1 /*
2  * drivers/gpu/drm/omapdrm/omap_fbdev.c
3  *
4  * Copyright (C) 2011 Texas Instruments
5  * Author: Rob Clark <rob@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "omap_drv.h"
21 
22 #include "drm_crtc.h"
23 #include "drm_fb_helper.h"
24 
25 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
26 static bool ywrap_enabled = true;
27 module_param_named(ywrap, ywrap_enabled, bool, 0644);
28 
29 /*
30  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
31  */
32 
33 #define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
34 
35 struct omap_fbdev {
36 	struct drm_fb_helper base;
37 	struct drm_framebuffer *fb;
38 	struct drm_gem_object *bo;
39 	bool ywrap_enabled;
40 
41 	/* for deferred dmm roll when getting called in atomic ctx */
42 	struct work_struct work;
43 };
44 
45 static void omap_fbdev_flush(struct fb_info *fbi, int x, int y, int w, int h);
46 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
47 
48 static ssize_t omap_fbdev_write(struct fb_info *fbi, const char __user *buf,
49 		size_t count, loff_t *ppos)
50 {
51 	ssize_t res;
52 
53 	res = fb_sys_write(fbi, buf, count, ppos);
54 	omap_fbdev_flush(fbi, 0, 0, fbi->var.xres, fbi->var.yres);
55 
56 	return res;
57 }
58 
59 static void omap_fbdev_fillrect(struct fb_info *fbi,
60 		const struct fb_fillrect *rect)
61 {
62 	sys_fillrect(fbi, rect);
63 	omap_fbdev_flush(fbi, rect->dx, rect->dy, rect->width, rect->height);
64 }
65 
66 static void omap_fbdev_copyarea(struct fb_info *fbi,
67 		const struct fb_copyarea *area)
68 {
69 	sys_copyarea(fbi, area);
70 	omap_fbdev_flush(fbi, area->dx, area->dy, area->width, area->height);
71 }
72 
73 static void omap_fbdev_imageblit(struct fb_info *fbi,
74 		const struct fb_image *image)
75 {
76 	sys_imageblit(fbi, image);
77 	omap_fbdev_flush(fbi, image->dx, image->dy,
78 				image->width, image->height);
79 }
80 
81 static void pan_worker(struct work_struct *work)
82 {
83 	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
84 	struct fb_info *fbi = fbdev->base.fbdev;
85 	int npages;
86 
87 	/* DMM roll shifts in 4K pages: */
88 	npages = fbi->fix.line_length >> PAGE_SHIFT;
89 	omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
90 }
91 
92 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
93 		struct fb_info *fbi)
94 {
95 	struct drm_fb_helper *helper = get_fb(fbi);
96 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
97 
98 	if (!helper)
99 		goto fallback;
100 
101 	if (!fbdev->ywrap_enabled)
102 		goto fallback;
103 
104 	if (drm_can_sleep()) {
105 		pan_worker(&fbdev->work);
106 	} else {
107 		struct omap_drm_private *priv = helper->dev->dev_private;
108 		queue_work(priv->wq, &fbdev->work);
109 	}
110 
111 	return 0;
112 
113 fallback:
114 	return drm_fb_helper_pan_display(var, fbi);
115 }
116 
117 static struct fb_ops omap_fb_ops = {
118 	.owner = THIS_MODULE,
119 
120 	/* Note: to properly handle manual update displays, we wrap the
121 	 * basic fbdev ops which write to the framebuffer
122 	 */
123 	.fb_read = fb_sys_read,
124 	.fb_write = omap_fbdev_write,
125 	.fb_fillrect = omap_fbdev_fillrect,
126 	.fb_copyarea = omap_fbdev_copyarea,
127 	.fb_imageblit = omap_fbdev_imageblit,
128 
129 	.fb_check_var = drm_fb_helper_check_var,
130 	.fb_set_par = drm_fb_helper_set_par,
131 	.fb_pan_display = omap_fbdev_pan_display,
132 	.fb_blank = drm_fb_helper_blank,
133 	.fb_setcmap = drm_fb_helper_setcmap,
134 };
135 
136 static int omap_fbdev_create(struct drm_fb_helper *helper,
137 		struct drm_fb_helper_surface_size *sizes)
138 {
139 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
140 	struct drm_device *dev = helper->dev;
141 	struct omap_drm_private *priv = dev->dev_private;
142 	struct drm_framebuffer *fb = NULL;
143 	union omap_gem_size gsize;
144 	struct fb_info *fbi = NULL;
145 	struct drm_mode_fb_cmd2 mode_cmd = {0};
146 	dma_addr_t paddr;
147 	int ret;
148 
149 	/* only doing ARGB32 since this is what is needed to alpha-blend
150 	 * with video overlays:
151 	 */
152 	sizes->surface_bpp = 32;
153 	sizes->surface_depth = 32;
154 
155 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
156 			sizes->surface_height, sizes->surface_bpp,
157 			sizes->fb_width, sizes->fb_height);
158 
159 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
160 			sizes->surface_depth);
161 
162 	mode_cmd.width = sizes->surface_width;
163 	mode_cmd.height = sizes->surface_height;
164 
165 	mode_cmd.pitches[0] = align_pitch(
166 			mode_cmd.width * ((sizes->surface_bpp + 7) / 8),
167 			mode_cmd.width, sizes->surface_bpp);
168 
169 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
170 	if (fbdev->ywrap_enabled) {
171 		/* need to align pitch to page size if using DMM scrolling */
172 		mode_cmd.pitches[0] = ALIGN(mode_cmd.pitches[0], PAGE_SIZE);
173 	}
174 
175 	/* allocate backing bo */
176 	gsize = (union omap_gem_size){
177 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
178 	};
179 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
180 	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
181 	if (!fbdev->bo) {
182 		dev_err(dev->dev, "failed to allocate buffer object\n");
183 		ret = -ENOMEM;
184 		goto fail;
185 	}
186 
187 	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
188 	if (IS_ERR(fb)) {
189 		dev_err(dev->dev, "failed to allocate fb\n");
190 		/* note: if fb creation failed, we can't rely on fb destroy
191 		 * to unref the bo:
192 		 */
193 		drm_gem_object_unreference(fbdev->bo);
194 		ret = PTR_ERR(fb);
195 		goto fail;
196 	}
197 
198 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
199 	 * but is needed as long as we use fb_mmap() to mmap to userspace
200 	 * (since this happens using fix.smem_start).  Possibly we could
201 	 * implement our own mmap using GEM mmap support to avoid this
202 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
203 	 * to it).  Then we just need to be sure that we are able to re-
204 	 * pin it in case of an opps.
205 	 */
206 	ret = omap_gem_get_paddr(fbdev->bo, &paddr, true);
207 	if (ret) {
208 		dev_err(dev->dev,
209 			"could not map (paddr)!  Skipping framebuffer alloc\n");
210 		ret = -ENOMEM;
211 		goto fail;
212 	}
213 
214 	mutex_lock(&dev->struct_mutex);
215 
216 	fbi = framebuffer_alloc(0, dev->dev);
217 	if (!fbi) {
218 		dev_err(dev->dev, "failed to allocate fb info\n");
219 		ret = -ENOMEM;
220 		goto fail_unlock;
221 	}
222 
223 	DBG("fbi=%p, dev=%p", fbi, dev);
224 
225 	fbdev->fb = fb;
226 	helper->fb = fb;
227 	helper->fbdev = fbi;
228 
229 	fbi->par = helper;
230 	fbi->flags = FBINFO_DEFAULT;
231 	fbi->fbops = &omap_fb_ops;
232 
233 	strcpy(fbi->fix.id, MODULE_NAME);
234 
235 	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
236 	if (ret) {
237 		ret = -ENOMEM;
238 		goto fail_unlock;
239 	}
240 
241 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
242 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
243 
244 	dev->mode_config.fb_base = paddr;
245 
246 	fbi->screen_base = omap_gem_vaddr(fbdev->bo);
247 	fbi->screen_size = fbdev->bo->size;
248 	fbi->fix.smem_start = paddr;
249 	fbi->fix.smem_len = fbdev->bo->size;
250 
251 	/* if we have DMM, then we can use it for scrolling by just
252 	 * shuffling pages around in DMM rather than doing sw blit.
253 	 */
254 	if (fbdev->ywrap_enabled) {
255 		DRM_INFO("Enabling DMM ywrap scrolling\n");
256 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
257 		fbi->fix.ywrapstep = 1;
258 	}
259 
260 
261 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
262 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
263 
264 	mutex_unlock(&dev->struct_mutex);
265 
266 	return 0;
267 
268 fail_unlock:
269 	mutex_unlock(&dev->struct_mutex);
270 fail:
271 
272 	if (ret) {
273 		if (fbi)
274 			framebuffer_release(fbi);
275 		if (fb) {
276 			drm_framebuffer_unregister_private(fb);
277 			drm_framebuffer_remove(fb);
278 		}
279 	}
280 
281 	return ret;
282 }
283 
284 static struct drm_fb_helper_funcs omap_fb_helper_funcs = {
285 	.fb_probe = omap_fbdev_create,
286 };
287 
288 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
289 {
290 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
291 		/* these are not the fb's you're looking for */
292 		return NULL;
293 	}
294 	return fbi->par;
295 }
296 
297 /* flush an area of the framebuffer (in case of manual update display that
298  * is not automatically flushed)
299  */
300 static void omap_fbdev_flush(struct fb_info *fbi, int x, int y, int w, int h)
301 {
302 	struct drm_fb_helper *helper = get_fb(fbi);
303 
304 	if (!helper)
305 		return;
306 
307 	VERB("flush fbdev: %d,%d %dx%d, fbi=%p", x, y, w, h, fbi);
308 
309 	omap_framebuffer_flush(helper->fb, x, y, w, h);
310 }
311 
312 /* initialize fbdev helper */
313 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
314 {
315 	struct omap_drm_private *priv = dev->dev_private;
316 	struct omap_fbdev *fbdev = NULL;
317 	struct drm_fb_helper *helper;
318 	int ret = 0;
319 
320 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
321 	if (!fbdev)
322 		goto fail;
323 
324 	INIT_WORK(&fbdev->work, pan_worker);
325 
326 	helper = &fbdev->base;
327 
328 	helper->funcs = &omap_fb_helper_funcs;
329 
330 	ret = drm_fb_helper_init(dev, helper,
331 			priv->num_crtcs, priv->num_connectors);
332 	if (ret) {
333 		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
334 		goto fail;
335 	}
336 
337 	drm_fb_helper_single_add_all_connectors(helper);
338 
339 	/* disable all the possible outputs/crtcs before entering KMS mode */
340 	drm_helper_disable_unused_functions(dev);
341 
342 	drm_fb_helper_initial_config(helper, 32);
343 
344 	priv->fbdev = helper;
345 
346 	return helper;
347 
348 fail:
349 	kfree(fbdev);
350 	return NULL;
351 }
352 
353 void omap_fbdev_free(struct drm_device *dev)
354 {
355 	struct omap_drm_private *priv = dev->dev_private;
356 	struct drm_fb_helper *helper = priv->fbdev;
357 	struct omap_fbdev *fbdev;
358 	struct fb_info *fbi;
359 
360 	DBG();
361 
362 	fbi = helper->fbdev;
363 
364 	/* only cleanup framebuffer if it is present */
365 	if (fbi) {
366 		unregister_framebuffer(fbi);
367 		framebuffer_release(fbi);
368 	}
369 
370 	drm_fb_helper_fini(helper);
371 
372 	fbdev = to_omap_fbdev(priv->fbdev);
373 
374 	/* release the ref taken in omap_fbdev_create() */
375 	omap_gem_put_paddr(fbdev->bo);
376 
377 	/* this will free the backing object */
378 	if (fbdev->fb) {
379 		drm_framebuffer_unregister_private(fbdev->fb);
380 		drm_framebuffer_remove(fbdev->fb);
381 	}
382 
383 	kfree(fbdev);
384 
385 	priv->fbdev = NULL;
386 }
387