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 
21 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
22 static bool ywrap_enabled = true;
23 module_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 
31 struct 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 
39 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
40 
pan_worker(struct work_struct * work)41 static 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 
FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,drm_fb_helper_damage_range,drm_fb_helper_damage_area)54 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev,
55 				   drm_fb_helper_damage_range,
56 				   drm_fb_helper_damage_area)
57 
58 static 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 
79 fallback:
80 	return drm_fb_helper_pan_display(var, fbi);
81 }
82 
omap_fbdev_fb_mmap(struct fb_info * info,struct vm_area_struct * vma)83 static 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 
omap_fbdev_fb_destroy(struct fb_info * info)90 static 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  */
114 static 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 
omap_fbdev_create(struct drm_fb_helper * helper,struct drm_fb_helper_surface_size * sizes)128 static 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 
247 fail:
248 
249 	if (ret) {
250 		if (fb)
251 			drm_framebuffer_remove(fb);
252 	}
253 
254 	return ret;
255 }
256 
omap_fbdev_dirty(struct drm_fb_helper * helper,struct drm_clip_rect * clip)257 static 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 
268 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
269 	.fb_probe = omap_fbdev_create,
270 	.fb_dirty = omap_fbdev_dirty,
271 };
272 
get_fb(struct fb_info * fbi)273 static 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 
omap_fbdev_client_unregister(struct drm_client_dev * client)286 static 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 
omap_fbdev_client_restore(struct drm_client_dev * client)299 static int omap_fbdev_client_restore(struct drm_client_dev *client)
300 {
301 	drm_fb_helper_lastclose(client->dev);
302 
303 	return 0;
304 }
305 
omap_fbdev_client_hotplug(struct drm_client_dev * client)306 static 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 
325 err_drm_fb_helper_fini:
326 	drm_fb_helper_fini(fb_helper);
327 err_drm_err:
328 	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
329 	return ret;
330 }
331 
332 static 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 
omap_fbdev_setup(struct drm_device * dev)339 void 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 
365 err_drm_client_init:
366 	drm_fb_helper_unprepare(helper);
367 	kfree(fbdev);
368 }
369