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 <linux/fb.h>
  8
  9#include <drm/drm_drv.h>
 10#include <drm/drm_crtc_helper.h>
 11#include <drm/drm_fb_helper.h>
 12#include <drm/drm_file.h>
 13#include <drm/drm_fourcc.h>
 14#include <drm/drm_framebuffer.h>
 15#include <drm/drm_gem_framebuffer_helper.h>
 16#include <drm/drm_util.h>
 17
 18#include "omap_drv.h"
 19#include "omap_fbdev.h"
 20
 21MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
 22static bool ywrap_enabled = true;
 23module_param_named(ywrap, ywrap_enabled, bool, 0644);
 24
 25/*
 26 * fbdev funcs, to implement legacy fbdev interface on top of drm driver
 27 */
 28
 29#define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
 30
 31struct omap_fbdev {
 32	struct drm_fb_helper base;
 33	bool ywrap_enabled;
 34
 35	/* for deferred dmm roll when getting called in atomic ctx */
 36	struct work_struct work;
 37};
 38
 39static struct drm_fb_helper *get_fb(struct fb_info *fbi);
 40
 41static void pan_worker(struct work_struct *work)
 42{
 43	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
 44	struct drm_fb_helper *helper = &fbdev->base;
 45	struct fb_info *fbi = helper->info;
 46	struct drm_gem_object *bo = drm_gem_fb_get_obj(helper->fb, 0);
 47	int npages;
 48
 49	/* DMM roll shifts in 4K pages: */
 50	npages = fbi->fix.line_length >> PAGE_SHIFT;
 51	omap_gem_roll(bo, fbi->var.yoffset * npages);
 52}
 53
 54FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,
 55				   drm_fb_helper_damage_range,
 56				   drm_fb_helper_damage_area)
 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 int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 84{
 85	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 86
 87	return fb_deferred_io_mmap(info, vma);
 88}
 89
 90static void omap_fbdev_fb_destroy(struct fb_info *info)
 91{
 92	struct drm_fb_helper *helper = info->par;
 93	struct drm_framebuffer *fb = helper->fb;
 94	struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
 95	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
 96
 97	DBG();
 98
 99	fb_deferred_io_cleanup(info);
100	drm_fb_helper_fini(helper);
101
102	omap_gem_unpin(bo);
103	drm_framebuffer_remove(fb);
104
105	drm_client_release(&helper->client);
106	drm_fb_helper_unprepare(helper);
107	kfree(fbdev);
108}
109
110/*
111 * For now, we cannot use FB_DEFAULT_DEFERRED_OPS and fb_deferred_io_mmap()
112 * because we use write-combine.
113 */
114static const struct fb_ops omap_fb_ops = {
115	.owner = THIS_MODULE,
116	__FB_DEFAULT_DEFERRED_OPS_RDWR(omap_fbdev),
117	.fb_check_var	= drm_fb_helper_check_var,
118	.fb_set_par	= drm_fb_helper_set_par,
119	.fb_setcmap	= drm_fb_helper_setcmap,
120	.fb_blank	= drm_fb_helper_blank,
121	.fb_pan_display = omap_fbdev_pan_display,
122	__FB_DEFAULT_DEFERRED_OPS_DRAW(omap_fbdev),
123	.fb_ioctl	= drm_fb_helper_ioctl,
124	.fb_mmap	= omap_fbdev_fb_mmap,
125	.fb_destroy	= omap_fbdev_fb_destroy,
126};
127
128static int omap_fbdev_create(struct drm_fb_helper *helper,
129		struct drm_fb_helper_surface_size *sizes)
130{
131	struct omap_fbdev *fbdev = to_omap_fbdev(helper);
132	struct drm_device *dev = helper->dev;
133	struct omap_drm_private *priv = dev->dev_private;
134	struct drm_framebuffer *fb = NULL;
135	union omap_gem_size gsize;
136	struct fb_info *fbi = NULL;
137	struct drm_mode_fb_cmd2 mode_cmd = {0};
138	struct drm_gem_object *bo;
139	dma_addr_t dma_addr;
140	int ret;
141
142	sizes->surface_bpp = 32;
143	sizes->surface_depth = 24;
144
145	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
146			sizes->surface_height, sizes->surface_bpp,
147			sizes->fb_width, sizes->fb_height);
148
149	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
150			sizes->surface_depth);
151
152	mode_cmd.width = sizes->surface_width;
153	mode_cmd.height = sizes->surface_height;
154
155	mode_cmd.pitches[0] =
156			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
157
158	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
159	if (fbdev->ywrap_enabled) {
160		/* need to align pitch to page size if using DMM scrolling */
161		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
162	}
163
164	/* allocate backing bo */
165	gsize = (union omap_gem_size){
166		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
167	};
168	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
169	bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
170	if (!bo) {
171		dev_err(dev->dev, "failed to allocate buffer object\n");
172		ret = -ENOMEM;
173		goto fail;
174	}
175
176	fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
177	if (IS_ERR(fb)) {
178		dev_err(dev->dev, "failed to allocate fb\n");
179		/* note: if fb creation failed, we can't rely on fb destroy
180		 * to unref the bo:
181		 */
182		drm_gem_object_put(bo);
183		ret = PTR_ERR(fb);
184		goto fail;
185	}
186
187	/* note: this keeps the bo pinned.. which is perhaps not ideal,
188	 * but is needed as long as we use fb_mmap() to mmap to userspace
189	 * (since this happens using fix.smem_start).  Possibly we could
190	 * implement our own mmap using GEM mmap support to avoid this
191	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
192	 * to it).  Then we just need to be sure that we are able to re-
193	 * pin it in case of an opps.
194	 */
195	ret = omap_gem_pin(bo, &dma_addr);
196	if (ret) {
197		dev_err(dev->dev, "could not pin framebuffer\n");
198		ret = -ENOMEM;
199		goto fail;
200	}
201
202	fbi = drm_fb_helper_alloc_info(helper);
203	if (IS_ERR(fbi)) {
204		dev_err(dev->dev, "failed to allocate fb info\n");
205		ret = PTR_ERR(fbi);
206		goto fail;
207	}
208
209	DBG("fbi=%p, dev=%p", fbi, dev);
210
211	helper->fb = fb;
212
213	fbi->fbops = &omap_fb_ops;
214
215	drm_fb_helper_fill_info(fbi, helper, sizes);
216
217	fbi->flags |= FBINFO_VIRTFB;
218	fbi->screen_buffer = omap_gem_vaddr(bo);
219	fbi->screen_size = bo->size;
220	fbi->fix.smem_start = dma_addr;
221	fbi->fix.smem_len = bo->size;
222
223	/* deferred I/O */
224	helper->fbdefio.delay = HZ / 20;
225	helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
226
227	fbi->fbdefio = &helper->fbdefio;
228	ret = fb_deferred_io_init(fbi);
229	if (ret)
230		goto fail;
231
232	/* if we have DMM, then we can use it for scrolling by just
233	 * shuffling pages around in DMM rather than doing sw blit.
234	 */
235	if (fbdev->ywrap_enabled) {
236		DRM_INFO("Enabling DMM ywrap scrolling\n");
237		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
238		fbi->fix.ywrapstep = 1;
239	}
240
241
242	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
243	DBG("allocated %dx%d fb", fb->width, fb->height);
244
245	return 0;
246
247fail:
248
249	if (ret) {
250		if (fb)
251			drm_framebuffer_remove(fb);
252	}
253
254	return ret;
255}
256
257static int omap_fbdev_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
258{
259	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
260		return 0;
261
262	if (helper->fb->funcs->dirty)
263		return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
264
265	return 0;
266}
267
268static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
269	.fb_probe = omap_fbdev_create,
270	.fb_dirty = omap_fbdev_dirty,
271};
272
273static struct drm_fb_helper *get_fb(struct fb_info *fbi)
274{
275	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
276		/* these are not the fb's you're looking for */
277		return NULL;
278	}
279	return fbi->par;
280}
281
282/*
283 * struct drm_client
284 */
285
286static void omap_fbdev_client_unregister(struct drm_client_dev *client)
287{
288	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
289
290	if (fb_helper->info) {
291		drm_fb_helper_unregister_info(fb_helper);
292	} else {
293		drm_client_release(&fb_helper->client);
294		drm_fb_helper_unprepare(fb_helper);
295		kfree(fb_helper);
296	}
297}
298
299static int omap_fbdev_client_restore(struct drm_client_dev *client)
300{
301	drm_fb_helper_lastclose(client->dev);
302
303	return 0;
304}
305
306static int omap_fbdev_client_hotplug(struct drm_client_dev *client)
307{
308	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
309	struct drm_device *dev = client->dev;
310	int ret;
311
312	if (dev->fb_helper)
313		return drm_fb_helper_hotplug_event(dev->fb_helper);
314
315	ret = drm_fb_helper_init(dev, fb_helper);
316	if (ret)
317		goto err_drm_err;
318
319	ret = drm_fb_helper_initial_config(fb_helper);
320	if (ret)
321		goto err_drm_fb_helper_fini;
322
323	return 0;
324
325err_drm_fb_helper_fini:
326	drm_fb_helper_fini(fb_helper);
327err_drm_err:
328	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
329	return ret;
330}
331
332static const struct drm_client_funcs omap_fbdev_client_funcs = {
333	.owner		= THIS_MODULE,
334	.unregister	= omap_fbdev_client_unregister,
335	.restore	= omap_fbdev_client_restore,
336	.hotplug	= omap_fbdev_client_hotplug,
337};
338
339void omap_fbdev_setup(struct drm_device *dev)
340{
341	struct omap_fbdev *fbdev;
342	struct drm_fb_helper *helper;
343	int ret;
344
345	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
346	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
347
348	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
349	if (!fbdev)
350		return;
351	helper = &fbdev->base;
352
353	drm_fb_helper_prepare(dev, helper, 32, &omap_fb_helper_funcs);
354
355	ret = drm_client_init(dev, &helper->client, "fbdev", &omap_fbdev_client_funcs);
356	if (ret)
357		goto err_drm_client_init;
358
359	INIT_WORK(&fbdev->work, pan_worker);
360
361	drm_client_register(&helper->client);
362
363	return;
364
365err_drm_client_init:
366	drm_fb_helper_unprepare(helper);
367	kfree(fbdev);
368}