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
 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	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
 99static 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->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
220fail_unlock:
221	mutex_unlock(&dev->struct_mutex);
222fail:
223
224	if (ret) {
225
226		drm_fb_helper_release_fbi(helper);
227
228		if (fb) {
229			drm_framebuffer_unregister_private(fb);
230			drm_framebuffer_remove(fb);
231		}
232	}
233
234	return ret;
235}
236
237static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
238	.fb_probe = omap_fbdev_create,
239};
240
241static struct drm_fb_helper *get_fb(struct fb_info *fbi)
242{
243	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
244		/* these are not the fb's you're looking for */
245		return NULL;
246	}
247	return fbi->par;
248}
249
250/* initialize fbdev helper */
251struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev)
252{
253	struct omap_drm_private *priv = dev->dev_private;
254	struct omap_fbdev *fbdev = NULL;
255	struct drm_fb_helper *helper;
256	int ret = 0;
257
258	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
259	if (!fbdev)
260		goto fail;
261
262	INIT_WORK(&fbdev->work, pan_worker);
263
264	helper = &fbdev->base;
265
266	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
267
268	ret = drm_fb_helper_init(dev, helper,
269			priv->num_crtcs, priv->num_connectors);
270	if (ret) {
271		dev_err(dev->dev, "could not init fbdev: ret=%d\n", ret);
272		goto fail;
273	}
274
275	ret = drm_fb_helper_single_add_all_connectors(helper);
276	if (ret)
277		goto fini;
278
279	ret = drm_fb_helper_initial_config(helper, 32);
280	if (ret)
281		goto fini;
282
283	priv->fbdev = helper;
284
285	return helper;
286
287fini:
288	drm_fb_helper_fini(helper);
289fail:
290	kfree(fbdev);
291
292	dev_warn(dev->dev, "omap_fbdev_init failed\n");
293	/* well, limp along without an fbdev.. maybe X11 will work? */
294
295	return NULL;
296}
297
298void omap_fbdev_free(struct drm_device *dev)
299{
300	struct omap_drm_private *priv = dev->dev_private;
301	struct drm_fb_helper *helper = priv->fbdev;
302	struct omap_fbdev *fbdev;
303
304	DBG();
305
306	drm_fb_helper_unregister_fbi(helper);
307	drm_fb_helper_release_fbi(helper);
308
309	drm_fb_helper_fini(helper);
310
311	fbdev = to_omap_fbdev(priv->fbdev);
312
313	/* release the ref taken in omap_fbdev_create() */
314	omap_gem_put_paddr(fbdev->bo);
315
316	/* this will free the backing object */
317	if (fbdev->fb) {
318		drm_framebuffer_unregister_private(fbdev->fb);
319		drm_framebuffer_remove(fbdev->fb);
320	}
321
322	kfree(fbdev);
323
324	priv->fbdev = NULL;
325}