usb/core: use bin2bcd() for bcdDevice in RH

The kernel's version number is used as decimal in the bcdDevice field of
the RH descriptor. For kernel version v3.12 we would see 3.0c in lsusb.
I am not sure how important it is to stick with bcd values since this is
this way since we started git history and nobody complained (however back
then we reported only 2.6).

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 22 insertions, 9 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index bc84106ac057..6e4fd28bc242 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -22,6 +22,7 @@
  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/bcd.h>
 #include <linux/module.h>
 #include <linux/version.h>
 #include <linux/kernel.h>
@@ -123,9 +124,8 @@ static inline int is_root_hub(struct usb_device *udev)
  */
 
 /*-------------------------------------------------------------------------*/
-
-#define KERNEL_REL      ((LINUX_VERSION_CODE >> 16) & 0x0ff)
-#define KERNEL_VER      ((LINUX_VERSION_CODE >> 8) & 0x0ff)
+#define KERNEL_REL      bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
+#define KERNEL_VER      bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
 
 /* usb 3.0 root hub device descriptor */
 static const u8 usb3_rh_dev_descriptor[18] = {
diff --git a/include/linux/bcd.h b/include/linux/bcd.h
index 22ea563ba3eb..18fff11fb3ea 100644
--- a/include/linux/bcd.h
+++ b/include/linux/bcd.h
@@ -3,7 +3,20 @@
 
 #include <linux/compiler.h>
 
-unsigned bcd2bin(unsigned char val) __attribute_const__;
-unsigned char bin2bcd(unsigned val) __attribute_const__;
+#define bcd2bin(x)                                      \
+                (__builtin_constant_p((u8 )(x)) ?       \
+                const_bcd2bin(x) :                      \
+                _bcd2bin(x))
+
+#define bin2bcd(x)                                      \
+                (__builtin_constant_p((u8 )(x)) ?       \
+                const_bin2bcd(x) :                      \
+                _bin2bcd(x))
+
+#define const_bcd2bin(x)        (((x) & 0x0f) + ((x) >> 4) * 10)
+#define const_bin2bcd(x)        ((((x) / 10) << 4) + (x) % 10)
+
+unsigned _bcd2bin(unsigned char val) __attribute_const__;
+unsigned char _bin2bcd(unsigned val) __attribute_const__;
 
 #endif /* _BCD_H */
diff --git a/lib/bcd.c b/lib/bcd.c
index 55efaf742346..40d304efe272 100644
--- a/lib/bcd.c
+++ b/lib/bcd.c
@@ -1,14 +1,14 @@
 #include <linux/bcd.h>
 #include <linux/export.h>
 
-unsigned bcd2bin(unsigned char val)
+unsigned _bcd2bin(unsigned char val)
 {
         return (val & 0x0f) + (val >> 4) * 10;
 }
-EXPORT_SYMBOL(bcd2bin);
+EXPORT_SYMBOL(_bcd2bin);
 
-unsigned char bin2bcd(unsigned val)
+unsigned char _bin2bcd(unsigned val)
 {
         return ((val / 10) << 4) + val % 10;
 }
-EXPORT_SYMBOL(bin2bcd);
+EXPORT_SYMBOL(_bin2bcd);