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 <drm/drm_crtc.h>
21 #include <drm/drm_fb_helper.h>
22 
23 #include "omap_drv.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 = drm_fb_helper_sys_read,
90 	.fb_write = drm_fb_helper_sys_write,
91 	.fb_fillrect = drm_fb_helper_sys_fillrect,
92 	.fb_copyarea = drm_fb_helper_sys_copyarea,
93 	.fb_imageblit = drm_fb_helper_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] = PAGE_ALIGN(mode_cmd.pitches[0]);
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 = drm_fb_helper_alloc_fbi(helper);
183 	if (IS_ERR(fbi)) {
184 		dev_err(dev->dev, "failed to allocate fb info\n");
185 		ret = PTR_ERR(fbi);
186 		goto fail_unlock;
187 	}
188 
189 	DBG("fbi=%p, dev=%p", fbi, dev);
190 
191 	fbdev->fb = fb;
192 	helper->fb = fb;
193 
194 	fbi->par = helper;
195 	fbi->flags = FBINFO_DEFAULT;
196 	fbi->fbops = &omap_fb_ops;
197 
198 	strcpy(fbi->fix.id, MODULE_NAME);
199 
200 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
201 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
202 
203 	dev->mode_config.fb_base = paddr;
204 
205 	fbi->screen_base = omap_gem_vaddr(fbdev->bo);
206 	fbi->screen_size = fbdev->bo->size;
207 	fbi->fix.smem_start = paddr;
208 	fbi->fix.smem_len = fbdev->bo->size;
209 
210 	/* if we have DMM, then we can use it for scrolling by just
211 	 * shuffling pages around in DMM rather than doing sw blit.
212 	 */
213 	if (fbdev->ywrap_enabled) {
214 		DRM_INFO("Enabling DMM ywrap scrolling\n");
215 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
216 		fbi->fix.ywrapstep = 1;
217 	}
218 
219 
220 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
221 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
222 
223 	mutex_unlock(&dev->struct_mutex);
224 
225 	return 0;
226 
227 fail_unlock:
228 	mutex_unlock(&dev->struct_mutex);
229 fail:
230 
231 	if (ret) {
232 
233 		drm_fb_helper_release_fbi(helper);
234 
235 		if (fb) {
236 			drm_framebuffer_unregister_private(fb);
237 			drm_framebuffer_remove(fb);
238 		}
239 	}
240 
241 	return ret;
242 }
243 
244 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
245 	.fb_probe = omap_fbdev_create,
246 };
247 
248 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
249 {
250 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
251 		/* these are not the fb's you're looking for */
252 		return NULL;
253 	}
254 	return fbi->par;
255 }
256 
257 /* initialize fbdev helper */
258 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
259 {
260 	struct omap_drm_private *priv = dev->dev_private;
261 	struct omap_fbdev *fbdev = NULL;
262 	struct drm_fb_helper *helper;
263 	int ret = 0;
264 
265 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
266 	if (!fbdev)
267 		goto fail;
268 
269 	INIT_WORK(&fbdev->work, pan_worker);
270 
271 	helper = &fbdev->base;
272 
273 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
274 
275 	ret = drm_fb_helper_init(dev, helper,
276 			priv->num_crtcs, priv->num_connectors);
277 	if (ret) {
278 		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
279 		goto fail;
280 	}
281 
282 	ret = drm_fb_helper_single_add_all_connectors(helper);
283 	if (ret)
284 		goto fini;
285 
286 	/* disable all the possible outputs/crtcs before entering KMS mode */
287 	drm_helper_disable_unused_functions(dev);
288 
289 	ret = drm_fb_helper_initial_config(helper, 32);
290 	if (ret)
291 		goto fini;
292 
293 	priv->fbdev = helper;
294 
295 	return helper;
296 
297 fini:
298 	drm_fb_helper_fini(helper);
299 fail:
300 	kfree(fbdev);
301 	return NULL;
302 }
303 
304 void omap_fbdev_free(struct drm_device *dev)
305 {
306 	struct omap_drm_private *priv = dev->dev_private;
307 	struct drm_fb_helper *helper = priv->fbdev;
308 	struct omap_fbdev *fbdev;
309 
310 	DBG();
311 
312 	drm_fb_helper_unregister_fbi(helper);
313 	drm_fb_helper_release_fbi(helper);
314 
315 	drm_fb_helper_fini(helper);
316 
317 	fbdev = to_omap_fbdev(priv->fbdev);
318 
319 	/* release the ref taken in omap_fbdev_create() */
320 	omap_gem_put_paddr(fbdev->bo);
321 
322 	/* this will free the backing object */
323 	if (fbdev->fb) {
324 		drm_framebuffer_unregister_private(fbdev->fb);
325 		drm_framebuffer_remove(fbdev->fb);
326 	}
327 
328 	kfree(fbdev);
329 
330 	priv->fbdev = NULL;
331 }
332