[PATCH 2/2] usbgadget: split usbgadget_register into prepare and register

[Marco Felsch <m.felsch@xxxxxxxxxxxxxx>]

Currently usbgadget_register() prepares the struct::f_multi_opts
according a given configuration string and registers the the usbgadget
device.

This is not optimal for adding custom fastboot_opts. Split the single
function into usbgadget_prepare() and usbgadget_register() to avoid code
duplication. This way it's easy to reuse the preparation code and add
the custom fastboot_opts afterwards.

In addition usbgadget_prepare_register() is added to keep the simplicity
of the single prepare and register functionality.

Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
 commands/dfu.c                   |  2 +-
 commands/usbgadget.c             |  2 +-
 common/usbgadget.c               | 36 ++++++++++++++++++++++++--------
 include/linux/usb/gadget-multi.h |  4 +++-
 4 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/commands/dfu.c b/commands/dfu.c
index bbe75841b914..ab784c638200 100644
--- a/commands/dfu.c
+++ b/commands/dfu.c
@@ -29,7 +29,7 @@ static int do_dfu(int argc, char *argv[])
 
 	funcs.flags |= USBGADGET_DFU;
 	funcs.dfu_opts = argv[optind];
-	ret = usbgadget_register(&funcs);
+	ret = usbgadget_prepare_register(&funcs);
 	if (ret)
 		return COMMAND_ERROR_USAGE;
 
diff --git a/commands/usbgadget.c b/commands/usbgadget.c
index 736ccb5d9185..1cd8c915b1b1 100644
--- a/commands/usbgadget.c
+++ b/commands/usbgadget.c
@@ -51,7 +51,7 @@ static int do_usbgadget(int argc, char *argv[])
 		}
 	}
 
-	ret = usbgadget_register(&funcs);
+	ret = usbgadget_prepare_register(&funcs);
 	return ret ? COMMAND_ERROR_USAGE : 0;
 }
 
diff --git a/common/usbgadget.c b/common/usbgadget.c
index 9974be57d1cb..1333eaa413ea 100644
--- a/common/usbgadget.c
+++ b/common/usbgadget.c
@@ -31,11 +31,9 @@ static inline struct file_list *get_dfu_function(void)
 	return system_partitions_get_null();
 }
 
-int usbgadget_register(const struct usbgadget_funcs *funcs)
+struct f_multi_opts *usbgadget_prepare(const struct usbgadget_funcs *funcs)
 {
-	int ret;
 	int flags = funcs->flags;
-	struct device *dev;
 	struct f_multi_opts *opts;
 
 	opts = xzalloc(sizeof(*opts));
@@ -71,10 +69,18 @@ int usbgadget_register(const struct usbgadget_funcs *funcs)
 
 	if (usb_multi_count_functions(opts) == 0) {
 		pr_warn("No functions to register\n");
-		ret = -EINVAL;
-		goto err;
+		usb_multi_opts_release(opts);
+		return ERR_PTR(-EINVAL);
 	}
 
+	return opts;
+}
+
+int usbgadget_register(struct f_multi_opts *opts)
+{
+	int ret;
+	struct device *dev;
+
 	/*
 	 * Creating a gadget with both DFU and Fastboot may not work.
 	 * fastboot 1:8.1.0+r23-5 can deal with it, but dfu-util 0.9
@@ -90,11 +96,23 @@ int usbgadget_register(const struct usbgadget_funcs *funcs)
 
 	ret = usb_multi_register(opts);
 	if (ret)
-		goto err;
+		return ret;
 
 	return 0;
-err:
-	usb_multi_opts_release(opts);
+}
+
+int usbgadget_prepare_register(const struct usbgadget_funcs *funcs)
+{
+	struct f_multi_opts *opts;
+	int ret;
+
+	opts = usbgadget_prepare(funcs);
+	if (IS_ERR(opts))
+		return PTR_ERR(opts);
+
+	ret = usbgadget_register(opts);
+	if (ret)
+		usb_multi_opts_release(opts);
 
 	return ret;
 }
@@ -122,7 +140,7 @@ static int usbgadget_do_autostart(void)
 
 	funcs.flags |= USBGADGET_DFU | USBGADGET_FASTBOOT | USBGADGET_MASS_STORAGE;
 
-	err = usbgadget_register(&funcs);
+	err = usbgadget_prepare_register(&funcs);
 	if (!err)
 		started = true;
 
diff --git a/include/linux/usb/gadget-multi.h b/include/linux/usb/gadget-multi.h
index 1027a10082e0..14aa609a5895 100644
--- a/include/linux/usb/gadget-multi.h
+++ b/include/linux/usb/gadget-multi.h
@@ -35,7 +35,9 @@ struct usbgadget_funcs {
 	const char *ums_opts;
 };
 
-int usbgadget_register(const struct usbgadget_funcs *funcs);
+struct f_multi_opts *usbgadget_prepare(const struct usbgadget_funcs *funcs);
+int usbgadget_register(struct f_multi_opts *opts);
+int usbgadget_prepare_register(const struct usbgadget_funcs *funcs);
 
 void usbgadget_autostart(bool enable);
 
-- 
2.39.2