omap_fbdev.c

  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/clients/drm_client_setup.h>
 10#include <drm/drm_drv.h>
 11#include <drm/drm_crtc_helper.h>
 12#include <drm/drm_fb_helper.h>
 13#include <drm/drm_file.h>
 14#include <drm/drm_fourcc.h>
 15#include <drm/drm_framebuffer.h>
 16#include <drm/drm_gem_framebuffer_helper.h>
 17#include <drm/drm_managed.h>
 18#include <drm/drm_print.h>
 19#include <drm/drm_util.h>
 20
 21#include "omap_drv.h"
 22#include "omap_fbdev.h"
 23
 24MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
 25static bool ywrap_enabled = true;
 26module_param_named(ywrap, ywrap_enabled, bool, 0644);
 27
 28/*
 29 * fbdev funcs, to implement legacy fbdev interface on top of drm driver
 30 */
 31
 32struct omap_fbdev {
 33	struct drm_device *dev;
 34	bool ywrap_enabled;
 35
 36	/* for deferred dmm roll when getting called in atomic ctx */
 37	struct work_struct work;
 38};
 39
 40static struct drm_fb_helper *get_fb(struct fb_info *fbi);
 41
 42static void pan_worker(struct work_struct *work)
 43{
 44	struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
 45	struct drm_fb_helper *helper = fbdev->dev->fb_helper;
 46	struct fb_info *fbi = helper->info;
 47	struct drm_gem_object *bo = drm_gem_fb_get_obj(helper->fb, 0);
 48	int npages;
 49
 50	/* DMM roll shifts in 4K pages: */
 51	npages = fbi->fix.line_length >> PAGE_SHIFT;
 52	omap_gem_roll(bo, fbi->var.yoffset * npages);
 53}
 54
 55FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,
 56				   drm_fb_helper_damage_range,
 57				   drm_fb_helper_damage_area)
 58
 59static int omap_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
 60{
 61	struct drm_fb_helper *helper = get_fb(fbi);
 62	struct omap_drm_private *priv;
 63	struct omap_fbdev *fbdev;
 64
 65	if (!helper)
 66		goto fallback;
 67
 68	priv = helper->dev->dev_private;
 69	fbdev = priv->fbdev;
 70
 71	if (!fbdev->ywrap_enabled)
 72		goto fallback;
 73
 74	if (drm_can_sleep())
 75		pan_worker(&fbdev->work);
 76	else
 77		queue_work(priv->wq, &fbdev->work);
 78
 79	return 0;
 80
 81fallback:
 82	return drm_fb_helper_pan_display(var, fbi);
 83}
 84
 85static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 86{
 87	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 88
 89	return fb_deferred_io_mmap(info, vma);
 90}
 91
 92static void omap_fbdev_fb_destroy(struct fb_info *info)
 93{
 94	struct drm_fb_helper *helper = info->par;
 95	struct drm_framebuffer *fb = helper->fb;
 96	struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
 97
 98	DBG();
 99
100	fb_deferred_io_cleanup(info);
101	drm_fb_helper_fini(helper);
102
103	omap_gem_unpin(bo);
104	drm_framebuffer_remove(fb);
105
106	drm_client_release(&helper->client);
107}
108
109/*
110 * For now, we cannot use FB_DEFAULT_DEFERRED_OPS and fb_deferred_io_mmap()
111 * because we use write-combine.
112 */
113static const struct fb_ops omap_fb_ops = {
114	.owner = THIS_MODULE,
115	__FB_DEFAULT_DEFERRED_OPS_RDWR(omap_fbdev),
116	.fb_check_var	= drm_fb_helper_check_var,
117	.fb_set_par	= drm_fb_helper_set_par,
118	.fb_setcmap	= drm_fb_helper_setcmap,
119	.fb_blank	= drm_fb_helper_blank,
120	.fb_pan_display = omap_fbdev_pan_display,
121	__FB_DEFAULT_DEFERRED_OPS_DRAW(omap_fbdev),
122	.fb_ioctl	= drm_fb_helper_ioctl,
123	.fb_mmap	= omap_fbdev_fb_mmap,
124	.fb_destroy	= omap_fbdev_fb_destroy,
125};
126
127static int omap_fbdev_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
128{
129	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
130		return 0;
131
132	if (helper->fb->funcs->dirty)
133		return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
134
135	return 0;
136}
137
138static const struct drm_fb_helper_funcs omap_fbdev_helper_funcs = {
139	.fb_dirty = omap_fbdev_dirty,
140};
141
142static struct drm_fb_helper *get_fb(struct fb_info *fbi)
143{
144	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
145		/* these are not the fb's you're looking for */
146		return NULL;
147	}
148	return fbi->par;
149}
150
151int omap_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
152				  struct drm_fb_helper_surface_size *sizes)
153{
154	struct drm_device *dev = helper->dev;
155	struct omap_drm_private *priv = dev->dev_private;
156	struct omap_fbdev *fbdev = priv->fbdev;
157	struct fb_info *fbi = helper->info;
158	struct drm_framebuffer *fb = NULL;
159	union omap_gem_size gsize;
160	struct drm_mode_fb_cmd2 mode_cmd = {0};
161	struct drm_gem_object *bo;
162	dma_addr_t dma_addr;
163	int ret;
164
165	sizes->surface_bpp = 32;
166	sizes->surface_depth = 24;
167
168	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
169			sizes->surface_height, sizes->surface_bpp,
170			sizes->fb_width, sizes->fb_height);
171
172	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
173			sizes->surface_depth);
174
175	mode_cmd.width = sizes->surface_width;
176	mode_cmd.height = sizes->surface_height;
177
178	mode_cmd.pitches[0] =
179			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
180
181	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
182	if (fbdev->ywrap_enabled) {
183		/* need to align pitch to page size if using DMM scrolling */
184		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
185	}
186
187	/* allocate backing bo */
188	gsize = (union omap_gem_size){
189		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
190	};
191	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
192	bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
193	if (!bo) {
194		dev_err(dev->dev, "failed to allocate buffer object\n");
195		ret = -ENOMEM;
196		goto fail;
197	}
198
199	fb = omap_framebuffer_init(dev,
200				   drm_get_format_info(dev, mode_cmd.pixel_format,
201						       mode_cmd.modifier[0]),
202				   &mode_cmd, &bo);
203	if (IS_ERR(fb)) {
204		dev_err(dev->dev, "failed to allocate fb\n");
205		/* note: if fb creation failed, we can't rely on fb destroy
206		 * to unref the bo:
207		 */
208		drm_gem_object_put(bo);
209		ret = PTR_ERR(fb);
210		goto fail;
211	}
212
213	/* note: this keeps the bo pinned.. which is perhaps not ideal,
214	 * but is needed as long as we use fb_mmap() to mmap to userspace
215	 * (since this happens using fix.smem_start).  Possibly we could
216	 * implement our own mmap using GEM mmap support to avoid this
217	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
218	 * to it).  Then we just need to be sure that we are able to re-
219	 * pin it in case of an opps.
220	 */
221	ret = omap_gem_pin(bo, &dma_addr);
222	if (ret) {
223		dev_err(dev->dev, "could not pin framebuffer\n");
224		ret = -ENOMEM;
225		goto fail;
226	}
227
228	DBG("fbi=%p, dev=%p", fbi, dev);
229
230	helper->funcs = &omap_fbdev_helper_funcs;
231	helper->fb = fb;
232
233	fbi->fbops = &omap_fb_ops;
234
235	drm_fb_helper_fill_info(fbi, helper, sizes);
236
237	fbi->flags |= FBINFO_VIRTFB;
238	fbi->screen_buffer = omap_gem_vaddr(bo);
239	fbi->screen_size = bo->size;
240	fbi->fix.smem_start = dma_addr;
241	fbi->fix.smem_len = bo->size;
242
243	/* deferred I/O */
244	helper->fbdefio.delay = HZ / 20;
245	helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
246
247	fbi->fbdefio = &helper->fbdefio;
248	ret = fb_deferred_io_init(fbi);
249	if (ret)
250		goto fail;
251
252	/* if we have DMM, then we can use it for scrolling by just
253	 * shuffling pages around in DMM rather than doing sw blit.
254	 */
255	if (fbdev->ywrap_enabled) {
256		DRM_INFO("Enabling DMM ywrap scrolling\n");
257		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
258		fbi->fix.ywrapstep = 1;
259	}
260
261
262	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
263	DBG("allocated %dx%d fb", fb->width, fb->height);
264
265	return 0;
266
267fail:
268
269	if (ret) {
270		if (fb)
271			drm_framebuffer_remove(fb);
272	}
273
274	return ret;
275}
276
277void omap_fbdev_setup(struct drm_device *dev)
278{
279	struct omap_drm_private *priv = dev->dev_private;
280	struct omap_fbdev *fbdev;
281
282	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
283	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
284
285	fbdev = drmm_kzalloc(dev, sizeof(*fbdev), GFP_KERNEL);
286	if (!fbdev)
287		return;
288	fbdev->dev = dev;
289	INIT_WORK(&fbdev->work, pan_worker);
290
291	priv->fbdev = fbdev;
292
293	drm_client_setup(dev, NULL);
294}