/*
 * vsp1_lif.c  --  R-Car VSP1 LCD Controller Interface
 *
 * Copyright (C) 2013 Renesas Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.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/device.h>
#include <linux/gfp.h>

#include <media/v4l2-subdev.h>

#include "vsp1.h"
#include "vsp1_lif.h"

#define LIF_MIN_SIZE                            2U
#define LIF_MAX_SIZE                            2048U

/* -----------------------------------------------------------------------------
 * Device Access
 */

static inline u32 vsp1_lif_read(struct vsp1_lif *lif, u32 reg)
{
        return vsp1_read(lif->entity.vsp1, reg);
}

static inline void vsp1_lif_write(struct vsp1_lif *lif, u32 reg, u32 data)
{
        vsp1_write(lif->entity.vsp1, reg, data);
}

/* -----------------------------------------------------------------------------
 * V4L2 Subdevice Core Operations
 */

static int lif_s_stream(struct v4l2_subdev *subdev, int enable)
{
        const struct v4l2_mbus_framefmt *format;
        struct vsp1_lif *lif = to_lif(subdev);
        unsigned int hbth = 1300;
        unsigned int obth = 400;
        unsigned int lbth = 200;

        if (!enable) {
                vsp1_lif_write(lif, VI6_LIF_CTRL, 0);
                return 0;
        }

        format = &lif->entity.formats[LIF_PAD_SOURCE];

        obth = min(obth, (format->width + 1) / 2 * format->height - 4);

        vsp1_lif_write(lif, VI6_LIF_CSBTH,
                        (hbth << VI6_LIF_CSBTH_HBTH_SHIFT) |
                        (lbth << VI6_LIF_CSBTH_LBTH_SHIFT));

        vsp1_lif_write(lif, VI6_LIF_CTRL,
                        (obth << VI6_LIF_CTRL_OBTH_SHIFT) |
                        (format->code == 0 ? VI6_LIF_CTRL_CFMT : 0) |
                        VI6_LIF_CTRL_REQSEL | VI6_LIF_CTRL_LIF_EN);

        return 0;
}

/* -----------------------------------------------------------------------------
 * V4L2 Subdevice Pad Operations
 */

static int lif_enum_mbus_code(struct v4l2_subdev *subdev,
                              struct v4l2_subdev_fh *fh,
                              struct v4l2_subdev_mbus_code_enum *code)
{
        static const unsigned int codes[] = {
                V4L2_MBUS_FMT_ARGB8888_1X32,
                V4L2_MBUS_FMT_AYUV8_1X32,
        };

        if (code->pad == LIF_PAD_SINK) {
                if (code->index >= ARRAY_SIZE(codes))
                        return -EINVAL;

                code->code = codes[code->index];
        } else {
                struct v4l2_mbus_framefmt *format;

                /* The LIF can't perform format conversion, the sink format is
                 * always identical to the source format.
                 */
                if (code->index)
                        return -EINVAL;

                format = v4l2_subdev_get_try_format(fh, LIF_PAD_SINK);
                code->code = format->code;
        }

        return 0;
}

static int lif_enum_frame_size(struct v4l2_subdev *subdev,
                               struct v4l2_subdev_fh *fh,
                               struct v4l2_subdev_frame_size_enum *fse)
{
        struct v4l2_mbus_framefmt *format;

        format = v4l2_subdev_get_try_format(fh, LIF_PAD_SINK);

        if (fse->index || fse->code != format->code)
                return -EINVAL;

        if (fse->pad == LIF_PAD_SINK) {
                fse->min_width = LIF_MIN_SIZE;
                fse->max_width = LIF_MAX_SIZE;
                fse->min_height = LIF_MIN_SIZE;
                fse->max_height = LIF_MAX_SIZE;
        } else {
                fse->min_width = format->width;
                fse->max_width = format->width;
                fse->min_height = format->height;
                fse->max_height = format->height;
        }

        return 0;
}

static int lif_get_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
                          struct v4l2_subdev_format *fmt)
{
        struct vsp1_lif *lif = to_lif(subdev);

        fmt->format = *vsp1_entity_get_pad_format(&lif->entity, fh, fmt->pad,
                                                  fmt->which);

        return 0;
}

static int lif_set_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
                          struct v4l2_subdev_format *fmt)
{
        struct vsp1_lif *lif = to_lif(subdev);
        struct v4l2_mbus_framefmt *format;

        /* Default to YUV if the requested format is not supported. */
        if (fmt->format.code != V4L2_MBUS_FMT_ARGB8888_1X32 &&
            fmt->format.code != V4L2_MBUS_FMT_AYUV8_1X32)
                fmt->format.code = V4L2_MBUS_FMT_AYUV8_1X32;

        format = vsp1_entity_get_pad_format(&lif->entity, fh, fmt->pad,
                                            fmt->which);

        if (fmt->pad == LIF_PAD_SOURCE) {
                /* The LIF source format is always identical to its sink
                 * format.
                 */
                fmt->format = *format;
                return 0;
        }

        format->code = fmt->format.code;
        format->width = clamp_t(unsigned int, fmt->format.width,
                                LIF_MIN_SIZE, LIF_MAX_SIZE);
        format->height = clamp_t(unsigned int, fmt->format.height,
                                 LIF_MIN_SIZE, LIF_MAX_SIZE);
        format->field = V4L2_FIELD_NONE;
        format->colorspace = V4L2_COLORSPACE_SRGB;

        fmt->format = *format;

        /* Propagate the format to the source pad. */
        format = vsp1_entity_get_pad_format(&lif->entity, fh, LIF_PAD_SOURCE,
                                            fmt->which);
        *format = fmt->format;

        return 0;
}

/* -----------------------------------------------------------------------------
 * V4L2 Subdevice Operations
 */

static struct v4l2_subdev_video_ops lif_video_ops = {
        .s_stream = lif_s_stream,
};

static struct v4l2_subdev_pad_ops lif_pad_ops = {
        .enum_mbus_code = lif_enum_mbus_code,
        .enum_frame_size = lif_enum_frame_size,
        .get_fmt = lif_get_format,
        .set_fmt = lif_set_format,
};

static struct v4l2_subdev_ops lif_ops = {
        .video  = &lif_video_ops,
        .pad    = &lif_pad_ops,
};

/* -----------------------------------------------------------------------------
 * Initialization and Cleanup
 */

struct vsp1_lif *vsp1_lif_create(struct vsp1_device *vsp1)
{
        struct v4l2_subdev *subdev;
        struct vsp1_lif *lif;
        int ret;

        lif = devm_kzalloc(vsp1->dev, sizeof(*lif), GFP_KERNEL);
        if (lif == NULL)
                return ERR_PTR(-ENOMEM);

        lif->entity.type = VSP1_ENTITY_LIF;
        lif->entity.id = VI6_DPR_NODE_LIF;

        ret = vsp1_entity_init(vsp1, &lif->entity, 2);
        if (ret < 0)
                return ERR_PTR(ret);

        /* Initialize the V4L2 subdev. */
        subdev = &lif->entity.subdev;
        v4l2_subdev_init(subdev, &lif_ops);

        subdev->entity.ops = &vsp1_media_ops;
        subdev->internal_ops = &vsp1_subdev_internal_ops;
        snprintf(subdev->name, sizeof(subdev->name), "%s lif",
                 dev_name(vsp1->dev));
        v4l2_set_subdevdata(subdev, lif);
        subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

        vsp1_entity_init_formats(subdev, NULL);

        return lif;
}