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 
84 	.fb_check_var	= drm_fb_helper_check_var,
85 	.fb_set_par	= drm_fb_helper_set_par,
86 	.fb_setcmap	= drm_fb_helper_setcmap,
87 	.fb_blank	= drm_fb_helper_blank,
88 	.fb_pan_display = omap_fbdev_pan_display,
89 	.fb_debug_enter = drm_fb_helper_debug_enter,
90 	.fb_debug_leave = drm_fb_helper_debug_leave,
91 	.fb_ioctl	= drm_fb_helper_ioctl,
92 
93 	.fb_read = drm_fb_helper_sys_read,
94 	.fb_write = drm_fb_helper_sys_write,
95 	.fb_fillrect = drm_fb_helper_sys_fillrect,
96 	.fb_copyarea = drm_fb_helper_sys_copyarea,
97 	.fb_imageblit = drm_fb_helper_sys_imageblit,
98 };
99 
100 static int omap_fbdev_create(struct drm_fb_helper *helper,
101 		struct drm_fb_helper_surface_size *sizes)
102 {
103 	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
104 	struct drm_device *dev = helper->dev;
105 	struct omap_drm_private *priv = dev->dev_private;
106 	struct drm_framebuffer *fb = NULL;
107 	union omap_gem_size gsize;
108 	struct fb_info *fbi = NULL;
109 	struct drm_mode_fb_cmd2 mode_cmd = {0};
110 	dma_addr_t dma_addr;
111 	int ret;
112 
113 	sizes->surface_bpp = 32;
114 	sizes->surface_depth = 24;
115 
116 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
117 			sizes->surface_height, sizes->surface_bpp,
118 			sizes->fb_width, sizes->fb_height);
119 
120 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
121 			sizes->surface_depth);
122 
123 	mode_cmd.width = sizes->surface_width;
124 	mode_cmd.height = sizes->surface_height;
125 
126 	mode_cmd.pitches[0] =
127 			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
128 
129 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
130 	if (fbdev->ywrap_enabled) {
131 		/* need to align pitch to page size if using DMM scrolling */
132 		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
133 	}
134 
135 	/* allocate backing bo */
136 	gsize = (union omap_gem_size){
137 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
138 	};
139 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
140 	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
141 	if (!fbdev->bo) {
142 		dev_err(dev->dev, "failed to allocate buffer object\n");
143 		ret = -ENOMEM;
144 		goto fail;
145 	}
146 
147 	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
148 	if (IS_ERR(fb)) {
149 		dev_err(dev->dev, "failed to allocate fb\n");
150 		/* note: if fb creation failed, we can't rely on fb destroy
151 		 * to unref the bo:
152 		 */
153 		drm_gem_object_unreference_unlocked(fbdev->bo);
154 		ret = PTR_ERR(fb);
155 		goto fail;
156 	}
157 
158 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
159 	 * but is needed as long as we use fb_mmap() to mmap to userspace
160 	 * (since this happens using fix.smem_start).  Possibly we could
161 	 * implement our own mmap using GEM mmap support to avoid this
162 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
163 	 * to it).  Then we just need to be sure that we are able to re-
164 	 * pin it in case of an opps.
165 	 */
166 	ret = omap_gem_pin(fbdev->bo, &dma_addr);
167 	if (ret) {
168 		dev_err(dev->dev, "could not pin framebuffer\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->fbops = &omap_fb_ops;
189 
190 	strcpy(fbi->fix.id, MODULE_NAME);
191 
192 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
193 	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
194 
195 	dev->mode_config.fb_base = dma_addr;
196 
197 	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
198 	fbi->screen_size = fbdev->bo->size;
199 	fbi->fix.smem_start = dma_addr;
200 	fbi->fix.smem_len = fbdev->bo->size;
201 
202 	/* if we have DMM, then we can use it for scrolling by just
203 	 * shuffling pages around in DMM rather than doing sw blit.
204 	 */
205 	if (fbdev->ywrap_enabled) {
206 		DRM_INFO("Enabling DMM ywrap scrolling\n");
207 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
208 		fbi->fix.ywrapstep = 1;
209 	}
210 
211 
212 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
213 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
214 
215 	mutex_unlock(&dev->struct_mutex);
216 
217 	return 0;
218 
219 fail_unlock:
220 	mutex_unlock(&dev->struct_mutex);
221 fail:
222 
223 	if (ret) {
224 		if (fb)
225 			drm_framebuffer_remove(fb);
226 	}
227 
228 	return ret;
229 }
230 
231 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
232 	.fb_probe = omap_fbdev_create,
233 };
234 
235 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
236 {
237 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
238 		/* these are not the fb's you're looking for */
239 		return NULL;
240 	}
241 	return fbi->par;
242 }
243 
244 /* initialize fbdev helper */
245 void omap_fbdev_init(struct drm_device *dev)
246 {
247 	struct omap_drm_private *priv = dev->dev_private;
248 	struct omap_fbdev *fbdev = NULL;
249 	struct drm_fb_helper *helper;
250 	int ret = 0;
251 
252 	if (!priv->num_crtcs || !priv->num_connectors)
253 		return;
254 
255 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
256 	if (!fbdev)
257 		goto fail;
258 
259 	INIT_WORK(&fbdev->work, pan_worker);
260 
261 	helper = &fbdev->base;
262 
263 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
264 
265 	ret = drm_fb_helper_init(dev, helper, priv->num_connectors);
266 	if (ret)
267 		goto fail;
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;
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 }
288 
289 void omap_fbdev_fini(struct drm_device *dev)
290 {
291 	struct omap_drm_private *priv = dev->dev_private;
292 	struct drm_fb_helper *helper = priv->fbdev;
293 	struct omap_fbdev *fbdev;
294 
295 	DBG();
296 
297 	if (!helper)
298 		return;
299 
300 	drm_fb_helper_unregister_fbi(helper);
301 
302 	drm_fb_helper_fini(helper);
303 
304 	fbdev = to_omap_fbdev(helper);
305 
306 	/* unpin the GEM object pinned in omap_fbdev_create() */
307 	if (fbdev->bo)
308 		omap_gem_unpin(fbdev->bo);
309 
310 	/* this will free the backing object */
311 	if (fbdev->fb)
312 		drm_framebuffer_remove(fbdev->fb);
313 
314 	kfree(fbdev);
315 
316 	priv->fbdev = NULL;
317 }
318