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