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