[U-Boot] [PATCH 21/25] SPEAr: explicitly select clk src for UART

[Amit Virdi]

From: Shiraz Hashim <shiraz.hashim at st.com>

UART in u-boot intends to run on 48MHz clock supplied by USB PLL.
Explicitly select the intended clock source.

Signed-off-by: Shiraz Hashim <shiraz.hashim at st.com>
Signed-off-by: Amit Virdi <amit.virdi at st.com>
---
 arch/arm/cpu/arm926ejs/spear/cpu.c         |    7 ++++++-
 arch/arm/include/asm/arch-spear/spr_misc.h |    2 ++
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/spear/cpu.c b/arch/arm/cpu/arm926ejs/spear/cpu.c
index 4dc7d69..8f34aed 100644
--- a/arch/arm/cpu/arm926ejs/spear/cpu.c
+++ b/arch/arm/cpu/arm926ejs/spear/cpu.c
@@ -31,7 +31,7 @@ int arch_cpu_init(void)
 {
 	struct misc_regs *const misc_p =
 	    (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
-	u32 periph1_clken;
+	u32 periph1_clken, periph_clk_cfg;
 
 	periph1_clken = readl(&misc_p->periph1_clken);
 
@@ -43,6 +43,11 @@ int arch_cpu_init(void)
 
 #if defined(CONFIG_PL011_SERIAL)
 	periph1_clken |= MISC_UART0ENB;
+
+	periph_clk_cfg = readl(&misc_p->periph_clk_cfg);
+	periph_clk_cfg &= ~CONFIG_SPEAR_UARTCLKMSK;
+	periph_clk_cfg |= CONFIG_SPEAR_UART48M;
+	writel(periph_clk_cfg, &misc_p->periph_clk_cfg);
 #endif
 #if defined(CONFIG_DESIGNWARE_ETH)
 	periph1_clken |= MISC_ETHENB;
diff --git a/arch/arm/include/asm/arch-spear/spr_misc.h b/arch/arm/include/asm/arch-spear/spr_misc.h
index b10c726..384944d 100644
--- a/arch/arm/include/asm/arch-spear/spr_misc.h
+++ b/arch/arm/include/asm/arch-spear/spr_misc.h
@@ -110,6 +110,8 @@ struct misc_regs {
 /* PERIPH_CLK_CFG value */
 #define MISC_GPT3SYNTH			0x00000400
 #define MISC_GPT4SYNTH			0x00000800
+#define CONFIG_SPEAR_UART48M		0
+#define CONFIG_SPEAR_UARTCLKMSK		(0x1 << 4)
 
 /* PRSC_CLK_CFG value */
 /*
-- 
1.7.2.2