xref: /linux/drivers/gpu/drm/msm/msm_fbdev.c (revision 52990390f91c1c39ca742fc8f390b29891d95127)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2013 Red Hat
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include <drm/drm_drv.h>
8 #include <drm/drm_crtc_helper.h>
9 #include <drm/drm_fb_helper.h>
10 #include <drm/drm_fourcc.h>
11 #include <drm/drm_framebuffer.h>
12 #include <drm/drm_prime.h>
13 
14 #include "msm_drv.h"
15 #include "msm_gem.h"
16 #include "msm_kms.h"
17 
18 static bool fbdev = true;
19 MODULE_PARM_DESC(fbdev, "Enable fbdev compat layer");
20 module_param(fbdev, bool, 0600);
21 
22 /*
23  * fbdev funcs, to implement legacy fbdev interface on top of drm driver
24  */
25 
26 static int msm_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
27 {
28 	struct drm_fb_helper *helper = (struct drm_fb_helper *)info->par;
29 	struct drm_gem_object *bo = msm_framebuffer_bo(helper->fb, 0);
30 
31 	return drm_gem_prime_mmap(bo, vma);
32 }
33 
34 static void msm_fbdev_fb_destroy(struct fb_info *info)
35 {
36 	struct drm_fb_helper *helper = (struct drm_fb_helper *)info->par;
37 	struct drm_framebuffer *fb = helper->fb;
38 	struct drm_gem_object *bo = msm_framebuffer_bo(fb, 0);
39 
40 	DBG();
41 
42 	drm_fb_helper_fini(helper);
43 
44 	/* this will free the backing object */
45 	msm_gem_put_vaddr(bo);
46 	drm_framebuffer_remove(fb);
47 
48 	drm_client_release(&helper->client);
49 	drm_fb_helper_unprepare(helper);
50 	kfree(helper);
51 }
52 
53 static const struct fb_ops msm_fb_ops = {
54 	.owner = THIS_MODULE,
55 	DRM_FB_HELPER_DEFAULT_OPS,
56 
57 	/* Note: to properly handle manual update displays, we wrap the
58 	 * basic fbdev ops which write to the framebuffer
59 	 */
60 	.fb_read = drm_fb_helper_sys_read,
61 	.fb_write = drm_fb_helper_sys_write,
62 	.fb_fillrect = drm_fb_helper_sys_fillrect,
63 	.fb_copyarea = drm_fb_helper_sys_copyarea,
64 	.fb_imageblit = drm_fb_helper_sys_imageblit,
65 	.fb_mmap = msm_fbdev_mmap,
66 	.fb_destroy = msm_fbdev_fb_destroy,
67 };
68 
69 static int msm_fbdev_create(struct drm_fb_helper *helper,
70 		struct drm_fb_helper_surface_size *sizes)
71 {
72 	struct drm_device *dev = helper->dev;
73 	struct msm_drm_private *priv = dev->dev_private;
74 	struct drm_framebuffer *fb = NULL;
75 	struct drm_gem_object *bo;
76 	struct fb_info *fbi = NULL;
77 	uint64_t paddr;
78 	uint32_t format;
79 	int ret, pitch;
80 
81 	format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
82 
83 	DBG("create fbdev: %dx%d@%d (%dx%d)", sizes->surface_width,
84 			sizes->surface_height, sizes->surface_bpp,
85 			sizes->fb_width, sizes->fb_height);
86 
87 	pitch = align_pitch(sizes->surface_width, sizes->surface_bpp);
88 	fb = msm_alloc_stolen_fb(dev, sizes->surface_width,
89 			sizes->surface_height, pitch, format);
90 
91 	if (IS_ERR(fb)) {
92 		DRM_DEV_ERROR(dev->dev, "failed to allocate fb\n");
93 		return PTR_ERR(fb);
94 	}
95 
96 	bo = msm_framebuffer_bo(fb, 0);
97 
98 	/*
99 	 * NOTE: if we can be guaranteed to be able to map buffer
100 	 * in panic (ie. lock-safe, etc) we could avoid pinning the
101 	 * buffer now:
102 	 */
103 	ret = msm_gem_get_and_pin_iova(bo, priv->kms->aspace, &paddr);
104 	if (ret) {
105 		DRM_DEV_ERROR(dev->dev, "failed to get buffer obj iova: %d\n", ret);
106 		goto fail;
107 	}
108 
109 	fbi = drm_fb_helper_alloc_info(helper);
110 	if (IS_ERR(fbi)) {
111 		DRM_DEV_ERROR(dev->dev, "failed to allocate fb info\n");
112 		ret = PTR_ERR(fbi);
113 		goto fail;
114 	}
115 
116 	DBG("fbi=%p, dev=%p", fbi, dev);
117 
118 	helper->fb = fb;
119 
120 	fbi->fbops = &msm_fb_ops;
121 
122 	drm_fb_helper_fill_info(fbi, helper, sizes);
123 
124 	fbi->screen_base = msm_gem_get_vaddr(bo);
125 	if (IS_ERR(fbi->screen_base)) {
126 		ret = PTR_ERR(fbi->screen_base);
127 		goto fail;
128 	}
129 	fbi->screen_size = bo->size;
130 	fbi->fix.smem_start = paddr;
131 	fbi->fix.smem_len = bo->size;
132 
133 	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);
134 	DBG("allocated %dx%d fb", fb->width, fb->height);
135 
136 	return 0;
137 
138 fail:
139 	drm_framebuffer_remove(fb);
140 	return ret;
141 }
142 
143 static const struct drm_fb_helper_funcs msm_fb_helper_funcs = {
144 	.fb_probe = msm_fbdev_create,
145 };
146 
147 /*
148  * struct drm_client
149  */
150 
151 static void msm_fbdev_client_unregister(struct drm_client_dev *client)
152 {
153 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
154 
155 	if (fb_helper->info) {
156 		drm_fb_helper_unregister_info(fb_helper);
157 	} else {
158 		drm_client_release(&fb_helper->client);
159 		drm_fb_helper_unprepare(fb_helper);
160 		kfree(fb_helper);
161 	}
162 }
163 
164 static int msm_fbdev_client_restore(struct drm_client_dev *client)
165 {
166 	drm_fb_helper_lastclose(client->dev);
167 
168 	return 0;
169 }
170 
171 static int msm_fbdev_client_hotplug(struct drm_client_dev *client)
172 {
173 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
174 	struct drm_device *dev = client->dev;
175 	int ret;
176 
177 	if (dev->fb_helper)
178 		return drm_fb_helper_hotplug_event(dev->fb_helper);
179 
180 	ret = drm_fb_helper_init(dev, fb_helper);
181 	if (ret)
182 		goto err_drm_err;
183 
184 	if (!drm_drv_uses_atomic_modeset(dev))
185 		drm_helper_disable_unused_functions(dev);
186 
187 	ret = drm_fb_helper_initial_config(fb_helper);
188 	if (ret)
189 		goto err_drm_fb_helper_fini;
190 
191 	return 0;
192 
193 err_drm_fb_helper_fini:
194 	drm_fb_helper_fini(fb_helper);
195 err_drm_err:
196 	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
197 	return ret;
198 }
199 
200 static const struct drm_client_funcs msm_fbdev_client_funcs = {
201 	.owner		= THIS_MODULE,
202 	.unregister	= msm_fbdev_client_unregister,
203 	.restore	= msm_fbdev_client_restore,
204 	.hotplug	= msm_fbdev_client_hotplug,
205 };
206 
207 /* initialize fbdev helper */
208 void msm_fbdev_setup(struct drm_device *dev)
209 {
210 	struct drm_fb_helper *helper;
211 	int ret;
212 
213 	if (!fbdev)
214 		return;
215 
216 	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
217 	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
218 
219 	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
220 	if (!helper)
221 		return;
222 	drm_fb_helper_prepare(dev, helper, 32, &msm_fb_helper_funcs);
223 
224 	ret = drm_client_init(dev, &helper->client, "fbdev", &msm_fbdev_client_funcs);
225 	if (ret) {
226 		drm_err(dev, "Failed to register client: %d\n", ret);
227 		goto err_drm_fb_helper_unprepare;
228 	}
229 
230 	ret = msm_fbdev_client_hotplug(&helper->client);
231 	if (ret)
232 		drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
233 
234 	drm_client_register(&helper->client);
235 
236 	return;
237 
238 err_drm_fb_helper_unprepare:
239 	drm_fb_helper_unprepare(helper);
240 	kfree(helper);
241 }
242