From 132ba667f4a88bb182e2d2abc7c4e60699398380 Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@redhat.com>
Date: Thu, 28 Feb 2008 12:59:39 +1000
Subject: drm: add a check for if modesetting is supported.
This is Linux only code, it just uses sysfs to see if a control
device has been registered on the requested PCI ID
---
libdrm/xf86drmMode.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
libdrm/xf86drmMode.h | 1 +
2 files changed, 49 insertions(+)
diff --git a/libdrm/xf86drmMode.c b/libdrm/xf86drmMode.c
index 52fef81b..717e1fe2 100644
--- a/libdrm/xf86drmMode.c
+++ b/libdrm/xf86drmMode.c
@@ -41,6 +41,8 @@
#include "xf86drm.h"
#include <drm.h>
#include <string.h>
+#include <dirent.h>
+#include <errno.h>
#define U642VOID(x) ((void *)(unsigned long)(x))
#define VOID2U64(x) ((uint64_t)(unsigned long)(x))
@@ -571,3 +573,49 @@ int drmModeOutputSetProperty(int fd, uint32_t output_id, uint32_t property_id,
return 0;
}
+
+/*
+ * checks if a modesetting capable driver has attached to the pci id
+ * returns 0 if modesetting supported.
+ * -EINVAL or invalid bus id
+ * -ENOSYS if no modesetting support
+*/
+int drmCheckModesettingSupported(const char *busid)
+{
+#ifdef __linux__
+ char pci_dev_dir[1024];
+ char *bus_id_path;
+ char *bus_type;
+ int domain, bus, dev, func;
+ DIR *sysdir;
+ struct dirent *dent;
+ int found = 0, ret;
+
+ ret = sscanf(busid, "pci:%04x:%02x:%02x.%d", &domain, &bus, &dev, &func);
+ if (ret != 4)
+ return -EINVAL;
+
+ sprintf(pci_dev_dir, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/",
+ domain, bus, dev, func);
+
+ sysdir = opendir(pci_dev_dir);
+ if (!sysdir)
+ return -EINVAL;
+
+ dent = readdir(sysdir);
+ while (dent) {
+ if (!strncmp(dent->d_name, "drm:controlD", 12)) {
+ found = 1;
+ break;
+ }
+
+ dent = readdir(sysdir);
+ }
+
+ closedir(sysdir);
+ if (found)
+ return 0;
+#endif
+ return -ENOSYS;
+
+}
diff --git a/libdrm/xf86drmMode.h b/libdrm/xf86drmMode.h
index 7cc3ceca..71e779d4 100644
--- a/libdrm/xf86drmMode.h
+++ b/libdrm/xf86drmMode.h
@@ -243,3 +243,4 @@ extern drmModePropertyBlobPtr drmModeGetPropertyBlob(int fd, uint32_t blob_id);
extern void drmModeFreePropertyBlob(drmModePropertyBlobPtr ptr);
extern int drmModeOutputSetProperty(int fd, uint32_t output_id, uint32_t property_id,
uint64_t value);
+extern int drmCheckModesettingSupported(const char *busid);
--
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