xref: /linux/drivers/gpu/drm/omapdrm/omap_fbdev.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 struct drm_fb_helper *get_fb(struct fb_info *fbi);
46 
47 static void pan_worker(struct work_struct *work)
48 {
49 	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
50 	struct fb_info *fbi = fbdev->base.fbdev;
51 	int npages;
52 
53 	/* DMM roll shifts in 4K pages: */
54 	npages = fbi->fix.line_length >> PAGE_SHIFT;
55 	omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
56 }
57 
58 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
59 		struct fb_info *fbi)
60 {
61 	struct drm_fb_helper *helper = get_fb(fbi);
62 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
63 
64 	if (!helper)
65 		goto fallback;
66 
67 	if (!fbdev->ywrap_enabled)
68 		goto fallback;
69 
70 	if (drm_can_sleep()) {
71 		pan_worker(&fbdev->work);
72 	} else {
73 		struct omap_drm_private *priv = helper->dev->dev_private;
74 		queue_work(priv->wq, &fbdev->work);
75 	}
76 
77 	return 0;
78 
79 fallback:
80 	return drm_fb_helper_pan_display(var, fbi);
81 }
82 
83 static struct fb_ops omap_fb_ops = {
84 	.owner = THIS_MODULE,
85 
86 	/* Note: to properly handle manual update displays, we wrap the
87 	 * basic fbdev ops which write to the framebuffer
88 	 */
89 	.fb_read = fb_sys_read,
90 	.fb_write = fb_sys_write,
91 	.fb_fillrect = sys_fillrect,
92 	.fb_copyarea = sys_copyarea,
93 	.fb_imageblit = sys_imageblit,
94 
95 	.fb_check_var = drm_fb_helper_check_var,
96 	.fb_set_par = drm_fb_helper_set_par,
97 	.fb_pan_display = omap_fbdev_pan_display,
98 	.fb_blank = drm_fb_helper_blank,
99 	.fb_setcmap = drm_fb_helper_setcmap,
100 };
101 
102 static int omap_fbdev_create(struct drm_fb_helper *helper,
103 		struct drm_fb_helper_surface_size *sizes)
104 {
105 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
106 	struct drm_device *dev = helper->dev;
107 	struct omap_drm_private *priv = dev->dev_private;
108 	struct drm_framebuffer *fb = NULL;
109 	union omap_gem_size gsize;
110 	struct fb_info *fbi = NULL;
111 	struct drm_mode_fb_cmd2 mode_cmd = {0};
112 	dma_addr_t paddr;
113 	int ret;
114 
115 	/* only doing ARGB32 since this is what is needed to alpha-blend
116 	 * with video overlays:
117 	 */
118 	sizes->surface_bpp = 32;
119 	sizes->surface_depth = 32;
120 
121 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
122 			sizes->surface_height, sizes->surface_bpp,
123 			sizes->fb_width, sizes->fb_height);
124 
125 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
126 			sizes->surface_depth);
127 
128 	mode_cmd.width = sizes->surface_width;
129 	mode_cmd.height = sizes->surface_height;
130 
131 	mode_cmd.pitches[0] = align_pitch(
132 			mode_cmd.width * ((sizes->surface_bpp + 7) / 8),
133 			mode_cmd.width, sizes->surface_bpp);
134 
135 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
136 	if (fbdev->ywrap_enabled) {
137 		/* need to align pitch to page size if using DMM scrolling */
138 		mode_cmd.pitches[0] = ALIGN(mode_cmd.pitches[0], PAGE_SIZE);
139 	}
140 
141 	/* allocate backing bo */
142 	gsize = (union omap_gem_size){
143 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
144 	};
145 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
146 	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
147 	if (!fbdev->bo) {
148 		dev_err(dev->dev, "failed to allocate buffer object\n");
149 		ret = -ENOMEM;
150 		goto fail;
151 	}
152 
153 	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
154 	if (IS_ERR(fb)) {
155 		dev_err(dev->dev, "failed to allocate fb\n");
156 		/* note: if fb creation failed, we can't rely on fb destroy
157 		 * to unref the bo:
158 		 */
159 		drm_gem_object_unreference(fbdev->bo);
160 		ret = PTR_ERR(fb);
161 		goto fail;
162 	}
163 
164 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
165 	 * but is needed as long as we use fb_mmap() to mmap to userspace
166 	 * (since this happens using fix.smem_start).  Possibly we could
167 	 * implement our own mmap using GEM mmap support to avoid this
168 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
169 	 * to it).  Then we just need to be sure that we are able to re-
170 	 * pin it in case of an opps.
171 	 */
172 	ret = omap_gem_get_paddr(fbdev->bo, &paddr, true);
173 	if (ret) {
174 		dev_err(dev->dev,
175 			"could not map (paddr)!  Skipping framebuffer alloc\n");
176 		ret = -ENOMEM;
177 		goto fail;
178 	}
179 
180 	mutex_lock(&dev->struct_mutex);
181 
182 	fbi = framebuffer_alloc(0, dev->dev);
183 	if (!fbi) {
184 		dev_err(dev->dev, "failed to allocate fb info\n");
185 		ret = -ENOMEM;
186 		goto fail_unlock;
187 	}
188 
189 	DBG("fbi=%p, dev=%p", fbi, dev);
190 
191 	fbdev->fb = fb;
192 	helper->fb = fb;
193 	helper->fbdev = fbi;
194 
195 	fbi->par = helper;
196 	fbi->flags = FBINFO_DEFAULT;
197 	fbi->fbops = &omap_fb_ops;
198 
199 	strcpy(fbi->fix.id, MODULE_NAME);
200 
201 	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
202 	if (ret) {
203 		ret = -ENOMEM;
204 		goto fail_unlock;
205 	}
206 
207 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
208 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
209 
210 	dev->mode_config.fb_base = paddr;
211 
212 	fbi->screen_base = omap_gem_vaddr(fbdev->bo);
213 	fbi->screen_size = fbdev->bo->size;
214 	fbi->fix.smem_start = paddr;
215 	fbi->fix.smem_len = fbdev->bo->size;
216 
217 	/* if we have DMM, then we can use it for scrolling by just
218 	 * shuffling pages around in DMM rather than doing sw blit.
219 	 */
220 	if (fbdev->ywrap_enabled) {
221 		DRM_INFO("Enabling DMM ywrap scrolling\n");
222 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
223 		fbi->fix.ywrapstep = 1;
224 	}
225 
226 
227 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
228 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
229 
230 	mutex_unlock(&dev->struct_mutex);
231 
232 	return 0;
233 
234 fail_unlock:
235 	mutex_unlock(&dev->struct_mutex);
236 fail:
237 
238 	if (ret) {
239 		if (fbi)
240 			framebuffer_release(fbi);
241 		if (fb) {
242 			drm_framebuffer_unregister_private(fb);
243 			drm_framebuffer_remove(fb);
244 		}
245 	}
246 
247 	return ret;
248 }
249 
250 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
251 	.fb_probe = omap_fbdev_create,
252 };
253 
254 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
255 {
256 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
257 		/* these are not the fb's you're looking for */
258 		return NULL;
259 	}
260 	return fbi->par;
261 }
262 
263 /* initialize fbdev helper */
264 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
265 {
266 	struct omap_drm_private *priv = dev->dev_private;
267 	struct omap_fbdev *fbdev = NULL;
268 	struct drm_fb_helper *helper;
269 	int ret = 0;
270 
271 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
272 	if (!fbdev)
273 		goto fail;
274 
275 	INIT_WORK(&fbdev->work, pan_worker);
276 
277 	helper = &fbdev->base;
278 
279 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
280 
281 	ret = drm_fb_helper_init(dev, helper,
282 			priv->num_crtcs, priv->num_connectors);
283 	if (ret) {
284 		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
285 		goto fail;
286 	}
287 
288 	ret = drm_fb_helper_single_add_all_connectors(helper);
289 	if (ret)
290 		goto fini;
291 
292 	/* disable all the possible outputs/crtcs before entering KMS mode */
293 	drm_helper_disable_unused_functions(dev);
294 
295 	ret = drm_fb_helper_initial_config(helper, 32);
296 	if (ret)
297 		goto fini;
298 
299 	priv->fbdev = helper;
300 
301 	return helper;
302 
303 fini:
304 	drm_fb_helper_fini(helper);
305 fail:
306 	kfree(fbdev);
307 	return NULL;
308 }
309 
310 void omap_fbdev_free(struct drm_device *dev)
311 {
312 	struct omap_drm_private *priv = dev->dev_private;
313 	struct drm_fb_helper *helper = priv->fbdev;
314 	struct omap_fbdev *fbdev;
315 	struct fb_info *fbi;
316 
317 	DBG();
318 
319 	fbi = helper->fbdev;
320 
321 	/* only cleanup framebuffer if it is present */
322 	if (fbi) {
323 		unregister_framebuffer(fbi);
324 		framebuffer_release(fbi);
325 	}
326 
327 	drm_fb_helper_fini(helper);
328 
329 	fbdev = to_omap_fbdev(priv->fbdev);
330 
331 	/* release the ref taken in omap_fbdev_create() */
332 	omap_gem_put_paddr(fbdev->bo);
333 
334 	/* this will free the backing object */
335 	if (fbdev->fb) {
336 		drm_framebuffer_unregister_private(fbdev->fb);
337 		drm_framebuffer_remove(fbdev->fb);
338 	}
339 
340 	kfree(fbdev);
341 
342 	priv->fbdev = NULL;
343 }
344