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
25MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
26static bool ywrap_enabled = true;
27module_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
35struct 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
45static struct drm_fb_helper *get_fb(struct fb_info *fbi);
46
47static 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
58static 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
79fallback:
80	return drm_fb_helper_pan_display(var, fbi);
81}
82
83static 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
102static 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
234fail_unlock:
235	mutex_unlock(&dev->struct_mutex);
236fail:
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
250static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
251	.fb_probe = omap_fbdev_create,
252};
253
254static 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 */
264struct 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
303fini:
304	drm_fb_helper_fini(helper);
305fail:
306	kfree(fbdev);
307	return NULL;
308}
309
310void 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