2 files changed, 51 insertions, 1 deletions

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 98ce0841f4c9..551588342898 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -355,9 +355,56 @@ static ssize_t guid_show(struct device *dev,
         return ret;
 }
 
+static int units_sprintf(char *buf, u32 *directory)
+{
+        struct fw_csr_iterator ci;
+        int key, value;
+        int specifier_id = 0;
+        int version = 0;
+
+        fw_csr_iterator_init(&ci, directory);
+        while (fw_csr_iterator_next(&ci, &key, &value)) {
+                switch (key) {
+                case CSR_SPECIFIER_ID:
+                        specifier_id = value;
+                        break;
+                case CSR_VERSION:
+                        version = value;
+                        break;
+                }
+        }
+
+        return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
+}
+
+static ssize_t units_show(struct device *dev,
+                          struct device_attribute *attr, char *buf)
+{
+        struct fw_device *device = fw_device(dev);
+        struct fw_csr_iterator ci;
+        int key, value, i = 0;
+
+        down_read(&fw_device_rwsem);
+        fw_csr_iterator_init(&ci, &device->config_rom[5]);
+        while (fw_csr_iterator_next(&ci, &key, &value)) {
+                if (key != (CSR_UNIT | CSR_DIRECTORY))
+                        continue;
+                i += units_sprintf(&buf[i], ci.p + value - 1);
+                if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
+                        break;
+        }
+        up_read(&fw_device_rwsem);
+
+        if (i)
+                buf[i - 1] = '\n';
+
+        return i;
+}
+
 static struct device_attribute fw_device_attributes[] = {
         __ATTR_RO(config_rom),
         __ATTR_RO(guid),
+        __ATTR_RO(units),
         __ATTR_NULL,
 };
 
@@ -1000,6 +1047,9 @@ static void fw_device_refresh(struct work_struct *work)
 
         create_units(device);
 
+        /* Userspace may want to re-read attributes. */
+        kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
+
         if (atomic_cmpxchg(&device->state,
                            FW_DEVICE_INITIALIZING,
                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
diff --git a/drivers/firewire/fw-device.h b/drivers/firewire/fw-device.h
index 623cfee289bd..892dd5916276 100644
--- a/drivers/firewire/fw-device.h
+++ b/drivers/firewire/fw-device.h
@@ -42,7 +42,7 @@ enum fw_device_state {
 struct fw_attribute_group {
         struct attribute_group *groups[2];
         struct attribute_group group;
-        struct attribute *attrs[11];
+        struct attribute *attrs[12];
 };
 
 struct fw_node;