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
 23MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
 24static bool ywrap_enabled = true;
 25module_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
 33struct 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
 43static struct drm_fb_helper *get_fb(struct fb_info *fbi);
 44
 45static 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
 56static 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
 77fallback:
 78	return drm_fb_helper_pan_display(var, fbi);
 79}
 80
 81static 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
100static 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
219fail_unlock:
220	mutex_unlock(&dev->struct_mutex);
221fail:
222
223	if (ret) {
224		if (fb)
225			drm_framebuffer_remove(fb);
226	}
227
228	return ret;
229}
230
231static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
232	.fb_probe = omap_fbdev_create,
233};
234
235static 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 */
245void 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
281fini:
282	drm_fb_helper_fini(helper);
283fail:
284	kfree(fbdev);
285
286	dev_warn(dev->dev, "omap_fbdev_init failed\n");
287}
288
289void 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}