[PATCH libdrm] WIP: expose boot_vga via drmDevice

[Emil Velikov]

- ifdef check around the sysfs handling - only Linux has comprehensive
sysfs
- compile and run-time test

Cc: Chih-Wei Huang <cwhuang at linux.org.tw>
Cc: Mauro Rossi <issor.oruam at gmail.com>
Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
---
Chih-Wei, Mauro

Here is a quick WIP which should get you going. I have _not_ tested it
so it might need some polish - please submit once you're happy with it.
---
 xf86drm.c | 53 ++++++++++++++++++++++++++++++++++++++++++-----------
 xf86drm.h |  2 ++
 2 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/xf86drm.c b/xf86drm.c
index b49d42f7..13162b81 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -3948,8 +3948,9 @@ process_device(drmDevicePtr *device, const char *d_name,
 {
     struct stat sbuf;
     char node[PATH_MAX + 1];
-    int node_type, subsystem_type;
+    int node_type, subsystem_type, ret;
     unsigned int maj, min;
+    FILE *fp;
 
     node_type = drmGetNodeType(d_name);
     if (node_type < 0)
@@ -3972,20 +3973,49 @@ process_device(drmDevicePtr *device, const char *d_name,
     switch (subsystem_type) {
     case DRM_BUS_PCI:
     case DRM_BUS_VIRTIO:
-        return drmProcessPciDevice(device, node, node_type, maj, min,
-                                   fetch_deviceinfo, flags);
+        ret = drmProcessPciDevice(device, node, node_type, maj, min,
+                                  fetch_deviceinfo, flags);
     case DRM_BUS_USB:
-        return drmProcessUsbDevice(device, node, node_type, maj, min,
-                                   fetch_deviceinfo, flags);
+        ret = drmProcessUsbDevice(device, node, node_type, maj, min,
+                                  fetch_deviceinfo, flags);
     case DRM_BUS_PLATFORM:
-        return drmProcessPlatformDevice(device, node, node_type, maj, min,
-                                        fetch_deviceinfo, flags);
+        ret = drmProcessPlatformDevice(device, node, node_type, maj, min,
+                                       fetch_deviceinfo, flags);
     case DRM_BUS_HOST1X:
-        return drmProcessHost1xDevice(device, node, node_type, maj, min,
-                                      fetch_deviceinfo, flags);
+        ret = drmProcessHost1xDevice(device, node, node_type, maj, min,
+                                     fetch_deviceinfo, flags);
     default:
         return -1;
-   }
+    }
+    if (!(flags & DRM_DEVICE_GET_BOOT_VGA))
+        return ret;
+
+    snprintf(node, sizeof(node), "/sys/dev/char/%d:%d/device/boot_vga",
+             maj, min);
+
+    fp = fopen(path, "r");
+    if (!fp) {
+#ifdef BOOT_VGA_FATAL
+        free(*device);
+        *device = NULL;
+        return -errno;
+#else
+        return 0;
+#endif
+    }
+
+    ret = fscanf(fp, "%d", &(device->boot_vga));
+    fclose(fp);
+    if (ret != 1) {
+#ifdef BOOT_VGA_FATAL
+        free(*device);
+        *device = NULL;
+        return -errno;
+#else
+        return 0;
+#endif
+    }
+    return 0;
 }
 
 /* Consider devices located on the same bus as duplicate and fold the respective
@@ -4014,7 +4044,8 @@ static void drmFoldDuplicatedDevices(drmDevicePtr local_devices[], int count)
 static int
 drm_device_validate_flags(uint32_t flags)
 {
-        return (flags & ~DRM_DEVICE_GET_PCI_REVISION);
+    return (flags & ~(DRM_DEVICE_GET_PCI_REVISION |
+                      DRM_DEVICE_GET_BOOT_VGA));
 }
 
 static bool
diff --git a/xf86drm.h b/xf86drm.h
index 7b85079a..da6f7e26 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -885,6 +885,7 @@ typedef struct _drmDevice {
         drmPlatformDeviceInfoPtr platform;
         drmHost1xDeviceInfoPtr host1x;
     } deviceinfo;
+    int boot_vga;
 } drmDevice, *drmDevicePtr;
 
 extern int drmGetDevice(int fd, drmDevicePtr *device);
@@ -894,6 +895,7 @@ extern int drmGetDevices(drmDevicePtr devices[], int max_devices);
 extern void drmFreeDevices(drmDevicePtr devices[], int count);
 
 #define DRM_DEVICE_GET_PCI_REVISION (1 << 0)
+#define DRM_DEVICE_GET_BOOT_VGA (1 << 1)
 extern int drmGetDevice2(int fd, uint32_t flags, drmDevicePtr *device);
 extern int drmGetDevices2(uint32_t flags, drmDevicePtr devices[], int max_devices);
 
-- 
2.25.1