add to dahdi_device a "hardware_id" attribute as an alternative to "location"

- The "hardware_id" does not change with device location (e.g: when a PCI
  card is moved from one slot to another).
- Not all devices have this attribute. It is legal for it to be NULL (that
  is the default for all low-level drivers that do not set it explicitly).
- When "hardware_id" is NULL, the sysfs attribute value is "\n"

1 files changed, 9 insertions, 4 deletions

diff --git a/include/dahdi/kernel.h b/include/dahdi/kernel.h
index d2f3dc7..2ca5acf 100644
--- a/include/dahdi/kernel.h
+++ b/include/dahdi/kernel.h
@@ -882,17 +882,22 @@ struct dahdi_span_ops {
 /**
  * dahdi_device - Represents a device that can contain one or more spans.
  *
- * @spans:	List of child spans.
+ * @spans:        List of child spans.
  * @manufacturer: Device manufacturer.
- * @location:	The location of this device
- * @devicetype: What type of device this is.
- * @irqmisses:  Count of "interrupt misses" for this device.
+ * @location:     The location of this device. This should not change if
+ *                the device is replaced (e.g: in the same PCI slot)
+ * @hardware_id:  The hardware_id of this device (NULL for devices without
+ *                a hardware_id). This should not change if the device is
+ *                relocated to a different location (e.g: different PCI slot)
+ * @devicetype:   What type of device this is.
+ * @irqmisses:    Count of "interrupt misses" for this device.
  *
  */
 struct dahdi_device {
 	struct list_head spans;
 	const char *manufacturer;
 	const char *location;
+	const char *hardware_id;
 	const char *devicetype;
 	struct device dev;
 	unsigned int irqmisses;