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 
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.info;
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 
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 
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_info(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 	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
181 	fbi->screen_size = fbdev->bo->size;
182 	fbi->fix.smem_start = dma_addr;
183 	fbi->fix.smem_len = fbdev->bo->size;
184 
185 	/* if we have DMM, then we can use it for scrolling by just
186 	 * shuffling pages around in DMM rather than doing sw blit.
187 	 */
188 	if (fbdev->ywrap_enabled) {
189 		DRM_INFO("Enabling DMM ywrap scrolling\n");
190 		fbi->flags |= FBINFO_HWACCEL_YWRAP | FBINFO_READS_FAST;
191 		fbi->fix.ywrapstep = 1;
192 	}
193 
194 
195 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
196 	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);
197 
198 	return 0;
199 
200 fail:
201 
202 	if (ret) {
203 		if (fb)
204 			drm_framebuffer_remove(fb);
205 	}
206 
207 	return ret;
208 }
209 
210 static const struct drm_fb_helper_funcs omap_fb_helper_funcs = {
211 	.fb_probe = omap_fbdev_create,
212 };
213 
214 static struct drm_fb_helper *get_fb(struct fb_info *fbi)
215 {
216 	if (!fbi || strcmp(fbi->fix.id, MODULE_NAME)) {
217 		/* these are not the fb's you're looking for */
218 		return NULL;
219 	}
220 	return fbi->par;
221 }
222 
223 /* initialize fbdev helper */
224 void omap_fbdev_init(struct drm_device *dev)
225 {
226 	struct omap_drm_private *priv = dev->dev_private;
227 	struct omap_fbdev *fbdev = NULL;
228 	struct drm_fb_helper *helper;
229 	int ret = 0;
230 
231 	if (!priv->num_pipes)
232 		return;
233 
234 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
235 	if (!fbdev)
236 		goto fail;
237 
238 	INIT_WORK(&fbdev->work, pan_worker);
239 
240 	helper = &fbdev->base;
241 
242 	drm_fb_helper_prepare(dev, helper, &omap_fb_helper_funcs);
243 
244 	ret = drm_fb_helper_init(dev, helper);
245 	if (ret)
246 		goto fail;
247 
248 	ret = drm_fb_helper_initial_config(helper, 32);
249 	if (ret)
250 		goto fini;
251 
252 	priv->fbdev = helper;
253 
254 	return;
255 
256 fini:
257 	drm_fb_helper_fini(helper);
258 fail:
259 	kfree(fbdev);
260 
261 	dev_warn(dev->dev, "omap_fbdev_init failed\n");
262 }
263 
264 void omap_fbdev_fini(struct drm_device *dev)
265 {
266 	struct omap_drm_private *priv = dev->dev_private;
267 	struct drm_fb_helper *helper = priv->fbdev;
268 	struct omap_fbdev *fbdev;
269 
270 	DBG();
271 
272 	if (!helper)
273 		return;
274 
275 	drm_fb_helper_unregister_info(helper);
276 
277 	drm_fb_helper_fini(helper);
278 
279 	fbdev = to_omap_fbdev(helper);
280 
281 	/* unpin the GEM object pinned in omap_fbdev_create() */
282 	if (fbdev->bo)
283 		omap_gem_unpin(fbdev->bo);
284 
285 	/* this will free the backing object */
286 	if (fbdev->fb)
287 		drm_framebuffer_remove(fbdev->fb);
288 
289 	kfree(fbdev);
290 
291 	priv->fbdev = NULL;
292 }
293