dm: Support parent devices with of-platdata

At present of-platdata does not provide parent information. But this is
useful for I2C devices, for example, since it allows them to determine
which bus they are on.

Add support for setting the parent correctly, by storing the parent
driver_info index in dtoc and reading this in lists_bind_drivers(). This
needs multiple passes since we must process children after their parents
already have been bound.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 52 insertions, 2 deletions

diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 2e6bd5006ce..b23ee3030e5 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -51,21 +51,48 @@ struct uclass_driver *lists_uclass_lookup(enum uclass_id id)
 	return NULL;
 }
 
-int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
+static int bind_drivers_pass(struct udevice *parent, bool pre_reloc_only)
 {
 	struct driver_info *info =
 		ll_entry_start(struct driver_info, driver_info);
 	const int n_ents = ll_entry_count(struct driver_info, driver_info);
+	bool missing_parent = false;
 	int result = 0;
 	uint idx;
 
+	/*
+	 * Do one iteration through the driver_info records. For of-platdata,
+	 * bind only devices whose parent is already bound. If we find any
+	 * device we can't bind, set missing_parent to true, which will cause
+	 * this function to be called again.
+	 */
 	for (idx = 0; idx < n_ents; idx++) {
+		struct udevice *par = parent;
 		const struct driver_info *entry = info + idx;
 		struct driver_rt *drt = gd_dm_driver_rt() + idx;
 		struct udevice *dev;
 		int ret;
 
-		ret = device_bind_by_name(parent, pre_reloc_only, entry, &dev);
+		if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
+			int parent_idx = driver_info_parent_id(entry);
+
+			if (drt->dev)
+				continue;
+
+			if (CONFIG_IS_ENABLED(OF_PLATDATA_PARENT) &&
+			    parent_idx != -1) {
+				struct driver_rt *parent_drt;
+
+				parent_drt = gd_dm_driver_rt() + parent_idx;
+				if (!parent_drt->dev) {
+					missing_parent = true;
+					continue;
+				}
+
+				par = parent_drt->dev;
+			}
+		}
+		ret = device_bind_by_name(par, pre_reloc_only, entry, &dev);
 		if (!ret) {
 			if (CONFIG_IS_ENABLED(OF_PLATDATA))
 				drt->dev = dev;
@@ -76,6 +103,29 @@ int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
 		}
 	}
 
+	return result ? result : missing_parent ? -EAGAIN : 0;
+}
+
+int lists_bind_drivers(struct udevice *parent, bool pre_reloc_only)
+{
+	int result = 0;
+	int pass;
+
+	/*
+	 * 10 passes is 10 levels deep in the devicetree, which is plenty. If
+	 * OF_PLATDATA_PARENT is not enabled, then bind_drivers_pass() will
+	 * always succeed on the first pass.
+	 */
+	for (pass = 0; pass < 10; pass++) {
+		int ret;
+
+		ret = bind_drivers_pass(parent, pre_reloc_only);
+		if (!ret)
+			break;
+		if (ret != -EAGAIN && !result)
+			result = ret;
+	}
+
 	return result;
 }