dm: Introduce device sequence numbering

[karo-tx-uboot.git] / drivers / core / uclass.c

diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index 34723ec42a75fccca2df41a95c3b5a37ae0ec9d6..c28cf6795f0662fdb9776d03f05124a575dc514b 100644 (file)
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -158,13 +158,48 @@ int uclass_find_device(enum uclass_id id, int index, struct udevice **devp)
        return -ENODEV;
 }
 
-int uclass_get_device(enum uclass_id id, int index, struct udevice **devp)
+int uclass_find_device_by_seq(enum uclass_id id, int seq_or_req_seq,
+                             bool find_req_seq, struct udevice **devp)
 {
+       struct uclass *uc;
        struct udevice *dev;
        int ret;
 
        *devp = NULL;
-       ret = uclass_find_device(id, index, &dev);
+       debug("%s: %d %d\n", __func__, find_req_seq, seq_or_req_seq);
+       if (seq_or_req_seq == -1)
+               return -ENODEV;
+       ret = uclass_get(id, &uc);
+       if (ret)
+               return ret;
+
+       list_for_each_entry(dev, &uc->dev_head, uclass_node) {
+               debug("   - %d %d\n", dev->req_seq, dev->seq);
+               if ((find_req_seq ? dev->req_seq : dev->seq) ==
+                               seq_or_req_seq) {
+                       *devp = dev;
+                       debug("   - found\n");
+                       return 0;
+               }
+       }
+       debug("   - not found\n");
+
+       return -ENODEV;
+}
+
+/**
+ * uclass_get_device_tail() - handle the end of a get_device call
+ *
+ * This handles returning an error or probing a device as needed.
+ *
+ * @dev: Device that needs to be probed
+ * @ret: Error to return. If non-zero then the device is not probed
+ * @devp: Returns the value of 'dev' if there is no error
+ * @return ret, if non-zero, else the result of the device_probe() call
+ */
+static int uclass_get_device_tail(struct udevice *dev, int ret,
+                                 struct udevice **devp)
+{
        if (ret)
                return ret;
 
@@ -177,6 +212,33 @@ int uclass_get_device(enum uclass_id id, int index, struct udevice **devp)
        return 0;
 }
 
+int uclass_get_device(enum uclass_id id, int index, struct udevice **devp)
+{
+       struct udevice *dev;
+       int ret;
+
+       *devp = NULL;
+       ret = uclass_find_device(id, index, &dev);
+       return uclass_get_device_tail(dev, ret, devp);
+}
+
+int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp)
+{
+       struct udevice *dev;
+       int ret;
+
+       *devp = NULL;
+       ret = uclass_find_device_by_seq(id, seq, false, &dev);
+       if (ret == -ENODEV) {
+               /*
+                * We didn't find it in probed devices. See if there is one
+                * that will request this seq if probed.
+                */
+               ret = uclass_find_device_by_seq(id, seq, true, &dev);
+       }
+       return uclass_get_device_tail(dev, ret, devp);
+}
+
 int uclass_first_device(enum uclass_id id, struct udevice **devp)
 {
        struct uclass *uc;
@@ -254,6 +316,37 @@ int uclass_unbind_device(struct udevice *dev)
        return 0;
 }
 
+int uclass_resolve_seq(struct udevice *dev)
+{
+       struct udevice *dup;
+       int seq;
+       int ret;
+
+       assert(dev->seq == -1);
+       ret = uclass_find_device_by_seq(dev->uclass->uc_drv->id, dev->req_seq,
+                                       false, &dup);
+       if (!ret) {
+               dm_warn("Device '%s': seq %d is in use by '%s'\n",
+                       dev->name, dev->req_seq, dup->name);
+       } else if (ret == -ENODEV) {
+               /* Our requested sequence number is available */
+               if (dev->req_seq != -1)
+                       return dev->req_seq;
+       } else {
+               return ret;
+       }
+
+       for (seq = 0; seq < DM_MAX_SEQ; seq++) {
+               ret = uclass_find_device_by_seq(dev->uclass->uc_drv->id, seq,
+                                               false, &dup);
+               if (ret == -ENODEV)
+                       break;
+               if (ret)
+                       return ret;
+       }
+       return seq;
+}
+
 int uclass_post_probe_device(struct udevice *dev)
 {
        struct uclass_driver *uc_drv = dev->uclass->uc_drv;
@@ -281,6 +374,7 @@ int uclass_pre_remove_device(struct udevice *dev)
                free(dev->uclass_priv);
                dev->uclass_priv = NULL;
        }
+       dev->seq = -1;
 
        return 0;
 }