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 <drm/drm_crtc.h>
8 #include <drm/drm_util.h>
9 #include <drm/drm_fb_helper.h>
10 #include <drm/drm_file.h>
11 #include <drm/drm_fourcc.h>
12 #include <drm/drm_framebuffer.h>
13
14 #include "omap_drv.h"
15
16 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
17 static bool ywrap_enabled = true;
18 module_param_named(ywrap, ywrap_enabled, bool, 0644);
19
20 /*
21 * fbdev funcs, to implement legacy fbdev interface on top of drm driver
22 */
23
24 #define to_omap_fbdev(x) container_of(x, struct omap_fbdev, base)
25
26 struct omap_fbdev {
27 struct drm_fb_helper base;
28 struct drm_framebuffer *fb;
29 struct drm_gem_object *bo;
30 bool ywrap_enabled;
31
32 /* for deferred dmm roll when getting called in atomic ctx */
33 struct work_struct work;
34 };
35
36 static struct drm_fb_helper *get_fb(struct fb_info *fbi);
37
pan_worker(struct work_struct * work)38 static void pan_worker(struct work_struct *work)
39 {
40 struct omap_fbdev *fbdev = container_of(work, struct omap_fbdev, work);
41 struct fb_info *fbi = fbdev->base.fbdev;
42 int npages;
43
44 /* DMM roll shifts in 4K pages: */
45 npages = fbi->fix.line_length >> PAGE_SHIFT;
46 omap_gem_roll(fbdev->bo, fbi->var.yoffset * npages);
47 }
48
omap_fbdev_pan_display(struct fb_var_screeninfo * var,struct fb_info * fbi)49 static int omap_fbdev_pan_display(struct fb_var_screeninfo *var,
50 struct fb_info *fbi)
51 {
52 struct drm_fb_helper *helper = get_fb(fbi);
53 struct omap_fbdev *fbdev = to_omap_fbdev(helper);
54
55 if (!helper)
56 goto fallback;
57
58 if (!fbdev->ywrap_enabled)
59 goto fallback;
60
61 if (drm_can_sleep()) {
62 pan_worker(&fbdev->work);
63 } else {
64 struct omap_drm_private *priv = helper->dev->dev_private;
65 queue_work(priv->wq, &fbdev->work);
66 }
67
68 return 0;
69
70 fallback:
71 return drm_fb_helper_pan_display(var, fbi);
72 }
73
74 static const struct fb_ops omap_fb_ops = {
75 .owner = THIS_MODULE,
76
77 .fb_check_var = drm_fb_helper_check_var,
78 .fb_set_par = drm_fb_helper_set_par,
79 .fb_setcmap = drm_fb_helper_setcmap,
80 .fb_blank = drm_fb_helper_blank,
81 .fb_pan_display = omap_fbdev_pan_display,
82 .fb_ioctl = drm_fb_helper_ioctl,
83
84 .fb_read = drm_fb_helper_sys_read,
85 .fb_write = drm_fb_helper_sys_write,
86 .fb_fillrect = drm_fb_helper_sys_fillrect,
87 .fb_copyarea = drm_fb_helper_sys_copyarea,
88 .fb_imageblit = drm_fb_helper_sys_imageblit,
89 };
90
omap_fbdev_create(struct drm_fb_helper * helper,struct drm_fb_helper_surface_size * sizes)91 static int omap_fbdev_create(struct drm_fb_helper *helper,
92 struct drm_fb_helper_surface_size *sizes)
93 {
94 struct omap_fbdev *fbdev = to_omap_fbdev(helper);
95 struct drm_device *dev = helper->dev;
96 struct omap_drm_private *priv = dev->dev_private;
97 struct drm_framebuffer *fb = NULL;
98 union omap_gem_size gsize;
99 struct fb_info *fbi = NULL;
100 struct drm_mode_fb_cmd2 mode_cmd = {0};
101 dma_addr_t dma_addr;
102 int ret;
103
104 sizes->surface_bpp = 32;
105 sizes->surface_depth = 24;
106
107 DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
108 sizes->surface_height, sizes->surface_bpp,
109 sizes->fb_width, sizes->fb_height);
110
111 mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
112 sizes->surface_depth);
113
114 mode_cmd.width = sizes->surface_width;
115 mode_cmd.height = sizes->surface_height;
116
117 mode_cmd.pitches[0] =
118 DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
119
120 fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
121 if (fbdev->ywrap_enabled) {
122 /* need to align pitch to page size if using DMM scrolling */
123 mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
124 }
125
126 /* allocate backing bo */
127 gsize = (union omap_gem_size){
128 .bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
129 };
130 DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
131 fbdev->bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
132 if (!fbdev->bo) {
133 dev_err(dev->dev, "failed to allocate buffer object\n");
134 ret = -ENOMEM;
135 goto fail;
136 }
137
138 fb = omap_framebuffer_init(dev, &mode_cmd, &fbdev->bo);
139 if (IS_ERR(fb)) {
140 dev_err(dev->dev, "failed to allocate fb\n");
141 /* note: if fb creation failed, we can't rely on fb destroy
142 * to unref the bo:
143 */
144 drm_gem_object_put(fbdev->bo);
145 ret = PTR_ERR(fb);
146 goto fail;
147 }
148
149 /* note: this keeps the bo pinned.. which is perhaps not ideal,
150 * but is needed as long as we use fb_mmap() to mmap to userspace
151 * (since this happens using fix.smem_start). Possibly we could
152 * implement our own mmap using GEM mmap support to avoid this
153 * (non-tiled buffer doesn't need to be pinned for fbcon to write
154 * to it). Then we just need to be sure that we are able to re-
155 * pin it in case of an opps.
156 */
157 ret = omap_gem_pin(fbdev->bo, &dma_addr);
158 if (ret) {
159 dev_err(dev->dev, "could not pin framebuffer\n");
160 ret = -ENOMEM;
161 goto fail;
162 }
163
164 fbi = drm_fb_helper_alloc_fbi(helper);
165 if (IS_ERR(fbi)) {
166 dev_err(dev->dev, "failed to allocate fb info\n");
167 ret = PTR_ERR(fbi);
168 goto fail;
169 }
170
171 DBG("fbi=%p, dev=%p", fbi, dev);
172
173 fbdev->fb = fb;
174 helper->fb = fb;
175
176 fbi->fbops = &omap_fb_ops;
177
178 drm_fb_helper_fill_info(fbi, helper, sizes);
179
180 dev->mode_config.fb_base = dma_addr;
181
182 fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
183 fbi->screen_size = fbdev->bo->size;
184 fbi->fix.smem_start = dma_addr;
185 fbi->fix.smem_len = fbdev->bo->size;
186
187 /* if we have DMM, then we can use it for scrolling by just
188 * shuffling pages around in DMM rather than doing sw blit.
189 */
190 if (fbdev->ywrap_enabled) {
191 DRM_INFO("Enabling DMM ywrap scrolling\n");
192 fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
193 fbi->fix.ywrapstep = 1;
194 }
195
196
197 DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
198 DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
199
200 return 0;
201
202 fail:
203
204 if (ret) {
205 if (fb)
206 drm_framebuffer_remove(fb);
207 }
208
209 return ret;
210 }
211
212 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
213 .fb_probe = omap_fbdev_create,
214 };
215
get_fb(struct fb_info * fbi)216 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
217 {
218 if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
219 /* these are not the fb's you're looking for */
220 return NULL;
221 }
222 return fbi->par;
223 }
224
225 /* initialize fbdev helper */
omap_fbdev_init(struct drm_device * dev)226 void omap_fbdev_init(struct drm_device *dev)
227 {
228 struct omap_drm_private *priv = dev->dev_private;
229 struct omap_fbdev *fbdev = NULL;
230 struct drm_fb_helper *helper;
231 int ret = 0;
232
233 if (!priv->num_pipes)
234 return;
235
236 fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
237 if (!fbdev)
238 goto fail;
239
240 INIT_WORK(&fbdev->work, pan_worker);
241
242 helper = &fbdev->base;
243
244 drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
245
246 ret = drm_fb_helper_init(dev, helper);
247 if (ret)
248 goto fail;
249
250 ret = drm_fb_helper_initial_config(helper, 32);
251 if (ret)
252 goto fini;
253
254 priv->fbdev = helper;
255
256 return;
257
258 fini:
259 drm_fb_helper_fini(helper);
260 fail:
261 kfree(fbdev);
262
263 dev_warn(dev->dev, "omap_fbdev_init failed\n");
264 }
265
omap_fbdev_fini(struct drm_device * dev)266 void omap_fbdev_fini(struct drm_device *dev)
267 {
268 struct omap_drm_private *priv = dev->dev_private;
269 struct drm_fb_helper *helper = priv->fbdev;
270 struct omap_fbdev *fbdev;
271
272 DBG();
273
274 if (!helper)
275 return;
276
277 drm_fb_helper_unregister_fbi(helper);
278
279 drm_fb_helper_fini(helper);
280
281 fbdev = to_omap_fbdev(helper);
282
283 /* unpin the GEM object pinned in omap_fbdev_create() */
284 if (fbdev->bo)
285 omap_gem_unpin(fbdev->bo);
286
287 /* this will free the backing object */
288 if (fbdev->fb)
289 drm_framebuffer_remove(fbdev->fb);
290
291 kfree(fbdev);
292
293 priv->fbdev = NULL;
294 }
295