dm: Introduce device sequence numbering

[karo-tx-uboot.git] / include / dm / device.h

diff --git a/include/dm/device.h b/include/dm/device.h
index 46799795e48730c99606b818237cda4e3e815dac..6005e7eeb5ab9e6d2b48de323c747482d0806c63 100644 (file)
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -55,6 +55,8 @@ struct driver_info;
  * @child_head: List of children of this device
  * @sibling_node: Next device in list of all devices
  * @flags: Flags for this device DM_FLAG_...
+ * @req_seq: Requested sequence number for this device (-1 = any)
+ * @seq: Allocated sequence number for this device (-1 = none)
  */
 struct udevice {
        struct driver *driver;
@@ -69,8 +71,13 @@ struct udevice {
        struct list_head child_head;
        struct list_head sibling_node;
        uint32_t flags;
+       int req_seq;
+       int seq;
 };
 
+/* Maximum sequence number supported */
+#define DM_MAX_SEQ     999
+
 /* Returns the operations for a device */
 #define device_get_ops(dev)    (dev->driver->ops)
 
@@ -161,4 +168,26 @@ void *dev_get_platdata(struct udevice *dev);
  */
 void *dev_get_priv(struct udevice *dev);
 
+/**
+ * device_find_child_by_seq() - Find a child device based on a sequence
+ *
+ * This searches for a device with the given seq or req_seq.
+ *
+ * For seq, if an active device has this sequence it will be returned.
+ * If there is no such device then this will return -ENODEV.
+ *
+ * For req_seq, if a device (whether activated or not) has this req_seq
+ * value, that device will be returned. This is a strong indication that
+ * the device will receive that sequence when activated.
+ *
+ * @parent: Parent device
+ * @seq_or_req_seq: Sequence number to find (0=first)
+ * @find_req_seq: true to find req_seq, false to find seq
+ * @devp: Returns pointer to device (there is only one per for each seq).
+ * Set to NULL if none is found
+ * @return 0 if OK, -ve on error
+ */
+int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
+                            bool find_req_seq, struct udevice **devp);
+
 #endif