fimc-mdevice.c

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/*
 * S5P/EXYNOS4 SoC series camera host interface media device driver
 *
 * Copyright (C) 2011 Samsung Electronics Co., Ltd.
 * Contact: Sylwester Nawrocki, <[email protected]>
 *
 * 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 <media/v4l2-ctrls.h>
#include <media/media-device.h>
#include <media/s5p_fimc.h>

#include "fimc-core.h"
#include "fimc-lite.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);
static void fimc_pipeline_prepare(struct fimc_pipeline *p,
                  struct media_entity *me)
{
    struct media_pad *pad = &me->pads[0];
    struct v4l2_subdev *sd;
    int i;

    for (i = 0; i < IDX_MAX; i++)
        p->subdevs[i] = NULL;

    while (1) {
        if (!(pad->flags & MEDIA_PAD_FL_SINK))
            break;

        /* source pad */
        pad = media_entity_remote_source(pad);
        if (pad == NULL ||
            media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
            break;

        sd = media_entity_to_v4l2_subdev(pad->entity);

        switch (sd->grp_id) {
        case SENSOR_GROUP_ID:
            p->subdevs[IDX_SENSOR] = sd;
            break;
        case CSIS_GROUP_ID:
            p->subdevs[IDX_CSIS] = sd;
            break;
        case FLITE_GROUP_ID:
            p->subdevs[IDX_FLITE] = sd;
            break;
        case FIMC_GROUP_ID:
            /* No need to control FIMC subdev through subdev ops */
            break;
        default:
            pr_warn("%s: Unknown subdev grp_id: %#x\n",
                __func__, sd->grp_id);
        }
        /* sink pad */
        pad = &sd->entity.pads[0];
    }
}

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;
}

static int fimc_pipeline_s_power(struct fimc_pipeline *p, bool state)
{
    unsigned int i;
    int ret;

    if (p->subdevs[IDX_SENSOR] == NULL)
        return -ENXIO;

    for (i = 0; i < IDX_MAX; i++) {
        unsigned int idx = state ? (IDX_MAX - 1) - i : i;

        ret = __subdev_set_power(p->subdevs[idx], state);
        if (ret < 0 && ret != -ENXIO)
            return ret;
    }

    return 0;
}

static int __fimc_pipeline_open(struct fimc_pipeline *p,
                struct media_entity *me, bool prep)
{
    int ret;

    if (prep)
        fimc_pipeline_prepare(p, me);

    if (p->subdevs[IDX_SENSOR] == NULL)
        return -EINVAL;

    ret = fimc_md_set_camclk(p->subdevs[IDX_SENSOR], true);
    if (ret)
        return ret;

    return fimc_pipeline_s_power(p, 1);
}

static int fimc_pipeline_open(struct fimc_pipeline *p,
                  struct media_entity *me, bool prep)
{
    int ret;

    mutex_lock(&me->parent->graph_mutex);
    ret =  __fimc_pipeline_open(p, me, prep);
    mutex_unlock(&me->parent->graph_mutex);

    return ret;
}

static int __fimc_pipeline_close(struct fimc_pipeline *p)
{
    int ret = 0;

    if (p->subdevs[IDX_SENSOR]) {
        ret = fimc_pipeline_s_power(p, 0);
        fimc_md_set_camclk(p->subdevs[IDX_SENSOR], false);
    }
    return ret == -ENXIO ? 0 : ret;
}

static int fimc_pipeline_close(struct fimc_pipeline *p)
{
    struct media_entity *me;
    int ret;

    if (!p || !p->subdevs[IDX_SENSOR])
        return -EINVAL;

    me = &p->subdevs[IDX_SENSOR]->entity;
    mutex_lock(&me->parent->graph_mutex);
    ret = __fimc_pipeline_close(p);
    mutex_unlock(&me->parent->graph_mutex);

    return ret;
}

int fimc_pipeline_s_stream(struct fimc_pipeline *p, bool on)
{
    int i, ret;

    if (p->subdevs[IDX_SENSOR] == NULL)
        return -ENODEV;

    for (i = 0; i < IDX_MAX; i++) {
        unsigned int idx = on ? (IDX_MAX - 1) - i : i;

        ret = v4l2_subdev_call(p->subdevs[idx], video, s_stream, on);

        if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
            return ret;
    }

    return 0;

}

/* Media pipeline operations for the FIMC/FIMC-LITE video device driver */
static const struct fimc_pipeline_ops fimc_pipeline_ops = {
    .open       = fimc_pipeline_open,
    .close      = fimc_pipeline_close,
    .set_stream = fimc_pipeline_s_stream,
};

/*
 * 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) {
        v4l2_warn(&fmd->v4l2_dev,
              "Failed to get I2C adapter %d, deferring probe\n",
              s_info->pdata.i2c_bus_num);
        return ERR_PTR(-EPROBE_DEFER);
    }
    sd = v4l2_i2c_new_subdev_board(&fmd->v4l2_dev, adapter,
                       s_info->pdata.board_info, NULL);
    if (IS_ERR_OR_NULL(sd)) {
        i2c_put_adapter(adapter);
        v4l2_warn(&fmd->v4l2_dev,
              "Failed to acquire subdev %s, deferring probe\n",
              s_info->pdata.board_info->type);
        return ERR_PTR(-EPROBE_DEFER);
    }
    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);
    struct i2c_adapter *adapter;

    if (!client)
        return;
    v4l2_device_unregister_subdev(sd);
    adapter = client->adapter;
    i2c_unregister_device(client);
    if (adapter)
        i2c_put_adapter(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++) {
        struct v4l2_subdev *sd;

        fmd->sensor[i].pdata = pdata->isp_info[i];
        ret = __fimc_md_set_camclk(fmd, &fmd->sensor[i], true);
        if (ret)
            break;
        sd = fimc_md_register_sensor(fmd, &fmd->sensor[i]);
        ret = __fimc_md_set_camclk(fmd, &fmd->sensor[i], false);

        if (!IS_ERR(sd)) {
            fmd->sensor[i].subdev = sd;
        } else {
            fmd->sensor[i].subdev = NULL;
            ret = PTR_ERR(sd);
            break;
        }
        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 v4l2_subdev *sd;
    struct fimc_md *fmd = p;
    int ret;

    if (fimc == NULL || fimc->id >= FIMC_MAX_DEVS)
        return 0;

    sd = &fimc->vid_cap.subdev;
    sd->grp_id = FIMC_GROUP_ID;
    v4l2_set_subdev_hostdata(sd, (void *)&fimc_pipeline_ops);

    ret = v4l2_device_register_subdev(&fmd->v4l2_dev, sd);
    if (ret) {
        v4l2_err(&fmd->v4l2_dev, "Failed to register FIMC.%d (%d)\n",
             fimc->id, ret);
        return ret;
    }

    fmd->fimc[fimc->id] = fimc;
    return 0;
}

static int fimc_lite_register_callback(struct device *dev, void *p)
{
    struct fimc_lite *fimc = dev_get_drvdata(dev);
    struct fimc_md *fmd = p;
    int ret;

    if (fimc == NULL || fimc->index >= FIMC_LITE_MAX_DEVS)
        return 0;

    fimc->subdev.grp_id = FLITE_GROUP_ID;
    v4l2_set_subdev_hostdata(&fimc->subdev, (void *)&fimc_pipeline_ops);

    ret = v4l2_device_register_subdev(&fmd->v4l2_dev, &fimc->subdev);
    if (ret) {
        v4l2_err(&fmd->v4l2_dev,
             "Failed to register FIMC-LITE.%d (%d)\n",
             fimc->index, ret);
        return ret;
    }

    fmd->fimc_lite[fimc->index] = fimc;
    return 0;
}

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;
    sd->grp_id = CSIS_GROUP_ID;

    ret = v4l2_device_register_subdev(&fmd->v4l2_dev, sd);
    if (!ret)
        fmd->csis[id].sd = sd;
    else
        v4l2_err(&fmd->v4l2_dev,
             "Failed to register CSIS subdevice: %d\n", ret);
    return ret;
}

static int fimc_md_register_platform_entities(struct fimc_md *fmd)
{
    struct s5p_platform_fimc *pdata = fmd->pdev->dev.platform_data;
    struct device_driver *driver;
    int ret, i;

    driver = driver_find(FIMC_MODULE_NAME, &platform_bus_type);
    if (!driver) {
        v4l2_warn(&fmd->v4l2_dev,
             "%s driver not found, deffering probe\n",
             FIMC_MODULE_NAME);
        return -EPROBE_DEFER;
    }

    ret = driver_for_each_device(driver, NULL, fmd,
                     fimc_register_callback);
    if (ret)
        return ret;

    driver = driver_find(FIMC_LITE_DRV_NAME, &platform_bus_type);
    if (driver && try_module_get(driver->owner)) {
        ret = driver_for_each_device(driver, NULL, fmd,
                         fimc_lite_register_callback);
        if (ret)
            return ret;
        module_put(driver->owner);
    }
    /*
     * Check if there is any sensor on the MIPI-CSI2 bus and
     * if not skip the s5p-csis module loading.
     */
    if (pdata == NULL)
        return 0;
    for (i = 0; i < pdata->num_clients; i++) {
        if (pdata->isp_info[i].bus_type == FIMC_MIPI_CSI2) {
            ret = 1;
            break;
        }
    }
    if (!ret)
        return 0;

    driver = driver_find(CSIS_DRIVER_NAME, &platform_bus_type);
    if (!driver || !try_module_get(driver->owner)) {
        v4l2_warn(&fmd->v4l2_dev,
             "%s driver not found, deffering probe\n",
             CSIS_DRIVER_NAME);
        return -EPROBE_DEFER;
    }

    return driver_for_each_device(driver, NULL, fmd,
                      csis_register_callback);
}

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;
        v4l2_device_unregister_subdev(&fmd->fimc[i]->vid_cap.subdev);
        fmd->fimc[i]->pipeline_ops = NULL;
        fmd->fimc[i] = NULL;
    }
    for (i = 0; i < FIMC_LITE_MAX_DEVS; i++) {
        if (fmd->fimc_lite[i] == NULL)
            continue;
        v4l2_device_unregister_subdev(&fmd->fimc_lite[i]->subdev);
        fmd->fimc[i]->pipeline_ops = NULL;
        fmd->fimc_lite[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);
        module_put(fmd->csis[i].sd->owner);
        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_create_fimc_sink_links(struct fimc_md *fmd,
                        struct media_entity *source,
                        struct v4l2_subdev *sensor,
                        int pad, int link_mask)
{
    struct fimc_sensor_info *s_info;
    struct media_entity *sink;
    unsigned int flags = 0;
    int ret, i;

    for (i = 0; i < FIMC_MAX_DEVS; i++) {
        if (!fmd->fimc[i])
            continue;
        /*
         * Some FIMC variants are not fitted with camera capture
         * interface. Skip creating a link from sensor for those.
         */
        if (!fmd->fimc[i]->variant->has_cam_if)
            continue;

        flags = ((1 << i) & link_mask) ? MEDIA_LNK_FL_ENABLED : 0;

        sink = &fmd->fimc[i]->vid_cap.subdev.entity;
        ret = media_entity_create_link(source, pad, sink,
                          FIMC_SD_PAD_SINK, flags);
        if (ret)
            return ret;

        /* Notify FIMC capture subdev entity */
        ret = media_entity_call(sink, link_setup, &sink->pads[0],
                    &source->pads[pad], flags);
        if (ret)
            break;

        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);
        }
    }

    for (i = 0; i < FIMC_LITE_MAX_DEVS; i++) {
        if (!fmd->fimc_lite[i])
            continue;

        if (link_mask & (1 << (i + FIMC_MAX_DEVS)))
            flags = MEDIA_LNK_FL_ENABLED;
        else
            flags = 0;

        sink = &fmd->fimc_lite[i]->subdev.entity;
        ret = media_entity_create_link(source, pad, sink,
                           FLITE_SD_PAD_SINK, flags);
        if (ret)
            return ret;

        /* Notify FIMC-LITE subdev entity */
        ret = media_entity_call(sink, link_setup, &sink->pads[0],
                    &source->pads[pad], flags);
        if (ret)
            break;

        v4l2_info(&fmd->v4l2_dev, "created link [%s] %c> [%s]",
              source->name, flags ? '=' : '-', sink->name);
    }
    return 0;
}

/* Create links from FIMC-LITE source pads to other entities */
static int __fimc_md_create_flite_source_links(struct fimc_md *fmd)
{
    struct media_entity *source, *sink;
    unsigned int flags = MEDIA_LNK_FL_ENABLED;
    int i, ret;

    for (i = 0; i < FIMC_LITE_MAX_DEVS; i++) {
        struct fimc_lite *fimc = fmd->fimc_lite[i];
        if (fimc == NULL)
            continue;
        source = &fimc->subdev.entity;
        sink = &fimc->vfd.entity;
        /* FIMC-LITE's subdev and video node */
        ret = media_entity_create_link(source, FIMC_SD_PAD_SOURCE,
                           sink, 0, flags);
        if (ret)
            break;
        /* TODO: create links to other entities */
    }

    return ret;
}

static int fimc_md_create_links(struct fimc_md *fmd)
{
    struct v4l2_subdev *csi_sensors[2] = { NULL };
    struct v4l2_subdev *sensor, *csis;
    struct s5p_fimc_isp_info *pdata;
    struct fimc_sensor_info *s_info;
    struct media_entity *source, *sink;
    int i, pad, fimc_id = 0, ret = 0;
    u32 flags, link_mask = 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)
            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"))
                return -EINVAL;

            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);

            source = NULL;
            csi_sensors[pdata->mux_id] = sensor;
            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;

        link_mask = 1 << fimc_id++;
        ret = __fimc_md_create_fimc_sink_links(fmd, source, sensor,
                               pad, link_mask);
    }

    for (i = 0; i < ARRAY_SIZE(fmd->csis); i++) {
        if (fmd->csis[i].sd == NULL)
            continue;
        source = &fmd->csis[i].sd->entity;
        pad = CSIS_PAD_SOURCE;
        sensor = csi_sensors[i];

        link_mask = 1 << fimc_id++;
        ret = __fimc_md_create_fimc_sink_links(fmd, source, sensor,
                               pad, link_mask);
    }

    /* Create immutable links between each FIMC's subdev and video node */
    flags = MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED;
    for (i = 0; i < FIMC_MAX_DEVS; i++) {
        if (!fmd->fimc[i])
            continue;
        source = &fmd->fimc[i]->vid_cap.subdev.entity;
        sink = &fmd->fimc[i]->vid_cap.vfd.entity;
        ret = media_entity_create_link(source, FIMC_SD_PAD_SOURCE,
                          sink, 0, flags);
        if (ret)
            break;
    }

    return __fimc_md_create_flite_source_links(fmd);
}

/*
 * 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;

    camclk = &fmd->camclk[pdata->clk_id];

    dbg("camclk %d, f: %lu, use_count: %d, on: %d",
        pdata->clk_id, pdata->clk_frequency, camclk->use_count, 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);
            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);
        dbg("Disabled camclk %d", pdata->clk_id);
    }
    return ret;
}

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 fimc_lite *fimc_lite = NULL;
    struct fimc_dev *fimc = NULL;
    struct fimc_pipeline *pipeline;
    struct v4l2_subdev *sd;
    int ret = 0;

    if (media_entity_type(sink->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
        return 0;

    sd = media_entity_to_v4l2_subdev(sink->entity);

    switch (sd->grp_id) {
    case FLITE_GROUP_ID:
        fimc_lite = v4l2_get_subdevdata(sd);
        pipeline = &fimc_lite->pipeline;
        break;
    case FIMC_GROUP_ID:
        fimc = v4l2_get_subdevdata(sd);
        pipeline = &fimc->pipeline;
        break;
    default:
        return 0;
    }

    if (!(flags & MEDIA_LNK_FL_ENABLED)) {
        ret = __fimc_pipeline_close(pipeline);
        pipeline->subdevs[IDX_SENSOR] = NULL;
        pipeline->subdevs[IDX_CSIS] = NULL;

        if (fimc) {
            mutex_lock(&fimc->lock);
            fimc_ctrls_delete(fimc->vid_cap.ctx);
            mutex_unlock(&fimc->lock);
        }
        return ret;
    }
    /*
     * Link activation. Enable power of pipeline elements only if the
     * pipeline is already in use, i.e. its video node is opened.
     * Recreate the controls destroyed during the link deactivation.
     */
    if (fimc) {
        mutex_lock(&fimc->lock);
        if (fimc->vid_cap.refcnt > 0) {
            ret = __fimc_pipeline_open(pipeline,
                           source->entity, true);
        if (!ret)
            ret = fimc_capture_ctrls_create(fimc);
        }
        mutex_unlock(&fimc->lock);
    } else {
        mutex_lock(&fimc_lite->lock);
        if (fimc_lite->ref_count > 0) {
            ret = __fimc_pipeline_open(pipeline,
                           source->entity, true);
        }
        mutex_unlock(&fimc_lite->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 fimc_md_probe(struct platform_device *pdev)
{
    struct v4l2_device *v4l2_dev;
    struct fimc_md *fmd;
    int ret;

    fmd = devm_kzalloc(&pdev->dev, sizeof(*fmd), 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;
    v4l2_dev->notify = fimc_sensor_notify;
    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);
        return ret;
    }
    ret = media_device_register(&fmd->media_dev);
    if (ret < 0) {
        v4l2_err(v4l2_dev, "Failed to register media device: %d\n", ret);
        goto err_md;
    }
    ret = fimc_md_get_clocks(fmd);
    if (ret)
        goto err_clk;

    fmd->user_subdev_api = false;

    /* Protect the media graph while we're registering entities */
    mutex_lock(&fmd->media_dev.graph_mutex);

    ret = fimc_md_register_platform_entities(fmd);
    if (ret)
        goto err_unlock;

    if (pdev->dev.platform_data) {
        ret = fimc_md_register_sensor_entities(fmd);
        if (ret)
            goto err_unlock;
    }
    ret = fimc_md_create_links(fmd);
    if (ret)
        goto err_unlock;
    ret = v4l2_device_register_subdev_nodes(&fmd->v4l2_dev);
    if (ret)
        goto err_unlock;

    ret = device_create_file(&pdev->dev, &dev_attr_subdev_conf_mode);
    if (ret)
        goto err_unlock;

    platform_set_drvdata(pdev, fmd);
    mutex_unlock(&fmd->media_dev.graph_mutex);
    return 0;

err_unlock:
    mutex_unlock(&fmd->media_dev.graph_mutex);
err_clk:
    media_device_unregister(&fmd->media_dev);
    fimc_md_put_clocks(fmd);
    fimc_md_unregister_entities(fmd);
err_md:
    v4l2_device_unregister(&fmd->v4l2_dev);
    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);
    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,
    }
};

static 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);
}

static 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 <[email protected]>");
MODULE_DESCRIPTION("S5P FIMC camera host interface/video postprocessor driver");
MODULE_LICENSE("GPL");
MODULE_VERSION("2.0.1");