk(fmd, s_info, on);
+}
+
+static int fimc_md_link_notify(struct media_pad *source,
+			       struct media_pad *sink, u32 flags)
+{
+	struct video_device *vid_dev;
+	struct fimc_dev *fimc;
+	int ret = 0;
+
+	if (WARN_ON(media_entity_type(sink->entity) != MEDIA_ENT_T_DEVNODE))
+		return 0;
+
+	vid_dev = media_entity_to_video_device(sink->entity);
+	fimc = video_get_drvdata(vid_dev);
+
+	if (!(flags & MEDIA_LNK_FL_ENABLED)) {
+		ret = __fimc_pipeline_shutdown(fimc);
+		fimc->pipeline.sensor = NULL;
+		fimc->pipeline.csis = NULL;
+		return ret;
+	}
+	/*
+	 * Link activation. Enable power of pipeline elements only if the
+	 * pipeline is already in use, i.e. its video node is opened.
+	 */
+	mutex_lock(&fimc->lock);
+	if (fimc->vid_cap.refcnt > 0)
+		ret = __fimc_pipeline_initialize(fimc, source->entity, true);
+	mutex_unlock(&fimc->lock);
+
+	return ret ? -EPIPE : ret;
+}
+
+static ssize_t fimc_md_sysfs_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct fimc_md *fmd = platform_get_drvdata(pdev);
+
+	if (fmd->user_subdev_api)
+		return strlcpy(buf, "Sub-device API (sub-dev)\n", PAGE_SIZE);
+
+	return strlcpy(buf, "V4L2 video node only API (vid-dev)\n", PAGE_SIZE);
+}
+
+static ssize_t fimc_md_sysfs_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct fimc_md *fmd = platform_get_drvdata(pdev);
+	bool subdev_api;
+	int i;
+
+	if (!strcmp(buf, "vid-dev\n"))
+		subdev_api = false;
+	else if (!strcmp(buf, "sub-dev\n"))
+		subdev_api = true;
+	else
+		return count;
+
+	fmd->user_subdev_api = subdev_api;
+	for (i = 0; i < FIMC_MAX_DEVS; i++)
+		if (fmd->fimc[i])
+			fmd->fimc[i]->vid_cap.user_subdev_api = subdev_api;
+	return count;
+}
+/*
+ * This device attribute is to select video pipeline configuration method.
+ * There are following valid values:
+ *  vid-dev - for V4L2 video node API only, subdevice will be configured
+ *  by the host driver.
+ *  sub-dev - for media controller API, subdevs must be configured in user
+ *  space before starting streaming.
+ */
+static DEVICE_ATTR(subdev_conf_mode, S_IWUSR | S_IRUGO,
+		   fimc_md_sysfs_show, fimc_md_sysfs_store);
+
+static int __devinit fimc_md_probe(struct platform_device *pdev)
+{
+	struct v4l2_device *v4l2_dev;
+	struct fimc_md *fmd;
+	int ret;
+
+	if (WARN(!pdev->dev.platform_data, "Platform data not specified!\n"))
+		return -EINVAL;
+
+	fmd = kzalloc(sizeof(struct fimc_md), GFP_KERNEL);
+	if (!fmd)
+		return -ENOMEM;
+
+	spin_lock_init(&fmd->slock);
+	fmd->pdev = pdev;
+
+	strlcpy(fmd->media_dev.model, "SAMSUNG S5P FIMC",
+		sizeof(fmd->media_dev.model));
+	fmd->media_dev.link_notify = fimc_md_link_notify;
+	fmd->media_dev.dev = &pdev->dev;
+
+	v4l2_dev = &fmd->v4l2_dev;
+	v4l2_dev->mdev = &fmd->media_dev;
+	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s",
+		 dev_name(&pdev->dev));
+
+	ret = v4l2_device_register(&pdev->dev, &fmd->v4l2_dev);
+	if (ret < 0) {
+		v4l2_err(v4l2_dev, "Failed to register v4l2_device: %d\n", ret);
+		goto err1;
+	}
+	ret = media_device_register(&fmd->media_dev);
+	if (ret < 0) {
+		v4l2_err(v4l2_dev, "Failed to register media device: %d\n", ret);
+		goto err2;
+	}
+	ret = fimc_md_get_clocks(fmd);
+	if (ret)
+		goto err3;
+
+	fmd->user_subdev_api = false;
+	ret = fimc_md_register_platform_entities(fmd);
+	if (ret)
+		goto err3;
+
+	ret = fimc_md_register_sensor_entities(fmd);
+	if (ret)
+		goto err3;
+	ret = fimc_md_create_links(fmd);
+	if (ret)
+		goto err3;
+	ret = v4l2_device_register_subdev_nodes(&fmd->v4l2_dev);
+	if (ret)
+		goto err3;
+	ret = fimc_md_register_video_nodes(fmd);
+	if (ret)
+		goto err3;
+
+	ret = device_create_file(&pdev->dev, &dev_attr_subdev_conf_mode);
+	if (!ret) {
+		platform_set_drvdata(pdev, fmd);
+		return 0;
+	}
+err3:
+	media_device_unregister(&fmd->media_dev);
+	fimc_md_put_clocks(fmd);
+	fimc_md_unregister_entities(fmd);
+err2:
+	v4l2_device_unregister(&fmd->v4l2_dev);
+err1:
+	kfree(fmd);
+	return ret;
+}
+
+static int __devexit fimc_md_remove(struct platform_device *pdev)
+{
+	struct fimc_md *fmd = platform_get_drvdata(pdev);
+
+	if (!fmd)
+		return 0;
+	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);
+	fimc_md_unregister_entities(fmd);
+	media_device_unregister(&fmd->media_dev);
+	fimc_md_put_clocks(fmd);
+	kfree(fmd);
+	return 0;
+}
+
+static struct platform_driver fimc_md_driver = {
+	.probe		= fimc_md_probe,
+	.remove		= __devexit_p(fimc_md_remove),
+	.driver = {
+		.name	= "s5p-fimc-md",
+		.owner	= THIS_MODULE,
+	}
+};
+
+int __init fimc_md_init(void)
+{
+	int ret;
+	request_module("s5p-csis");
+	ret = fimc_register_driver();
+	if (ret)
+		return ret;
+	return platform_driver_register(&fimc_md_driver);
+}
+void __exit fimc_md_exit(void)
+{
+	platform_driver_unregister(&fimc_md_driver);
+	fimc_unregister_driver();
+}
+
+module_init(fimc_md_init);
+module_exit(fimc_md_exit);
+
+MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
+MODULE_DESCRIPTION("S5P FIMC camera host interface/video postprocessor driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("2.0.1");