xref: /linux/drivers/gpu/drm/tegra/fbdev.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 
25 static 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 
40 static 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 	drm_fb_helper_unprepare(helper);
57 	kfree(helper);
58 }
59 
60 static const struct fb_ops tegra_fb_ops = {
61 	.owner = THIS_MODULE,
62 	__FB_DEFAULT_DMAMEM_OPS_RDWR,
63 	DRM_FB_HELPER_DEFAULT_OPS,
64 	__FB_DEFAULT_DMAMEM_OPS_DRAW,
65 	.fb_mmap = tegra_fb_mmap,
66 	.fb_destroy = tegra_fbdev_fb_destroy,
67 };
68 
69 static const struct drm_fb_helper_funcs tegra_fbdev_helper_funcs = {
70 };
71 
72 int tegra_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
73 				   struct drm_fb_helper_surface_size *sizes)
74 {
75 	struct tegra_drm *tegra = helper->dev->dev_private;
76 	struct drm_device *drm = helper->dev;
77 	struct drm_mode_fb_cmd2 cmd = { 0 };
78 	unsigned int bytes_per_pixel;
79 	struct drm_framebuffer *fb;
80 	unsigned long offset;
81 	struct fb_info *info;
82 	struct tegra_bo *bo;
83 	size_t size;
84 	int err;
85 
86 	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
87 
88 	cmd.width = sizes->surface_width;
89 	cmd.height = sizes->surface_height;
90 	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
91 				  tegra->pitch_align);
92 
93 	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
94 						     sizes->surface_depth);
95 
96 	size = cmd.pitches[0] * cmd.height;
97 
98 	bo = tegra_bo_create(drm, size, 0);
99 	if (IS_ERR(bo))
100 		return PTR_ERR(bo);
101 
102 	info = drm_fb_helper_alloc_info(helper);
103 	if (IS_ERR(info)) {
104 		dev_err(drm->dev, "failed to allocate framebuffer info\n");
105 		drm_gem_object_put(&bo->gem);
106 		return PTR_ERR(info);
107 	}
108 
109 	fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
110 	if (IS_ERR(fb)) {
111 		err = PTR_ERR(fb);
112 		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
113 			err);
114 		drm_gem_object_put(&bo->gem);
115 		return PTR_ERR(fb);
116 	}
117 
118 	helper->funcs = &tegra_fbdev_helper_funcs;
119 	helper->fb = fb;
120 	helper->info = info;
121 
122 	info->fbops = &tegra_fb_ops;
123 
124 	drm_fb_helper_fill_info(info, helper, sizes);
125 
126 	offset = info->var.xoffset * bytes_per_pixel +
127 		 info->var.yoffset * fb->pitches[0];
128 
129 	if (bo->pages) {
130 		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
131 				 pgprot_writecombine(PAGE_KERNEL));
132 		if (!bo->vaddr) {
133 			dev_err(drm->dev, "failed to vmap() framebuffer\n");
134 			err = -ENOMEM;
135 			goto destroy;
136 		}
137 	}
138 
139 	info->flags |= FBINFO_VIRTFB;
140 	info->screen_buffer = bo->vaddr + offset;
141 	info->screen_size = size;
142 	info->fix.smem_start = (unsigned long)(bo->iova + offset);
143 	info->fix.smem_len = size;
144 
145 	return 0;
146 
147 destroy:
148 	drm_framebuffer_remove(fb);
149 	return err;
150 }
151