xref: /linux/drivers/gpu/drm/clients/drm_fbdev_client.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
1 // SPDX-License-Identifier: MIT
2 
3 #include <drm/drm_client.h>
4 #include <drm/drm_crtc_helper.h>
5 #include <drm/drm_drv.h>
6 #include <drm/drm_fb_helper.h>
7 #include <drm/drm_fourcc.h>
8 #include <drm/drm_print.h>
9 
10 #include "drm_client_internal.h"
11 
12 /*
13  * struct drm_client_funcs
14  */
15 
16 static void drm_fbdev_client_free(struct drm_client_dev *client)
17 {
18 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
19 
20 	drm_fb_helper_unprepare(fb_helper);
21 	kfree(fb_helper);
22 }
23 
24 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
25 {
26 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
27 
28 	if (fb_helper->info) {
29 		/*
30 		 * Fully probed framebuffer device
31 		 */
32 		drm_fb_helper_unregister_info(fb_helper);
33 	} else {
34 		/*
35 		 * Partially initialized client, no framebuffer device yet
36 		 */
37 		drm_client_release(&fb_helper->client);
38 	}
39 }
40 
41 static int drm_fbdev_client_restore(struct drm_client_dev *client, bool force)
42 {
43 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
44 
45 	drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
46 
47 	return 0;
48 }
49 
50 static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
51 {
52 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
53 	struct drm_device *dev = client->dev;
54 	int ret;
55 
56 	if (dev->fb_helper)
57 		return drm_fb_helper_hotplug_event(dev->fb_helper);
58 
59 	ret = drm_fb_helper_init(dev, fb_helper);
60 	if (ret)
61 		goto err_drm_err;
62 
63 	if (!drm_drv_uses_atomic_modeset(dev))
64 		drm_helper_disable_unused_functions(dev);
65 
66 	ret = drm_fb_helper_initial_config(fb_helper);
67 	if (ret)
68 		goto err_drm_fb_helper_fini;
69 
70 	return 0;
71 
72 err_drm_fb_helper_fini:
73 	drm_fb_helper_fini(fb_helper);
74 err_drm_err:
75 	drm_err(dev, "fbdev: Failed to setup emulation (ret=%d)\n", ret);
76 	return ret;
77 }
78 
79 static int drm_fbdev_client_suspend(struct drm_client_dev *client)
80 {
81 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
82 
83 	drm_fb_helper_set_suspend_unlocked(fb_helper, true);
84 
85 	return 0;
86 }
87 
88 static int drm_fbdev_client_resume(struct drm_client_dev *client)
89 {
90 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
91 
92 	drm_fb_helper_set_suspend_unlocked(fb_helper, false);
93 
94 	return 0;
95 }
96 
97 static const struct drm_client_funcs drm_fbdev_client_funcs = {
98 	.owner		= THIS_MODULE,
99 	.free		= drm_fbdev_client_free,
100 	.unregister	= drm_fbdev_client_unregister,
101 	.restore	= drm_fbdev_client_restore,
102 	.hotplug	= drm_fbdev_client_hotplug,
103 	.suspend	= drm_fbdev_client_suspend,
104 	.resume		= drm_fbdev_client_resume,
105 };
106 
107 /**
108  * drm_fbdev_client_setup() - Setup fbdev emulation
109  * @dev: DRM device
110  * @format: Preferred color format for the device. DRM_FORMAT_XRGB8888
111  *          is used if this is zero.
112  *
113  * This function sets up fbdev emulation. Restore, hotplug events and
114  * teardown are all taken care of. Drivers that do suspend/resume need
115  * to call drm_client_dev_suspend() and drm_client_dev_resume() by
116  * themselves. Simple drivers might use drm_mode_config_helper_suspend().
117  *
118  * This function is safe to call even when there are no connectors present.
119  * Setup will be retried on the next hotplug event.
120  *
121  * The fbdev client is destroyed by drm_dev_unregister().
122  *
123  * Returns:
124  * 0 on success, or a negative errno code otherwise.
125  */
126 int drm_fbdev_client_setup(struct drm_device *dev, const struct drm_format_info *format)
127 {
128 	struct drm_fb_helper *fb_helper;
129 	unsigned int color_mode;
130 	int ret;
131 
132 	/* TODO: Use format info throughout DRM */
133 	if (format) {
134 		unsigned int bpp = drm_format_info_bpp(format, 0);
135 
136 		switch (bpp) {
137 		case 16:
138 			color_mode = format->depth; // could also be 15
139 			break;
140 		default:
141 			color_mode = bpp;
142 		}
143 	} else {
144 		switch (dev->mode_config.preferred_depth) {
145 		case 0:
146 		case 24:
147 			color_mode = 32;
148 			break;
149 		default:
150 			color_mode = dev->mode_config.preferred_depth;
151 		}
152 	}
153 
154 	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
155 	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
156 
157 	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
158 	if (!fb_helper)
159 		return -ENOMEM;
160 	drm_fb_helper_prepare(dev, fb_helper, color_mode, NULL);
161 
162 	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
163 	if (ret) {
164 		drm_err(dev, "Failed to register client: %d\n", ret);
165 		goto err_drm_client_init;
166 	}
167 
168 	drm_client_register(&fb_helper->client);
169 
170 	return 0;
171 
172 err_drm_client_init:
173 	drm_fb_helper_unprepare(fb_helper);
174 	kfree(fb_helper);
175 	return ret;
176 }
177