misc: fs_loader: Replace label with DT phandle

In previously label which will be expanded to the node's full path was
used, and now replacing label with most commonly used DT phandle. The
codes were changed accordingly to the use of DT phandle and supporting
multiple instances.

Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>

1 files changed, 49 insertions, 13 deletions

diff --git a/doc/driver-model/fs_firmware_loader.txt b/doc/driver-model/fs_firmware_loader.txt
index b9aee848cc..8be6185371 100644
--- a/doc/driver-model/fs_firmware_loader.txt
+++ b/doc/driver-model/fs_firmware_loader.txt
@@ -1,4 +1,4 @@
-# Copyright (C) 2018 Intel Corporation <www.intel.com>
+# Copyright (C) 2018-2019 Intel Corporation <www.intel.com>
 #
 # SPDX-License-Identifier:    GPL-2.0
 
@@ -27,7 +27,7 @@ Firmware storage device described in device tree source
 	defined in fs-loader node as shown in below:
 
 	Example for block device:
-	fs_loader0: fs-loader@0 {
+	fs_loader0: fs-loader {
 		u-boot,dm-pre-reloc;
 		compatible = "u-boot,fs-loader";
 		phandlepart = <&mmc 1>;
@@ -39,22 +39,55 @@ Firmware storage device described in device tree source
 	device, it can be described in FDT as shown in below:
 
 	Example for ubi:
-	fs_loader1: fs-loader@1 {
+	fs_loader1: fs-loader {
 		u-boot,dm-pre-reloc;
 		compatible = "u-boot,fs-loader";
 		mtdpart = "UBI",
 		ubivol = "ubi0";
 	};
 
-	Then, firmware_loader property would be set with the path of fs_loader
-	node under /chosen node such as:
+	Then, firmware-loader property can be added with any device node, which
+	driver would use the firmware loader for loading.
+
+	The value of the firmware-loader property should be set with phandle
+	of the fs-loader node.
+	For example:
+		firmware-loader = <&fs_loader0>;
+
+	If there are majority of devices using the same fs-loader node, then
+	firmware-loader property can be added under /chosen node instead of
+	adding to each of device node.
+
+	For example:
 	/{
 		chosen {
-			firmware_loader = &fs_loader0;
+			firmware-loader = <&fs_loader0>;
 		};
 	};
 
-	However, this driver is also designed to support U-boot environment
+	In each respective driver of devices using firmware loader, the firmware
+	loaded instance	should be created by DT phandle.
+
+	For example of getting DT phandle from /chosen and creating instance:
+	chosen_node = ofnode_path("/chosen");
+	if (!ofnode_valid(chosen_node)) {
+		debug("/chosen node was not found.\n");
+		return -ENOENT;
+	}
+
+	phandle_p = ofnode_get_property(chosen_node, "firmware-loader", &size);
+	if (!phandle_p) {
+		debug("firmware-loader property was not found.\n");
+		return -ENOENT;
+	}
+
+	phandle = fdt32_to_cpu(*phandle_p);
+	ret = uclass_get_device_by_phandle_id(UCLASS_FS_FIRMWARE_LOADER,
+					     phandle, &dev);
+	if (ret)
+		return ret;
+
+	Firmware loader driver is also designed to support U-boot environment
 	variables, so all these data from FDT can be overwritten
 	through the U-boot environment variable during run time.
 	For examples:
@@ -104,9 +137,12 @@ return:
 Description:
 	The firmware is loaded directly into the buffer pointed to by buf
 
-Example of creating firmware loader instance and calling
-request_firmware_into_buf API:
-	if (uclass_get_device(UCLASS_FS_FIRMWARE_LOADER, 0, &dev)) {
-		request_firmware_into_buf(dev, filename, buffer_location,
-					 buffer_size, offset_ofreading);
-	}
+Example of calling request_firmware_into_buf API after creating firmware loader
+instance:
+	ret = uclass_get_device_by_phandle_id(UCLASS_FS_FIRMWARE_LOADER,
+					     phandle, &dev);
+	if (ret)
+		return ret;
+
+	request_firmware_into_buf(dev, filename, buffer_location, buffer_size,
+				 offset_ofreading);