/*
 * Copyright © 2007 David Airlie
 *
 * 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 (including the next
 * paragraph) 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 AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *     David Airlie
 */
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fb.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
#include "cikd.h"

#include <drm/drm_fb_helper.h>

#include <linux/vga_switcheroo.h>

/* object hierarchy -
   this contains a helper + a amdgpu fb
   the helper contains a pointer to amdgpu framebuffer baseclass.
*/
struct amdgpu_fbdev {
        struct drm_fb_helper helper;
        struct amdgpu_framebuffer rfb;
        struct amdgpu_device *adev;
};

static struct fb_ops amdgpufb_ops = {
        .owner = THIS_MODULE,
        .fb_check_var = drm_fb_helper_check_var,
        .fb_set_par = drm_fb_helper_set_par,
        .fb_fillrect = drm_fb_helper_cfb_fillrect,
        .fb_copyarea = drm_fb_helper_cfb_copyarea,
        .fb_imageblit = drm_fb_helper_cfb_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,
};


int amdgpu_align_pitch(struct amdgpu_device *adev, int width, int bpp, bool tiled)
{
        int aligned = width;
        int pitch_mask = 0;

        switch (bpp / 8) {
        case 1:
                pitch_mask = 255;
                break;
        case 2:
                pitch_mask = 127;
                break;
        case 3:
        case 4:
                pitch_mask = 63;
                break;
        }

        aligned += pitch_mask;
        aligned &= ~pitch_mask;
        return aligned;
}

static void amdgpufb_destroy_pinned_object(struct drm_gem_object *gobj)
{
        struct amdgpu_bo *rbo = gem_to_amdgpu_bo(gobj);
        int ret;

        ret = amdgpu_bo_reserve(rbo, false);
        if (likely(ret == 0)) {
                amdgpu_bo_kunmap(rbo);
                amdgpu_bo_unpin(rbo);
                amdgpu_bo_unreserve(rbo);
        }
        drm_gem_object_unreference_unlocked(gobj);
}

static int amdgpufb_create_pinned_object(struct amdgpu_fbdev *rfbdev,
                                         struct drm_mode_fb_cmd2 *mode_cmd,
                                         struct drm_gem_object **gobj_p)
{
        struct amdgpu_device *adev = rfbdev->adev;
        struct drm_gem_object *gobj = NULL;
        struct amdgpu_bo *rbo = NULL;
        bool fb_tiled = false; /* useful for testing */
        u32 tiling_flags = 0;
        int ret;
        int aligned_size, size;
        int height = mode_cmd->height;
        u32 bpp, depth;

        drm_fb_get_bpp_depth(mode_cmd->pixel_format, &depth, &bpp);

        /* need to align pitch with crtc limits */
        mode_cmd->pitches[0] = amdgpu_align_pitch(adev, mode_cmd->width, bpp,
                                                  fb_tiled) * ((bpp + 1) / 8);

        height = ALIGN(mode_cmd->height, 8);
        size = mode_cmd->pitches[0] * height;
        aligned_size = ALIGN(size, PAGE_SIZE);
        ret = amdgpu_gem_object_create(adev, aligned_size, 0,
                                       AMDGPU_GEM_DOMAIN_VRAM,
                                       AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED,
                                       true, &gobj);
        if (ret) {
                printk(KERN_ERR "failed to allocate framebuffer (%d)\n",
                       aligned_size);
                return -ENOMEM;
        }
        rbo = gem_to_amdgpu_bo(gobj);

        if (fb_tiled)
                tiling_flags = AMDGPU_TILING_SET(ARRAY_MODE, GRPH_ARRAY_2D_TILED_THIN1);

        ret = amdgpu_bo_reserve(rbo, false);
        if (unlikely(ret != 0))
                goto out_unref;

        if (tiling_flags) {
                ret = amdgpu_bo_set_tiling_flags(rbo,
                                                 tiling_flags);
                if (ret)
                        dev_err(adev->dev, "FB failed to set tiling flags\n");
        }


        ret = amdgpu_bo_pin_restricted(rbo, AMDGPU_GEM_DOMAIN_VRAM, 0, 0, NULL);
        if (ret) {
                amdgpu_bo_unreserve(rbo);
                goto out_unref;
        }
        ret = amdgpu_bo_kmap(rbo, NULL);
        amdgpu_bo_unreserve(rbo);
        if (ret) {
                goto out_unref;
        }

        *gobj_p = gobj;
        return 0;
out_unref:
        amdgpufb_destroy_pinned_object(gobj);
        *gobj_p = NULL;
        return ret;
}

static int amdgpufb_create(struct drm_fb_helper *helper,
                           struct drm_fb_helper_surface_size *sizes)
{
        struct amdgpu_fbdev *rfbdev = (struct amdgpu_fbdev *)helper;
        struct amdgpu_device *adev = rfbdev->adev;
        struct fb_info *info;
        struct drm_framebuffer *fb = NULL;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct drm_gem_object *gobj = NULL;
        struct amdgpu_bo *rbo = NULL;
        int ret;
        unsigned long tmp;

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;

        if (sizes->surface_bpp == 24)
                sizes->surface_bpp = 32;

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

        ret = amdgpufb_create_pinned_object(rfbdev, &mode_cmd, &gobj);
        if (ret) {
                DRM_ERROR("failed to create fbcon object %d\n", ret);
                return ret;
        }

        rbo = gem_to_amdgpu_bo(gobj);

        /* okay we have an object now allocate the framebuffer */
        info = drm_fb_helper_alloc_fbi(helper);
        if (IS_ERR(info)) {
                ret = PTR_ERR(info);
                goto out_unref;
        }

        info->par = rfbdev;
        info->skip_vt_switch = true;

        ret = amdgpu_framebuffer_init(adev->ddev, &rfbdev->rfb, &mode_cmd, gobj);
        if (ret) {
                DRM_ERROR("failed to initialize framebuffer %d\n", ret);
                goto out_destroy_fbi;
        }

        fb = &rfbdev->rfb.base;

        /* setup helper */
        rfbdev->helper.fb = fb;

        memset_io(rbo->kptr, 0x0, amdgpu_bo_size(rbo));

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

        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);

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

        tmp = amdgpu_bo_gpu_offset(rbo) - adev->mc.vram_start;
        info->fix.smem_start = adev->mc.aper_base + tmp;
        info->fix.smem_len = amdgpu_bo_size(rbo);
        info->screen_base = rbo->kptr;
        info->screen_size = amdgpu_bo_size(rbo);

        drm_fb_helper_fill_var(info, &rfbdev->helper, sizes->fb_width, sizes->fb_height);

        /* setup aperture base/size for vesafb takeover */
        info->apertures->ranges[0].base = adev->ddev->mode_config.fb_base;
        info->apertures->ranges[0].size = adev->mc.aper_size;

        /* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */

        if (info->screen_base == NULL) {
                ret = -ENOSPC;
                goto out_destroy_fbi;
        }

        DRM_INFO("fb mappable at 0x%lX\n",  info->fix.smem_start);
        DRM_INFO("vram apper at 0x%lX\n",  (unsigned long)adev->mc.aper_base);
        DRM_INFO("size %lu\n", (unsigned long)amdgpu_bo_size(rbo));
        DRM_INFO("fb depth is %d\n", fb->depth);
        DRM_INFO("   pitch is %d\n", fb->pitches[0]);

        vga_switcheroo_client_fb_set(adev->ddev->pdev, info);
        return 0;

out_destroy_fbi:
        drm_fb_helper_release_fbi(helper);
out_unref:
        if (rbo) {

        }
        if (fb && ret) {
                drm_gem_object_unreference_unlocked(gobj);
                drm_framebuffer_unregister_private(fb);
                drm_framebuffer_cleanup(fb);
                kfree(fb);
        }
        return ret;
}

void amdgpu_fb_output_poll_changed(struct amdgpu_device *adev)
{
        if (adev->mode_info.rfbdev)
                drm_fb_helper_hotplug_event(&adev->mode_info.rfbdev->helper);
}

static int amdgpu_fbdev_destroy(struct drm_device *dev, struct amdgpu_fbdev *rfbdev)
{
        struct amdgpu_framebuffer *rfb = &rfbdev->rfb;

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

        if (rfb->obj) {
                amdgpufb_destroy_pinned_object(rfb->obj);
                rfb->obj = NULL;
        }
        drm_fb_helper_fini(&rfbdev->helper);
        drm_framebuffer_unregister_private(&rfb->base);
        drm_framebuffer_cleanup(&rfb->base);

        return 0;
}

/** Sets the color ramps on behalf of fbcon */
static void amdgpu_crtc_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
                                      u16 blue, int regno)
{
        struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);

        amdgpu_crtc->lut_r[regno] = red >> 6;
        amdgpu_crtc->lut_g[regno] = green >> 6;
        amdgpu_crtc->lut_b[regno] = blue >> 6;
}

/** Gets the color ramps on behalf of fbcon */
static void amdgpu_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
                                      u16 *blue, int regno)
{
        struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);

        *red = amdgpu_crtc->lut_r[regno] << 6;
        *green = amdgpu_crtc->lut_g[regno] << 6;
        *blue = amdgpu_crtc->lut_b[regno] << 6;
}

static const struct drm_fb_helper_funcs amdgpu_fb_helper_funcs = {
        .gamma_set = amdgpu_crtc_fb_gamma_set,
        .gamma_get = amdgpu_crtc_fb_gamma_get,
        .fb_probe = amdgpufb_create,
};

int amdgpu_fbdev_init(struct amdgpu_device *adev)
{
        struct amdgpu_fbdev *rfbdev;
        int bpp_sel = 32;
        int ret;

        /* don't init fbdev on hw without DCE */
        if (!adev->mode_info.mode_config_initialized)
                return 0;

        /* don't init fbdev if there are no connectors */
        if (list_empty(&adev->ddev->mode_config.connector_list))
                return 0;

        /* select 8 bpp console on low vram cards */
        if (adev->mc.real_vram_size <= (32*1024*1024))
                bpp_sel = 8;

        rfbdev = kzalloc(sizeof(struct amdgpu_fbdev), GFP_KERNEL);
        if (!rfbdev)
                return -ENOMEM;

        rfbdev->adev = adev;
        adev->mode_info.rfbdev = rfbdev;

        drm_fb_helper_prepare(adev->ddev, &rfbdev->helper,
                        &amdgpu_fb_helper_funcs);

        ret = drm_fb_helper_init(adev->ddev, &rfbdev->helper,
                                 adev->mode_info.num_crtc,
                                 AMDGPUFB_CONN_LIMIT);
        if (ret) {
                kfree(rfbdev);
                return ret;
        }

        drm_fb_helper_single_add_all_connectors(&rfbdev->helper);

        /* disable all the possible outputs/crtcs before entering KMS mode */
        drm_helper_disable_unused_functions(adev->ddev);

        drm_fb_helper_initial_config(&rfbdev->helper, bpp_sel);
        return 0;
}

void amdgpu_fbdev_fini(struct amdgpu_device *adev)
{
        if (!adev->mode_info.rfbdev)
                return;

        amdgpu_fbdev_destroy(adev->ddev, adev->mode_info.rfbdev);
        kfree(adev->mode_info.rfbdev);
        adev->mode_info.rfbdev = NULL;
}

void amdgpu_fbdev_set_suspend(struct amdgpu_device *adev, int state)
{
        if (adev->mode_info.rfbdev)
                drm_fb_helper_set_suspend(&adev->mode_info.rfbdev->helper,
                        state);
}

int amdgpu_fbdev_total_size(struct amdgpu_device *adev)
{
        struct amdgpu_bo *robj;
        int size = 0;

        if (!adev->mode_info.rfbdev)
                return 0;

        robj = gem_to_amdgpu_bo(adev->mode_info.rfbdev->rfb.obj);
        size += amdgpu_bo_size(robj);
        return size;
}

bool amdgpu_fbdev_robj_is_fb(struct amdgpu_device *adev, struct amdgpu_bo *robj)
{
        if (!adev->mode_info.rfbdev)
                return false;
        if (robj == gem_to_amdgpu_bo(adev->mode_info.rfbdev->rfb.obj))
                return true;
        return false;
}

void amdgpu_fbdev_restore_mode(struct amdgpu_device *adev)
{
        struct amdgpu_fbdev *afbdev = adev->mode_info.rfbdev;
        struct drm_fb_helper *fb_helper;
        int ret;

        if (!afbdev)
                return;

        fb_helper = &afbdev->helper;

        ret = drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
        if (ret)
                DRM_DEBUG("failed to restore crtc mode\n");
}