drivers/gpu/drm/drm_fbdev_client.c

   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 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
  76 static 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
  88 static 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  */
 116 int 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
 162 err_drm_client_init:
 163         drm_fb_helper_unprepare(fb_helper);
 164         kfree(fb_helper);
 165         return ret;
 166 }
 167 EXPORT_SYMBOL(drm_fbdev_client_setup);