/* exynos_drm_vidi.c
 *
 * Copyright (C) 2012 Samsung Electronics Co.Ltd
 * Authors:
 *      Inki Dae <inki.dae@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 <drm/drmP.h>

#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/component.h>

#include <drm/exynos_drm.h>

#include <drm/drm_edid.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_atomic_helper.h>

#include "exynos_drm_drv.h"
#include "exynos_drm_crtc.h"
#include "exynos_drm_fb.h"
#include "exynos_drm_plane.h"
#include "exynos_drm_vidi.h"

/* vidi has totally three virtual windows. */
#define WINDOWS_NR              3

#define ctx_from_connector(c)   container_of(c, struct vidi_context, \
                                        connector)

struct vidi_context {
        struct drm_encoder              encoder;
        struct platform_device          *pdev;
        struct drm_device               *drm_dev;
        struct exynos_drm_crtc          *crtc;
        struct drm_connector            connector;
        struct exynos_drm_plane         planes[WINDOWS_NR];
        struct edid                     *raw_edid;
        unsigned int                    clkdiv;
        unsigned long                   irq_flags;
        unsigned int                    connected;
        bool                            vblank_on;
        bool                            suspended;
        bool                            direct_vblank;
        struct work_struct              work;
        struct mutex                    lock;
        int                             pipe;
};

static inline struct vidi_context *encoder_to_vidi(struct drm_encoder *e)
{
        return container_of(e, struct vidi_context, encoder);
}

static const char fake_edid_info[] = {
        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x4c, 0x2d, 0x05, 0x05,
        0x00, 0x00, 0x00, 0x00, 0x30, 0x12, 0x01, 0x03, 0x80, 0x10, 0x09, 0x78,
        0x0a, 0xee, 0x91, 0xa3, 0x54, 0x4c, 0x99, 0x26, 0x0f, 0x50, 0x54, 0xbd,
        0xee, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x66, 0x21, 0x50, 0xb0, 0x51, 0x00,
        0x1b, 0x30, 0x40, 0x70, 0x36, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e,
        0x01, 0x1d, 0x00, 0x72, 0x51, 0xd0, 0x1e, 0x20, 0x6e, 0x28, 0x55, 0x00,
        0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x18,
        0x4b, 0x1a, 0x44, 0x17, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
        0x00, 0x00, 0x00, 0xfc, 0x00, 0x53, 0x41, 0x4d, 0x53, 0x55, 0x4e, 0x47,
        0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x01, 0xbc, 0x02, 0x03, 0x1e, 0xf1,
        0x46, 0x84, 0x05, 0x03, 0x10, 0x20, 0x22, 0x23, 0x09, 0x07, 0x07, 0x83,
        0x01, 0x00, 0x00, 0xe2, 0x00, 0x0f, 0x67, 0x03, 0x0c, 0x00, 0x10, 0x00,
        0xb8, 0x2d, 0x01, 0x1d, 0x80, 0x18, 0x71, 0x1c, 0x16, 0x20, 0x58, 0x2c,
        0x25, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x9e, 0x8c, 0x0a, 0xd0, 0x8a,
        0x20, 0xe0, 0x2d, 0x10, 0x10, 0x3e, 0x96, 0x00, 0xa0, 0x5a, 0x00, 0x00,
        0x00, 0x18, 0x02, 0x3a, 0x80, 0x18, 0x71, 0x38, 0x2d, 0x40, 0x58, 0x2c,
        0x45, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x06
};

static const uint32_t formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
        DRM_FORMAT_NV12,
};

static const enum drm_plane_type vidi_win_types[WINDOWS_NR] = {
        DRM_PLANE_TYPE_PRIMARY,
        DRM_PLANE_TYPE_OVERLAY,
        DRM_PLANE_TYPE_CURSOR,
};

static int vidi_enable_vblank(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        if (ctx->suspended)
                return -EPERM;

        if (!test_and_set_bit(0, &ctx->irq_flags))
                ctx->vblank_on = true;

        ctx->direct_vblank = true;

        /*
         * in case of page flip request, vidi_finish_pageflip function
         * will not be called because direct_vblank is true and then
         * that function will be called by crtc_ops->update_plane callback
         */
        schedule_work(&ctx->work);

        return 0;
}

static void vidi_disable_vblank(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        if (ctx->suspended)
                return;

        if (test_and_clear_bit(0, &ctx->irq_flags))
                ctx->vblank_on = false;
}

static void vidi_update_plane(struct exynos_drm_crtc *crtc,
                              struct exynos_drm_plane *plane)
{
        struct drm_plane_state *state = plane->base.state;
        struct vidi_context *ctx = crtc->ctx;
        dma_addr_t addr;

        if (ctx->suspended)
                return;

        addr = exynos_drm_fb_dma_addr(state->fb, 0);
        DRM_DEBUG_KMS("dma_addr = %pad\n", &addr);

        if (ctx->vblank_on)
                schedule_work(&ctx->work);
}

static void vidi_enable(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        mutex_lock(&ctx->lock);

        ctx->suspended = false;

        /* if vblank was enabled status, enable it again. */
        if (test_and_clear_bit(0, &ctx->irq_flags))
                vidi_enable_vblank(ctx->crtc);

        mutex_unlock(&ctx->lock);
}

static void vidi_disable(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        mutex_lock(&ctx->lock);

        ctx->suspended = true;

        mutex_unlock(&ctx->lock);
}

static int vidi_ctx_initialize(struct vidi_context *ctx,
                        struct drm_device *drm_dev)
{
        struct exynos_drm_private *priv = drm_dev->dev_private;

        ctx->drm_dev = drm_dev;
        ctx->pipe = priv->pipe++;

        return 0;
}

static const struct exynos_drm_crtc_ops vidi_crtc_ops = {
        .enable = vidi_enable,
        .disable = vidi_disable,
        .enable_vblank = vidi_enable_vblank,
        .disable_vblank = vidi_disable_vblank,
        .update_plane = vidi_update_plane,
};

static void vidi_fake_vblank_handler(struct work_struct *work)
{
        struct vidi_context *ctx = container_of(work, struct vidi_context,
                                        work);
        int win;

        if (ctx->pipe < 0)
                return;

        /* refresh rate is about 50Hz. */
        usleep_range(16000, 20000);

        mutex_lock(&ctx->lock);

        if (ctx->direct_vblank) {
                drm_crtc_handle_vblank(&ctx->crtc->base);
                ctx->direct_vblank = false;
                mutex_unlock(&ctx->lock);
                return;
        }

        mutex_unlock(&ctx->lock);

        for (win = 0 ; win < WINDOWS_NR ; win++) {
                struct exynos_drm_plane *plane = &ctx->planes[win];

                if (!plane->pending_fb)
                        continue;

                exynos_drm_crtc_finish_update(ctx->crtc, plane);
        }
}

static ssize_t vidi_show_connection(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        int rc;

        mutex_lock(&ctx->lock);

        rc = sprintf(buf, "%d\n", ctx->connected);

        mutex_unlock(&ctx->lock);

        return rc;
}

static ssize_t vidi_store_connection(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t len)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        int ret;

        ret = kstrtoint(buf, 0, &ctx->connected);
        if (ret)
                return ret;

        if (ctx->connected > 1)
                return -EINVAL;

        /* use fake edid data for test. */
        if (!ctx->raw_edid)
                ctx->raw_edid = (struct edid *)fake_edid_info;

        /* if raw_edid isn't same as fake data then it can't be tested. */
        if (ctx->raw_edid != (struct edid *)fake_edid_info) {
                DRM_DEBUG_KMS("edid data is not fake data.\n");
                return -EINVAL;
        }

        DRM_DEBUG_KMS("requested connection.\n");

        drm_helper_hpd_irq_event(ctx->drm_dev);

        return len;
}

static DEVICE_ATTR(connection, 0644, vidi_show_connection,
                        vidi_store_connection);

int vidi_connection_ioctl(struct drm_device *drm_dev, void *data,
                                struct drm_file *file_priv)
{
        struct vidi_context *ctx = dev_get_drvdata(drm_dev->dev);
        struct drm_exynos_vidi_connection *vidi = data;

        if (!vidi) {
                DRM_DEBUG_KMS("user data for vidi is null.\n");
                return -EINVAL;
        }

        if (vidi->connection > 1) {
                DRM_DEBUG_KMS("connection should be 0 or 1.\n");
                return -EINVAL;
        }

        if (ctx->connected == vidi->connection) {
                DRM_DEBUG_KMS("same connection request.\n");
                return -EINVAL;
        }

        if (vidi->connection) {
                struct edid *raw_edid;

                raw_edid = (struct edid *)(unsigned long)vidi->edid;
                if (!drm_edid_is_valid(raw_edid)) {
                        DRM_DEBUG_KMS("edid data is invalid.\n");
                        return -EINVAL;
                }
                ctx->raw_edid = drm_edid_duplicate(raw_edid);
                if (!ctx->raw_edid) {
                        DRM_DEBUG_KMS("failed to allocate raw_edid.\n");
                        return -ENOMEM;
                }
        } else {
                /*
                 * with connection = 0, free raw_edid
                 * only if raw edid data isn't same as fake data.
                 */
                if (ctx->raw_edid && ctx->raw_edid !=
                                (struct edid *)fake_edid_info) {
                        kfree(ctx->raw_edid);
                        ctx->raw_edid = NULL;
                }
        }

        ctx->connected = vidi->connection;
        drm_helper_hpd_irq_event(ctx->drm_dev);

        return 0;
}

static enum drm_connector_status vidi_detect(struct drm_connector *connector,
                        bool force)
{
        struct vidi_context *ctx = ctx_from_connector(connector);

        /*
         * connection request would come from user side
         * to do hotplug through specific ioctl.
         */
        return ctx->connected ? connector_status_connected :
                        connector_status_disconnected;
}

static void vidi_connector_destroy(struct drm_connector *connector)
{
}

static const struct drm_connector_funcs vidi_connector_funcs = {
        .dpms = drm_atomic_helper_connector_dpms,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .detect = vidi_detect,
        .destroy = vidi_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int vidi_get_modes(struct drm_connector *connector)
{
        struct vidi_context *ctx = ctx_from_connector(connector);
        struct edid *edid;
        int edid_len;

        /*
         * the edid data comes from user side and it would be set
         * to ctx->raw_edid through specific ioctl.
         */
        if (!ctx->raw_edid) {
                DRM_DEBUG_KMS("raw_edid is null.\n");
                return -EFAULT;
        }

        edid_len = (1 + ctx->raw_edid->extensions) * EDID_LENGTH;
        edid = kmemdup(ctx->raw_edid, edid_len, GFP_KERNEL);
        if (!edid) {
                DRM_DEBUG_KMS("failed to allocate edid\n");
                return -ENOMEM;
        }

        drm_mode_connector_update_edid_property(connector, edid);

        return drm_add_edid_modes(connector, edid);
}

static struct drm_encoder *vidi_best_encoder(struct drm_connector *connector)
{
        struct vidi_context *ctx = ctx_from_connector(connector);

        return &ctx->encoder;
}

static const struct drm_connector_helper_funcs vidi_connector_helper_funcs = {
        .get_modes = vidi_get_modes,
        .best_encoder = vidi_best_encoder,
};

static int vidi_create_connector(struct drm_encoder *encoder)
{
        struct vidi_context *ctx = encoder_to_vidi(encoder);
        struct drm_connector *connector = &ctx->connector;
        int ret;

        connector->polled = DRM_CONNECTOR_POLL_HPD;

        ret = drm_connector_init(ctx->drm_dev, connector,
                        &vidi_connector_funcs, DRM_MODE_CONNECTOR_VIRTUAL);
        if (ret) {
                DRM_ERROR("Failed to initialize connector with drm\n");
                return ret;
        }

        drm_connector_helper_add(connector, &vidi_connector_helper_funcs);
        drm_connector_register(connector);
        drm_mode_connector_attach_encoder(connector, encoder);

        return 0;
}

static void exynos_vidi_mode_set(struct drm_encoder *encoder,
                               struct drm_display_mode *mode,
                               struct drm_display_mode *adjusted_mode)
{
}

static void exynos_vidi_enable(struct drm_encoder *encoder)
{
}

static void exynos_vidi_disable(struct drm_encoder *encoder)
{
}

static const struct drm_encoder_helper_funcs exynos_vidi_encoder_helper_funcs = {
        .mode_set = exynos_vidi_mode_set,
        .enable = exynos_vidi_enable,
        .disable = exynos_vidi_disable,
};

static const struct drm_encoder_funcs exynos_vidi_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
};

static int vidi_bind(struct device *dev, struct device *master, void *data)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        struct drm_device *drm_dev = data;
        struct drm_encoder *encoder = &ctx->encoder;
        struct exynos_drm_plane *exynos_plane;
        struct exynos_drm_plane_config plane_config = { 0 };
        unsigned int i;
        int pipe, ret;

        vidi_ctx_initialize(ctx, drm_dev);

        plane_config.pixel_formats = formats;
        plane_config.num_pixel_formats = ARRAY_SIZE(formats);

        for (i = 0; i < WINDOWS_NR; i++) {
                plane_config.zpos = i;
                plane_config.type = vidi_win_types[i];

                ret = exynos_plane_init(drm_dev, &ctx->planes[i], i,
                                        1 << ctx->pipe, &plane_config);
                if (ret)
                        return ret;
        }

        exynos_plane = &ctx->planes[DEFAULT_WIN];
        ctx->crtc = exynos_drm_crtc_create(drm_dev, &exynos_plane->base,
                                           ctx->pipe, EXYNOS_DISPLAY_TYPE_VIDI,
                                           &vidi_crtc_ops, ctx);
        if (IS_ERR(ctx->crtc)) {
                DRM_ERROR("failed to create crtc.\n");
                return PTR_ERR(ctx->crtc);
        }

        pipe = exynos_drm_crtc_get_pipe_from_type(drm_dev,
                                                  EXYNOS_DISPLAY_TYPE_VIDI);
        if (pipe < 0)
                return pipe;

        encoder->possible_crtcs = 1 << pipe;

        DRM_DEBUG_KMS("possible_crtcs = 0x%x\n", encoder->possible_crtcs);

        drm_encoder_init(drm_dev, encoder, &exynos_vidi_encoder_funcs,
                         DRM_MODE_ENCODER_TMDS, NULL);

        drm_encoder_helper_add(encoder, &exynos_vidi_encoder_helper_funcs);

        ret = vidi_create_connector(encoder);
        if (ret) {
                DRM_ERROR("failed to create connector ret = %d\n", ret);
                drm_encoder_cleanup(encoder);
                return ret;
        }

        return 0;
}


static void vidi_unbind(struct device *dev, struct device *master, void *data)
{
}

static const struct component_ops vidi_component_ops = {
        .bind   = vidi_bind,
        .unbind = vidi_unbind,
};

static int vidi_probe(struct platform_device *pdev)
{
        struct vidi_context *ctx;
        int ret;

        ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;

        ctx->pdev = pdev;

        INIT_WORK(&ctx->work, vidi_fake_vblank_handler);

        mutex_init(&ctx->lock);

        platform_set_drvdata(pdev, ctx);

        ret = device_create_file(&pdev->dev, &dev_attr_connection);
        if (ret < 0) {
                DRM_ERROR("failed to create connection sysfs.\n");
                return ret;
        }

        ret = component_add(&pdev->dev, &vidi_component_ops);
        if (ret)
                goto err_remove_file;

        return ret;

err_remove_file:
        device_remove_file(&pdev->dev, &dev_attr_connection);

        return ret;
}

static int vidi_remove(struct platform_device *pdev)
{
        struct vidi_context *ctx = platform_get_drvdata(pdev);

        if (ctx->raw_edid != (struct edid *)fake_edid_info) {
                kfree(ctx->raw_edid);
                ctx->raw_edid = NULL;

                return -EINVAL;
        }

        component_del(&pdev->dev, &vidi_component_ops);

        return 0;
}

struct platform_driver vidi_driver = {
        .probe          = vidi_probe,
        .remove         = vidi_remove,
        .driver         = {
                .name   = "exynos-drm-vidi",
                .owner  = THIS_MODULE,
        },
};