1 files changed, 45 insertions, 4 deletions

diff --git a/include/dm/platdata.h b/include/dm/platdata.h
index cab93b071b..216efa8ef7 100644
--- a/include/dm/platdata.h
+++ b/include/dm/platdata.h
@@ -22,30 +22,71 @@
  * @name:	Driver name
  * @platdata:	Driver-specific platform data
  * @platdata_size: Size of platform data structure
- * @dev:	Device created from this structure data
+ * @parent_idx:	Index of the parent driver_info structure
  */
 struct driver_info {
 	const char *name;
 	const void *platdata;
 #if CONFIG_IS_ENABLED(OF_PLATDATA)
-	uint platdata_size;
-	struct udevice *dev;
+	unsigned short platdata_size;
+	short parent_idx;
 #endif
 };
 
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+#define driver_info_parent_id(driver_info)	driver_info->parent_idx
+#else
+#define driver_info_parent_id(driver_info)	(-1)
+#endif
+
+/**
+ * driver_rt - runtime information set up by U-Boot
+ *
+ * There is one of these for every driver_info in the linker list, indexed by
+ * the driver_info idx value.
+ *
+ * @dev: Device created from this idx
+ */
+struct driver_rt {
+	struct udevice *dev;
+};
+
 /**
  * NOTE: Avoid using these except in extreme circumstances, where device tree
  * is not feasible (e.g. serial driver in SPL where <8KB of SRAM is
  * available). U-Boot's driver model uses device tree for configuration.
+ *
+ * When of-platdata is in use, U_BOOT_DEVICE() cannot be used outside of the
+ * dt-platdata.c file created by dtoc
  */
+#if CONFIG_IS_ENABLED(OF_PLATDATA) && !defined(DT_PLATDATA_C)
+#define U_BOOT_DEVICE(__name)	_Static_assert(false, \
+	"Cannot use U_BOOT_DEVICE with of-platdata. Please use devicetree instead")
+#else
 #define U_BOOT_DEVICE(__name)						\
 	ll_entry_declare(struct driver_info, __name, driver_info)
+#endif
 
 /* Declare a list of devices. The argument is a driver_info[] array */
 #define U_BOOT_DEVICES(__name)						\
 	ll_entry_declare_list(struct driver_info, __name, driver_info)
 
-/* Get a pointer to a given driver */
+/**
+ * Get a pointer to a given device info given its name
+ *
+ * With the declaration U_BOOT_DEVICE(name), DM_GET_DEVICE(name) will return a
+ * pointer to the struct driver_info created by that declaration.
+ *
+ * if OF_PLATDATA is enabled, from this it is possible to use the @dev member of
+ * struct driver_info to find the device pointer itself.
+ *
+ * TODO(sjg@chromium.org): U_BOOT_DEVICE() tells U-Boot to create a device, so
+ * the naming seems sensible, but DM_GET_DEVICE() is a bit of misnomer, since it
+ * finds the driver_info record, not the device.
+ *
+ * @__name: Driver name (C identifier, not a string. E.g. gpio7_at_ff7e0000)
+ * @return struct driver_info * to the driver that created the device
+ */
 #define DM_GET_DEVICE(__name)						\
 	ll_entry_get(struct driver_info, __name, driver_info)