Allow AM335x MPU core clock speed to be specified in the board config file

Allow AM335x MPU core clock speed to be specified in the board config file.
To use, add the following to the board's config file:-

#define CONFIG_SYS_MPUCLK	<desired clock freq in MHz>

Signed-off-by: Mark Jackson <mpfj@newflow.co.uk>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>

diff --git a/README b/README
index 7f2506a9b9c2335fdfd9ef3644797bb1b60509e3..a73234efdc6130fc6a41574328f503844a20973d 100644 (file)
--- a/README
+++ b/README
@@ -3878,6 +3878,10 @@ Low Level (hardware related) configuration options:
                If defined, the x86 reset vector code is included. This is not
                needed when U-Boot is running from Coreboot.
 
+- CONFIG_SYS_MPUCLK
+               Defines the MPU clock speed (in MHz).
+
+               NOTE : currently only supported on AM335x platforms.
 
 Freescale QE/FMAN Firmware Support:
 -----------------------------------

diff --git a/arch/arm/include/asm/arch-am33xx/clocks_am33xx.h b/arch/arm/include/asm/arch-am33xx/clocks_am33xx.h
index d748dd27873a0bac3e75c00c63f8471fcd2c2108..2d960070f10f3c5afbeb13689043591ff9d2211d 100644 (file)
--- a/arch/arm/include/asm/arch-am33xx/clocks_am33xx.h
+++ b/arch/arm/include/asm/arch-am33xx/clocks_am33xx.h
@@ -21,8 +21,11 @@
 
 #define OSC    (V_OSCK/1000000)
 
-/* MAIN PLL Fdll = 550 MHZ, */
-#define MPUPLL_M       550
+/* MAIN PLL Fdll = 550 MHz, by default */
+#ifndef CONFIG_SYS_MPUCLK
+#define CONFIG_SYS_MPUCLK      550
+#endif
+#define MPUPLL_M       CONFIG_SYS_MPUCLK
 #define MPUPLL_N       (OSC-1)
 #define MPUPLL_M2      1