[U-Boot] [PATCH v3 04/13] fastboot: Extract fastboot_okay/fail to fb_common.c

[Alex Kiernan]

Add drivers/fastboot/fb_common.c, where fastboot_okay/fail are implemented
so we can call them from a non-USB implementation.

Introduce fastboot_response which takes varargs parameters so we can
use it to generate formatted response strings. Refactor fastboot_okay/fail
to use it.

Signed-off-by: Alex Kiernan <alex.kiernan at gmail.com>
Reviewed-by: Joe Hershberger <joe.hershberger at ni.com>
---

Changes in v3:
- Merge subsequent patch for formatting response strings into this one
- allow NULL to fastboot_okay() when there's no message to send

Changes in v2: None

 drivers/fastboot/Makefile       |  2 ++
 drivers/fastboot/fb_common.c    | 49 +++++++++++++++++++++++++++++++++++++++++
 drivers/usb/gadget/f_fastboot.c | 13 -----------
 include/fastboot.h              |  4 ++++
 4 files changed, 55 insertions(+), 13 deletions(-)
 create mode 100644 drivers/fastboot/fb_common.c

diff --git a/drivers/fastboot/Makefile b/drivers/fastboot/Makefile
index 651fbf0..b38dcff 100644
--- a/drivers/fastboot/Makefile
+++ b/drivers/fastboot/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier:      GPL-2.0+
 
+obj-y += fb_common.o
+
 ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
 obj-y += fb_mmc.o
 endif
diff --git a/drivers/fastboot/fb_common.c b/drivers/fastboot/fb_common.c
new file mode 100644
index 0000000..c9638f1
--- /dev/null
+++ b/drivers/fastboot/fb_common.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2008 - 2009
+ * Windriver, <www.windriver.com>
+ * Tom Rix <Tom.Rix at windriver.com>
+ *
+ * Copyright 2011 Sebastian Andrzej Siewior <bigeasy at linutronix.de>
+ *
+ * Copyright 2014 Linaro, Ltd.
+ * Rob Herring <robh at kernel.org>
+ */
+
+#include <common.h>
+#include <fastboot.h>
+
+/**
+ * Writes a response to response buffer of the form "$tag$reason".
+ *
+ * @param tag		The first part of the response
+ * @param response	Pointer to fastboot response buffer
+ * @param format	printf style format string
+ */
+void fastboot_response(const char *tag, char *response,
+		       const char *format, ...)
+{
+	va_list args;
+
+	strlcpy(response, tag, FASTBOOT_RESPONSE_LEN);
+	if (format) {
+		va_start(args, format);
+		vsnprintf(response + strlen(response),
+			  FASTBOOT_RESPONSE_LEN - strlen(response) - 1,
+			  format, args);
+		va_end(args);
+	}
+}
+
+void fastboot_fail(const char *reason, char *response)
+{
+	fastboot_response("FAIL", response, "%s", reason);
+}
+
+void fastboot_okay(const char *reason, char *response)
+{
+	if (reason)
+		fastboot_response("OKAY", response, "%s", reason);
+	else
+		fastboot_response("OKAY", response, NULL);
+}
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index bb60612..2e6e161 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -149,19 +149,6 @@ static struct usb_gadget_strings *fastboot_strings[] = {
 static void rx_handler_command(struct usb_ep *ep, struct usb_request *req);
 static int strcmp_l1(const char *s1, const char *s2);
 
-
-void fastboot_fail(const char *reason, char *response)
-{
-	strncpy(response, "FAIL\0", 5);
-	strncat(response, reason, FASTBOOT_RESPONSE_LEN - 4 - 1);
-}
-
-void fastboot_okay(const char *reason, char *response)
-{
-	strncpy(response, "OKAY\0", 5);
-	strncat(response, reason, FASTBOOT_RESPONSE_LEN - 4 - 1);
-}
-
 static void fastboot_complete(struct usb_ep *ep, struct usb_request *req)
 {
 	int status = req->status;
diff --git a/include/fastboot.h b/include/fastboot.h
index ed52dae..434c46b 100644
--- a/include/fastboot.h
+++ b/include/fastboot.h
@@ -15,6 +15,10 @@
 /* The 64 defined bytes plus \0 */
 #define FASTBOOT_RESPONSE_LEN	(64 + 1)
 
+void fastboot_response(const char *tag, char *response,
+		       const char *format, ...)
+	__attribute__ ((format (__printf__, 3, 4)));
+
 void fastboot_fail(const char *reason, char *response);
 void fastboot_okay(const char *reason, char *response);
 
-- 
2.7.4