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