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(fb: helper->fb, plane: 0);
47 int npages;
48
49 /* DMM roll shifts in 4K pages: */
50 npages = fbi->fix.line_length >> PAGE_SHIFT;
51 omap_gem_roll(obj: bo, roll: fbi->var.yoffset * npages);
52}
53
54static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
55 struct fb_info *fbi)
56{
57 struct drm_fb_helper *helper = get_fb(fbi);
58 struct omap_fbdev *fbdev = to_omap_fbdev(helper);
59
60 if (!helper)
61 goto fallback;
62
63 if (!fbdev->ywrap_enabled)
64 goto fallback;
65
66 if (drm_can_sleep()) {
67 pan_worker(work: &fbdev->work);
68 } else {
69 struct omap_drm_private *priv = helper->dev->dev_private;
70 queue_work(wq: priv->wq, work: &fbdev->work);
71 }
72
73 return 0;
74
75fallback:
76 return drm_fb_helper_pan_display(var, info: fbi);
77}
78
79static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
80{
81 struct drm_fb_helper *helper = info->par;
82 struct drm_framebuffer *fb = helper->fb;
83 struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, plane: 0);
84
85 return drm_gem_mmap_obj(obj: bo, obj_size: omap_gem_mmap_size(obj: bo), vma);
86}
87
88static void omap_fbdev_fb_destroy(struct fb_info *info)
89{
90 struct drm_fb_helper *helper = info->par;
91 struct drm_framebuffer *fb = helper->fb;
92 struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, plane: 0);
93 struct omap_fbdev *fbdev = to_omap_fbdev(helper);
94
95 DBG();
96
97 drm_fb_helper_fini(helper);
98
99 omap_gem_unpin(obj: bo);
100 drm_framebuffer_remove(fb);
101
102 drm_client_release(client: &helper->client);
103 drm_fb_helper_unprepare(fb_helper: helper);
104 kfree(objp: fbdev);
105}
106
107static const struct fb_ops omap_fb_ops = {
108 .owner = THIS_MODULE,
109 __FB_DEFAULT_DMAMEM_OPS_RDWR,
110 .fb_check_var = drm_fb_helper_check_var,
111 .fb_set_par = drm_fb_helper_set_par,
112 .fb_setcmap = drm_fb_helper_setcmap,
113 .fb_blank = drm_fb_helper_blank,
114 .fb_pan_display = omap_fbdev_pan_display,
115 __FB_DEFAULT_DMAMEM_OPS_DRAW,
116 .fb_ioctl = drm_fb_helper_ioctl,
117 .fb_mmap = omap_fbdev_fb_mmap,
118 .fb_destroy = omap_fbdev_fb_destroy,
119};
120
121static int omap_fbdev_create(struct drm_fb_helper *helper,
122 struct drm_fb_helper_surface_size *sizes)
123{
124 struct omap_fbdev *fbdev = to_omap_fbdev(helper);
125 struct drm_device *dev = helper->dev;
126 struct omap_drm_private *priv = dev->dev_private;
127 struct drm_framebuffer *fb = NULL;
128 union omap_gem_size gsize;
129 struct fb_info *fbi = NULL;
130 struct drm_mode_fb_cmd2 mode_cmd = {0};
131 struct drm_gem_object *bo;
132 dma_addr_t dma_addr;
133 int ret;
134
135 sizes->surface_bpp = 32;
136 sizes->surface_depth = 24;
137
138 DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
139 sizes->surface_height, sizes->surface_bpp,
140 sizes->fb_width, sizes->fb_height);
141
142 mode_cmd.pixel_format = drm_mode_legacy_fb_format(bpp: sizes->surface_bpp,
143 depth: sizes->surface_depth);
144
145 mode_cmd.width = sizes->surface_width;
146 mode_cmd.height = sizes->surface_height;
147
148 mode_cmd.pitches[0] =
149 DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
150
151 fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
152 if (fbdev->ywrap_enabled) {
153 /* need to align pitch to page size if using DMM scrolling */
154 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
155 }
156
157 /* allocate backing bo */
158 gsize = (union omap_gem_size){
159 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
160 };
161 DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
162 bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
163 if (!bo) {
164 dev_err(dev->dev, "failed to allocate buffer object\n");
165 ret = -ENOMEM;
166 goto fail;
167 }
168
169 fb = omap_framebuffer_init(dev, mode_cmd: &mode_cmd, bos: &bo);
170 if (IS_ERR(ptr: fb)) {
171 dev_err(dev->dev, "failed to allocate fb\n");
172 /* note: if fb creation failed, we can't rely on fb destroy
173 * to unref the bo:
174 */
175 drm_gem_object_put(obj: bo);
176 ret = PTR_ERR(ptr: fb);
177 goto fail;
178 }
179
180 /* note: this keeps the bo pinned.. which is perhaps not ideal,
181 * but is needed as long as we use fb_mmap() to mmap to userspace
182 * (since this happens using fix.smem_start). Possibly we could
183 * implement our own mmap using GEM mmap support to avoid this
184 * (non-tiled buffer doesn't need to be pinned for fbcon to write
185 * to it). Then we just need to be sure that we are able to re-
186 * pin it in case of an opps.
187 */
188 ret = omap_gem_pin(obj: bo, dma_addr: &dma_addr);
189 if (ret) {
190 dev_err(dev->dev, "could not pin framebuffer\n");
191 ret = -ENOMEM;
192 goto fail;
193 }
194
195 fbi = drm_fb_helper_alloc_info(fb_helper: helper);
196 if (IS_ERR(ptr: fbi)) {
197 dev_err(dev->dev, "failed to allocate fb info\n");
198 ret = PTR_ERR(ptr: fbi);
199 goto fail;
200 }
201
202 DBG("fbi=%p, dev=%p", fbi, dev);
203
204 helper->fb = fb;
205
206 fbi->fbops = &omap_fb_ops;
207
208 drm_fb_helper_fill_info(info: fbi, fb_helper: helper, sizes);
209
210 fbi->flags |= FBINFO_VIRTFB;
211 fbi->screen_buffer = omap_gem_vaddr(obj: bo);
212 fbi->screen_size = bo->size;
213 fbi->fix.smem_start = dma_addr;
214 fbi->fix.smem_len = bo->size;
215
216 /* if we have DMM, then we can use it for scrolling by just
217 * shuffling pages around in DMM rather than doing sw blit.
218 */
219 if (fbdev->ywrap_enabled) {
220 DRM_INFO("Enabling DMM ywrap scrolling\n");
221 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
222 fbi->fix.ywrapstep = 1;
223 }
224
225
226 DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
227 DBG("allocated %dx%d fb", fb->width, fb->height);
228
229 return 0;
230
231fail:
232
233 if (ret) {
234 if (fb)
235 drm_framebuffer_remove(fb);
236 }
237
238 return ret;
239}
240
241static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
242 .fb_probe = omap_fbdev_create,
243};
244
245static struct drm_fb_helper *get_fb(struct fb_info *fbi)
246{
247 if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
248 /* these are not the fb's you're looking for */
249 return NULL;
250 }
251 return fbi->par;
252}
253
254/*
255 * struct drm_client
256 */
257
258static void omap_fbdev_client_unregister(struct drm_client_dev *client)
259{
260 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
261
262 if (fb_helper->info) {
263 drm_fb_helper_unregister_info(fb_helper);
264 } else {
265 drm_client_release(client: &fb_helper->client);
266 drm_fb_helper_unprepare(fb_helper);
267 kfree(objp: fb_helper);
268 }
269}
270
271static int omap_fbdev_client_restore(struct drm_client_dev *client)
272{
273 drm_fb_helper_lastclose(dev: client->dev);
274
275 return 0;
276}
277
278static int omap_fbdev_client_hotplug(struct drm_client_dev *client)
279{
280 struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
281 struct drm_device *dev = client->dev;
282 int ret;
283
284 if (dev->fb_helper)
285 return drm_fb_helper_hotplug_event(fb_helper: dev->fb_helper);
286
287 ret = drm_fb_helper_init(dev, helper: fb_helper);
288 if (ret)
289 goto err_drm_err;
290
291 ret = drm_fb_helper_initial_config(fb_helper);
292 if (ret)
293 goto err_drm_fb_helper_fini;
294
295 return 0;
296
297err_drm_fb_helper_fini:
298 drm_fb_helper_fini(helper: fb_helper);
299err_drm_err:
300 drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
301 return ret;
302}
303
304static const struct drm_client_funcs omap_fbdev_client_funcs = {
305 .owner = THIS_MODULE,
306 .unregister = omap_fbdev_client_unregister,
307 .restore = omap_fbdev_client_restore,
308 .hotplug = omap_fbdev_client_hotplug,
309};
310
311void omap_fbdev_setup(struct drm_device *dev)
312{
313 struct omap_fbdev *fbdev;
314 struct drm_fb_helper *helper;
315 int ret;
316
317 drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
318 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
319
320 fbdev = kzalloc(size: sizeof(*fbdev), GFP_KERNEL);
321 if (!fbdev)
322 return;
323 helper = &fbdev->base;
324
325 drm_fb_helper_prepare(dev, helper, preferred_bpp: 32, funcs: &omap_fb_helper_funcs);
326
327 ret = drm_client_init(dev, client: &helper->client, name: "fbdev", funcs: &omap_fbdev_client_funcs);
328 if (ret)
329 goto err_drm_client_init;
330
331 INIT_WORK(&fbdev->work, pan_worker);
332
333 drm_client_register(client: &helper->client);
334
335 return;
336
337err_drm_client_init:
338 drm_fb_helper_unprepare(fb_helper: helper);
339 kfree(objp: fbdev);
340}
341

source code of linux/drivers/gpu/drm/omapdrm/omap_fbdev.c