1 /*
2  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
3  * Author: Rob Clark <rob@ti.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <drm/drm_crtc.h>
19 #include <drm/drm_fb_helper.h>
20 
21 #include "omap_drv.h"
22 
23 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
24 static bool ywrap_enabled = true;
25 module_param_named(ywrap, ywrap_enabled, bool, 0644);
26 
27 /*
28  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
29  */
30 
31 #define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
32 
33 struct omap_fbdev {
34 	struct drm_fb_helper base;
35 	struct drm_framebuffer *fb;
36 	struct drm_gem_object *bo;
37 	bool ywrap_enabled;
38 
39 	/* for deferred dmm roll when getting called in atomic ctx */
40 	struct work_struct work;
41 };
42 
43 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
44 
45 static void pan_worker(struct work_struct *work)
46 {
47 	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
48 	struct fb_info *fbi = fbdev->base.fbdev;
49 	int npages;
50 
51 	/* DMM roll shifts in 4K pages: */
52 	npages = fbi->fix.line_length >> PAGE_SHIFT;
53 	omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
54 }
55 
56 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
57 		struct fb_info *fbi)
58 {
59 	struct drm_fb_helper *helper = get_fb(fbi);
60 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
61 
62 	if (!helper)
63 		goto fallback;
64 
65 	if (!fbdev->ywrap_enabled)
66 		goto fallback;
67 
68 	if (drm_can_sleep()) {
69 		pan_worker(&fbdev->work);
70 	} else {
71 		struct omap_drm_private *priv = helper->dev->dev_private;
72 		queue_work(priv->wq, &fbdev->work);
73 	}
74 
75 	return 0;
76 
77 fallback:
78 	return drm_fb_helper_pan_display(var, fbi);
79 }
80 
81 static struct fb_ops omap_fb_ops = {
82 	.owner = THIS_MODULE,
83 	DRM_FB_HELPER_DEFAULT_OPS,
84 
85 	.fb_read = drm_fb_helper_sys_read,
86 	.fb_write = drm_fb_helper_sys_write,
87 	.fb_fillrect = drm_fb_helper_sys_fillrect,
88 	.fb_copyarea = drm_fb_helper_sys_copyarea,
89 	.fb_imageblit = drm_fb_helper_sys_imageblit,
90 
91 	.fb_pan_display = omap_fbdev_pan_display,
92 };
93 
94 static int omap_fbdev_create(struct drm_fb_helper *helper,
95 		struct drm_fb_helper_surface_size *sizes)
96 {
97 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
98 	struct drm_device *dev = helper->dev;
99 	struct omap_drm_private *priv = dev->dev_private;
100 	struct drm_framebuffer *fb = NULL;
101 	union omap_gem_size gsize;
102 	struct fb_info *fbi = NULL;
103 	struct drm_mode_fb_cmd2 mode_cmd = {0};
104 	dma_addr_t dma_addr;
105 	int ret;
106 
107 	sizes->surface_bpp = 32;
108 	sizes->surface_depth = 24;
109 
110 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
111 			sizes->surface_height, sizes->surface_bpp,
112 			sizes->fb_width, sizes->fb_height);
113 
114 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
115 			sizes->surface_depth);
116 
117 	mode_cmd.width = sizes->surface_width;
118 	mode_cmd.height = sizes->surface_height;
119 
120 	mode_cmd.pitches[0] =
121 			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
122 
123 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
124 	if (fbdev->ywrap_enabled) {
125 		/* need to align pitch to page size if using DMM scrolling */
126 		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
127 	}
128 
129 	/* allocate backing bo */
130 	gsize = (union omap_gem_size){
131 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
132 	};
133 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
134 	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
135 	if (!fbdev->bo) {
136 		dev_err(dev->dev, "failed to allocate buffer object\n");
137 		ret = -ENOMEM;
138 		goto fail;
139 	}
140 
141 	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
142 	if (IS_ERR(fb)) {
143 		dev_err(dev->dev, "failed to allocate fb\n");
144 		/* note: if fb creation failed, we can't rely on fb destroy
145 		 * to unref the bo:
146 		 */
147 		drm_gem_object_unreference_unlocked(fbdev->bo);
148 		ret = PTR_ERR(fb);
149 		goto fail;
150 	}
151 
152 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
153 	 * but is needed as long as we use fb_mmap() to mmap to userspace
154 	 * (since this happens using fix.smem_start).  Possibly we could
155 	 * implement our own mmap using GEM mmap support to avoid this
156 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
157 	 * to it).  Then we just need to be sure that we are able to re-
158 	 * pin it in case of an opps.
159 	 */
160 	ret = omap_gem_pin(fbdev->bo, &dma_addr);
161 	if (ret) {
162 		dev_err(dev->dev, "could not pin framebuffer\n");
163 		ret = -ENOMEM;
164 		goto fail;
165 	}
166 
167 	mutex_lock(&dev->struct_mutex);
168 
169 	fbi = drm_fb_helper_alloc_fbi(helper);
170 	if (IS_ERR(fbi)) {
171 		dev_err(dev->dev, "failed to allocate fb info\n");
172 		ret = PTR_ERR(fbi);
173 		goto fail_unlock;
174 	}
175 
176 	DBG("fbi=%p, dev=%p", fbi, dev);
177 
178 	fbdev->fb = fb;
179 	helper->fb = fb;
180 
181 	fbi->par = helper;
182 	fbi->fbops = &omap_fb_ops;
183 
184 	strcpy(fbi->fix.id, MODULE_NAME);
185 
186 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
187 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
188 
189 	dev->mode_config.fb_base = dma_addr;
190 
191 	fbi->screen_base = omap_gem_vaddr(fbdev->bo);
192 	fbi->screen_size = fbdev->bo->size;
193 	fbi->fix.smem_start = dma_addr;
194 	fbi->fix.smem_len = fbdev->bo->size;
195 
196 	/* if we have DMM, then we can use it for scrolling by just
197 	 * shuffling pages around in DMM rather than doing sw blit.
198 	 */
199 	if (fbdev->ywrap_enabled) {
200 		DRM_INFO("Enabling DMM ywrap scrolling\n");
201 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
202 		fbi->fix.ywrapstep = 1;
203 	}
204 
205 
206 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
207 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
208 
209 	mutex_unlock(&dev->struct_mutex);
210 
211 	return 0;
212 
213 fail_unlock:
214 	mutex_unlock(&dev->struct_mutex);
215 fail:
216 
217 	if (ret) {
218 		if (fb)
219 			drm_framebuffer_remove(fb);
220 	}
221 
222 	return ret;
223 }
224 
225 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
226 	.fb_probe = omap_fbdev_create,
227 };
228 
229 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
230 {
231 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
232 		/* these are not the fb's you're looking for */
233 		return NULL;
234 	}
235 	return fbi->par;
236 }
237 
238 /* initialize fbdev helper */
239 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
240 {
241 	struct omap_drm_private *priv = dev->dev_private;
242 	struct omap_fbdev *fbdev = NULL;
243 	struct drm_fb_helper *helper;
244 	int ret = 0;
245 
246 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
247 	if (!fbdev)
248 		goto fail;
249 
250 	INIT_WORK(&fbdev->work, pan_worker);
251 
252 	helper = &fbdev->base;
253 
254 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
255 
256 	ret = drm_fb_helper_init(dev, helper, priv->num_connectors);
257 	if (ret) {
258 		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
259 		goto fail;
260 	}
261 
262 	ret = drm_fb_helper_single_add_all_connectors(helper);
263 	if (ret)
264 		goto fini;
265 
266 	ret = drm_fb_helper_initial_config(helper, 32);
267 	if (ret)
268 		goto fini;
269 
270 	priv->fbdev = helper;
271 
272 	return helper;
273 
274 fini:
275 	drm_fb_helper_fini(helper);
276 fail:
277 	kfree(fbdev);
278 
279 	dev_warn(dev->dev, "omap_fbdev_init failed\n");
280 	/* well, limp along without an fbdev.. maybe X11 will work? */
281 
282 	return NULL;
283 }
284 
285 void omap_fbdev_free(struct drm_device *dev)
286 {
287 	struct omap_drm_private *priv = dev->dev_private;
288 	struct drm_fb_helper *helper = priv->fbdev;
289 	struct omap_fbdev *fbdev;
290 
291 	DBG();
292 
293 	drm_fb_helper_unregister_fbi(helper);
294 
295 	drm_fb_helper_fini(helper);
296 
297 	fbdev = to_omap_fbdev(priv->fbdev);
298 
299 	/* unpin the GEM object pinned in omap_fbdev_create() */
300 	omap_gem_unpin(fbdev->bo);
301 
302 	/* this will free the backing object */
303 	if (fbdev->fb)
304 		drm_framebuffer_remove(fbdev->fb);
305 
306 	kfree(fbdev);
307 
308 	priv->fbdev = NULL;
309 }
310