/*
 * Copyright (C) 2015 Red Hat, Inc.
 * All Rights Reserved.
 *
 * Authors:
 *    Dave Airlie
 *    Alon Levy
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>
#include <drm/drm_vblank_helper.h>

#include "virtgpu_drv.h"

#define XRES_MIN    32
#define YRES_MIN    32

#define XRES_DEF  1024
#define YRES_DEF   768

#define XRES_MAX  8192
#define YRES_MAX  8192

#define drm_connector_to_virtio_gpu_output(x) \
        container_of(x, struct virtio_gpu_output, conn)

static const struct drm_crtc_funcs virtio_gpu_crtc_funcs = {
        .set_config             = drm_atomic_helper_set_config,
        .destroy                = drm_crtc_cleanup,

        .page_flip              = drm_atomic_helper_page_flip,
        .reset                  = drm_atomic_helper_crtc_reset,
        .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
        .atomic_destroy_state   = drm_atomic_helper_crtc_destroy_state,
        DRM_CRTC_VBLANK_TIMER_FUNCS,
};

static const struct drm_framebuffer_funcs virtio_gpu_fb_funcs = {
        .create_handle = drm_gem_fb_create_handle,
        .destroy = drm_gem_fb_destroy,
        .dirty = drm_atomic_helper_dirtyfb,
};

static int
virtio_gpu_framebuffer_init(struct drm_device *dev,
                            struct virtio_gpu_framebuffer *vgfb,
                            const struct drm_format_info *info,
                            const struct drm_mode_fb_cmd2 *mode_cmd,
                            struct drm_gem_object *obj)
{
        int ret;

        vgfb->base.obj[0] = obj;

        drm_helper_mode_fill_fb_struct(dev, &vgfb->base, info, mode_cmd);

        ret = drm_framebuffer_init(dev, &vgfb->base, &virtio_gpu_fb_funcs);
        if (ret) {
                vgfb->base.obj[0] = NULL;
                return ret;
        }
        return 0;
}

static void virtio_gpu_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct virtio_gpu_device *vgdev = dev->dev_private;
        struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);

        virtio_gpu_cmd_set_scanout(vgdev, output->index, 0,
                                   crtc->mode.hdisplay,
                                   crtc->mode.vdisplay, 0, 0);
        virtio_gpu_notify(vgdev);
}

static void virtio_gpu_crtc_atomic_enable(struct drm_crtc *crtc,
                                          struct drm_atomic_state *state)
{
        drm_crtc_vblank_on(crtc);
}

static void virtio_gpu_crtc_atomic_disable(struct drm_crtc *crtc,
                                           struct drm_atomic_state *state)
{
        struct drm_device *dev = crtc->dev;
        struct virtio_gpu_device *vgdev = dev->dev_private;
        struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);

        drm_crtc_vblank_off(crtc);

        virtio_gpu_cmd_set_scanout(vgdev, output->index, 0, 0, 0, 0, 0);
        virtio_gpu_notify(vgdev);
}

static int virtio_gpu_crtc_atomic_check(struct drm_crtc *crtc,
                                        struct drm_atomic_state *state)
{
        return 0;
}

static void virtio_gpu_crtc_atomic_flush(struct drm_crtc *crtc,
                                         struct drm_atomic_state *state)
{
        struct drm_device *dev = crtc->dev;
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
        struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);
        struct drm_pending_vblank_event *event;

        /*
         * virtio-gpu can't do modeset and plane update operations
         * independent from each other.  So the actual modeset happens
         * in the plane update callback, and here we just check
         * whenever we must force the modeset.
         */
        if (drm_atomic_crtc_needs_modeset(crtc_state))
                output->needs_modeset = true;

        spin_lock_irq(&dev->event_lock);

        event = crtc_state->event;
        crtc_state->event = NULL;

        if (event) {
                if (drm_crtc_vblank_get(crtc) == 0)
                        drm_crtc_arm_vblank_event(crtc, event);
                else
                        drm_crtc_send_vblank_event(crtc, event);
        }

        spin_unlock_irq(&dev->event_lock);
}

static const struct drm_crtc_helper_funcs virtio_gpu_crtc_helper_funcs = {
        .mode_set_nofb = virtio_gpu_crtc_mode_set_nofb,
        .atomic_check  = virtio_gpu_crtc_atomic_check,
        .atomic_flush  = virtio_gpu_crtc_atomic_flush,
        .atomic_enable = virtio_gpu_crtc_atomic_enable,
        .atomic_disable = virtio_gpu_crtc_atomic_disable,
};

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

static void virtio_gpu_enc_enable(struct drm_encoder *encoder)
{
}

static void virtio_gpu_enc_disable(struct drm_encoder *encoder)
{
}

static int virtio_gpu_conn_get_modes(struct drm_connector *connector)
{
        struct virtio_gpu_output *output =
                drm_connector_to_virtio_gpu_output(connector);
        struct drm_display_mode *mode = NULL;
        int count, width, height;

        count = drm_edid_connector_add_modes(connector);
        if (count)
                return count;

        width  = le32_to_cpu(output->info.r.width);
        height = le32_to_cpu(output->info.r.height);
        count = drm_add_modes_noedid(connector, XRES_MAX, YRES_MAX);

        if (width == 0 || height == 0) {
                drm_set_preferred_mode(connector, XRES_DEF, YRES_DEF);
        } else {
                DRM_DEBUG("add mode: %dx%d\n", width, height);
                mode = drm_cvt_mode(connector->dev, width, height, 60,
                                    false, false, false);
                if (!mode)
                        return count;
                mode->type |= DRM_MODE_TYPE_PREFERRED;
                drm_mode_probed_add(connector, mode);
                count++;
        }

        return count;
}

static enum drm_mode_status virtio_gpu_conn_mode_valid(struct drm_connector *connector,
                                      const struct drm_display_mode *mode)
{
        struct virtio_gpu_output *output =
                drm_connector_to_virtio_gpu_output(connector);
        int width, height;

        width  = le32_to_cpu(output->info.r.width);
        height = le32_to_cpu(output->info.r.height);

        if (!(mode->type & DRM_MODE_TYPE_PREFERRED))
                return MODE_OK;
        if (mode->hdisplay == XRES_DEF && mode->vdisplay == YRES_DEF)
                return MODE_OK;
        if (mode->hdisplay <= width  && mode->hdisplay >= width - 16 &&
            mode->vdisplay <= height && mode->vdisplay >= height - 16)
                return MODE_OK;

        DRM_DEBUG("del mode: %dx%d\n", mode->hdisplay, mode->vdisplay);
        return MODE_BAD;
}

static const struct drm_encoder_helper_funcs virtio_gpu_enc_helper_funcs = {
        .mode_set   = virtio_gpu_enc_mode_set,
        .enable     = virtio_gpu_enc_enable,
        .disable    = virtio_gpu_enc_disable,
};

static const struct drm_connector_helper_funcs virtio_gpu_conn_helper_funcs = {
        .get_modes    = virtio_gpu_conn_get_modes,
        .mode_valid   = virtio_gpu_conn_mode_valid,
};

static enum drm_connector_status virtio_gpu_conn_detect(
                        struct drm_connector *connector,
                        bool force)
{
        struct virtio_gpu_output *output =
                drm_connector_to_virtio_gpu_output(connector);

        if (output->info.enabled)
                return connector_status_connected;
        else
                return connector_status_disconnected;
}

static void virtio_gpu_conn_destroy(struct drm_connector *connector)
{
        drm_connector_unregister(connector);
        drm_connector_cleanup(connector);
}

static const struct drm_connector_funcs virtio_gpu_connector_funcs = {
        .detect = virtio_gpu_conn_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = virtio_gpu_conn_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 vgdev_output_init(struct virtio_gpu_device *vgdev, int index)
{
        struct drm_device *dev = vgdev->ddev;
        struct virtio_gpu_output *output = vgdev->outputs + index;
        struct drm_connector *connector = &output->conn;
        struct drm_encoder *encoder = &output->enc;
        struct drm_crtc *crtc = &output->crtc;
        struct drm_plane *primary, *cursor;
        int ret;

        output->index = index;
        if (index == 0) {
                output->info.enabled = cpu_to_le32(true);
                output->info.r.width = cpu_to_le32(XRES_DEF);
                output->info.r.height = cpu_to_le32(YRES_DEF);
        }

        primary = virtio_gpu_plane_init(vgdev, DRM_PLANE_TYPE_PRIMARY, index);
        if (IS_ERR(primary))
                return PTR_ERR(primary);
        cursor = virtio_gpu_plane_init(vgdev, DRM_PLANE_TYPE_CURSOR, index);
        if (IS_ERR(cursor))
                return PTR_ERR(cursor);
        ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
                                        &virtio_gpu_crtc_funcs, NULL);
        if (ret)
                return ret;
        drm_crtc_helper_add(crtc, &virtio_gpu_crtc_helper_funcs);

        drm_connector_init(dev, connector, &virtio_gpu_connector_funcs,
                           DRM_MODE_CONNECTOR_VIRTUAL);
        drm_connector_helper_add(connector, &virtio_gpu_conn_helper_funcs);
        if (vgdev->has_edid)
                drm_connector_attach_edid_property(connector);

        drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_VIRTUAL);
        drm_encoder_helper_add(encoder, &virtio_gpu_enc_helper_funcs);
        encoder->possible_crtcs = 1 << index;

        drm_connector_attach_encoder(connector, encoder);
        drm_connector_register(connector);
        return 0;
}

static struct drm_framebuffer *
virtio_gpu_user_framebuffer_create(struct drm_device *dev,
                                   struct drm_file *file_priv,
                                   const struct drm_format_info *info,
                                   const struct drm_mode_fb_cmd2 *mode_cmd)
{
        struct drm_gem_object *obj = NULL;
        struct virtio_gpu_framebuffer *virtio_gpu_fb;
        int ret;

        if (mode_cmd->pixel_format != DRM_FORMAT_HOST_XRGB8888 &&
            mode_cmd->pixel_format != DRM_FORMAT_HOST_ARGB8888)
                return ERR_PTR(-ENOENT);

        /* lookup object associated with res handle */
        obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
        if (!obj)
                return ERR_PTR(-EINVAL);

        virtio_gpu_fb = kzalloc_obj(*virtio_gpu_fb);
        if (virtio_gpu_fb == NULL) {
                drm_gem_object_put(obj);
                return ERR_PTR(-ENOMEM);
        }

        ret = virtio_gpu_framebuffer_init(dev, virtio_gpu_fb, info, mode_cmd, obj);
        if (ret) {
                kfree(virtio_gpu_fb);
                drm_gem_object_put(obj);
                return NULL;
        }

        return &virtio_gpu_fb->base;
}

static const struct drm_mode_config_funcs virtio_gpu_mode_funcs = {
        .fb_create = virtio_gpu_user_framebuffer_create,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev)
{
        int i, ret;

        if (!vgdev->num_scanouts)
                return 0;

        ret = drmm_mode_config_init(vgdev->ddev);
        if (ret)
                return ret;

        vgdev->ddev->mode_config.quirk_addfb_prefer_host_byte_order = true;
        vgdev->ddev->mode_config.funcs = &virtio_gpu_mode_funcs;

        /* modes will be validated against the framebuffer size */
        vgdev->ddev->mode_config.min_width = XRES_MIN;
        vgdev->ddev->mode_config.min_height = YRES_MIN;
        vgdev->ddev->mode_config.max_width = XRES_MAX;
        vgdev->ddev->mode_config.max_height = YRES_MAX;

        vgdev->ddev->mode_config.fb_modifiers_not_supported = true;

        for (i = 0 ; i < vgdev->num_scanouts; ++i)
                vgdev_output_init(vgdev, i);

        ret = drm_vblank_init(vgdev->ddev, vgdev->num_scanouts);
        if (ret)
                return ret;

        drm_mode_config_reset(vgdev->ddev);
        return 0;
}

void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev)
{
        int i;

        if (!vgdev->num_scanouts)
                return;

        for (i = 0 ; i < vgdev->num_scanouts; ++i)
                drm_edid_free(vgdev->outputs[i].drm_edid);
}