1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
  4 * Author: Rob Clark <rob@ti.com>
  5 */
  6
  7#include <drm/drm_crtc.h>
  8#include <drm/drm_util.h>
  9#include <drm/drm_fb_helper.h>
 10#include <drm/drm_file.h>
 11#include <drm/drm_fourcc.h>
 12
 13#include "omap_drv.h"
 14
 15MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
 16static bool ywrap_enabled = true;
 17module_param_named(ywrap, ywrap_enabled, bool, 0644);
 18
 19/*
 20 * fbdev funcs, to implement legacy fbdev interface on top of drm driver
 21 */
 22
 23#define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
 24
 25struct omap_fbdev {
 26	struct drm_fb_helper base;
 27	struct drm_framebuffer *fb;
 28	struct drm_gem_object *bo;
 29	bool ywrap_enabled;
 30
 31	/* for deferred dmm roll when getting called in atomic ctx */
 32	struct work_struct work;
 33};
 34
 35static struct drm_fb_helper *get_fb(struct fb_info *fbi);
 36
 37static void pan_worker(struct work_struct *work)
 38{
 39	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
 40	struct fb_info *fbi = fbdev->base.fbdev;
 41	int npages;
 42
 43	/* DMM roll shifts in 4K pages: */
 44	npages = fbi->fix.line_length >> PAGE_SHIFT;
 45	omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
 46}
 47
 48static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
 49		struct fb_info *fbi)
 50{
 51	struct drm_fb_helper *helper = get_fb(fbi);
 52	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 53
 54	if (!helper)
 55		goto fallback;
 56
 57	if (!fbdev->ywrap_enabled)
 58		goto fallback;
 59
 60	if (drm_can_sleep()) {
 61		pan_worker(&fbdev->work);
 62	} else {
 63		struct omap_drm_private *priv = helper->dev->dev_private;
 64		queue_work(priv->wq, &fbdev->work);
 65	}
 66
 67	return 0;
 68
 69fallback:
 70	return drm_fb_helper_pan_display(var, fbi);
 71}
 72
 73static struct fb_ops omap_fb_ops = {
 74	.owner = THIS_MODULE,
 75
 76	.fb_check_var	= drm_fb_helper_check_var,
 77	.fb_set_par	= drm_fb_helper_set_par,
 78	.fb_setcmap	= drm_fb_helper_setcmap,
 79	.fb_blank	= drm_fb_helper_blank,
 80	.fb_pan_display = omap_fbdev_pan_display,
 81	.fb_ioctl	= drm_fb_helper_ioctl,
 82
 83	.fb_read = drm_fb_helper_sys_read,
 84	.fb_write = drm_fb_helper_sys_write,
 85	.fb_fillrect = drm_fb_helper_sys_fillrect,
 86	.fb_copyarea = drm_fb_helper_sys_copyarea,
 87	.fb_imageblit = drm_fb_helper_sys_imageblit,
 88};
 89
 90static int omap_fbdev_create(struct drm_fb_helper *helper,
 91		struct drm_fb_helper_surface_size *sizes)
 92{
 93	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 94	struct drm_device *dev = helper->dev;
 95	struct omap_drm_private *priv = dev->dev_private;
 96	struct drm_framebuffer *fb = NULL;
 97	union omap_gem_size gsize;
 98	struct fb_info *fbi = NULL;
 99	struct drm_mode_fb_cmd2 mode_cmd = {0};
100	dma_addr_t dma_addr;
101	int ret;
102
103	sizes->surface_bpp = 32;
104	sizes->surface_depth = 24;
105
106	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
107			sizes->surface_height, sizes->surface_bpp,
108			sizes->fb_width, sizes->fb_height);
109
110	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
111			sizes->surface_depth);
112
113	mode_cmd.width = sizes->surface_width;
114	mode_cmd.height = sizes->surface_height;
115
116	mode_cmd.pitches[0] =
117			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
118
119	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
120	if (fbdev->ywrap_enabled) {
121		/* need to align pitch to page size if using DMM scrolling */
122		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
123	}
124
125	/* allocate backing bo */
126	gsize = (union omap_gem_size){
127		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
128	};
129	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
130	fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
131	if (!fbdev->bo) {
132		dev_err(dev->dev, "failed to allocate buffer object\n");
133		ret = -ENOMEM;
134		goto fail;
135	}
136
137	fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
138	if (IS_ERR(fb)) {
139		dev_err(dev->dev, "failed to allocate fb\n");
140		/* note: if fb creation failed, we can't rely on fb destroy
141		 * to unref the bo:
142		 */
143		drm_gem_object_put_unlocked(fbdev->bo);
144		ret = PTR_ERR(fb);
145		goto fail;
146	}
147
148	/* note: this keeps the bo pinned.. which is perhaps not ideal,
149	 * but is needed as long as we use fb_mmap() to mmap to userspace
150	 * (since this happens using fix.smem_start).  Possibly we could
151	 * implement our own mmap using GEM mmap support to avoid this
152	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
153	 * to it).  Then we just need to be sure that we are able to re-
154	 * pin it in case of an opps.
155	 */
156	ret = omap_gem_pin(fbdev->bo, &dma_addr);
157	if (ret) {
158		dev_err(dev->dev, "could not pin framebuffer\n");
159		ret = -ENOMEM;
160		goto fail;
161	}
162
163	fbi = drm_fb_helper_alloc_fbi(helper);
164	if (IS_ERR(fbi)) {
165		dev_err(dev->dev, "failed to allocate fb info\n");
166		ret = PTR_ERR(fbi);
167		goto fail;
168	}
169
170	DBG("fbi=%p, dev=%p", fbi, dev);
171
172	fbdev->fb = fb;
173	helper->fb = fb;
174
175	fbi->fbops = &omap_fb_ops;
176
177	drm_fb_helper_fill_info(fbi, helper, sizes);
178
179	dev->mode_config.fb_base = dma_addr;
180
181	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
182	fbi->screen_size = fbdev->bo->size;
183	fbi->fix.smem_start = dma_addr;
184	fbi->fix.smem_len = fbdev->bo->size;
185
186	/* if we have DMM, then we can use it for scrolling by just
187	 * shuffling pages around in DMM rather than doing sw blit.
188	 */
189	if (fbdev->ywrap_enabled) {
190		DRM_INFO("Enabling DMM ywrap scrolling\n");
191		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
192		fbi->fix.ywrapstep = 1;
193	}
194
195
196	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
197	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
198
199	return 0;
200
201fail:
202
203	if (ret) {
204		if (fb)
205			drm_framebuffer_remove(fb);
206	}
207
208	return ret;
209}
210
211static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
212	.fb_probe = omap_fbdev_create,
213};
214
215static struct drm_fb_helper *get_fb(struct fb_info *fbi)
216{
217	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
218		/* these are not the fb's you're looking for */
219		return NULL;
220	}
221	return fbi->par;
222}
223
224/* initialize fbdev helper */
225void omap_fbdev_init(struct drm_device *dev)
226{
227	struct omap_drm_private *priv = dev->dev_private;
228	struct omap_fbdev *fbdev = NULL;
229	struct drm_fb_helper *helper;
230	int ret = 0;
231
232	if (!priv->num_pipes)
233		return;
234
235	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
236	if (!fbdev)
237		goto fail;
238
239	INIT_WORK(&fbdev->work, pan_worker);
240
241	helper = &fbdev->base;
242
243	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
244
245	ret = drm_fb_helper_init(dev, helper, priv->num_pipes);
246	if (ret)
247		goto fail;
248
249	ret = drm_fb_helper_single_add_all_connectors(helper);
250	if (ret)
251		goto fini;
252
253	ret = drm_fb_helper_initial_config(helper, 32);
254	if (ret)
255		goto fini;
256
257	priv->fbdev = helper;
258
259	return;
260
261fini:
262	drm_fb_helper_fini(helper);
263fail:
264	kfree(fbdev);
265
266	dev_warn(dev->dev, "omap_fbdev_init failed\n");
267}
268
269void omap_fbdev_fini(struct drm_device *dev)
270{
271	struct omap_drm_private *priv = dev->dev_private;
272	struct drm_fb_helper *helper = priv->fbdev;
273	struct omap_fbdev *fbdev;
274
275	DBG();
276
277	if (!helper)
278		return;
279
280	drm_fb_helper_unregister_fbi(helper);
281
282	drm_fb_helper_fini(helper);
283
284	fbdev = to_omap_fbdev(helper);
285
286	/* unpin the GEM object pinned in omap_fbdev_create() */
287	if (fbdev->bo)
288		omap_gem_unpin(fbdev->bo);
289
290	/* this will free the backing object */
291	if (fbdev->fb)
292		drm_framebuffer_remove(fbdev->fb);
293
294	kfree(fbdev);
295
296	priv->fbdev = NULL;
297}