fbdev.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2012-2013 Avionic Design GmbH
  4 * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
  5 *
  6 * Based on the KMS/FB DMA helpers
  7 *   Copyright (C) 2012 Analog Devices Inc.
  8 */
  9
 10#include <linux/console.h>
 11#include <linux/fb.h>
 12#include <linux/vmalloc.h>
 13
 14#include <drm/drm_drv.h>
 15#include <drm/drm_crtc_helper.h>
 16#include <drm/drm_fb_helper.h>
 17#include <drm/drm_fourcc.h>
 18#include <drm/drm_framebuffer.h>
 19#include <drm/drm_gem_framebuffer_helper.h>
 20#include <drm/drm_modeset_helper.h>
 21
 22#include "drm.h"
 23#include "gem.h"
 24
 25static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 26{
 27	struct drm_fb_helper *helper = info->par;
 28	struct tegra_bo *bo;
 29	int err;
 30
 31	bo = tegra_fb_get_plane(helper->fb, 0);
 32
 33	err = drm_gem_mmap_obj(&bo->gem, bo->gem.size, vma);
 34	if (err < 0)
 35		return err;
 36
 37	return __tegra_gem_mmap(&bo->gem, vma);
 38}
 39
 40static void tegra_fbdev_fb_destroy(struct fb_info *info)
 41{
 42	struct drm_fb_helper *helper = info->par;
 43	struct drm_framebuffer *fb = helper->fb;
 44	struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
 45
 46	drm_fb_helper_fini(helper);
 47
 48	/* Undo the special mapping we made in fbdev probe. */
 49	if (bo->pages) {
 50		vunmap(bo->vaddr);
 51		bo->vaddr = NULL;
 52	}
 53	drm_framebuffer_remove(fb);
 54
 55	drm_client_release(&helper->client);
 56}
 57
 58static const struct fb_ops tegra_fb_ops = {
 59	.owner = THIS_MODULE,
 60	__FB_DEFAULT_DMAMEM_OPS_RDWR,
 61	DRM_FB_HELPER_DEFAULT_OPS,
 62	__FB_DEFAULT_DMAMEM_OPS_DRAW,
 63	.fb_mmap = tegra_fb_mmap,
 64	.fb_destroy = tegra_fbdev_fb_destroy,
 65};
 66
 67static const struct drm_fb_helper_funcs tegra_fbdev_helper_funcs = {
 68};
 69
 70int tegra_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
 71				   struct drm_fb_helper_surface_size *sizes)
 72{
 73	struct tegra_drm *tegra = helper->dev->dev_private;
 74	struct drm_device *drm = helper->dev;
 75	struct drm_mode_fb_cmd2 cmd = { 0 };
 76	struct fb_info *info = helper->info;
 77	unsigned int bytes_per_pixel;
 78	struct drm_framebuffer *fb;
 79	unsigned long offset;
 80	struct tegra_bo *bo;
 81	size_t size;
 82	int err;
 83
 84	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
 85
 86	cmd.width = sizes->surface_width;
 87	cmd.height = sizes->surface_height;
 88	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
 89				  tegra->pitch_align);
 90
 91	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 92						     sizes->surface_depth);
 93
 94	size = cmd.pitches[0] * cmd.height;
 95
 96	bo = tegra_bo_create(drm, size, 0);
 97	if (IS_ERR(bo))
 98		return PTR_ERR(bo);
 99
100	fb = tegra_fb_alloc(drm,
101			    drm_get_format_info(drm, cmd.pixel_format, cmd.modifier[0]),
102			    &cmd, &bo, 1);
103	if (IS_ERR(fb)) {
104		err = PTR_ERR(fb);
105		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
106			err);
107		drm_gem_object_put(&bo->gem);
108		return PTR_ERR(fb);
109	}
110
111	helper->funcs = &tegra_fbdev_helper_funcs;
112	helper->fb = fb;
113	helper->info = info;
114
115	info->fbops = &tegra_fb_ops;
116
117	drm_fb_helper_fill_info(info, helper, sizes);
118
119	offset = info->var.xoffset * bytes_per_pixel +
120		 info->var.yoffset * fb->pitches[0];
121
122	if (bo->pages) {
123		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
124				 pgprot_writecombine(PAGE_KERNEL));
125		if (!bo->vaddr) {
126			dev_err(drm->dev, "failed to vmap() framebuffer\n");
127			err = -ENOMEM;
128			goto destroy;
129		}
130	}
131
132	info->flags |= FBINFO_VIRTFB;
133	info->screen_buffer = bo->vaddr + offset;
134	info->screen_size = size;
135	info->fix.smem_start = (unsigned long)(bo->iova + offset);
136	info->fix.smem_len = size;
137
138	return 0;
139
140destroy:
141	drm_framebuffer_remove(fb);
142	return err;
143}