[U-Boot] [PATCH] at91: Enable slow master clock on meesc board

[U-Boot] [PATCH] at91: Enable slow master clock on meesc board

[Daniel Gorsulowski]

In some cases, we need low speed master clock. So depending on the
"mdiv" variable, the processor clock is divided by 2 (default) or 4.

Signed-off-by: Daniel Gorsulowski <Daniel.Gorsulowski@esd.eu>
---
PS: Tom, are you still temporary at91 custodian?

 board/esd/meesc/meesc.c |   24 ++++++++++++++++++++++++
 include/configs/meesc.h |    1 +
 2 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/board/esd/meesc/meesc.c b/board/esd/meesc/meesc.c
index efba60d..4f6c5b7 100644
--- a/board/esd/meesc/meesc.c
+++ b/board/esd/meesc/meesc.c
@@ -219,6 +219,30 @@ u32 get_board_rev(void)
 }
 #endif
 
+#ifdef CONFIG_MISC_INIT_R
+int misc_init_r(void)
+{
+	char *str;
+	char buf[32];
+
+	/*
+	 * In some cases, we need low speed master clock. So depending on the
+	 * "mdiv" variable, the processor clock is divided by 2 (default) or 4.
+	 */
+	if ((str = getenv("mdiv")) && (!strcmp(str, "4"))) {
+		at91_sys_write(AT91_PMC_MCKR,
+			(at91_sys_read(AT91_PMC_MCKR) & ~AT91_PMC_MDIV) |
+			AT91SAM9_PMC_MDIV_4);
+		at91_clock_init(0);
+		serial_setbrg();
+		printf("Setting master clock to %s MHz\n",
+			strmhz(buf, get_mck_clk_rate()));
+	}
+
+	return 0;
+}
+#endif /* CONFIG_MISC_INIT_R */
+
 int board_init(void)
 {
 	/* Peripheral Clock Enable Register */
diff --git a/include/configs/meesc.h b/include/configs/meesc.h
index b996854..034e81c 100644
--- a/include/configs/meesc.h
+++ b/include/configs/meesc.h
@@ -48,6 +48,7 @@
 
 #define CONFIG_SKIP_LOWLEVEL_INIT
 #define CONFIG_SKIP_RELOCATE_UBOOT
+#define CONFIG_MISC_INIT_R			/* Call misc_init_r */
 
 #define CONFIG_ARCH_CPU_INIT
 
-- 
1.5.3