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
 28struct drm_fb_cma {
 29	struct drm_framebuffer		fb;
 30	struct drm_gem_cma_object	*obj[4];
 31};
 32
 33struct drm_fbdev_cma {
 34	struct drm_fb_helper	fb_helper;
 35	struct drm_fb_cma	*fb;
 36};
 37
 38static 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
 43static 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
 48static 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
 62static 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
 71static struct drm_framebuffer_funcs drm_fb_cma_funcs = {
 72	.destroy	= drm_fb_cma_destroy,
 73	.create_handle	= drm_fb_cma_create_handle,
 74};
 75
 76static 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 */
109struct 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
155err_gem_object_unreference:
156	for (i--; i >= 0; i--)
157		drm_gem_object_unreference_unlocked(&objs[i]->base);
158	return ERR_PTR(ret);
159}
160EXPORT_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 */
171struct 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}
181EXPORT_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 */
188static 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 */
207int 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}
232EXPORT_SYMBOL_GPL(drm_fb_cma_debugfs_show);
233#endif
234
235static 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
247static 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
320err_drm_fb_cma_destroy:
321	drm_framebuffer_unregister_private(fb);
322	drm_fb_cma_destroy(fb);
323err_framebuffer_release:
324	framebuffer_release(fbi);
325err_drm_gem_cma_free_object:
326	drm_gem_cma_free_object(&obj->base);
327	return ret;
328}
329
330static 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 */
343struct 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	fbdev_cma->fb_helper.funcs = &drm_fb_cma_helper_funcs;
358	helper = &fbdev_cma->fb_helper;
359
360	ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
361	if (ret < 0) {
362		dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
363		goto err_free;
364	}
365
366	ret = drm_fb_helper_single_add_all_connectors(helper);
367	if (ret < 0) {
368		dev_err(dev->dev, "Failed to add connectors.\n");
369		goto err_drm_fb_helper_fini;
370
371	}
372
373	/* disable all the possible outputs/crtcs before entering KMS mode */
374	drm_helper_disable_unused_functions(dev);
375
376	ret = drm_fb_helper_initial_config(helper, preferred_bpp);
377	if (ret < 0) {
378		dev_err(dev->dev, "Failed to set initial hw configuration.\n");
379		goto err_drm_fb_helper_fini;
380	}
381
382	return fbdev_cma;
383
384err_drm_fb_helper_fini:
385	drm_fb_helper_fini(helper);
386err_free:
387	kfree(fbdev_cma);
388
389	return ERR_PTR(ret);
390}
391EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
392
393/**
394 * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
395 * @fbdev_cma: The drm_fbdev_cma struct
396 */
397void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
398{
399	if (fbdev_cma->fb_helper.fbdev) {
400		struct fb_info *info;
401		int ret;
402
403		info = fbdev_cma->fb_helper.fbdev;
404		ret = unregister_framebuffer(info);
405		if (ret < 0)
406			DRM_DEBUG_KMS("failed unregister_framebuffer()\n");
407
408		if (info->cmap.len)
409			fb_dealloc_cmap(&info->cmap);
410
411		framebuffer_release(info);
412	}
413
414	if (fbdev_cma->fb) {
415		drm_framebuffer_unregister_private(&fbdev_cma->fb->fb);
416		drm_fb_cma_destroy(&fbdev_cma->fb->fb);
417	}
418
419	drm_fb_helper_fini(&fbdev_cma->fb_helper);
420	kfree(fbdev_cma);
421}
422EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
423
424/**
425 * drm_fbdev_cma_restore_mode() - Restores initial framebuffer mode
426 * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
427 *
428 * This function is usually called from the DRM drivers lastclose callback.
429 */
430void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
431{
432	if (fbdev_cma) {
433		struct drm_device *dev = fbdev_cma->fb_helper.dev;
434
435		drm_modeset_lock_all(dev);
436		drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
437		drm_modeset_unlock_all(dev);
438	}
439}
440EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
441
442/**
443 * drm_fbdev_cma_hotplug_event() - Poll for hotpulug events
444 * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
445 *
446 * This function is usually called from the DRM drivers output_poll_changed
447 * callback.
448 */
449void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
450{
451	if (fbdev_cma)
452		drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
453}
454EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);