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 	DRM_FB_HELPER_DEFAULT_OPS,
86 
87 	/* Note: to properly handle manual update displays, we wrap the
88 	 * basic fbdev ops which write to the framebuffer
89 	 */
90 	.fb_read = drm_fb_helper_sys_read,
91 	.fb_write = drm_fb_helper_sys_write,
92 	.fb_fillrect = drm_fb_helper_sys_fillrect,
93 	.fb_copyarea = drm_fb_helper_sys_copyarea,
94 	.fb_imageblit = drm_fb_helper_sys_imageblit,
95 
96 	.fb_pan_display = omap_fbdev_pan_display,
97 };
98 
99 static int omap_fbdev_create(struct drm_fb_helper *helper,
100 		struct drm_fb_helper_surface_size *sizes)
101 {
102 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
103 	struct drm_device *dev = helper->dev;
104 	struct omap_drm_private *priv = dev->dev_private;
105 	struct drm_framebuffer *fb = NULL;
106 	union omap_gem_size gsize;
107 	struct fb_info *fbi = NULL;
108 	struct drm_mode_fb_cmd2 mode_cmd = {0};
109 	dma_addr_t paddr;
110 	int ret;
111 
112 	sizes->surface_bpp = 32;
113 	sizes->surface_depth = 24;
114 
115 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
116 			sizes->surface_height, sizes->surface_bpp,
117 			sizes->fb_width, sizes->fb_height);
118 
119 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
120 			sizes->surface_depth);
121 
122 	mode_cmd.width = sizes->surface_width;
123 	mode_cmd.height = sizes->surface_height;
124 
125 	mode_cmd.pitches[0] =
126 			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
127 
128 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
129 	if (fbdev->ywrap_enabled) {
130 		/* need to align pitch to page size if using DMM scrolling */
131 		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
132 	}
133 
134 	/* allocate backing bo */
135 	gsize = (union omap_gem_size){
136 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
137 	};
138 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
139 	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
140 	if (!fbdev->bo) {
141 		dev_err(dev->dev, "failed to allocate buffer object\n");
142 		ret = -ENOMEM;
143 		goto fail;
144 	}
145 
146 	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
147 	if (IS_ERR(fb)) {
148 		dev_err(dev->dev, "failed to allocate fb\n");
149 		/* note: if fb creation failed, we can't rely on fb destroy
150 		 * to unref the bo:
151 		 */
152 		drm_gem_object_unreference_unlocked(fbdev->bo);
153 		ret = PTR_ERR(fb);
154 		goto fail;
155 	}
156 
157 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
158 	 * but is needed as long as we use fb_mmap() to mmap to userspace
159 	 * (since this happens using fix.smem_start).  Possibly we could
160 	 * implement our own mmap using GEM mmap support to avoid this
161 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
162 	 * to it).  Then we just need to be sure that we are able to re-
163 	 * pin it in case of an opps.
164 	 */
165 	ret = omap_gem_get_paddr(fbdev->bo, &paddr, true);
166 	if (ret) {
167 		dev_err(dev->dev,
168 			"could not map (paddr)!  Skipping framebuffer alloc\n");
169 		ret = -ENOMEM;
170 		goto fail;
171 	}
172 
173 	mutex_lock(&dev->struct_mutex);
174 
175 	fbi = drm_fb_helper_alloc_fbi(helper);
176 	if (IS_ERR(fbi)) {
177 		dev_err(dev->dev, "failed to allocate fb info\n");
178 		ret = PTR_ERR(fbi);
179 		goto fail_unlock;
180 	}
181 
182 	DBG("fbi=%p, dev=%p", fbi, dev);
183 
184 	fbdev->fb = fb;
185 	helper->fb = fb;
186 
187 	fbi->par = helper;
188 	fbi->flags = FBINFO_DEFAULT;
189 	fbi->fbops = &omap_fb_ops;
190 
191 	strcpy(fbi->fix.id, MODULE_NAME);
192 
193 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
194 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
195 
196 	dev->mode_config.fb_base = paddr;
197 
198 	fbi->screen_base = omap_gem_vaddr(fbdev->bo);
199 	fbi->screen_size = fbdev->bo->size;
200 	fbi->fix.smem_start = paddr;
201 	fbi->fix.smem_len = fbdev->bo->size;
202 
203 	/* if we have DMM, then we can use it for scrolling by just
204 	 * shuffling pages around in DMM rather than doing sw blit.
205 	 */
206 	if (fbdev->ywrap_enabled) {
207 		DRM_INFO("Enabling DMM ywrap scrolling\n");
208 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
209 		fbi->fix.ywrapstep = 1;
210 	}
211 
212 
213 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
214 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
215 
216 	mutex_unlock(&dev->struct_mutex);
217 
218 	return 0;
219 
220 fail_unlock:
221 	mutex_unlock(&dev->struct_mutex);
222 fail:
223 
224 	if (ret) {
225 		if (fb)
226 			drm_framebuffer_remove(fb);
227 	}
228 
229 	return ret;
230 }
231 
232 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
233 	.fb_probe = omap_fbdev_create,
234 };
235 
236 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
237 {
238 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
239 		/* these are not the fb's you're looking for */
240 		return NULL;
241 	}
242 	return fbi->par;
243 }
244 
245 /* initialize fbdev helper */
246 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
247 {
248 	struct omap_drm_private *priv = dev->dev_private;
249 	struct omap_fbdev *fbdev = NULL;
250 	struct drm_fb_helper *helper;
251 	int ret = 0;
252 
253 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
254 	if (!fbdev)
255 		goto fail;
256 
257 	INIT_WORK(&fbdev->work, pan_worker);
258 
259 	helper = &fbdev->base;
260 
261 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
262 
263 	ret = drm_fb_helper_init(dev, helper, priv->num_connectors);
264 	if (ret) {
265 		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
266 		goto fail;
267 	}
268 
269 	ret = drm_fb_helper_single_add_all_connectors(helper);
270 	if (ret)
271 		goto fini;
272 
273 	ret = drm_fb_helper_initial_config(helper, 32);
274 	if (ret)
275 		goto fini;
276 
277 	priv->fbdev = helper;
278 
279 	return helper;
280 
281 fini:
282 	drm_fb_helper_fini(helper);
283 fail:
284 	kfree(fbdev);
285 
286 	dev_warn(dev->dev, "omap_fbdev_init failed\n");
287 	/* well, limp along without an fbdev.. maybe X11 will work? */
288 
289 	return NULL;
290 }
291 
292 void omap_fbdev_free(struct drm_device *dev)
293 {
294 	struct omap_drm_private *priv = dev->dev_private;
295 	struct drm_fb_helper *helper = priv->fbdev;
296 	struct omap_fbdev *fbdev;
297 
298 	DBG();
299 
300 	drm_fb_helper_unregister_fbi(helper);
301 
302 	drm_fb_helper_fini(helper);
303 
304 	fbdev = to_omap_fbdev(priv->fbdev);
305 
306 	/* release the ref taken in omap_fbdev_create() */
307 	omap_gem_put_paddr(fbdev->bo);
308 
309 	/* this will free the backing object */
310 	if (fbdev->fb)
311 		drm_framebuffer_remove(fbdev->fb);
312 
313 	kfree(fbdev);
314 
315 	priv->fbdev = NULL;
316 }
317