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 15 static 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 28 static int drm_fbdev_client_restore(struct drm_client_dev *client) 29 { 30 drm_fb_helper_lastclose(client->dev); 31 32 return 0; 33 } 34 35 static 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 57 err_drm_fb_helper_fini: 58 drm_fb_helper_fini(fb_helper); 59 err_drm_err: 60 drm_err(dev, "fbdev: Failed to setup emulation (ret=%d)\n", ret); 61 return ret; 62 } 63 64 static const struct drm_client_funcs drm_fbdev_client_funcs = { 65 .owner = THIS_MODULE, 66 .unregister = drm_fbdev_client_unregister, 67 .restore = drm_fbdev_client_restore, 68 .hotplug = drm_fbdev_client_hotplug, 69 }; 70 71 /** 72 * drm_fbdev_client_setup() - Setup fbdev emulation 73 * @dev: DRM device 74 * @format: Preferred color format for the device. DRM_FORMAT_XRGB8888 75 * is used if this is zero. 76 * 77 * This function sets up fbdev emulation. Restore, hotplug events and 78 * teardown are all taken care of. Drivers that do suspend/resume need 79 * to call drm_fb_helper_set_suspend_unlocked() themselves. Simple 80 * drivers might use drm_mode_config_helper_suspend(). 81 * 82 * This function is safe to call even when there are no connectors present. 83 * Setup will be retried on the next hotplug event. 84 * 85 * The fbdev client is destroyed by drm_dev_unregister(). 86 * 87 * Returns: 88 * 0 on success, or a negative errno code otherwise. 89 */ 90 int drm_fbdev_client_setup(struct drm_device *dev, const struct drm_format_info *format) 91 { 92 struct drm_fb_helper *fb_helper; 93 unsigned int color_mode; 94 int ret; 95 96 /* TODO: Use format info throughout DRM */ 97 if (format) { 98 unsigned int bpp = drm_format_info_bpp(format, 0); 99 100 switch (bpp) { 101 case 16: 102 color_mode = format->depth; // could also be 15 103 break; 104 default: 105 color_mode = bpp; 106 } 107 } else { 108 switch (dev->mode_config.preferred_depth) { 109 case 0: 110 case 24: 111 color_mode = 32; 112 break; 113 default: 114 color_mode = dev->mode_config.preferred_depth; 115 } 116 } 117 118 drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); 119 drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 120 121 fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); 122 if (!fb_helper) 123 return -ENOMEM; 124 drm_fb_helper_prepare(dev, fb_helper, color_mode, NULL); 125 126 ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs); 127 if (ret) { 128 drm_err(dev, "Failed to register client: %d\n", ret); 129 goto err_drm_client_init; 130 } 131 132 drm_client_register(&fb_helper->client); 133 134 return 0; 135 136 err_drm_client_init: 137 drm_fb_helper_unprepare(fb_helper); 138 kfree(fb_helper); 139 return ret; 140 } 141 EXPORT_SYMBOL(drm_fbdev_client_setup); 142