aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/tinydrm/core/tinydrm-core.c
blob: 554abd5d3b5382d565ad00b7f1aca1668e156b9e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/*
 * Copyright (C) 2016 Noralf Trønnes
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_print.h>
#include <drm/tinydrm/tinydrm.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/module.h>

/**
 * DOC: overview
 *
 * This library provides driver helpers for very simple display hardware.
 *
 * It is based on &drm_simple_display_pipe coupled with a &drm_connector which
 * has only one fixed &drm_display_mode. The framebuffers are backed by the
 * cma helper and have support for framebuffer flushing (dirty).
 * fbdev support is also included.
 *
 */

/**
 * DOC: core
 *
 * The driver allocates &tinydrm_device, initializes it using
 * devm_tinydrm_init(), sets up the pipeline using tinydrm_display_pipe_init()
 * and registers the DRM device using devm_tinydrm_register().
 */

static const struct drm_mode_config_funcs tinydrm_mode_config_funcs = {
	.fb_create = drm_gem_fb_create_with_dirty,
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = drm_atomic_helper_commit,
};

static int tinydrm_init(struct device *parent, struct tinydrm_device *tdev,
			struct drm_driver *driver)
{
	struct drm_device *drm;

	/*
	 * We don't embed drm_device, because that prevent us from using
	 * devm_kzalloc() to allocate tinydrm_device in the driver since
	 * drm_dev_put() frees the structure. The devm_ functions provide
	 * for easy error handling.
	 */
	drm = drm_dev_alloc(driver, parent);
	if (IS_ERR(drm))
		return PTR_ERR(drm);

	tdev->drm = drm;
	drm->dev_private = tdev;
	drm_mode_config_init(drm);
	drm->mode_config.funcs = &tinydrm_mode_config_funcs;
	drm->mode_config.allow_fb_modifiers = true;

	return 0;
}

static void tinydrm_fini(struct tinydrm_device *tdev)
{
	drm_mode_config_cleanup(tdev->drm);
	tdev->drm->dev_private = NULL;
	drm_dev_put(tdev->drm);
}

static void devm_tinydrm_release(void *data)
{
	tinydrm_fini(data);
}

/**
 * devm_tinydrm_init - Initialize tinydrm device
 * @parent: Parent device object
 * @tdev: tinydrm device
 * @driver: DRM driver
 *
 * This function initializes @tdev, the underlying DRM device and it's
 * mode_config. Resources will be automatically freed on driver detach (devres)
 * using drm_mode_config_cleanup() and drm_dev_put().
 *
 * Returns:
 * Zero on success, negative error code on failure.
 */
int devm_tinydrm_init(struct device *parent, struct tinydrm_device *tdev,
		      struct drm_driver *driver)
{
	int ret;

	ret = tinydrm_init(parent, tdev, driver);
	if (ret)
		return ret;

	ret = devm_add_action(parent, devm_tinydrm_release, tdev);
	if (ret)
		tinydrm_fini(tdev);

	return ret;
}
EXPORT_SYMBOL(devm_tinydrm_init);

static int tinydrm_register(struct tinydrm_device *tdev)
{
	struct drm_device *drm = tdev->drm;
	int ret;

	ret = drm_dev_register(tdev->drm, 0);
	if (ret)
		return ret;

	ret = drm_fbdev_generic_setup(drm, 0);
	if (ret)
		DRM_ERROR("Failed to initialize fbdev: %d\n", ret);

	return 0;
}

static void tinydrm_unregister(struct tinydrm_device *tdev)
{
	drm_atomic_helper_shutdown(tdev->drm);
	drm_dev_unregister(tdev->drm);
}

static void devm_tinydrm_register_release(void *data)
{
	tinydrm_unregister(data);
}

/**
 * devm_tinydrm_register - Register tinydrm device
 * @tdev: tinydrm device
 *
 * This function registers the underlying DRM device and fbdev.
 * These resources will be automatically unregistered on driver detach (devres)
 * and the display pipeline will be disabled.
 *
 * Returns:
 * Zero on success, negative error code on failure.
 */
int devm_tinydrm_register(struct tinydrm_device *tdev)
{
	struct device *dev = tdev->drm->dev;
	int ret;

	ret = tinydrm_register(tdev);
	if (ret)
		return ret;

	ret = devm_add_action(dev, devm_tinydrm_register_release, tdev);
	if (ret)
		tinydrm_unregister(tdev);

	return ret;
}
EXPORT_SYMBOL(devm_tinydrm_register);

/**
 * tinydrm_shutdown - Shutdown tinydrm
 * @tdev: tinydrm device
 *
 * This function makes sure that the display pipeline is disabled.
 * Used by drivers in their shutdown callback to turn off the display
 * on machine shutdown and reboot.
 */
void tinydrm_shutdown(struct tinydrm_device *tdev)
{
	drm_atomic_helper_shutdown(tdev->drm);
}
EXPORT_SYMBOL(tinydrm_shutdown);

MODULE_LICENSE("GPL");