/*
 * 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/console.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/vga_switcheroo.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_print.h>

#include "i915_vma.h"
#include "intel_bo.h"
#include "intel_display_core.h"
#include "intel_display_rpm.h"
#include "intel_display_types.h"
#include "intel_fb.h"
#include "intel_fb_pin.h"
#include "intel_fbdev.h"
#include "intel_fbdev_fb.h"
#include "intel_frontbuffer.h"
#include "i915_drv.h"

struct intel_fbdev {
        struct intel_framebuffer *fb;
        struct i915_vma *vma;
        unsigned long vma_flags;
};

static struct intel_fbdev *to_intel_fbdev(struct drm_fb_helper *fb_helper)
{
        struct intel_display *display = to_intel_display(fb_helper->client.dev);

        return display->fbdev.fbdev;
}

static struct intel_frontbuffer *to_frontbuffer(struct intel_fbdev *ifbdev)
{
        return ifbdev->fb->frontbuffer;
}

static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
{
        intel_frontbuffer_invalidate(to_frontbuffer(ifbdev), ORIGIN_CPU);
}

FB_GEN_DEFAULT_DEFERRED_IOMEM_OPS(intel_fbdev,
                                  drm_fb_helper_damage_range,
                                  drm_fb_helper_damage_area)

static int intel_fbdev_set_par(struct fb_info *info)
{
        struct intel_fbdev *ifbdev = to_intel_fbdev(info->par);
        int ret;

        ret = drm_fb_helper_set_par(info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}

static int intel_fbdev_blank(int blank, struct fb_info *info)
{
        struct intel_fbdev *ifbdev = to_intel_fbdev(info->par);
        int ret;

        ret = drm_fb_helper_blank(blank, info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}

static int intel_fbdev_pan_display(struct fb_var_screeninfo *var,
                                   struct fb_info *info)
{
        struct intel_fbdev *ifbdev = to_intel_fbdev(info->par);
        int ret;

        ret = drm_fb_helper_pan_display(var, info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}

#ifdef notyet
static int intel_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct drm_gem_object *obj = drm_gem_fb_get_obj(fb_helper->fb, 0);

        return intel_bo_fb_mmap(obj, vma);
}

static void intel_fbdev_fb_destroy(struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct intel_fbdev *ifbdev = to_intel_fbdev(fb_helper);

        drm_fb_helper_fini(fb_helper);

        /*
         * We rely on the object-free to release the VMA pinning for
         * the info->screen_base mmaping. Leaking the VMA is simpler than
         * trying to rectify all the possible error paths leading here.
         */
        intel_fb_unpin_vma(ifbdev->vma, ifbdev->vma_flags);
        drm_framebuffer_remove(fb_helper->fb);

        drm_client_release(&fb_helper->client);
        drm_fb_helper_unprepare(fb_helper);
        kfree(fb_helper);
}

__diag_push();
__diag_ignore_all("-Woverride-init", "Allow field initialization overrides for fb ops");

#endif /* notyet */

static const struct fb_ops intelfb_ops = {
#ifdef notyet
        .owner = THIS_MODULE,
        __FB_DEFAULT_DEFERRED_OPS_RDWR(intel_fbdev),
        DRM_FB_HELPER_DEFAULT_OPS,
#endif
        .fb_set_par = intel_fbdev_set_par,
#ifdef notyet
        .fb_blank = intel_fbdev_blank,
        .fb_pan_display = intel_fbdev_pan_display,
        __FB_DEFAULT_DEFERRED_OPS_DRAW(intel_fbdev),
        .fb_mmap = intel_fbdev_mmap,
        .fb_destroy = intel_fbdev_fb_destroy,
#endif
};

__diag_pop();

static int intelfb_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
{
        if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
                return 0;

        if (helper->fb->funcs->dirty)
                return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);

        return 0;
}

static void intelfb_restore(struct drm_fb_helper *fb_helper)
{
        struct intel_fbdev *ifbdev = to_intel_fbdev(fb_helper);

        intel_fbdev_invalidate(ifbdev);
}

static void intelfb_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
{
        struct fb_info *info = fb_helper->info;

        /*
         * When resuming from hibernation, Linux restores the object's
         * content from swap if the buffer is backed by shmemfs. If the
         * object is stolen however, it will be full of whatever garbage
         * was left in there. Clear it to zero in this case.
         */
        if (!suspend && !intel_bo_is_shmem(intel_fb_bo(fb_helper->fb)))
                memset_io(info->screen_base, 0, info->screen_size);

        fb_set_suspend(info, suspend);
}

static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {
        .fb_dirty = intelfb_dirty,
        .fb_restore = intelfb_restore,
        .fb_set_suspend = intelfb_set_suspend,
};

static void intel_fbdev_fill_mode_cmd(struct drm_fb_helper_surface_size *sizes,
                                      struct drm_mode_fb_cmd2 *mode_cmd)
{
        /* we don't do packed 24bpp */
        if (sizes->surface_bpp == 24)
                sizes->surface_bpp = 32;

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

        mode_cmd->pitches[0] = ALIGN(mode_cmd->width * DIV_ROUND_UP(sizes->surface_bpp, 8), 64);
        mode_cmd->pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                           sizes->surface_depth);
}

static struct intel_framebuffer *
__intel_fbdev_fb_alloc(struct intel_display *display,
                       struct drm_fb_helper_surface_size *sizes)
{
        struct drm_mode_fb_cmd2 mode_cmd = {};
        struct intel_framebuffer *fb;

        intel_fbdev_fill_mode_cmd(sizes, &mode_cmd);

        fb = intel_fbdev_fb_alloc(display->drm, &mode_cmd);

        return fb;
}

int intel_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
                                   struct drm_fb_helper_surface_size *sizes)
{
        struct intel_display *display = to_intel_display(helper->dev);
        struct intel_fbdev *ifbdev = to_intel_fbdev(helper);
        struct intel_framebuffer *fb = ifbdev->fb;
        struct ref_tracker *wakeref;
        struct fb_info *info;
        struct i915_vma *vma;
        unsigned long flags = 0;
        bool prealloc = false;
        struct drm_gem_object *obj;
        int ret;

        ifbdev->fb = NULL;

        if (fb &&
            (sizes->fb_width > fb->base.width ||
             sizes->fb_height > fb->base.height)) {
                drm_dbg_kms(display->drm,
                            "BIOS fb too small (%dx%d), we require (%dx%d),"
                            " releasing it\n",
                            fb->base.width, fb->base.height,
                            sizes->fb_width, sizes->fb_height);
                drm_framebuffer_put(&fb->base);
                fb = NULL;
        }

        wakeref = intel_display_rpm_get(display);

        if (!fb || drm_WARN_ON(display->drm, !intel_fb_bo(&fb->base))) {
                drm_dbg_kms(display->drm,
                            "no BIOS fb, allocating a new one\n");

                fb = __intel_fbdev_fb_alloc(display, sizes);
                if (IS_ERR(fb)) {
                        ret = PTR_ERR(fb);
                        goto out_unlock;
                }
        } else {
                drm_dbg_kms(display->drm, "re-using BIOS fb\n");
                prealloc = true;
#ifdef __linux__
                sizes->fb_width = fb->base.width;
                sizes->fb_height = fb->base.height;
#endif
        }

        /* Pin the GGTT vma for our access via info->screen_base.
         * This also validates that any existing fb inherited from the
         * BIOS is suitable for own access.
         */
        vma = intel_fb_pin_to_ggtt(&fb->base, &fb->normal_view.gtt,
                                   fb->min_alignment, 0,
                                   intel_fb_view_vtd_guard(&fb->base, &fb->normal_view,
                                                           DRM_MODE_ROTATE_0),
                                   false, &flags);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
                goto out_unlock;
        }

        info = drm_fb_helper_alloc_info(helper);
        if (IS_ERR(info)) {
                drm_err(display->drm, "Failed to allocate fb_info (%pe)\n", info);
                ret = PTR_ERR(info);
                goto out_unpin;
        }

        helper->funcs = &intel_fb_helper_funcs;
        helper->fb = &fb->base;

        info->fbops = &intelfb_ops;

        obj = intel_fb_bo(&fb->base);

        ret = intel_fbdev_fb_fill_info(display, info, obj, vma);
        if (ret)
                goto out_unpin;

        drm_fb_helper_fill_info(info, display->drm->fb_helper, sizes);

        /* If the object is shmemfs backed, it will have given us zeroed pages.
         * If the object is stolen however, it will be full of whatever
         * garbage was left in there.
         */
        if (!intel_bo_is_shmem(obj) && !prealloc)
                memset_io(info->screen_base, 0, info->screen_size);

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

        drm_dbg_kms(display->drm, "allocated %dx%d fb: 0x%08x\n",
                    fb->base.width, fb->base.height,
                    i915_ggtt_offset(vma));
        ifbdev->fb = fb;
        ifbdev->vma = vma;
        ifbdev->vma_flags = flags;

        intel_display_rpm_put(display, wakeref);
{
        struct drm_framebuffer *fb = helper->fb;
        struct drm_i915_private *i915 = to_i915(display->drm);
        struct rasops_info *ri = &i915->ro;

        ri->ri_bits = info->screen_base;
        ri->ri_depth = fb->format->cpp[0] * 8;
        ri->ri_stride = fb->pitches[0];
        ri->ri_width = sizes->fb_width;
        ri->ri_height = sizes->fb_height;

        switch (fb->format->format) {
        case DRM_FORMAT_XRGB8888:
                ri->ri_rnum = 8;
                ri->ri_rpos = 16;
                ri->ri_gnum = 8;
                ri->ri_gpos = 8;
                ri->ri_bnum = 8;
                ri->ri_bpos = 0;
                break;
        case DRM_FORMAT_RGB565:
                ri->ri_rnum = 5;
                ri->ri_rpos = 11;
                ri->ri_gnum = 6;
                ri->ri_gpos = 5;
                ri->ri_bnum = 5;
                ri->ri_bpos = 0;
                break;
        }
        intel_fbdev_invalidate(ifbdev);
}
        return 0;

out_unpin:
        intel_fb_unpin_vma(vma, flags);
out_unlock:
        intel_display_rpm_put(display, wakeref);

        return ret;
}

/*
 * Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.
 * The core display code will have read out the current plane configuration,
 * so we use that to figure out if there's an object for us to use as the
 * fb, and if so, we re-use it for the fbdev configuration.
 *
 * Note we only support a single fb shared across pipes for boot (mostly for
 * fbcon), so we just find the biggest and use that.
 */
static bool intel_fbdev_init_bios(struct intel_display *display,
                                  struct intel_fbdev *ifbdev)
{
        struct intel_framebuffer *fb = NULL;
        struct intel_crtc *crtc;
        unsigned int max_size = 0;

        /* Find the largest fb */
        for_each_intel_crtc(display->drm, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct intel_plane *plane =
                        to_intel_plane(crtc->base.primary);
                struct intel_plane_state *plane_state =
                        to_intel_plane_state(plane->base.state);
                struct drm_gem_object *obj = intel_fb_bo(plane_state->uapi.fb);

                if (!crtc_state->uapi.active) {
                        drm_dbg_kms(display->drm,
                                    "[CRTC:%d:%s] not active, skipping\n",
                                    crtc->base.base.id, crtc->base.name);
                        continue;
                }

                if (!obj) {
                        drm_dbg_kms(display->drm,
                                    "[PLANE:%d:%s] no fb, skipping\n",
                                    plane->base.base.id, plane->base.name);
                        continue;
                }

                if (obj->size > max_size) {
                        drm_dbg_kms(display->drm,
                                    "found possible fb from [PLANE:%d:%s]\n",
                                    plane->base.base.id, plane->base.name);
                        fb = to_intel_framebuffer(plane_state->uapi.fb);
                        max_size = obj->size;
                }
        }

        if (!fb) {
                drm_dbg_kms(display->drm,
                            "no active fbs found, not using BIOS config\n");
                goto out;
        }

        /* Now make sure all the pipes will fit into it */
        for_each_intel_crtc(display->drm, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct intel_plane *plane =
                        to_intel_plane(crtc->base.primary);
                unsigned int cur_size;

                if (!crtc_state->uapi.active) {
                        drm_dbg_kms(display->drm,
                                    "[CRTC:%d:%s] not active, skipping\n",
                                    crtc->base.base.id, crtc->base.name);
                        continue;
                }

                drm_dbg_kms(display->drm, "checking [PLANE:%d:%s] for BIOS fb\n",
                            plane->base.base.id, plane->base.name);

                /*
                 * See if the plane fb we found above will fit on this
                 * pipe.  Note we need to use the selected fb's pitch and bpp
                 * rather than the current pipe's, since they differ.
                 */
                cur_size = crtc_state->uapi.adjusted_mode.crtc_hdisplay;
                cur_size = cur_size * fb->base.format->cpp[0];
                if (fb->base.pitches[0] < cur_size) {
                        drm_dbg_kms(display->drm,
                                    "fb not wide enough for [PLANE:%d:%s] (%d vs %d)\n",
                                    plane->base.base.id, plane->base.name,
                                    cur_size, fb->base.pitches[0]);
                        fb = NULL;
                        break;
                }

                cur_size = crtc_state->uapi.adjusted_mode.crtc_vdisplay;
                cur_size = intel_fb_align_height(&fb->base, 0, cur_size);
                cur_size *= fb->base.pitches[0];
                drm_dbg_kms(display->drm,
                            "[CRTC:%d:%s] area: %dx%d, bpp: %d, size: %d\n",
                            crtc->base.base.id, crtc->base.name,
                            crtc_state->uapi.adjusted_mode.crtc_hdisplay,
                            crtc_state->uapi.adjusted_mode.crtc_vdisplay,
                            fb->base.format->cpp[0] * 8,
                            cur_size);

                if (cur_size > max_size) {
                        drm_dbg_kms(display->drm,
                                    "fb not big enough for [PLANE:%d:%s] (%d vs %d)\n",
                                    plane->base.base.id, plane->base.name,
                                    cur_size, max_size);
                        fb = NULL;
                        break;
                }

                drm_dbg_kms(display->drm,
                            "fb big enough [PLANE:%d:%s] (%d >= %d)\n",
                            plane->base.base.id, plane->base.name,
                            max_size, cur_size);
        }

        if (!fb) {
                drm_dbg_kms(display->drm,
                            "BIOS fb not suitable for all pipes, not using\n");
                goto out;
        }

        ifbdev->fb = fb;

        drm_framebuffer_get(&ifbdev->fb->base);

        /* Final pass to check if any active pipes don't have fbs */
        for_each_intel_crtc(display->drm, crtc) {
                struct intel_crtc_state *crtc_state =
                        to_intel_crtc_state(crtc->base.state);
                struct intel_plane *plane =
                        to_intel_plane(crtc->base.primary);
                struct intel_plane_state *plane_state =
                        to_intel_plane_state(plane->base.state);

                if (!crtc_state->uapi.active)
                        continue;

                drm_WARN(display->drm, !plane_state->uapi.fb,
                         "re-used BIOS config but lost an fb on [PLANE:%d:%s]\n",
                         plane->base.base.id, plane->base.name);
        }


        drm_dbg_kms(display->drm, "using BIOS fb for initial console\n");
        return true;

out:

        return false;
}

static unsigned int intel_fbdev_color_mode(const struct drm_format_info *info)
{
        unsigned int bpp;

        if (!info->depth || info->num_planes != 1 || info->has_alpha || info->is_yuv)
                return 0;

        bpp = drm_format_info_bpp(info, 0);

        switch (bpp) {
        case 16:
                return info->depth; // 15 or 16
        default:
                return bpp;
        }
}

void intel_fbdev_setup(struct intel_display *display)
{
        struct intel_fbdev *ifbdev;
        unsigned int preferred_bpp = 0;

        if (!HAS_DISPLAY(display))
                return;

        ifbdev = drmm_kzalloc(display->drm, sizeof(*ifbdev), GFP_KERNEL);
        if (!ifbdev)
                return;

        display->fbdev.fbdev = ifbdev;
        if (intel_fbdev_init_bios(display, ifbdev))
                preferred_bpp = intel_fbdev_color_mode(ifbdev->fb->base.format);
        if (!preferred_bpp)
                preferred_bpp = 32;

        drm_client_setup_with_color_mode(display->drm, preferred_bpp);
}

struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev)
{
        if (!fbdev)
                return NULL;

        return fbdev->fb;
}

struct i915_vma *intel_fbdev_vma_pointer(struct intel_fbdev *fbdev)
{
        return fbdev ? fbdev->vma : NULL;
}

void intel_fbdev_get_map(struct intel_fbdev *fbdev, struct iosys_map *map)
{
        intel_fb_get_map(fbdev->vma, map);
}