xref: /linux/drivers/gpu/drm/clients/drm_fbdev_client.c (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
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 
drm_fbdev_client_unregister(struct drm_client_dev * client)16 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
17 {
18 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
19 
20 	if (fb_helper->info) {
21 		drm_fb_helper_unregister_info(fb_helper);
22 	} else {
23 		drm_client_release(&fb_helper->client);
24 		drm_fb_helper_unprepare(fb_helper);
25 		kfree(fb_helper);
26 	}
27 }
28 
drm_fbdev_client_restore(struct drm_client_dev * client)29 static int drm_fbdev_client_restore(struct drm_client_dev *client)
30 {
31 	drm_fb_helper_lastclose(client->dev);
32 
33 	return 0;
34 }
35 
drm_fbdev_client_hotplug(struct drm_client_dev * client)36 static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
37 {
38 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
39 	struct drm_device *dev = client->dev;
40 	int ret;
41 
42 	if (dev->fb_helper)
43 		return drm_fb_helper_hotplug_event(dev->fb_helper);
44 
45 	ret = drm_fb_helper_init(dev, fb_helper);
46 	if (ret)
47 		goto err_drm_err;
48 
49 	if (!drm_drv_uses_atomic_modeset(dev))
50 		drm_helper_disable_unused_functions(dev);
51 
52 	ret = drm_fb_helper_initial_config(fb_helper);
53 	if (ret)
54 		goto err_drm_fb_helper_fini;
55 
56 	return 0;
57 
58 err_drm_fb_helper_fini:
59 	drm_fb_helper_fini(fb_helper);
60 err_drm_err:
61 	drm_err(dev, "fbdev: Failed to setup emulation (ret=%d)\n", ret);
62 	return ret;
63 }
64 
drm_fbdev_client_suspend(struct drm_client_dev * client,bool holds_console_lock)65 static int drm_fbdev_client_suspend(struct drm_client_dev *client, bool holds_console_lock)
66 {
67 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
68 
69 	if (holds_console_lock)
70 		drm_fb_helper_set_suspend(fb_helper, true);
71 	else
72 		drm_fb_helper_set_suspend_unlocked(fb_helper, true);
73 
74 	return 0;
75 }
76 
drm_fbdev_client_resume(struct drm_client_dev * client,bool holds_console_lock)77 static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_console_lock)
78 {
79 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
80 
81 	if (holds_console_lock)
82 		drm_fb_helper_set_suspend(fb_helper, false);
83 	else
84 		drm_fb_helper_set_suspend_unlocked(fb_helper, false);
85 
86 	return 0;
87 }
88 
89 static const struct drm_client_funcs drm_fbdev_client_funcs = {
90 	.owner		= THIS_MODULE,
91 	.unregister	= drm_fbdev_client_unregister,
92 	.restore	= drm_fbdev_client_restore,
93 	.hotplug	= drm_fbdev_client_hotplug,
94 	.suspend	= drm_fbdev_client_suspend,
95 	.resume		= drm_fbdev_client_resume,
96 };
97 
98 /**
99  * drm_fbdev_client_setup() - Setup fbdev emulation
100  * @dev: DRM device
101  * @format: Preferred color format for the device. DRM_FORMAT_XRGB8888
102  *          is used if this is zero.
103  *
104  * This function sets up fbdev emulation. Restore, hotplug events and
105  * teardown are all taken care of. Drivers that do suspend/resume need
106  * to call drm_client_dev_suspend() and drm_client_dev_resume() by
107  * themselves. Simple drivers might use drm_mode_config_helper_suspend().
108  *
109  * This function is safe to call even when there are no connectors present.
110  * Setup will be retried on the next hotplug event.
111  *
112  * The fbdev client is destroyed by drm_dev_unregister().
113  *
114  * Returns:
115  * 0 on success, or a negative errno code otherwise.
116  */
drm_fbdev_client_setup(struct drm_device * dev,const struct drm_format_info * format)117 int drm_fbdev_client_setup(struct drm_device *dev, const struct drm_format_info *format)
118 {
119 	struct drm_fb_helper *fb_helper;
120 	unsigned int color_mode;
121 	int ret;
122 
123 	/* TODO: Use format info throughout DRM */
124 	if (format) {
125 		unsigned int bpp = drm_format_info_bpp(format, 0);
126 
127 		switch (bpp) {
128 		case 16:
129 			color_mode = format->depth; // could also be 15
130 			break;
131 		default:
132 			color_mode = bpp;
133 		}
134 	} else {
135 		switch (dev->mode_config.preferred_depth) {
136 		case 0:
137 		case 24:
138 			color_mode = 32;
139 			break;
140 		default:
141 			color_mode = dev->mode_config.preferred_depth;
142 		}
143 	}
144 
145 	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
146 	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
147 
148 	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
149 	if (!fb_helper)
150 		return -ENOMEM;
151 	drm_fb_helper_prepare(dev, fb_helper, color_mode, NULL);
152 
153 	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
154 	if (ret) {
155 		drm_err(dev, "Failed to register client: %d\n", ret);
156 		goto err_drm_client_init;
157 	}
158 
159 	drm_client_register(&fb_helper->client);
160 
161 	return 0;
162 
163 err_drm_client_init:
164 	drm_fb_helper_unprepare(fb_helper);
165 	kfree(fb_helper);
166 	return ret;
167 }
168