[PATCH libdrm v3 2/5] xf86drm: Add USB support
Thierry Reding
thierry.reding at gmail.com
Wed Jan 18 09:02:06 UTC 2017
Allow DRM/KMS devices hosted on USB to be detected by the drmDevice
infrastructure.
v3:
- guard Linux-specific sysfs parsing code with #ifdef __linux__
v2:
- make sysfs_uevent_get() more flexible using a format string
Signed-off-by: Thierry Reding <thierry.reding at gmail.com>
---
xf86drm.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
xf86drm.h | 13 +++++
2 files changed, 188 insertions(+)
diff --git a/xf86drm.c b/xf86drm.c
index 7766bfe937db..d83674e638c4 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -2886,6 +2886,50 @@ char *drmGetRenderDeviceNameFromFd(int fd)
return drmGetMinorNameForFD(fd, DRM_NODE_RENDER);
}
+#ifdef __linux__
+static char * DRM_PRINTFLIKE(2, 3)
+sysfs_uevent_get(const char *path, const char *fmt, ...)
+{
+ char filename[PATH_MAX + 1], *key, *line = NULL, *value = NULL;
+ size_t size = 0, len;
+ ssize_t num;
+ va_list ap;
+ FILE *fp;
+
+ va_start(ap, fmt);
+ num = vasprintf(&key, fmt, ap);
+ va_end(ap);
+ len = num;
+
+ snprintf(filename, sizeof(filename), "%s/uevent", path);
+
+ fp = fopen(filename, "r");
+ if (!fp) {
+ free(key);
+ return NULL;
+ }
+
+ while ((num = getline(&line, &size, fp)) >= 0) {
+ if ((strncmp(line, key, len) == 0) && (line[len] == '=')) {
+ char *start = line + len + 1, *end = line + num - 1;
+
+ if (*end != '\n')
+ end++;
+
+ value = strndup(start, end - start);
+ break;
+ }
+ }
+
+ free(line);
+ fclose(fp);
+
+ free(key);
+
+ return value;
+}
+#endif
+
static int drmParseSubsystemType(int maj, int min)
{
#ifdef __linux__
@@ -2906,6 +2950,9 @@ static int drmParseSubsystemType(int maj, int min)
if (strncmp(name, "/pci", 4) == 0)
return DRM_BUS_PCI;
+ if (strncmp(name, "/usb", 4) == 0)
+ return DRM_BUS_USB;
+
return -EINVAL;
#elif defined(__OpenBSD__)
return DRM_BUS_PCI;
@@ -2992,6 +3039,10 @@ static int drmCompareBusInfo(drmDevicePtr a, drmDevicePtr b)
switch (a->bustype) {
case DRM_BUS_PCI:
return memcmp(a->businfo.pci, b->businfo.pci, sizeof(drmPciBusInfo));
+
+ case DRM_BUS_USB:
+ return memcmp(a->businfo.usb, b->businfo.usb, sizeof(drmUsbBusInfo));
+
default:
break;
}
@@ -3235,6 +3286,113 @@ free_device:
return ret;
}
+static int drmParseUsbBusInfo(int maj, int min, drmUsbBusInfoPtr info)
+{
+#ifdef __linux__
+ char path[PATH_MAX + 1], *value;
+ unsigned int bus, dev;
+ int ret;
+
+ snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min);
+
+ value = sysfs_uevent_get(path, "BUSNUM");
+ if (!value)
+ return -ENOENT;
+
+ ret = sscanf(value, "%03u", &bus);
+ free(value);
+
+ if (ret <= 0)
+ return -errno;
+
+ value = sysfs_uevent_get(path, "DEVNUM");
+ if (!value)
+ return -ENOENT;
+
+ ret = sscanf(value, "%03u", &dev);
+ free(value);
+
+ if (ret <= 0)
+ return -errno;
+
+ info->bus = bus;
+ info->dev = dev;
+
+ return 0;
+#else
+#warning "Missing implementation of drmParseUsbBusInfo"
+ return -EINVAL;
+#endif
+}
+
+static int drmParseUsbDeviceInfo(int maj, int min, drmUsbDeviceInfoPtr info)
+{
+#ifdef __linux__
+ char path[PATH_MAX + 1], *value;
+ unsigned int vendor, product;
+ int ret;
+
+ snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min);
+
+ value = sysfs_uevent_get(path, "PRODUCT");
+ if (!value)
+ return -ENOENT;
+
+ ret = sscanf(value, "%x/%x", &vendor, &product);
+ free(value);
+
+ if (ret <= 0)
+ return -errno;
+
+ info->vendor = vendor;
+ info->product = product;
+
+ return 0;
+#else
+#warning "Missing implementation of drmParseUsbDeviceInfo"
+ return -EINVAL;
+#endif
+}
+
+static int drmProcessUsbDevice(drmDevicePtr *device, const char *node,
+ int node_type, int maj, int min,
+ bool fetch_deviceinfo, uint32_t flags)
+{
+ drmDevicePtr dev;
+ char *ptr;
+ int ret;
+
+ dev = drmDeviceAlloc(node_type, node, sizeof(drmUsbBusInfo),
+ sizeof(drmUsbDeviceInfo), &ptr);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->bustype = DRM_BUS_USB;
+
+ dev->businfo.usb = (drmUsbBusInfoPtr)ptr;
+
+ ret = drmParseUsbBusInfo(maj, min, dev->businfo.usb);
+ if (ret < 0)
+ goto free_device;
+
+ if (fetch_deviceinfo) {
+ ptr += sizeof(drmUsbBusInfo);
+ dev->deviceinfo.usb = (drmUsbDeviceInfoPtr)ptr;
+
+ ret = drmParseUsbDeviceInfo(maj, min, dev->deviceinfo.usb);
+ if (ret < 0)
+ goto free_device;
+ }
+
+ *device = dev;
+
+ return 0;
+
+free_device:
+ free(dev);
+ return ret;
+}
+
/* Consider devices located on the same bus as duplicate and fold the respective
* entries into a single one.
*
@@ -3410,6 +3568,14 @@ int drmGetDevice2(int fd, uint32_t flags, drmDevicePtr *device)
continue;
break;
+
+ case DRM_BUS_USB:
+ ret = drmProcessUsbDevice(&d, node, node_type, maj, min, true, flags);
+ if (ret)
+ goto free_devices;
+
+ break;
+
default:
continue;
}
@@ -3541,6 +3707,15 @@ int drmGetDevices2(uint32_t flags, drmDevicePtr devices[], int max_devices)
continue;
break;
+
+ case DRM_BUS_USB:
+ ret = drmProcessUsbDevice(&device, node, node_type, maj, min,
+ devices != NULL, flags);
+ if (ret)
+ goto free_devices;
+
+ break;
+
default:
continue;
}
diff --git a/xf86drm.h b/xf86drm.h
index b340fc46cd44..65d5321950fc 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -767,6 +767,7 @@ extern char *drmGetPrimaryDeviceNameFromFd(int fd);
extern char *drmGetRenderDeviceNameFromFd(int fd);
#define DRM_BUS_PCI 0
+#define DRM_BUS_USB 1
typedef struct _drmPciBusInfo {
uint16_t domain;
@@ -783,15 +784,27 @@ typedef struct _drmPciDeviceInfo {
uint8_t revision_id;
} drmPciDeviceInfo, *drmPciDeviceInfoPtr;
+typedef struct _drmUsbBusInfo {
+ uint8_t bus;
+ uint8_t dev;
+} drmUsbBusInfo, *drmUsbBusInfoPtr;
+
+typedef struct _drmUsbDeviceInfo {
+ uint16_t vendor;
+ uint16_t product;
+} drmUsbDeviceInfo, *drmUsbDeviceInfoPtr;
+
typedef struct _drmDevice {
char **nodes; /* DRM_NODE_MAX sized array */
int available_nodes; /* DRM_NODE_* bitmask */
int bustype;
union {
drmPciBusInfoPtr pci;
+ drmUsbBusInfoPtr usb;
} businfo;
union {
drmPciDeviceInfoPtr pci;
+ drmUsbDeviceInfoPtr usb;
} deviceinfo;
} drmDevice, *drmDevicePtr;
--
2.11.0
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