[U-Boot] [PATCH] Kconfig: update FASTBOOT_FLASH_MMC_DEV

[Steve Rae]

handle FASTBOOT_FLASH_MMC_DEV default properly

Signed-off-by: Steve Rae <steve.rae at raedomain.com>
---
I was hoping that the FASTBOOT_FLASH_MMC_DEV Kconfig option could be
an integer (eg. 0, 1, or 2 etc.) or undefined (to signify that it
is not being used). However, it seems that (Kconfig experts please!)
this is not correct within Kconfig.
Therefore, I have implemented "-1" to signify that it is not used.
Is this the "best practice" for handling this scenario?

 cmd/fastboot/Kconfig            |  4 +++-
 common/Makefile                 |  4 +++-
 drivers/usb/gadget/f_fastboot.c | 12 ++++++++----
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/cmd/fastboot/Kconfig b/cmd/fastboot/Kconfig
index a93d1c0..fdd5475 100644
--- a/cmd/fastboot/Kconfig
+++ b/cmd/fastboot/Kconfig
@@ -50,10 +50,12 @@ config FASTBOOT_FLASH
 
 config FASTBOOT_FLASH_MMC_DEV
 	int "Define FASTBOOT MMC FLASH default device"
+	default -1
 	help
 	  The fastboot "flash" command requires additional information
 	  regarding the non-volatile storage device. Define this to
-	  the eMMC device that fastboot should use to store the image.
+	  the eMMC device that fastboot should use to store the image,
+	  or define '-1' to disable storing to an eMMC device.
 
 endif # USB_FUNCTION_FASTBOOT
 
diff --git a/common/Makefile b/common/Makefile
index 21619b3..56e95b3 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -142,12 +142,14 @@ obj-$(CONFIG_IO_TRACE) += iotrace.o
 obj-y += memsize.o
 obj-y += stdio.o
 
-# This option is not just y/n - it can have a numeric value
 ifdef CONFIG_FASTBOOT_FLASH
 obj-y += image-sparse.o
+# This option is not just y/n - it is a numeric value
 ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+ifneq ($(CONFIG_FASTBOOT_FLASH_MMC_DEV), -1)
 obj-y += fb_mmc.o
 endif
+endif
 ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV
 obj-y += fb_nand.o
 endif
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index 2160b1c..5df6b8b 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -21,7 +21,8 @@
 #include <linux/compiler.h>
 #include <version.h>
 #include <g_dnl.h>
-#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+#if defined(CONFIG_FASTBOOT_FLASH_MMC_DEV) && \
+	   (CONFIG_FASTBOOT_FLASH_MMC_DEV != -1)
 #include <fb_mmc.h>
 #endif
 #ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV
@@ -594,7 +595,8 @@ static void cb_flash(struct usb_ep *ep, struct usb_request *req)
 	fb_response_str = response;
 
 	fastboot_fail("no flash device defined");
-#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+#if defined(CONFIG_FASTBOOT_FLASH_MMC_DEV) && \
+	   (CONFIG_FASTBOOT_FLASH_MMC_DEV != -1)
 	fb_mmc_flash_write(cmd, (void *)CONFIG_FASTBOOT_BUF_ADDR,
 			   download_bytes);
 #endif
@@ -610,7 +612,8 @@ static void cb_flash(struct usb_ep *ep, struct usb_request *req)
 static void cb_oem(struct usb_ep *ep, struct usb_request *req)
 {
 	char *cmd = req->buf;
-#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+#if defined(CONFIG_FASTBOOT_FLASH_MMC_DEV) && \
+	   (CONFIG_FASTBOOT_FLASH_MMC_DEV != -1)
 	if (strncmp("format", cmd + 4, 6) == 0) {
 		char cmdbuf[32];
                 sprintf(cmdbuf, "gpt write mmc %x $partitions",
@@ -646,7 +649,8 @@ static void cb_erase(struct usb_ep *ep, struct usb_request *req)
 	fb_response_str = response;
 
 	fastboot_fail("no flash device defined");
-#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+#if defined(CONFIG_FASTBOOT_FLASH_MMC_DEV) && \
+	   (CONFIG_FASTBOOT_FLASH_MMC_DEV != -1)
 	fb_mmc_erase(cmd);
 #endif
 #ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV
-- 
1.8.5