fastboot: Extract fastboot_okay/fail to fb_common.c

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@gmail.com>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>

2 files changed, 63 insertions, 0 deletions

diff --git a/drivers/fastboot/Makefile b/drivers/fastboot/Makefile
index 651fbf0935..b38dcff202 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 0000000000..c4a7702bb3
--- /dev/null
+++ b/drivers/fastboot/fb_common.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2008 - 2009
+ * Windriver, <www.windriver.com>
+ * Tom Rix <Tom.Rix@windriver.com>
+ *
+ * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ *
+ * Copyright 2014 Linaro, Ltd.
+ * Rob Herring <robh@kernel.org>
+ */
+
+#include <common.h>
+#include <fastboot.h>
+
+/**
+ * fastboot_response() - Writes a response of the form "$tag$reason".
+ *
+ * @tag: The first part of the response
+ * @response: Pointer to fastboot response buffer
+ * @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);
+	}
+}
+
+/**
+ * fastboot_fail() - Write a FAIL response of the form "FAIL$reason".
+ *
+ * @reason: Pointer to returned reason string
+ * @response: Pointer to fastboot response buffer
+ */
+void fastboot_fail(const char *reason, char *response)
+{
+	fastboot_response("FAIL", response, "%s", reason);
+}
+
+/**
+ * fastboot_okay() - Write an OKAY response of the form "OKAY$reason".
+ *
+ * @reason: Pointer to returned reason string, or NULL to send a bare "OKAY"
+ * @response: Pointer to fastboot response buffer
+ */
+void fastboot_okay(const char *reason, char *response)
+{
+	if (reason)
+		fastboot_response("OKAY", response, "%s", reason);
+	else
+		fastboot_response("OKAY", response, NULL);
+}