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1 /*
2  * drm kms/fb cma (contiguous memory allocator) helper functions
3  *
4  * Copyright (C) 2012 Analog Device Inc.
5  *   Author: Lars-Peter Clausen <lars@metafoo.de>
6  *
7  * Based on udl_fbdev.c
8  *  Copyright (C) 2012 Red Hat
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * as published by the Free Software Foundation; either version 2
13  * of the License, or (at your option) any later version.
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <drm/drmP.h>
21 #include <drm/drm_crtc.h>
22 #include <drm/drm_fb_helper.h>
23 #include <drm/drm_crtc_helper.h>
24 #include <drm/drm_gem_cma_helper.h>
25 #include <drm/drm_fb_cma_helper.h>
26 #include <linux/module.h>
27 
28 struct drm_fb_cma {
29 	struct drm_framebuffer		fb;
30 	struct drm_gem_cma_object	*obj[4];
31 };
32 
33 struct drm_fbdev_cma {
34 	struct drm_fb_helper	fb_helper;
35 	struct drm_fb_cma	*fb;
36 };
37 
to_fbdev_cma(struct drm_fb_helper * helper)38 static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper *helper)
39 {
40 	return container_of(helper, struct drm_fbdev_cma, fb_helper);
41 }
42 
to_fb_cma(struct drm_framebuffer * fb)43 static inline struct drm_fb_cma *to_fb_cma(struct drm_framebuffer *fb)
44 {
45 	return container_of(fb, struct drm_fb_cma, fb);
46 }
47 
drm_fb_cma_destroy(struct drm_framebuffer * fb)48 static void drm_fb_cma_destroy(struct drm_framebuffer *fb)
49 {
50 	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
51 	int i;
52 
53 	for (i = 0; i < 4; i++) {
54 		if (fb_cma->obj[i])
55 			drm_gem_object_unreference_unlocked(&fb_cma->obj[i]->base);
56 	}
57 
58 	drm_framebuffer_cleanup(fb);
59 	kfree(fb_cma);
60 }
61 
drm_fb_cma_create_handle(struct drm_framebuffer * fb,struct drm_file * file_priv,unsigned int * handle)62 static int drm_fb_cma_create_handle(struct drm_framebuffer *fb,
63 	struct drm_file *file_priv, unsigned int *handle)
64 {
65 	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
66 
67 	return drm_gem_handle_create(file_priv,
68 			&fb_cma->obj[0]->base, handle);
69 }
70 
71 static struct drm_framebuffer_funcs drm_fb_cma_funcs = {
72 	.destroy	= drm_fb_cma_destroy,
73 	.create_handle	= drm_fb_cma_create_handle,
74 };
75 
drm_fb_cma_alloc(struct drm_device * dev,struct drm_mode_fb_cmd2 * mode_cmd,struct drm_gem_cma_object ** obj,unsigned int num_planes)76 static struct drm_fb_cma *drm_fb_cma_alloc(struct drm_device *dev,
77 	struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_cma_object **obj,
78 	unsigned int num_planes)
79 {
80 	struct drm_fb_cma *fb_cma;
81 	int ret;
82 	int i;
83 
84 	fb_cma = kzalloc(sizeof(*fb_cma), GFP_KERNEL);
85 	if (!fb_cma)
86 		return ERR_PTR(-ENOMEM);
87 
88 	drm_helper_mode_fill_fb_struct(&fb_cma->fb, mode_cmd);
89 
90 	for (i = 0; i < num_planes; i++)
91 		fb_cma->obj[i] = obj[i];
92 
93 	ret = drm_framebuffer_init(dev, &fb_cma->fb, &drm_fb_cma_funcs);
94 	if (ret) {
95 		dev_err(dev->dev, "Failed to initialize framebuffer: %d\n", ret);
96 		kfree(fb_cma);
97 		return ERR_PTR(ret);
98 	}
99 
100 	return fb_cma;
101 }
102 
103 /**
104  * drm_fb_cma_create() - (struct drm_mode_config_funcs *)->fb_create callback function
105  *
106  * If your hardware has special alignment or pitch requirements these should be
107  * checked before calling this function.
108  */
drm_fb_cma_create(struct drm_device * dev,struct drm_file * file_priv,struct drm_mode_fb_cmd2 * mode_cmd)109 struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
110 	struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd)
111 {
112 	struct drm_fb_cma *fb_cma;
113 	struct drm_gem_cma_object *objs[4];
114 	struct drm_gem_object *obj;
115 	unsigned int hsub;
116 	unsigned int vsub;
117 	int ret;
118 	int i;
119 
120 	hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
121 	vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);
122 
123 	for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
124 		unsigned int width = mode_cmd->width / (i ? hsub : 1);
125 		unsigned int height = mode_cmd->height / (i ? vsub : 1);
126 		unsigned int min_size;
127 
128 		obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[i]);
129 		if (!obj) {
130 			dev_err(dev->dev, "Failed to lookup GEM object\n");
131 			ret = -ENXIO;
132 			goto err_gem_object_unreference;
133 		}
134 
135 		min_size = (height - 1) * mode_cmd->pitches[i]
136 			 + width * drm_format_plane_cpp(mode_cmd->pixel_format, i)
137 			 + mode_cmd->offsets[i];
138 
139 		if (obj->size < min_size) {
140 			drm_gem_object_unreference_unlocked(obj);
141 			ret = -EINVAL;
142 			goto err_gem_object_unreference;
143 		}
144 		objs[i] = to_drm_gem_cma_obj(obj);
145 	}
146 
147 	fb_cma = drm_fb_cma_alloc(dev, mode_cmd, objs, i);
148 	if (IS_ERR(fb_cma)) {
149 		ret = PTR_ERR(fb_cma);
150 		goto err_gem_object_unreference;
151 	}
152 
153 	return &fb_cma->fb;
154 
155 err_gem_object_unreference:
156 	for (i--; i >= 0; i--)
157 		drm_gem_object_unreference_unlocked(&objs[i]->base);
158 	return ERR_PTR(ret);
159 }
160 EXPORT_SYMBOL_GPL(drm_fb_cma_create);
161 
162 /**
163  * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
164  * @fb: The framebuffer
165  * @plane: Which plane
166  *
167  * Return the CMA GEM object for given framebuffer.
168  *
169  * This function will usually be called from the CRTC callback functions.
170  */
drm_fb_cma_get_gem_obj(struct drm_framebuffer * fb,unsigned int plane)171 struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
172 	unsigned int plane)
173 {
174 	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
175 
176 	if (plane >= 4)
177 		return NULL;
178 
179 	return fb_cma->obj[plane];
180 }
181 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
182 
183 #ifdef CONFIG_DEBUG_FS
184 /*
185  * drm_fb_cma_describe() - Helper to dump information about a single
186  * CMA framebuffer object
187  */
drm_fb_cma_describe(struct drm_framebuffer * fb,struct seq_file * m)188 static void drm_fb_cma_describe(struct drm_framebuffer *fb, struct seq_file *m)
189 {
190 	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
191 	int i, n = drm_format_num_planes(fb->pixel_format);
192 
193 	seq_printf(m, "fb: %dx%d@%4.4s\n", fb->width, fb->height,
194 			(char *)&fb->pixel_format);
195 
196 	for (i = 0; i < n; i++) {
197 		seq_printf(m, "   %d: offset=%d pitch=%d, obj: ",
198 				i, fb->offsets[i], fb->pitches[i]);
199 		drm_gem_cma_describe(fb_cma->obj[i], m);
200 	}
201 }
202 
203 /**
204  * drm_fb_cma_debugfs_show() - Helper to list CMA framebuffer objects
205  * in debugfs.
206  */
drm_fb_cma_debugfs_show(struct seq_file * m,void * arg)207 int drm_fb_cma_debugfs_show(struct seq_file *m, void *arg)
208 {
209 	struct drm_info_node *node = (struct drm_info_node *) m->private;
210 	struct drm_device *dev = node->minor->dev;
211 	struct drm_framebuffer *fb;
212 	int ret;
213 
214 	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
215 	if (ret)
216 		return ret;
217 
218 	ret = mutex_lock_interruptible(&dev->struct_mutex);
219 	if (ret) {
220 		mutex_unlock(&dev->mode_config.mutex);
221 		return ret;
222 	}
223 
224 	list_for_each_entry(fb, &dev->mode_config.fb_list, head)
225 		drm_fb_cma_describe(fb, m);
226 
227 	mutex_unlock(&dev->struct_mutex);
228 	mutex_unlock(&dev->mode_config.mutex);
229 
230 	return 0;
231 }
232 EXPORT_SYMBOL_GPL(drm_fb_cma_debugfs_show);
233 #endif
234 
235 static struct fb_ops drm_fbdev_cma_ops = {
236 	.owner		= THIS_MODULE,
237 	.fb_fillrect	= sys_fillrect,
238 	.fb_copyarea	= sys_copyarea,
239 	.fb_imageblit	= sys_imageblit,
240 	.fb_check_var	= drm_fb_helper_check_var,
241 	.fb_set_par	= drm_fb_helper_set_par,
242 	.fb_blank	= drm_fb_helper_blank,
243 	.fb_pan_display	= drm_fb_helper_pan_display,
244 	.fb_setcmap	= drm_fb_helper_setcmap,
245 };
246 
drm_fbdev_cma_create(struct drm_fb_helper * helper,struct drm_fb_helper_surface_size * sizes)247 static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
248 	struct drm_fb_helper_surface_size *sizes)
249 {
250 	struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
251 	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
252 	struct drm_device *dev = helper->dev;
253 	struct drm_gem_cma_object *obj;
254 	struct drm_framebuffer *fb;
255 	unsigned int bytes_per_pixel;
256 	unsigned long offset;
257 	struct fb_info *fbi;
258 	size_t size;
259 	int ret;
260 
261 	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
262 			sizes->surface_width, sizes->surface_height,
263 			sizes->surface_bpp);
264 
265 	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
266 
267 	mode_cmd.width = sizes->surface_width;
268 	mode_cmd.height = sizes->surface_height;
269 	mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
270 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
271 		sizes->surface_depth);
272 
273 	size = mode_cmd.pitches[0] * mode_cmd.height;
274 	obj = drm_gem_cma_create(dev, size);
275 	if (IS_ERR(obj))
276 		return -ENOMEM;
277 
278 	fbi = framebuffer_alloc(0, dev->dev);
279 	if (!fbi) {
280 		dev_err(dev->dev, "Failed to allocate framebuffer info.\n");
281 		ret = -ENOMEM;
282 		goto err_drm_gem_cma_free_object;
283 	}
284 
285 	fbdev_cma->fb = drm_fb_cma_alloc(dev, &mode_cmd, &obj, 1);
286 	if (IS_ERR(fbdev_cma->fb)) {
287 		dev_err(dev->dev, "Failed to allocate DRM framebuffer.\n");
288 		ret = PTR_ERR(fbdev_cma->fb);
289 		goto err_framebuffer_release;
290 	}
291 
292 	fb = &fbdev_cma->fb->fb;
293 	helper->fb = fb;
294 	helper->fbdev = fbi;
295 
296 	fbi->par = helper;
297 	fbi->flags = FBINFO_FLAG_DEFAULT;
298 	fbi->fbops = &drm_fbdev_cma_ops;
299 
300 	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
301 	if (ret) {
302 		dev_err(dev->dev, "Failed to allocate color map.\n");
303 		goto err_drm_fb_cma_destroy;
304 	}
305 
306 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
307 	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);
308 
309 	offset = fbi->var.xoffset * bytes_per_pixel;
310 	offset += fbi->var.yoffset * fb->pitches[0];
311 
312 	dev->mode_config.fb_base = (resource_size_t)obj->paddr;
313 	fbi->screen_base = obj->vaddr + offset;
314 	fbi->fix.smem_start = (unsigned long)(obj->paddr + offset);
315 	fbi->screen_size = size;
316 	fbi->fix.smem_len = size;
317 
318 	return 0;
319 
320 err_drm_fb_cma_destroy:
321 	drm_framebuffer_unregister_private(fb);
322 	drm_fb_cma_destroy(fb);
323 err_framebuffer_release:
324 	framebuffer_release(fbi);
325 err_drm_gem_cma_free_object:
326 	drm_gem_cma_free_object(&obj->base);
327 	return ret;
328 }
329 
330 static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
331 	.fb_probe = drm_fbdev_cma_create,
332 };
333 
334 /**
335  * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
336  * @dev: DRM device
337  * @preferred_bpp: Preferred bits per pixel for the device
338  * @num_crtc: Number of CRTCs
339  * @max_conn_count: Maximum number of connectors
340  *
341  * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
342  */
drm_fbdev_cma_init(struct drm_device * dev,unsigned int preferred_bpp,unsigned int num_crtc,unsigned int max_conn_count)343 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
344 	unsigned int preferred_bpp, unsigned int num_crtc,
345 	unsigned int max_conn_count)
346 {
347 	struct drm_fbdev_cma *fbdev_cma;
348 	struct drm_fb_helper *helper;
349 	int ret;
350 
351 	fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
352 	if (!fbdev_cma) {
353 		dev_err(dev->dev, "Failed to allocate drm fbdev.\n");
354 		return ERR_PTR(-ENOMEM);
355 	}
356 
357 	helper = &fbdev_cma->fb_helper;
358 
359 	drm_fb_helper_prepare(dev, helper, &drm_fb_cma_helper_funcs);
360 
361 	ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
362 	if (ret < 0) {
363 		dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
364 		goto err_free;
365 	}
366 
367 	ret = drm_fb_helper_single_add_all_connectors(helper);
368 	if (ret < 0) {
369 		dev_err(dev->dev, "Failed to add connectors.\n");
370 		goto err_drm_fb_helper_fini;
371 
372 	}
373 
374 	/* disable all the possible outputs/crtcs before entering KMS mode */
375 	drm_helper_disable_unused_functions(dev);
376 
377 	ret = drm_fb_helper_initial_config(helper, preferred_bpp);
378 	if (ret < 0) {
379 		dev_err(dev->dev, "Failed to set initial hw configuration.\n");
380 		goto err_drm_fb_helper_fini;
381 	}
382 
383 	return fbdev_cma;
384 
385 err_drm_fb_helper_fini:
386 	drm_fb_helper_fini(helper);
387 err_free:
388 	kfree(fbdev_cma);
389 
390 	return ERR_PTR(ret);
391 }
392 EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
393 
394 /**
395  * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
396  * @fbdev_cma: The drm_fbdev_cma struct
397  */
drm_fbdev_cma_fini(struct drm_fbdev_cma * fbdev_cma)398 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
399 {
400 	if (fbdev_cma->fb_helper.fbdev) {
401 		struct fb_info *info;
402 		int ret;
403 
404 		info = fbdev_cma->fb_helper.fbdev;
405 		ret = unregister_framebuffer(info);
406 		if (ret < 0)
407 			DRM_DEBUG_KMS("failed unregister_framebuffer()\n");
408 
409 		if (info->cmap.len)
410 			fb_dealloc_cmap(&info->cmap);
411 
412 		framebuffer_release(info);
413 	}
414 
415 	if (fbdev_cma->fb) {
416 		drm_framebuffer_unregister_private(&fbdev_cma->fb->fb);
417 		drm_fb_cma_destroy(&fbdev_cma->fb->fb);
418 	}
419 
420 	drm_fb_helper_fini(&fbdev_cma->fb_helper);
421 	kfree(fbdev_cma);
422 }
423 EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
424 
425 /**
426  * drm_fbdev_cma_restore_mode() - Restores initial framebuffer mode
427  * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
428  *
429  * This function is usually called from the DRM drivers lastclose callback.
430  */
drm_fbdev_cma_restore_mode(struct drm_fbdev_cma * fbdev_cma)431 void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
432 {
433 	if (fbdev_cma)
434 		drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev_cma->fb_helper);
435 }
436 EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
437 
438 /**
439  * drm_fbdev_cma_hotplug_event() - Poll for hotpulug events
440  * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
441  *
442  * This function is usually called from the DRM drivers output_poll_changed
443  * callback.
444  */
drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma * fbdev_cma)445 void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
446 {
447 	if (fbdev_cma)
448 		drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
449 }
450 EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);
451