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