xref: /linux/drivers/gpu/drm/omapdrm/omap_fbdev.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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_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_util.h>
19 
20 #include "omap_drv.h"
21 #include "omap_fbdev.h"
22 
23 MODULE_PARM_DESC(ywrap, "Enable ywrap scrolling (omap44xx and later, default 'y')");
24 static bool ywrap_enabled = true;
25 module_param_named(ywrap, ywrap_enabled, bool, 0644);
26 
27 /*
28  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
29  */
30 
31 struct omap_fbdev {
32 	struct drm_device *dev;
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 
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->dev->fb_helper;
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 
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, struct fb_info *fbi)
59 {
60 	struct drm_fb_helper *helper = get_fb(fbi);
61 	struct omap_drm_private *priv;
62 	struct omap_fbdev *fbdev;
63 
64 	if (!helper)
65 		goto fallback;
66 
67 	priv = helper->dev->dev_private;
68 	fbdev = priv->fbdev;
69 
70 	if (!fbdev->ywrap_enabled)
71 		goto fallback;
72 
73 	if (drm_can_sleep())
74 		pan_worker(&fbdev->work);
75 	else
76 		queue_work(priv->wq, &fbdev->work);
77 
78 	return 0;
79 
80 fallback:
81 	return drm_fb_helper_pan_display(var, fbi);
82 }
83 
84 static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
85 {
86 	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
87 
88 	return fb_deferred_io_mmap(info, vma);
89 }
90 
91 static void omap_fbdev_fb_destroy(struct fb_info *info)
92 {
93 	struct drm_fb_helper *helper = info->par;
94 	struct drm_framebuffer *fb = helper->fb;
95 	struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0);
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(helper);
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 
128 static int omap_fbdev_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
129 {
130 	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
131 		return 0;
132 
133 	if (helper->fb->funcs->dirty)
134 		return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
135 
136 	return 0;
137 }
138 
139 static const struct drm_fb_helper_funcs omap_fbdev_helper_funcs = {
140 	.fb_dirty = omap_fbdev_dirty,
141 };
142 
143 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
144 {
145 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
146 		/* these are not the fb's you're looking for */
147 		return NULL;
148 	}
149 	return fbi->par;
150 }
151 
152 int omap_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
153 				  struct drm_fb_helper_surface_size *sizes)
154 {
155 	struct drm_device *dev = helper->dev;
156 	struct omap_drm_private *priv = dev->dev_private;
157 	struct omap_fbdev *fbdev = priv->fbdev;
158 	struct drm_framebuffer *fb = NULL;
159 	union omap_gem_size gsize;
160 	struct fb_info *fbi = NULL;
161 	struct drm_mode_fb_cmd2 mode_cmd = {0};
162 	struct drm_gem_object *bo;
163 	dma_addr_t dma_addr;
164 	int ret;
165 
166 	sizes->surface_bpp = 32;
167 	sizes->surface_depth = 24;
168 
169 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
170 			sizes->surface_height, sizes->surface_bpp,
171 			sizes->fb_width, sizes->fb_height);
172 
173 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
174 			sizes->surface_depth);
175 
176 	mode_cmd.width = sizes->surface_width;
177 	mode_cmd.height = sizes->surface_height;
178 
179 	mode_cmd.pitches[0] =
180 			DIV_ROUND_UP(mode_cmd.width * sizes->surface_bpp, 8);
181 
182 	fbdev->ywrap_enabled = priv->has_dmm && ywrap_enabled;
183 	if (fbdev->ywrap_enabled) {
184 		/* need to align pitch to page size if using DMM scrolling */
185 		mode_cmd.pitches[0] = PAGE_ALIGN(mode_cmd.pitches[0]);
186 	}
187 
188 	/* allocate backing bo */
189 	gsize = (union omap_gem_size){
190 		.bytes = PAGE_ALIGN(mode_cmd.pitches[0] * mode_cmd.height),
191 	};
192 	DBG("allocating %d bytes for fb %d", gsize.bytes, dev->primary->index);
193 	bo = omap_gem_new(dev, gsize, OMAP_BO_SCANOUT | OMAP_BO_WC);
194 	if (!bo) {
195 		dev_err(dev->dev, "failed to allocate buffer object\n");
196 		ret = -ENOMEM;
197 		goto fail;
198 	}
199 
200 	fb = omap_framebuffer_init(dev, &mode_cmd, &bo);
201 	if (IS_ERR(fb)) {
202 		dev_err(dev->dev, "failed to allocate fb\n");
203 		/* note: if fb creation failed, we can't rely on fb destroy
204 		 * to unref the bo:
205 		 */
206 		drm_gem_object_put(bo);
207 		ret = PTR_ERR(fb);
208 		goto fail;
209 	}
210 
211 	/* note: this keeps the bo pinned.. which is perhaps not ideal,
212 	 * but is needed as long as we use fb_mmap() to mmap to userspace
213 	 * (since this happens using fix.smem_start).  Possibly we could
214 	 * implement our own mmap using GEM mmap support to avoid this
215 	 * (non-tiled buffer doesn't need to be pinned for fbcon to write
216 	 * to it).  Then we just need to be sure that we are able to re-
217 	 * pin it in case of an opps.
218 	 */
219 	ret = omap_gem_pin(bo, &dma_addr);
220 	if (ret) {
221 		dev_err(dev->dev, "could not pin framebuffer\n");
222 		ret = -ENOMEM;
223 		goto fail;
224 	}
225 
226 	fbi = drm_fb_helper_alloc_info(helper);
227 	if (IS_ERR(fbi)) {
228 		dev_err(dev->dev, "failed to allocate fb info\n");
229 		ret = PTR_ERR(fbi);
230 		goto fail;
231 	}
232 
233 	DBG("fbi=%p, dev=%p", fbi, dev);
234 
235 	helper->funcs = &omap_fbdev_helper_funcs;
236 	helper->fb = fb;
237 
238 	fbi->fbops = &omap_fb_ops;
239 
240 	drm_fb_helper_fill_info(fbi, helper, sizes);
241 
242 	fbi->flags |= FBINFO_VIRTFB;
243 	fbi->screen_buffer = omap_gem_vaddr(bo);
244 	fbi->screen_size = bo->size;
245 	fbi->fix.smem_start = dma_addr;
246 	fbi->fix.smem_len = bo->size;
247 
248 	/* deferred I/O */
249 	helper->fbdefio.delay = HZ / 20;
250 	helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
251 
252 	fbi->fbdefio = &helper->fbdefio;
253 	ret = fb_deferred_io_init(fbi);
254 	if (ret)
255 		goto fail;
256 
257 	/* if we have DMM, then we can use it for scrolling by just
258 	 * shuffling pages around in DMM rather than doing sw blit.
259 	 */
260 	if (fbdev->ywrap_enabled) {
261 		DRM_INFO("Enabling DMM ywrap scrolling\n");
262 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
263 		fbi->fix.ywrapstep = 1;
264 	}
265 
266 
267 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
268 	DBG("allocated %dx%d fb", fb->width, fb->height);
269 
270 	return 0;
271 
272 fail:
273 
274 	if (ret) {
275 		if (fb)
276 			drm_framebuffer_remove(fb);
277 	}
278 
279 	return ret;
280 }
281 
282 void omap_fbdev_setup(struct drm_device *dev)
283 {
284 	struct omap_drm_private *priv = dev->dev_private;
285 	struct omap_fbdev *fbdev;
286 
287 	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
288 	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
289 
290 	fbdev = drmm_kzalloc(dev, sizeof(*fbdev), GFP_KERNEL);
291 	if (!fbdev)
292 		return;
293 	fbdev->dev = dev;
294 	INIT_WORK(&fbdev->work, pan_worker);
295 
296 	priv->fbdev = fbdev;
297 
298 	drm_client_setup(dev, NULL);
299 }
300