/*
 * Copyright 2012 Red Hat Inc.
 *
 * 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors: Dave Airlie <airlied@redhat.com>
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/init.h>


#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
#include "ast_drv.h"

static void ast_dirty_update(struct ast_fbdev *afbdev,
                             int x, int y, int width, int height)
{
        int i;
        struct drm_gem_object *obj;
        struct ast_bo *bo;
        int src_offset, dst_offset;
        int bpp = (afbdev->afb.base.bits_per_pixel + 7)/8;
        int ret = -EBUSY;
        bool unmap = false;
        bool store_for_later = false;
        int x2, y2;
        unsigned long flags;

        obj = afbdev->afb.obj;
        bo = gem_to_ast_bo(obj);

        /*
         * try and reserve the BO, if we fail with busy
         * then the BO is being moved and we should
         * store up the damage until later.
         */
        if (drm_can_sleep())
                ret = ast_bo_reserve(bo, true);
        if (ret) {
                if (ret != -EBUSY)
                        return;

                store_for_later = true;
        }

        x2 = x + width - 1;
        y2 = y + height - 1;
        spin_lock_irqsave(&afbdev->dirty_lock, flags);

        if (afbdev->y1 < y)
                y = afbdev->y1;
        if (afbdev->y2 > y2)
                y2 = afbdev->y2;
        if (afbdev->x1 < x)
                x = afbdev->x1;
        if (afbdev->x2 > x2)
                x2 = afbdev->x2;

        if (store_for_later) {
                afbdev->x1 = x;
                afbdev->x2 = x2;
                afbdev->y1 = y;
                afbdev->y2 = y2;
                spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
                return;
        }

        afbdev->x1 = afbdev->y1 = INT_MAX;
        afbdev->x2 = afbdev->y2 = 0;
        spin_unlock_irqrestore(&afbdev->dirty_lock, flags);

        if (!bo->kmap.virtual) {
                ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
                if (ret) {
                        DRM_ERROR("failed to kmap fb updates\n");
                        ast_bo_unreserve(bo);
                        return;
                }
                unmap = true;
        }
        for (i = y; i <= y2; i++) {
                /* assume equal stride for now */
                src_offset = dst_offset = i * afbdev->afb.base.pitches[0] + (x * bpp);
                memcpy_toio(bo->kmap.virtual + src_offset, afbdev->sysram + src_offset, (x2 - x + 1) * bpp);

        }
        if (unmap)
                ttm_bo_kunmap(&bo->kmap);

        ast_bo_unreserve(bo);
}

static void ast_fillrect(struct fb_info *info,
                         const struct fb_fillrect *rect)
{
        struct ast_fbdev *afbdev = info->par;
        drm_fb_helper_sys_fillrect(info, rect);
        ast_dirty_update(afbdev, rect->dx, rect->dy, rect->width,
                         rect->height);
}

static void ast_copyarea(struct fb_info *info,
                         const struct fb_copyarea *area)
{
        struct ast_fbdev *afbdev = info->par;
        drm_fb_helper_sys_copyarea(info, area);
        ast_dirty_update(afbdev, area->dx, area->dy, area->width,
                         area->height);
}

static void ast_imageblit(struct fb_info *info,
                          const struct fb_image *image)
{
        struct ast_fbdev *afbdev = info->par;
        drm_fb_helper_sys_imageblit(info, image);
        ast_dirty_update(afbdev, image->dx, image->dy, image->width,
                         image->height);
}

static struct fb_ops astfb_ops = {
        .owner = THIS_MODULE,
        .fb_check_var = drm_fb_helper_check_var,
        .fb_set_par = drm_fb_helper_set_par,
        .fb_fillrect = ast_fillrect,
        .fb_copyarea = ast_copyarea,
        .fb_imageblit = ast_imageblit,
        .fb_pan_display = drm_fb_helper_pan_display,
        .fb_blank = drm_fb_helper_blank,
        .fb_setcmap = drm_fb_helper_setcmap,
        .fb_debug_enter = drm_fb_helper_debug_enter,
        .fb_debug_leave = drm_fb_helper_debug_leave,
};

static int astfb_create_object(struct ast_fbdev *afbdev,
                               const struct drm_mode_fb_cmd2 *mode_cmd,
                               struct drm_gem_object **gobj_p)
{
        struct drm_device *dev = afbdev->helper.dev;
        u32 size;
        struct drm_gem_object *gobj;
        int ret = 0;

        size = mode_cmd->pitches[0] * mode_cmd->height;
        ret = ast_gem_create(dev, size, true, &gobj);
        if (ret)
                return ret;

        *gobj_p = gobj;
        return ret;
}

static int astfb_create(struct drm_fb_helper *helper,
                        struct drm_fb_helper_surface_size *sizes)
{
        struct ast_fbdev *afbdev =
                container_of(helper, struct ast_fbdev, helper);
        struct drm_device *dev = afbdev->helper.dev;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct drm_framebuffer *fb;
        struct fb_info *info;
        int size, ret;
        void *sysram;
        struct drm_gem_object *gobj = NULL;
        struct ast_bo *bo = NULL;
        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;
        mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7)/8);

        mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                          sizes->surface_depth);

        size = mode_cmd.pitches[0] * mode_cmd.height;

        ret = astfb_create_object(afbdev, &mode_cmd, &gobj);
        if (ret) {
                DRM_ERROR("failed to create fbcon backing object %d\n", ret);
                return ret;
        }
        bo = gem_to_ast_bo(gobj);

        sysram = vmalloc(size);
        if (!sysram)
                return -ENOMEM;

        info = drm_fb_helper_alloc_fbi(helper);
        if (IS_ERR(info)) {
                ret = PTR_ERR(info);
                goto err_free_vram;
        }
        info->par = afbdev;

        ret = ast_framebuffer_init(dev, &afbdev->afb, &mode_cmd, gobj);
        if (ret)
                goto err_release_fbi;

        afbdev->sysram = sysram;
        afbdev->size = size;

        fb = &afbdev->afb.base;
        afbdev->helper.fb = fb;

        strcpy(info->fix.id, "astdrmfb");

        info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT;
        info->fbops = &astfb_ops;

        info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
        info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);

        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
        drm_fb_helper_fill_var(info, &afbdev->helper, sizes->fb_width, sizes->fb_height);

        info->screen_base = sysram;
        info->screen_size = size;

        info->pixmap.flags = FB_PIXMAP_SYSTEM;

        DRM_DEBUG_KMS("allocated %dx%d\n",
                      fb->width, fb->height);

        return 0;

err_release_fbi:
        drm_fb_helper_release_fbi(helper);
err_free_vram:
        vfree(afbdev->sysram);
        return ret;
}

static void ast_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
                               u16 blue, int regno)
{
        struct ast_crtc *ast_crtc = to_ast_crtc(crtc);
        ast_crtc->lut_r[regno] = red >> 8;
        ast_crtc->lut_g[regno] = green >> 8;
        ast_crtc->lut_b[regno] = blue >> 8;
}

static void ast_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
                               u16 *blue, int regno)
{
        struct ast_crtc *ast_crtc = to_ast_crtc(crtc);
        *red = ast_crtc->lut_r[regno] << 8;
        *green = ast_crtc->lut_g[regno] << 8;
        *blue = ast_crtc->lut_b[regno] << 8;
}

static const struct drm_fb_helper_funcs ast_fb_helper_funcs = {
        .gamma_set = ast_fb_gamma_set,
        .gamma_get = ast_fb_gamma_get,
        .fb_probe = astfb_create,
};

static void ast_fbdev_destroy(struct drm_device *dev,
                              struct ast_fbdev *afbdev)
{
        struct ast_framebuffer *afb = &afbdev->afb;

        drm_fb_helper_unregister_fbi(&afbdev->helper);
        drm_fb_helper_release_fbi(&afbdev->helper);

        if (afb->obj) {
                drm_gem_object_unreference_unlocked(afb->obj);
                afb->obj = NULL;
        }
        drm_fb_helper_fini(&afbdev->helper);

        vfree(afbdev->sysram);
        drm_framebuffer_unregister_private(&afb->base);
        drm_framebuffer_cleanup(&afb->base);
}

int ast_fbdev_init(struct drm_device *dev)
{
        struct ast_private *ast = dev->dev_private;
        struct ast_fbdev *afbdev;
        int ret;

        afbdev = kzalloc(sizeof(struct ast_fbdev), GFP_KERNEL);
        if (!afbdev)
                return -ENOMEM;

        ast->fbdev = afbdev;
        spin_lock_init(&afbdev->dirty_lock);

        drm_fb_helper_prepare(dev, &afbdev->helper, &ast_fb_helper_funcs);

        ret = drm_fb_helper_init(dev, &afbdev->helper,
                                 1, 1);
        if (ret)
                goto free;

        ret = drm_fb_helper_single_add_all_connectors(&afbdev->helper);
        if (ret)
                goto fini;

        /* disable all the possible outputs/crtcs before entering KMS mode */
        drm_helper_disable_unused_functions(dev);

        ret = drm_fb_helper_initial_config(&afbdev->helper, 32);
        if (ret)
                goto fini;

        return 0;

fini:
        drm_fb_helper_fini(&afbdev->helper);
free:
        kfree(afbdev);
        return ret;
}

void ast_fbdev_fini(struct drm_device *dev)
{
        struct ast_private *ast = dev->dev_private;

        if (!ast->fbdev)
                return;

        ast_fbdev_destroy(dev, ast->fbdev);
        kfree(ast->fbdev);
        ast->fbdev = NULL;
}

void ast_fbdev_set_suspend(struct drm_device *dev, int state)
{
        struct ast_private *ast = dev->dev_private;

        if (!ast->fbdev)
                return;

        drm_fb_helper_set_suspend(&ast->fbdev->helper, state);
}

void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr)
{
        ast->fbdev->helper.fbdev->fix.smem_start =
                ast->fbdev->helper.fbdev->apertures->ranges[0].base + gpu_addr;
        ast->fbdev->helper.fbdev->fix.smem_len = ast->vram_size - gpu_addr;
}