1// SPDX-License-Identifier: MIT
2
3#include <linux/fb.h>
4
5#include <drm/drm_crtc_helper.h>
6#include <drm/drm_drv.h>
7#include <drm/drm_fb_helper.h>
8#include <drm/drm_framebuffer.h>
9#include <drm/drm_gem_dma_helper.h>
10
11#include <drm/drm_fbdev_dma.h>
12
13/*
14 * struct fb_ops
15 */
16
17static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
18{
19 struct drm_fb_helper *fb_helper = info->par;
20
21 /* No need to take a ref for fbcon because it unbinds on unregister */
22 if (user && !try_module_get(module: fb_helper->dev->driver->fops->owner))
23 return -ENODEV;
24
25 return 0;
26}
27
28static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
29{
30 struct drm_fb_helper *fb_helper = info->par;
31
32 if (user)
33 module_put(module: fb_helper->dev->driver->fops->owner);
34
35 return 0;
36}
37
38static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
39{
40 struct drm_fb_helper *fb_helper = info->par;
41
42 if (!fb_helper->dev)
43 return;
44
45 drm_fb_helper_fini(helper: fb_helper);
46
47 drm_client_buffer_vunmap(buffer: fb_helper->buffer);
48 drm_client_framebuffer_delete(buffer: fb_helper->buffer);
49 drm_client_release(client: &fb_helper->client);
50 drm_fb_helper_unprepare(fb_helper);
51 kfree(objp: fb_helper);
52}
53
54static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
55{
56 struct drm_fb_helper *fb_helper = info->par;
57
58 return drm_gem_prime_mmap(obj: fb_helper->buffer->gem, vma);
59}
60
61static const struct fb_ops drm_fbdev_dma_fb_ops = {
62 .owner = THIS_MODULE,
63 .fb_open = drm_fbdev_dma_fb_open,
64 .fb_release = drm_fbdev_dma_fb_release,
65 __FB_DEFAULT_DMAMEM_OPS_RDWR,
66 DRM_FB_HELPER_DEFAULT_OPS,
67 __FB_DEFAULT_DMAMEM_OPS_DRAW,
68 .fb_mmap = drm_fbdev_dma_fb_mmap,
69 .fb_destroy = drm_fbdev_dma_fb_destroy,
70};
71
72/*
73 * struct drm_fb_helper
74 */
75
76static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,
77 struct drm_fb_helper_surface_size *sizes)
78{
79 struct drm_client_dev *client = &fb_helper->client;
80 struct drm_device *dev = fb_helper->dev;
81 struct drm_client_buffer *buffer;
82 struct drm_gem_dma_object *dma_obj;
83 struct drm_framebuffer *fb;
84 struct fb_info *info;
85 u32 format;
86 struct iosys_map map;
87 int ret;
88
89 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
90 sizes->surface_width, sizes->surface_height,
91 sizes->surface_bpp);
92
93 format = drm_mode_legacy_fb_format(bpp: sizes->surface_bpp, depth: sizes->surface_depth);
94 buffer = drm_client_framebuffer_create(client, width: sizes->surface_width,
95 height: sizes->surface_height, format);
96 if (IS_ERR(ptr: buffer))
97 return PTR_ERR(ptr: buffer);
98 dma_obj = to_drm_gem_dma_obj(buffer->gem);
99
100 fb = buffer->fb;
101 if (drm_WARN_ON(dev, fb->funcs->dirty)) {
102 ret = -ENODEV; /* damage handling not supported; use generic emulation */
103 goto err_drm_client_buffer_delete;
104 }
105
106 ret = drm_client_buffer_vmap(buffer, map: &map);
107 if (ret) {
108 goto err_drm_client_buffer_delete;
109 } else if (drm_WARN_ON(dev, map.is_iomem)) {
110 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
111 goto err_drm_client_buffer_delete;
112 }
113
114 fb_helper->buffer = buffer;
115 fb_helper->fb = buffer->fb;
116
117 info = drm_fb_helper_alloc_info(fb_helper);
118 if (IS_ERR(ptr: info)) {
119 ret = PTR_ERR(ptr: info);
120 goto err_drm_client_buffer_vunmap;
121 }
122
123 drm_fb_helper_fill_info(info, fb_helper, sizes);
124
125 info->fbops = &drm_fbdev_dma_fb_ops;
126
127 /* screen */
128 info->flags |= FBINFO_VIRTFB; /* system memory */
129 if (dma_obj->map_noncoherent)
130 info->flags |= FBINFO_READS_FAST; /* signal caching */
131 info->screen_size = sizes->surface_height * fb->pitches[0];
132 info->screen_buffer = map.vaddr;
133 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
134 info->fix.smem_len = info->screen_size;
135
136 return 0;
137
138err_drm_client_buffer_vunmap:
139 fb_helper->fb = NULL;
140 fb_helper->buffer = NULL;
141 drm_client_buffer_vunmap(buffer);
142err_drm_client_buffer_delete:
143 drm_client_framebuffer_delete(buffer);
144 return ret;
145}
146
147static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
148 .fb_probe = drm_fbdev_dma_helper_fb_probe,
149};
150
151/*
152 * struct drm_client_funcs
153 */
154
155static void drm_fbdev_dma_client_unregister(struct drm_client_dev *client)
156{
157 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
158
159 if (fb_helper->info) {
160 drm_fb_helper_unregister_info(fb_helper);
161 } else {
162 drm_client_release(client: &fb_helper->client);
163 drm_fb_helper_unprepare(fb_helper);
164 kfree(objp: fb_helper);
165 }
166}
167
168static int drm_fbdev_dma_client_restore(struct drm_client_dev *client)
169{
170 drm_fb_helper_lastclose(dev: client->dev);
171
172 return 0;
173}
174
175static int drm_fbdev_dma_client_hotplug(struct drm_client_dev *client)
176{
177 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
178 struct drm_device *dev = client->dev;
179 int ret;
180
181 if (dev->fb_helper)
182 return drm_fb_helper_hotplug_event(fb_helper: dev->fb_helper);
183
184 ret = drm_fb_helper_init(dev, helper: fb_helper);
185 if (ret)
186 goto err_drm_err;
187
188 if (!drm_drv_uses_atomic_modeset(dev))
189 drm_helper_disable_unused_functions(dev);
190
191 ret = drm_fb_helper_initial_config(fb_helper);
192 if (ret)
193 goto err_drm_fb_helper_fini;
194
195 return 0;
196
197err_drm_fb_helper_fini:
198 drm_fb_helper_fini(helper: fb_helper);
199err_drm_err:
200 drm_err(dev, "fbdev-dma: Failed to setup generic emulation (ret=%d)\n", ret);
201 return ret;
202}
203
204static const struct drm_client_funcs drm_fbdev_dma_client_funcs = {
205 .owner = THIS_MODULE,
206 .unregister = drm_fbdev_dma_client_unregister,
207 .restore = drm_fbdev_dma_client_restore,
208 .hotplug = drm_fbdev_dma_client_hotplug,
209};
210
211/**
212 * drm_fbdev_dma_setup() - Setup fbdev emulation for GEM DMA helpers
213 * @dev: DRM device
214 * @preferred_bpp: Preferred bits per pixel for the device.
215 * 32 is used if this is zero.
216 *
217 * This function sets up fbdev emulation for GEM DMA drivers that support
218 * dumb buffers with a virtual address and that can be mmap'ed.
219 * drm_fbdev_dma_setup() shall be called after the DRM driver registered
220 * the new DRM device with drm_dev_register().
221 *
222 * Restore, hotplug events and teardown are all taken care of. Drivers that do
223 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
224 * Simple drivers might use drm_mode_config_helper_suspend().
225 *
226 * This function is safe to call even when there are no connectors present.
227 * Setup will be retried on the next hotplug event.
228 *
229 * The fbdev is destroyed by drm_dev_unregister().
230 */
231void drm_fbdev_dma_setup(struct drm_device *dev, unsigned int preferred_bpp)
232{
233 struct drm_fb_helper *fb_helper;
234 int ret;
235
236 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
237 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
238
239 fb_helper = kzalloc(size: sizeof(*fb_helper), GFP_KERNEL);
240 if (!fb_helper)
241 return;
242 drm_fb_helper_prepare(dev, helper: fb_helper, preferred_bpp, funcs: &drm_fbdev_dma_helper_funcs);
243
244 ret = drm_client_init(dev, client: &fb_helper->client, name: "fbdev", funcs: &drm_fbdev_dma_client_funcs);
245 if (ret) {
246 drm_err(dev, "Failed to register client: %d\n", ret);
247 goto err_drm_client_init;
248 }
249
250 drm_client_register(client: &fb_helper->client);
251
252 return;
253
254err_drm_client_init:
255 drm_fb_helper_unprepare(fb_helper);
256 kfree(objp: fb_helper);
257}
258EXPORT_SYMBOL(drm_fbdev_dma_setup);
259

source code of linux/drivers/gpu/drm/drm_fbdev_dma.c