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1// SPDX-License-Identifier: MIT
2
3#include <linux/moduleparam.h>
4#include <linux/vmalloc.h>
5
6#include <drm/drm_crtc_helper.h>
7#include <drm/drm_drv.h>
8#include <drm/drm_fb_helper.h>
9#include <drm/drm_framebuffer.h>
10#include <drm/drm_gem.h>
11#include <drm/drm_print.h>
12
13#include <drm/drm_fbdev_generic.h>
14
15/* @user: 1=userspace, 0=fbcon */
16static int drm_fbdev_generic_fb_open(struct fb_info *info, int user)
17{
18 struct drm_fb_helper *fb_helper = info->par;
19
20 /* No need to take a ref for fbcon because it unbinds on unregister */
21 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
22 return -ENODEV;
23
24 return 0;
25}
26
27static int drm_fbdev_generic_fb_release(struct fb_info *info, int user)
28{
29 struct drm_fb_helper *fb_helper = info->par;
30
31 if (user)
32 module_put(fb_helper->dev->driver->fops->owner);
33
34 return 0;
35}
36
37FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_generic,
38 drm_fb_helper_damage_range,
39 drm_fb_helper_damage_area);
40
41static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
42{
43 struct drm_fb_helper *fb_helper = info->par;
44 void *shadow = info->screen_buffer;
45
46 if (!fb_helper->dev)
47 return;
48
49 fb_deferred_io_cleanup(info);
50 drm_fb_helper_fini(fb_helper);
51 vfree(shadow);
52 drm_client_framebuffer_delete(fb_helper->buffer);
53
54 drm_client_release(&fb_helper->client);
55 drm_fb_helper_unprepare(fb_helper);
56 kfree(fb_helper);
57}
58
59static const struct fb_ops drm_fbdev_generic_fb_ops = {
60 .owner = THIS_MODULE,
61 .fb_open = drm_fbdev_generic_fb_open,
62 .fb_release = drm_fbdev_generic_fb_release,
63 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),
64 DRM_FB_HELPER_DEFAULT_OPS,
65 .fb_destroy = drm_fbdev_generic_fb_destroy,
66};
67
68/*
69 * This function uses the client API to create a framebuffer backed by a dumb buffer.
70 */
71static int drm_fbdev_generic_helper_fb_probe(struct drm_fb_helper *fb_helper,
72 struct drm_fb_helper_surface_size *sizes)
73{
74 struct drm_client_dev *client = &fb_helper->client;
75 struct drm_device *dev = fb_helper->dev;
76 struct drm_client_buffer *buffer;
77 struct fb_info *info;
78 size_t screen_size;
79 void *screen_buffer;
80 u32 format;
81 int ret;
82
83 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
84 sizes->surface_width, sizes->surface_height,
85 sizes->surface_bpp);
86
87 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
88 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
89 sizes->surface_height, format);
90 if (IS_ERR(buffer))
91 return PTR_ERR(buffer);
92
93 fb_helper->buffer = buffer;
94 fb_helper->fb = buffer->fb;
95
96 screen_size = buffer->gem->size;
97 screen_buffer = vzalloc(screen_size);
98 if (!screen_buffer) {
99 ret = -ENOMEM;
100 goto err_drm_client_framebuffer_delete;
101 }
102
103 info = drm_fb_helper_alloc_info(fb_helper);
104 if (IS_ERR(info)) {
105 ret = PTR_ERR(info);
106 goto err_vfree;
107 }
108
109 drm_fb_helper_fill_info(info, fb_helper, sizes);
110
111 info->fbops = &drm_fbdev_generic_fb_ops;
112
113 /* screen */
114 info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
115 info->screen_buffer = screen_buffer;
116 info->fix.smem_start = page_to_phys(vmalloc_to_page(info->screen_buffer));
117 info->fix.smem_len = screen_size;
118
119 /* deferred I/O */
120 fb_helper->fbdefio.delay = HZ / 20;
121 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
122
123 info->fbdefio = &fb_helper->fbdefio;
124 ret = fb_deferred_io_init(info);
125 if (ret)
126 goto err_drm_fb_helper_release_info;
127
128 return 0;
129
130err_drm_fb_helper_release_info:
131 drm_fb_helper_release_info(fb_helper);
132err_vfree:
133 vfree(screen_buffer);
134err_drm_client_framebuffer_delete:
135 fb_helper->fb = NULL;
136 fb_helper->buffer = NULL;
137 drm_client_framebuffer_delete(buffer);
138 return ret;
139}
140
141static void drm_fbdev_generic_damage_blit_real(struct drm_fb_helper *fb_helper,
142 struct drm_clip_rect *clip,
143 struct iosys_map *dst)
144{
145 struct drm_framebuffer *fb = fb_helper->fb;
146 size_t offset = clip->y1 * fb->pitches[0];
147 size_t len = clip->x2 - clip->x1;
148 unsigned int y;
149 void *src;
150
151 switch (drm_format_info_bpp(fb->format, 0)) {
152 case 1:
153 offset += clip->x1 / 8;
154 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
155 break;
156 case 2:
157 offset += clip->x1 / 4;
158 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
159 break;
160 case 4:
161 offset += clip->x1 / 2;
162 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
163 break;
164 default:
165 offset += clip->x1 * fb->format->cpp[0];
166 len *= fb->format->cpp[0];
167 break;
168 }
169
170 src = fb_helper->info->screen_buffer + offset;
171 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
172
173 for (y = clip->y1; y < clip->y2; y++) {
174 iosys_map_memcpy_to(dst, 0, src, len);
175 iosys_map_incr(dst, fb->pitches[0]);
176 src += fb->pitches[0];
177 }
178}
179
180static int drm_fbdev_generic_damage_blit(struct drm_fb_helper *fb_helper,
181 struct drm_clip_rect *clip)
182{
183 struct drm_client_buffer *buffer = fb_helper->buffer;
184 struct iosys_map map, dst;
185 int ret;
186
187 /*
188 * We have to pin the client buffer to its current location while
189 * flushing the shadow buffer. In the general case, concurrent
190 * modesetting operations could try to move the buffer and would
191 * fail. The modeset has to be serialized by acquiring the reservation
192 * object of the underlying BO here.
193 *
194 * For fbdev emulation, we only have to protect against fbdev modeset
195 * operations. Nothing else will involve the client buffer's BO. So it
196 * is sufficient to acquire struct drm_fb_helper.lock here.
197 */
198 mutex_lock(&fb_helper->lock);
199
200 ret = drm_client_buffer_vmap(buffer, &map);
201 if (ret)
202 goto out;
203
204 dst = map;
205 drm_fbdev_generic_damage_blit_real(fb_helper, clip, &dst);
206
207 drm_client_buffer_vunmap(buffer);
208
209out:
210 mutex_unlock(&fb_helper->lock);
211
212 return ret;
213}
214
215static int drm_fbdev_generic_helper_fb_dirty(struct drm_fb_helper *helper,
216 struct drm_clip_rect *clip)
217{
218 struct drm_device *dev = helper->dev;
219 int ret;
220
221 /* Call damage handlers only if necessary */
222 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
223 return 0;
224
225 ret = drm_fbdev_generic_damage_blit(helper, clip);
226 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
227 return ret;
228
229 if (helper->fb->funcs->dirty) {
230 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
231 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
232 return ret;
233 }
234
235 return 0;
236}
237
238static const struct drm_fb_helper_funcs drm_fbdev_generic_helper_funcs = {
239 .fb_probe = drm_fbdev_generic_helper_fb_probe,
240 .fb_dirty = drm_fbdev_generic_helper_fb_dirty,
241};
242
243static void drm_fbdev_generic_client_unregister(struct drm_client_dev *client)
244{
245 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
246
247 if (fb_helper->info) {
248 drm_fb_helper_unregister_info(fb_helper);
249 } else {
250 drm_client_release(&fb_helper->client);
251 drm_fb_helper_unprepare(fb_helper);
252 kfree(fb_helper);
253 }
254}
255
256static int drm_fbdev_generic_client_restore(struct drm_client_dev *client)
257{
258 drm_fb_helper_lastclose(client->dev);
259
260 return 0;
261}
262
263static int drm_fbdev_generic_client_hotplug(struct drm_client_dev *client)
264{
265 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
266 struct drm_device *dev = client->dev;
267 int ret;
268
269 if (dev->fb_helper)
270 return drm_fb_helper_hotplug_event(dev->fb_helper);
271
272 ret = drm_fb_helper_init(dev, fb_helper);
273 if (ret)
274 goto err_drm_err;
275
276 if (!drm_drv_uses_atomic_modeset(dev))
277 drm_helper_disable_unused_functions(dev);
278
279 ret = drm_fb_helper_initial_config(fb_helper);
280 if (ret)
281 goto err_drm_fb_helper_fini;
282
283 return 0;
284
285err_drm_fb_helper_fini:
286 drm_fb_helper_fini(fb_helper);
287err_drm_err:
288 drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
289 return ret;
290}
291
292static const struct drm_client_funcs drm_fbdev_generic_client_funcs = {
293 .owner = THIS_MODULE,
294 .unregister = drm_fbdev_generic_client_unregister,
295 .restore = drm_fbdev_generic_client_restore,
296 .hotplug = drm_fbdev_generic_client_hotplug,
297};
298
299/**
300 * drm_fbdev_generic_setup() - Setup generic fbdev emulation
301 * @dev: DRM device
302 * @preferred_bpp: Preferred bits per pixel for the device.
303 *
304 * This function sets up generic fbdev emulation for drivers that supports
305 * dumb buffers with a virtual address and that can be mmap'ed.
306 * drm_fbdev_generic_setup() shall be called after the DRM driver registered
307 * the new DRM device with drm_dev_register().
308 *
309 * Restore, hotplug events and teardown are all taken care of. Drivers that do
310 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
311 * Simple drivers might use drm_mode_config_helper_suspend().
312 *
313 * In order to provide fixed mmap-able memory ranges, generic fbdev emulation
314 * uses a shadow buffer in system memory. The implementation blits the shadow
315 * fbdev buffer onto the real buffer in regular intervals.
316 *
317 * This function is safe to call even when there are no connectors present.
318 * Setup will be retried on the next hotplug event.
319 *
320 * The fbdev is destroyed by drm_dev_unregister().
321 */
322void drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
323{
324 struct drm_fb_helper *fb_helper;
325 int ret;
326
327 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
328 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
329
330 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
331 if (!fb_helper)
332 return;
333 drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_generic_helper_funcs);
334
335 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_generic_client_funcs);
336 if (ret) {
337 drm_err(dev, "Failed to register client: %d\n", ret);
338 goto err_drm_client_init;
339 }
340
341 drm_client_register(&fb_helper->client);
342
343 return;
344
345err_drm_client_init:
346 drm_fb_helper_unprepare(fb_helper);
347 kfree(fb_helper);
348 return;
349}
350EXPORT_SYMBOL(drm_fbdev_generic_setup);
1// SPDX-License-Identifier: MIT
2
3#include <linux/moduleparam.h>
4#include <linux/vmalloc.h>
5
6#include <drm/drm_crtc_helper.h>
7#include <drm/drm_drv.h>
8#include <drm/drm_fb_helper.h>
9#include <drm/drm_framebuffer.h>
10#include <drm/drm_print.h>
11
12#include <drm/drm_fbdev_generic.h>
13
14static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
15{
16 struct drm_device *dev = fb_helper->dev;
17 struct drm_framebuffer *fb = fb_helper->fb;
18
19 return dev->mode_config.prefer_shadow_fbdev ||
20 dev->mode_config.prefer_shadow ||
21 fb->funcs->dirty;
22}
23
24/* @user: 1=userspace, 0=fbcon */
25static int drm_fbdev_fb_open(struct fb_info *info, int user)
26{
27 struct drm_fb_helper *fb_helper = info->par;
28
29 /* No need to take a ref for fbcon because it unbinds on unregister */
30 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
31 return -ENODEV;
32
33 return 0;
34}
35
36static int drm_fbdev_fb_release(struct fb_info *info, int user)
37{
38 struct drm_fb_helper *fb_helper = info->par;
39
40 if (user)
41 module_put(fb_helper->dev->driver->fops->owner);
42
43 return 0;
44}
45
46static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
47{
48 struct fb_info *fbi = fb_helper->info;
49 void *shadow = NULL;
50
51 if (!fb_helper->dev)
52 return;
53
54 if (fbi) {
55 if (fbi->fbdefio)
56 fb_deferred_io_cleanup(fbi);
57 if (drm_fbdev_use_shadow_fb(fb_helper))
58 shadow = fbi->screen_buffer;
59 }
60
61 drm_fb_helper_fini(fb_helper);
62
63 if (shadow)
64 vfree(shadow);
65 else if (fb_helper->buffer)
66 drm_client_buffer_vunmap(fb_helper->buffer);
67
68 drm_client_framebuffer_delete(fb_helper->buffer);
69}
70
71static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
72{
73 drm_fbdev_cleanup(fb_helper);
74 drm_client_release(&fb_helper->client);
75 kfree(fb_helper);
76}
77
78/*
79 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
80 * unregister_framebuffer() or fb_release().
81 */
82static void drm_fbdev_fb_destroy(struct fb_info *info)
83{
84 drm_fbdev_release(info->par);
85}
86
87static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
88{
89 struct drm_fb_helper *fb_helper = info->par;
90
91 if (drm_fbdev_use_shadow_fb(fb_helper))
92 return fb_deferred_io_mmap(info, vma);
93 else if (fb_helper->dev->driver->gem_prime_mmap)
94 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
95 else
96 return -ENODEV;
97}
98
99static bool drm_fbdev_use_iomem(struct fb_info *info)
100{
101 struct drm_fb_helper *fb_helper = info->par;
102 struct drm_client_buffer *buffer = fb_helper->buffer;
103
104 return !drm_fbdev_use_shadow_fb(fb_helper) && buffer->map.is_iomem;
105}
106
107static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf,
108 size_t count, loff_t *ppos)
109{
110 ssize_t ret;
111
112 if (drm_fbdev_use_iomem(info))
113 ret = drm_fb_helper_cfb_read(info, buf, count, ppos);
114 else
115 ret = drm_fb_helper_sys_read(info, buf, count, ppos);
116
117 return ret;
118}
119
120static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf,
121 size_t count, loff_t *ppos)
122{
123 ssize_t ret;
124
125 if (drm_fbdev_use_iomem(info))
126 ret = drm_fb_helper_cfb_write(info, buf, count, ppos);
127 else
128 ret = drm_fb_helper_sys_write(info, buf, count, ppos);
129
130 return ret;
131}
132
133static void drm_fbdev_fb_fillrect(struct fb_info *info,
134 const struct fb_fillrect *rect)
135{
136 if (drm_fbdev_use_iomem(info))
137 drm_fb_helper_cfb_fillrect(info, rect);
138 else
139 drm_fb_helper_sys_fillrect(info, rect);
140}
141
142static void drm_fbdev_fb_copyarea(struct fb_info *info,
143 const struct fb_copyarea *area)
144{
145 if (drm_fbdev_use_iomem(info))
146 drm_fb_helper_cfb_copyarea(info, area);
147 else
148 drm_fb_helper_sys_copyarea(info, area);
149}
150
151static void drm_fbdev_fb_imageblit(struct fb_info *info,
152 const struct fb_image *image)
153{
154 if (drm_fbdev_use_iomem(info))
155 drm_fb_helper_cfb_imageblit(info, image);
156 else
157 drm_fb_helper_sys_imageblit(info, image);
158}
159
160static const struct fb_ops drm_fbdev_fb_ops = {
161 .owner = THIS_MODULE,
162 DRM_FB_HELPER_DEFAULT_OPS,
163 .fb_open = drm_fbdev_fb_open,
164 .fb_release = drm_fbdev_fb_release,
165 .fb_destroy = drm_fbdev_fb_destroy,
166 .fb_mmap = drm_fbdev_fb_mmap,
167 .fb_read = drm_fbdev_fb_read,
168 .fb_write = drm_fbdev_fb_write,
169 .fb_fillrect = drm_fbdev_fb_fillrect,
170 .fb_copyarea = drm_fbdev_fb_copyarea,
171 .fb_imageblit = drm_fbdev_fb_imageblit,
172};
173
174/*
175 * This function uses the client API to create a framebuffer backed by a dumb buffer.
176 */
177static int drm_fbdev_fb_probe(struct drm_fb_helper *fb_helper,
178 struct drm_fb_helper_surface_size *sizes)
179{
180 struct drm_client_dev *client = &fb_helper->client;
181 struct drm_device *dev = fb_helper->dev;
182 struct drm_client_buffer *buffer;
183 struct drm_framebuffer *fb;
184 struct fb_info *fbi;
185 u32 format;
186 struct iosys_map map;
187 int ret;
188
189 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
190 sizes->surface_width, sizes->surface_height,
191 sizes->surface_bpp);
192
193 format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
194 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
195 sizes->surface_height, format);
196 if (IS_ERR(buffer))
197 return PTR_ERR(buffer);
198
199 fb_helper->buffer = buffer;
200 fb_helper->fb = buffer->fb;
201 fb = buffer->fb;
202
203 fbi = drm_fb_helper_alloc_info(fb_helper);
204 if (IS_ERR(fbi))
205 return PTR_ERR(fbi);
206
207 fbi->fbops = &drm_fbdev_fb_ops;
208 fbi->screen_size = sizes->surface_height * fb->pitches[0];
209 fbi->fix.smem_len = fbi->screen_size;
210 fbi->flags = FBINFO_DEFAULT;
211
212 drm_fb_helper_fill_info(fbi, fb_helper, sizes);
213
214 if (drm_fbdev_use_shadow_fb(fb_helper)) {
215 fbi->screen_buffer = vzalloc(fbi->screen_size);
216 if (!fbi->screen_buffer)
217 return -ENOMEM;
218 fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
219
220 /* Set a default deferred I/O handler */
221 fb_helper->fbdefio.delay = HZ / 20;
222 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
223
224 fbi->fbdefio = &fb_helper->fbdefio;
225 ret = fb_deferred_io_init(fbi);
226 if (ret)
227 return ret;
228 } else {
229 /* buffer is mapped for HW framebuffer */
230 ret = drm_client_buffer_vmap(fb_helper->buffer, &map);
231 if (ret)
232 return ret;
233 if (map.is_iomem) {
234 fbi->screen_base = map.vaddr_iomem;
235 } else {
236 fbi->screen_buffer = map.vaddr;
237 fbi->flags |= FBINFO_VIRTFB;
238 }
239
240 /*
241 * Shamelessly leak the physical address to user-space. As
242 * page_to_phys() is undefined for I/O memory, warn in this
243 * case.
244 */
245#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
246 if (fb_helper->hint_leak_smem_start && fbi->fix.smem_start == 0 &&
247 !drm_WARN_ON_ONCE(dev, map.is_iomem))
248 fbi->fix.smem_start =
249 page_to_phys(virt_to_page(fbi->screen_buffer));
250#endif
251 }
252
253 return 0;
254}
255
256static void drm_fbdev_damage_blit_real(struct drm_fb_helper *fb_helper,
257 struct drm_clip_rect *clip,
258 struct iosys_map *dst)
259{
260 struct drm_framebuffer *fb = fb_helper->fb;
261 size_t offset = clip->y1 * fb->pitches[0];
262 size_t len = clip->x2 - clip->x1;
263 unsigned int y;
264 void *src;
265
266 switch (drm_format_info_bpp(fb->format, 0)) {
267 case 1:
268 offset += clip->x1 / 8;
269 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
270 break;
271 case 2:
272 offset += clip->x1 / 4;
273 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
274 break;
275 case 4:
276 offset += clip->x1 / 2;
277 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
278 break;
279 default:
280 offset += clip->x1 * fb->format->cpp[0];
281 len *= fb->format->cpp[0];
282 break;
283 }
284
285 src = fb_helper->info->screen_buffer + offset;
286 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
287
288 for (y = clip->y1; y < clip->y2; y++) {
289 iosys_map_memcpy_to(dst, 0, src, len);
290 iosys_map_incr(dst, fb->pitches[0]);
291 src += fb->pitches[0];
292 }
293}
294
295static int drm_fbdev_damage_blit(struct drm_fb_helper *fb_helper,
296 struct drm_clip_rect *clip)
297{
298 struct drm_client_buffer *buffer = fb_helper->buffer;
299 struct iosys_map map, dst;
300 int ret;
301
302 /*
303 * We have to pin the client buffer to its current location while
304 * flushing the shadow buffer. In the general case, concurrent
305 * modesetting operations could try to move the buffer and would
306 * fail. The modeset has to be serialized by acquiring the reservation
307 * object of the underlying BO here.
308 *
309 * For fbdev emulation, we only have to protect against fbdev modeset
310 * operations. Nothing else will involve the client buffer's BO. So it
311 * is sufficient to acquire struct drm_fb_helper.lock here.
312 */
313 mutex_lock(&fb_helper->lock);
314
315 ret = drm_client_buffer_vmap(buffer, &map);
316 if (ret)
317 goto out;
318
319 dst = map;
320 drm_fbdev_damage_blit_real(fb_helper, clip, &dst);
321
322 drm_client_buffer_vunmap(buffer);
323
324out:
325 mutex_unlock(&fb_helper->lock);
326
327 return ret;
328}
329
330static int drm_fbdev_fb_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
331{
332 struct drm_device *dev = helper->dev;
333 int ret;
334
335 if (!drm_fbdev_use_shadow_fb(helper))
336 return 0;
337
338 /* Call damage handlers only if necessary */
339 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
340 return 0;
341
342 if (helper->buffer) {
343 ret = drm_fbdev_damage_blit(helper, clip);
344 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
345 return ret;
346 }
347
348 if (helper->fb->funcs->dirty) {
349 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
350 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
351 return ret;
352 }
353
354 return 0;
355}
356
357static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
358 .fb_probe = drm_fbdev_fb_probe,
359 .fb_dirty = drm_fbdev_fb_dirty,
360};
361
362static void drm_fbdev_client_unregister(struct drm_client_dev *client)
363{
364 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
365
366 if (fb_helper->info)
367 /* drm_fbdev_fb_destroy() takes care of cleanup */
368 drm_fb_helper_unregister_info(fb_helper);
369 else
370 drm_fbdev_release(fb_helper);
371}
372
373static int drm_fbdev_client_restore(struct drm_client_dev *client)
374{
375 drm_fb_helper_lastclose(client->dev);
376
377 return 0;
378}
379
380static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
381{
382 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
383 struct drm_device *dev = client->dev;
384 int ret;
385
386 /* Setup is not retried if it has failed */
387 if (!fb_helper->dev && fb_helper->funcs)
388 return 0;
389
390 if (dev->fb_helper)
391 return drm_fb_helper_hotplug_event(dev->fb_helper);
392
393 if (!dev->mode_config.num_connector) {
394 drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
395 return 0;
396 }
397
398 drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
399
400 ret = drm_fb_helper_init(dev, fb_helper);
401 if (ret)
402 goto err;
403
404 if (!drm_drv_uses_atomic_modeset(dev))
405 drm_helper_disable_unused_functions(dev);
406
407 ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
408 if (ret)
409 goto err_cleanup;
410
411 return 0;
412
413err_cleanup:
414 drm_fbdev_cleanup(fb_helper);
415err:
416 fb_helper->dev = NULL;
417 fb_helper->info = NULL;
418
419 drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
420
421 return ret;
422}
423
424static const struct drm_client_funcs drm_fbdev_client_funcs = {
425 .owner = THIS_MODULE,
426 .unregister = drm_fbdev_client_unregister,
427 .restore = drm_fbdev_client_restore,
428 .hotplug = drm_fbdev_client_hotplug,
429};
430
431/**
432 * drm_fbdev_generic_setup() - Setup generic fbdev emulation
433 * @dev: DRM device
434 * @preferred_bpp: Preferred bits per pixel for the device.
435 * @dev->mode_config.preferred_depth is used if this is zero.
436 *
437 * This function sets up generic fbdev emulation for drivers that supports
438 * dumb buffers with a virtual address and that can be mmap'ed.
439 * drm_fbdev_generic_setup() shall be called after the DRM driver registered
440 * the new DRM device with drm_dev_register().
441 *
442 * Restore, hotplug events and teardown are all taken care of. Drivers that do
443 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
444 * Simple drivers might use drm_mode_config_helper_suspend().
445 *
446 * Drivers that set the dirty callback on their framebuffer will get a shadow
447 * fbdev buffer that is blitted onto the real buffer. This is done in order to
448 * make deferred I/O work with all kinds of buffers. A shadow buffer can be
449 * requested explicitly by setting struct drm_mode_config.prefer_shadow or
450 * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is
451 * required to use generic fbdev emulation with SHMEM helpers.
452 *
453 * This function is safe to call even when there are no connectors present.
454 * Setup will be retried on the next hotplug event.
455 *
456 * The fbdev is destroyed by drm_dev_unregister().
457 */
458void drm_fbdev_generic_setup(struct drm_device *dev,
459 unsigned int preferred_bpp)
460{
461 struct drm_fb_helper *fb_helper;
462 int ret;
463
464 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
465 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
466
467 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
468 if (!fb_helper)
469 return;
470
471 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
472 if (ret) {
473 kfree(fb_helper);
474 drm_err(dev, "Failed to register client: %d\n", ret);
475 return;
476 }
477
478 /*
479 * FIXME: This mixes up depth with bpp, which results in a glorious
480 * mess, resulting in some drivers picking wrong fbdev defaults and
481 * others wrong preferred_depth defaults.
482 */
483 if (!preferred_bpp)
484 preferred_bpp = dev->mode_config.preferred_depth;
485 if (!preferred_bpp)
486 preferred_bpp = 32;
487 fb_helper->preferred_bpp = preferred_bpp;
488
489 ret = drm_fbdev_client_hotplug(&fb_helper->client);
490 if (ret)
491 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
492
493 drm_client_register(&fb_helper->client);
494}
495EXPORT_SYMBOL(drm_fbdev_generic_setup);