/*
 * 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/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 <linux/screen_info.h>
#include <linux/vga_switcheroo.h>
#include <linux/console.h>

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

#include "nouveau_drv.h"
#include "nouveau_gem.h"
#include "nouveau_bo.h"
#include "nouveau_fbcon.h"
#include "nouveau_chan.h"

#include "nouveau_crtc.h"

MODULE_PARM_DESC(nofbaccel, "Disable fbcon acceleration");
int nouveau_nofbaccel = 0;
module_param_named(nofbaccel, nouveau_nofbaccel, int, 0400);

static void
nouveau_fbcon_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	struct nvif_device *device = &drm->client.device;
	int ret;

	if (info->state != FBINFO_STATE_RUNNING)
		return;

	ret = -ENODEV;
	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
	    mutex_trylock(&drm->client.mutex)) {
		if (device->info.family < NV_DEVICE_INFO_V0_TESLA)
			ret = nv04_fbcon_fillrect(info, rect);
		else
		if (device->info.family < NV_DEVICE_INFO_V0_FERMI)
			ret = nv50_fbcon_fillrect(info, rect);
		else
			ret = nvc0_fbcon_fillrect(info, rect);
		mutex_unlock(&drm->client.mutex);
	}

	if (ret == 0)
		return;

	if (ret != -ENODEV)
		nouveau_fbcon_gpu_lockup(info);
	drm_fb_helper_cfb_fillrect(info, rect);
}

static void
nouveau_fbcon_copyarea(struct fb_info *info, const struct fb_copyarea *image)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	struct nvif_device *device = &drm->client.device;
	int ret;

	if (info->state != FBINFO_STATE_RUNNING)
		return;

	ret = -ENODEV;
	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
	    mutex_trylock(&drm->client.mutex)) {
		if (device->info.family < NV_DEVICE_INFO_V0_TESLA)
			ret = nv04_fbcon_copyarea(info, image);
		else
		if (device->info.family < NV_DEVICE_INFO_V0_FERMI)
			ret = nv50_fbcon_copyarea(info, image);
		else
			ret = nvc0_fbcon_copyarea(info, image);
		mutex_unlock(&drm->client.mutex);
	}

	if (ret == 0)
		return;

	if (ret != -ENODEV)
		nouveau_fbcon_gpu_lockup(info);
	drm_fb_helper_cfb_copyarea(info, image);
}

static void
nouveau_fbcon_imageblit(struct fb_info *info, const struct fb_image *image)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	struct nvif_device *device = &drm->client.device;
	int ret;

	if (info->state != FBINFO_STATE_RUNNING)
		return;

	ret = -ENODEV;
	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED) &&
	    mutex_trylock(&drm->client.mutex)) {
		if (device->info.family < NV_DEVICE_INFO_V0_TESLA)
			ret = nv04_fbcon_imageblit(info, image);
		else
		if (device->info.family < NV_DEVICE_INFO_V0_FERMI)
			ret = nv50_fbcon_imageblit(info, image);
		else
			ret = nvc0_fbcon_imageblit(info, image);
		mutex_unlock(&drm->client.mutex);
	}

	if (ret == 0)
		return;

	if (ret != -ENODEV)
		nouveau_fbcon_gpu_lockup(info);
	drm_fb_helper_cfb_imageblit(info, image);
}

static int
nouveau_fbcon_sync(struct fb_info *info)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	struct nouveau_channel *chan = drm->channel;
	int ret;

	if (!chan || !chan->accel_done || in_interrupt() ||
	    info->state != FBINFO_STATE_RUNNING ||
	    info->flags & FBINFO_HWACCEL_DISABLED)
		return 0;

	if (!mutex_trylock(&drm->client.mutex))
		return 0;

	ret = nouveau_channel_idle(chan);
	mutex_unlock(&drm->client.mutex);
	if (ret) {
		nouveau_fbcon_gpu_lockup(info);
		return 0;
	}

	chan->accel_done = false;
	return 0;
}

static int
nouveau_fbcon_open(struct fb_info *info, int user)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	int ret = pm_runtime_get_sync(drm->dev->dev);
	if (ret < 0 && ret != -EACCES)
		return ret;
	return 0;
}

static int
nouveau_fbcon_release(struct fb_info *info, int user)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);
	pm_runtime_put(drm->dev->dev);
	return 0;
}

static struct fb_ops nouveau_fbcon_ops = {
	.owner = THIS_MODULE,
	DRM_FB_HELPER_DEFAULT_OPS,
	.fb_open = nouveau_fbcon_open,
	.fb_release = nouveau_fbcon_release,
	.fb_fillrect = nouveau_fbcon_fillrect,
	.fb_copyarea = nouveau_fbcon_copyarea,
	.fb_imageblit = nouveau_fbcon_imageblit,
	.fb_sync = nouveau_fbcon_sync,
};

static struct fb_ops nouveau_fbcon_sw_ops = {
	.owner = THIS_MODULE,
	DRM_FB_HELPER_DEFAULT_OPS,
	.fb_open = nouveau_fbcon_open,
	.fb_release = nouveau_fbcon_release,
	.fb_fillrect = drm_fb_helper_cfb_fillrect,
	.fb_copyarea = drm_fb_helper_cfb_copyarea,
	.fb_imageblit = drm_fb_helper_cfb_imageblit,
};

void
nouveau_fbcon_accel_save_disable(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	if (drm->fbcon) {
		drm->fbcon->saved_flags = drm->fbcon->helper.fbdev->flags;
		drm->fbcon->helper.fbdev->flags |= FBINFO_HWACCEL_DISABLED;
	}
}

void
nouveau_fbcon_accel_restore(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	if (drm->fbcon) {
		drm->fbcon->helper.fbdev->flags = drm->fbcon->saved_flags;
	}
}

static void
nouveau_fbcon_accel_fini(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	struct nouveau_fbdev *fbcon = drm->fbcon;
	if (fbcon && drm->channel) {
		console_lock();
		fbcon->helper.fbdev->flags |= FBINFO_HWACCEL_DISABLED;
		console_unlock();
		nouveau_channel_idle(drm->channel);
		nvif_object_fini(&fbcon->twod);
		nvif_object_fini(&fbcon->blit);
		nvif_object_fini(&fbcon->gdi);
		nvif_object_fini(&fbcon->patt);
		nvif_object_fini(&fbcon->rop);
		nvif_object_fini(&fbcon->clip);
		nvif_object_fini(&fbcon->surf2d);
	}
}

static void
nouveau_fbcon_accel_init(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	struct nouveau_fbdev *fbcon = drm->fbcon;
	struct fb_info *info = fbcon->helper.fbdev;
	int ret;

	if (drm->client.device.info.family < NV_DEVICE_INFO_V0_TESLA)
		ret = nv04_fbcon_accel_init(info);
	else
	if (drm->client.device.info.family < NV_DEVICE_INFO_V0_FERMI)
		ret = nv50_fbcon_accel_init(info);
	else
		ret = nvc0_fbcon_accel_init(info);

	if (ret == 0)
		info->fbops = &nouveau_fbcon_ops;
}

static void nouveau_fbcon_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
				    u16 blue, int regno)
{
	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);

	nv_crtc->lut.r[regno] = red;
	nv_crtc->lut.g[regno] = green;
	nv_crtc->lut.b[regno] = blue;
}

static void nouveau_fbcon_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
				    u16 *blue, int regno)
{
	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);

	*red = nv_crtc->lut.r[regno];
	*green = nv_crtc->lut.g[regno];
	*blue = nv_crtc->lut.b[regno];
}

static void
nouveau_fbcon_zfill(struct drm_device *dev, struct nouveau_fbdev *fbcon)
{
	struct fb_info *info = fbcon->helper.fbdev;
	struct fb_fillrect rect;

	/* Clear the entire fbcon.  The drm will program every connector
	 * with it's preferred mode.  If the sizes differ, one display will
	 * quite likely have garbage around the console.
	 */
	rect.dx = rect.dy = 0;
	rect.width = info->var.xres_virtual;
	rect.height = info->var.yres_virtual;
	rect.color = 0;
	rect.rop = ROP_COPY;
	info->fbops->fb_fillrect(info, &rect);
}

static int
nouveau_fbcon_create(struct drm_fb_helper *helper,
		     struct drm_fb_helper_surface_size *sizes)
{
	struct nouveau_fbdev *fbcon =
		container_of(helper, struct nouveau_fbdev, helper);
	struct drm_device *dev = fbcon->helper.dev;
	struct nouveau_drm *drm = nouveau_drm(dev);
	struct nvif_device *device = &drm->client.device;
	struct fb_info *info;
	struct nouveau_framebuffer *fb;
	struct nouveau_channel *chan;
	struct nouveau_bo *nvbo;
	struct drm_mode_fb_cmd2 mode_cmd;
	int ret;

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

	mode_cmd.pitches[0] = mode_cmd.width * (sizes->surface_bpp >> 3);
	mode_cmd.pitches[0] = roundup(mode_cmd.pitches[0], 256);

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

	ret = nouveau_gem_new(&drm->client, mode_cmd.pitches[0] *
			      mode_cmd.height, 0, NOUVEAU_GEM_DOMAIN_VRAM,
			      0, 0x0000, &nvbo);
	if (ret) {
		NV_ERROR(drm, "failed to allocate framebuffer\n");
		goto out;
	}

	ret = nouveau_framebuffer_new(dev, &mode_cmd, nvbo, &fb);
	if (ret)
		goto out_unref;

	ret = nouveau_bo_pin(nvbo, TTM_PL_FLAG_VRAM, false);
	if (ret) {
		NV_ERROR(drm, "failed to pin fb: %d\n", ret);
		goto out_unref;
	}

	ret = nouveau_bo_map(nvbo);
	if (ret) {
		NV_ERROR(drm, "failed to map fb: %d\n", ret);
		goto out_unpin;
	}

	chan = nouveau_nofbaccel ? NULL : drm->channel;
	if (chan && device->info.family >= NV_DEVICE_INFO_V0_TESLA) {
		ret = nouveau_bo_vma_add(nvbo, drm->client.vm, &fb->vma);
		if (ret) {
			NV_ERROR(drm, "failed to map fb into chan: %d\n", ret);
			chan = NULL;
		}
	}

	info = drm_fb_helper_alloc_fbi(helper);
	if (IS_ERR(info)) {
		ret = PTR_ERR(info);
		goto out_unlock;
	}
	info->skip_vt_switch = 1;

	info->par = fbcon;

	/* setup helper */
	fbcon->helper.fb = &fb->base;

	strcpy(info->fix.id, "nouveaufb");
	if (!chan)
		info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_DISABLED;
	else
		info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_COPYAREA |
			      FBINFO_HWACCEL_FILLRECT |
			      FBINFO_HWACCEL_IMAGEBLIT;
	info->flags |= FBINFO_CAN_FORCE_OUTPUT;
	info->fbops = &nouveau_fbcon_sw_ops;
	info->fix.smem_start = fb->nvbo->bo.mem.bus.base +
			       fb->nvbo->bo.mem.bus.offset;
	info->fix.smem_len = fb->nvbo->bo.mem.num_pages << PAGE_SHIFT;

	info->screen_base = nvbo_kmap_obj_iovirtual(fb->nvbo);
	info->screen_size = fb->nvbo->bo.mem.num_pages << PAGE_SHIFT;

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

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

	if (chan)
		nouveau_fbcon_accel_init(dev);
	nouveau_fbcon_zfill(dev, fbcon);

	/* To allow resizeing without swapping buffers */
	NV_INFO(drm, "allocated %dx%d fb: 0x%llx, bo %p\n",
		fb->base.width, fb->base.height, fb->nvbo->bo.offset, nvbo);

	vga_switcheroo_client_fb_set(dev->pdev, info);
	return 0;

out_unlock:
	if (chan)
		nouveau_bo_vma_del(fb->nvbo, &fb->vma);
	nouveau_bo_unmap(fb->nvbo);
out_unpin:
	nouveau_bo_unpin(fb->nvbo);
out_unref:
	nouveau_bo_ref(NULL, &fb->nvbo);
out:
	return ret;
}

void
nouveau_fbcon_output_poll_changed(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	if (drm->fbcon)
		drm_fb_helper_hotplug_event(&drm->fbcon->helper);
}

static int
nouveau_fbcon_destroy(struct drm_device *dev, struct nouveau_fbdev *fbcon)
{
	struct nouveau_framebuffer *nouveau_fb = nouveau_framebuffer(fbcon->helper.fb);

	drm_fb_helper_unregister_fbi(&fbcon->helper);
	drm_fb_helper_fini(&fbcon->helper);

	if (nouveau_fb->nvbo) {
		nouveau_bo_vma_del(nouveau_fb->nvbo, &nouveau_fb->vma);
		nouveau_bo_unmap(nouveau_fb->nvbo);
		nouveau_bo_unpin(nouveau_fb->nvbo);
		drm_framebuffer_unreference(&nouveau_fb->base);
	}

	return 0;
}

void nouveau_fbcon_gpu_lockup(struct fb_info *info)
{
	struct nouveau_fbdev *fbcon = info->par;
	struct nouveau_drm *drm = nouveau_drm(fbcon->helper.dev);

	NV_ERROR(drm, "GPU lockup - switching to software fbcon\n");
	info->flags |= FBINFO_HWACCEL_DISABLED;
}

static const struct drm_fb_helper_funcs nouveau_fbcon_helper_funcs = {
	.gamma_set = nouveau_fbcon_gamma_set,
	.gamma_get = nouveau_fbcon_gamma_get,
	.fb_probe = nouveau_fbcon_create,
};

static void
nouveau_fbcon_set_suspend_work(struct work_struct *work)
{
	struct nouveau_drm *drm = container_of(work, typeof(*drm), fbcon_work);
	int state = READ_ONCE(drm->fbcon_new_state);

	if (state == FBINFO_STATE_RUNNING)
		pm_runtime_get_sync(drm->dev->dev);

	console_lock();
	if (state == FBINFO_STATE_RUNNING)
		nouveau_fbcon_accel_restore(drm->dev);
	drm_fb_helper_set_suspend(&drm->fbcon->helper, state);
	if (state != FBINFO_STATE_RUNNING)
		nouveau_fbcon_accel_save_disable(drm->dev);
	console_unlock();

	if (state == FBINFO_STATE_RUNNING) {
		pm_runtime_mark_last_busy(drm->dev->dev);
		pm_runtime_put_sync(drm->dev->dev);
	}
}

void
nouveau_fbcon_set_suspend(struct drm_device *dev, int state)
{
	struct nouveau_drm *drm = nouveau_drm(dev);

	if (!drm->fbcon)
		return;

	drm->fbcon_new_state = state;
	/* Since runtime resume can happen as a result of a sysfs operation,
	 * it's possible we already have the console locked. So handle fbcon
	 * init/deinit from a seperate work thread
	 */
	schedule_work(&drm->fbcon_work);
}

int
nouveau_fbcon_init(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);
	struct nouveau_fbdev *fbcon;
	int preferred_bpp;
	int ret;

	if (!dev->mode_config.num_crtc ||
	    (dev->pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
		return 0;

	fbcon = kzalloc(sizeof(struct nouveau_fbdev), GFP_KERNEL);
	if (!fbcon)
		return -ENOMEM;

	drm->fbcon = fbcon;
	INIT_WORK(&drm->fbcon_work, nouveau_fbcon_set_suspend_work);

	drm_fb_helper_prepare(dev, &fbcon->helper, &nouveau_fbcon_helper_funcs);

	ret = drm_fb_helper_init(dev, &fbcon->helper, 4);
	if (ret)
		goto free;

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

	if (drm->client.device.info.ram_size <= 32 * 1024 * 1024)
		preferred_bpp = 8;
	else
	if (drm->client.device.info.ram_size <= 64 * 1024 * 1024)
		preferred_bpp = 16;
	else
		preferred_bpp = 32;

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

	ret = drm_fb_helper_initial_config(&fbcon->helper, preferred_bpp);
	if (ret)
		goto fini;

	if (fbcon->helper.fbdev)
		fbcon->helper.fbdev->pixmap.buf_align = 4;
	return 0;

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

void
nouveau_fbcon_fini(struct drm_device *dev)
{
	struct nouveau_drm *drm = nouveau_drm(dev);

	if (!drm->fbcon)
		return;

	nouveau_fbcon_accel_fini(dev);
	nouveau_fbcon_destroy(dev, drm->fbcon);
	kfree(drm->fbcon);
	drm->fbcon = NULL;
}