[U-Boot] [PATCH v2 2/5] arm, am33x: make RTC32K OSC enable configurable

[Heiko Schocher <hs@denx.de>]

As
http://www.denx.de/wiki/view/U-Boot/DesignPrinciples#2_Keep_it_Fast
states:
"Initialize devices only when they are needed within U-Boot"

enable the RTC32K OSC only, if CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC is
enabled. Enable this in ti_am335x_common.h, so all boards in mainline
should work as before.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@ti.com>

---

On the dxr2 board the RTC32K_OSC it is not used, so disable it for
this board, done in the 5th patch of this patchserie
"arm-am335x-update-for-the-siemens-boards"

- no changes for v2
---
 README                             | 3 +++
 arch/arm/cpu/armv7/am33xx/board.c  | 4 ++++
 include/configs/ti_am335x_common.h | 1 +
 3 files changed, 8 insertions(+)

diff --git a/README b/README
index 2558e42..529c2d4 100644
--- a/README
+++ b/README
@@ -4300,6 +4300,9 @@ Low Level (hardware related) configuration options:
 
 		NOTE : currently only supported on AM335x platforms.
 
+- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
+		Enables the RTC32K OSC on AM33xx based plattforms
+
 Freescale QE/FMAN Firmware Support:
 -----------------------------------
 
diff --git a/arch/arm/cpu/armv7/am33xx/board.c b/arch/arm/cpu/armv7/am33xx/board.c
index a31bf40..7465ec5 100644
--- a/arch/arm/cpu/armv7/am33xx/board.c
+++ b/arch/arm/cpu/armv7/am33xx/board.c
@@ -148,6 +148,7 @@ __weak void am33xx_spl_board_init(void)
 	do_setup_dpll(&dpll_mpu_regs, &dpll_mpu_opp100);
 }
 
+#if defined(CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC)
 static void rtc32k_enable(void)
 {
 	struct rtc_regs *rtc = (struct rtc_regs *)RTC_BASE;
@@ -163,6 +164,7 @@ static void rtc32k_enable(void)
 	/* Enable the RTC 32K OSC by setting bits 3 and 6. */
 	writel((1 << 3) | (1 << 6), &rtc->osc);
 }
+#endif
 
 static void uart_soft_reset(void)
 {
@@ -231,8 +233,10 @@ void s_init(void)
 #if defined(CONFIG_SPL_BUILD) || defined(CONFIG_NOR_BOOT)
 	prcm_init();
 	set_mux_conf_regs();
+#if defined(CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC)
 	/* Enable RTC32K clock */
 	rtc32k_enable();
+#endif
 	sdram_init();
 #endif
 }
diff --git a/include/configs/ti_am335x_common.h b/include/configs/ti_am335x_common.h
index d2e34ae..3441b0a 100644
--- a/include/configs/ti_am335x_common.h
+++ b/include/configs/ti_am335x_common.h
@@ -18,6 +18,7 @@
 #define CONFIG_SYS_CACHELINE_SIZE       64
 #define CONFIG_MAX_RAM_BANK_SIZE	(1024 << 20)	/* 1GB */
 #define CONFIG_SYS_TIMERBASE		0x48040000	/* Use Timer2 */
+#define CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC
 
 #include <asm/arch/omap.h>
 
-- 
1.8.3.1