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	drm_fb_helper_unprepare(helper);
 57	kfree(helper);
 58}
 59
 60static 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
 69static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 70			     struct drm_fb_helper_surface_size *sizes)
 71{
 72	struct tegra_drm *tegra = helper->dev->dev_private;
 73	struct drm_device *drm = helper->dev;
 74	struct drm_mode_fb_cmd2 cmd = { 0 };
 75	unsigned int bytes_per_pixel;
 76	struct drm_framebuffer *fb;
 77	unsigned long offset;
 78	struct fb_info *info;
 79	struct tegra_bo *bo;
 80	size_t size;
 81	int err;
 82
 83	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
 84
 85	cmd.width = sizes->surface_width;
 86	cmd.height = sizes->surface_height;
 87	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
 88				  tegra->pitch_align);
 89
 90	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 91						     sizes->surface_depth);
 92
 93	size = cmd.pitches[0] * cmd.height;
 94
 95	bo = tegra_bo_create(drm, size, 0);
 96	if (IS_ERR(bo))
 97		return PTR_ERR(bo);
 98
 99	info = drm_fb_helper_alloc_info(helper);
100	if (IS_ERR(info)) {
101		dev_err(drm->dev, "failed to allocate framebuffer info\n");
102		drm_gem_object_put(&bo->gem);
103		return PTR_ERR(info);
104	}
105
106	fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
107	if (IS_ERR(fb)) {
108		err = PTR_ERR(fb);
109		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
110			err);
111		drm_gem_object_put(&bo->gem);
112		return PTR_ERR(fb);
113	}
114
115	helper->fb = fb;
116	helper->info = info;
117
118	info->fbops = &tegra_fb_ops;
119
120	drm_fb_helper_fill_info(info, helper, sizes);
121
122	offset = info->var.xoffset * bytes_per_pixel +
123		 info->var.yoffset * fb->pitches[0];
124
125	if (bo->pages) {
126		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
127				 pgprot_writecombine(PAGE_KERNEL));
128		if (!bo->vaddr) {
129			dev_err(drm->dev, "failed to vmap() framebuffer\n");
130			err = -ENOMEM;
131			goto destroy;
132		}
133	}
134
135	info->flags |= FBINFO_VIRTFB;
136	info->screen_buffer = bo->vaddr + offset;
137	info->screen_size = size;
138	info->fix.smem_start = (unsigned long)(bo->iova + offset);
139	info->fix.smem_len = size;
140
141	return 0;
142
143destroy:
144	drm_framebuffer_remove(fb);
145	return err;
146}
147
148static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
149	.fb_probe = tegra_fbdev_probe,
150};
151
152/*
153 * struct drm_client
154 */
155
156static void tegra_fbdev_client_unregister(struct drm_client_dev *client)
157{
158	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
159
160	if (fb_helper->info) {
161		drm_fb_helper_unregister_info(fb_helper);
162	} else {
163		drm_client_release(&fb_helper->client);
164		drm_fb_helper_unprepare(fb_helper);
165		kfree(fb_helper);
166	}
167}
168
169static int tegra_fbdev_client_restore(struct drm_client_dev *client)
170{
171	drm_fb_helper_lastclose(client->dev);
172
173	return 0;
174}
175
176static int tegra_fbdev_client_hotplug(struct drm_client_dev *client)
177{
178	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
179	struct drm_device *dev = client->dev;
180	int ret;
181
182	if (dev->fb_helper)
183		return drm_fb_helper_hotplug_event(dev->fb_helper);
184
185	ret = drm_fb_helper_init(dev, fb_helper);
186	if (ret)
187		goto err_drm_err;
188
189	if (!drm_drv_uses_atomic_modeset(dev))
190		drm_helper_disable_unused_functions(dev);
191
192	ret = drm_fb_helper_initial_config(fb_helper);
193	if (ret)
194		goto err_drm_fb_helper_fini;
195
196	return 0;
197
198err_drm_fb_helper_fini:
199	drm_fb_helper_fini(fb_helper);
200err_drm_err:
201	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
202	return ret;
203}
204
205static const struct drm_client_funcs tegra_fbdev_client_funcs = {
206	.owner		= THIS_MODULE,
207	.unregister	= tegra_fbdev_client_unregister,
208	.restore	= tegra_fbdev_client_restore,
209	.hotplug	= tegra_fbdev_client_hotplug,
210};
211
212void tegra_fbdev_setup(struct drm_device *dev)
213{
214	struct drm_fb_helper *helper;
215	int ret;
216
217	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
218	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
219
220	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
221	if (!helper)
222		return;
223	drm_fb_helper_prepare(dev, helper, 32, &tegra_fb_helper_funcs);
224
225	ret = drm_client_init(dev, &helper->client, "fbdev", &tegra_fbdev_client_funcs);
226	if (ret)
227		goto err_drm_client_init;
228
229	drm_client_register(&helper->client);
230
231	return;
232
233err_drm_client_init:
234	drm_fb_helper_unprepare(helper);
235	kfree(helper);
236}