[U-Boot] [PATCH 1/3] arm: Tegra2: Add missing PLLX init

Tom Warren twarren.nvidia at gmail.com
Wed Apr 13 22:07:36 CEST 2011


Signed-off-by: Tom Warren <twarren at nvidia.com>
---
 arch/arm/cpu/armv7/tegra2/ap20.c           |   29 ++++++++++++++++++++++++++++
 arch/arm/include/asm/arch-tegra2/clk_rst.h |    6 +++-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/armv7/tegra2/ap20.c b/arch/arm/cpu/armv7/tegra2/ap20.c
index 075341e..ebbbbd4 100644
--- a/arch/arm/cpu/armv7/tegra2/ap20.c
+++ b/arch/arm/cpu/armv7/tegra2/ap20.c
@@ -32,6 +32,32 @@
 
 u32 s_first_boot = 1;
 
+void init_pllx(void)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 reg;
+
+	/* If PLLX is already enabled, just return */
+	reg = readl(&clkrst->crc_pllx_base);
+	if (reg & PLL_ENABLE)
+		return;
+
+	/* Set PLLX_MISC */
+	reg = CPCON;		/* CPCON = 0001 */
+	writel(reg, &clkrst->crc_pllx_misc);
+
+	/* Use 12MHz clock here */
+	reg = (PLL_BYPASS | PLL_DIVM);
+	reg |= (1000 << 8);			/* DIVN = 0x3E8 */
+	writel(reg, &clkrst->crc_pllx_base);
+
+	reg |= PLL_ENABLE;
+	writel(reg, &clkrst->crc_pllx_base);
+
+	reg &= ~PLL_BYPASS;
+	writel(reg, &clkrst->crc_pllx_base);
+}
+
 static void enable_cpu_clock(int enable)
 {
 	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
@@ -47,6 +73,9 @@ static void enable_cpu_clock(int enable)
 	 */
 
 	if (enable) {
+		/* Initialize PLLX */
+		init_pllx();
+
 		/* Wait until all clocks are stable */
 		udelay(PLL_STABILIZATION_DELAY);
 
diff --git a/arch/arm/include/asm/arch-tegra2/clk_rst.h b/arch/arm/include/asm/arch-tegra2/clk_rst.h
index d67a5d7..bd8ad2c 100644
--- a/arch/arm/include/asm/arch-tegra2/clk_rst.h
+++ b/arch/arm/include/asm/arch-tegra2/clk_rst.h
@@ -160,8 +160,8 @@ struct clk_rst_ctlr {
 #define PLL_DIVP		(1 << 20)	/* post divider, b22:20 */
 #define PLL_DIVM		0x0C		/* input divider, b4:0 */
 
-#define SWR_UARTD_RST		(1 << 2)
-#define CLK_ENB_UARTD		(1 << 2)
+#define SWR_UARTD_RST		(1 << 1)
+#define CLK_ENB_UARTD		(1 << 1)
 #define SWR_UARTA_RST		(1 << 6)
 #define CLK_ENB_UARTA		(1 << 6)
 
@@ -189,4 +189,6 @@ struct clk_rst_ctlr {
 #define CPU0_CLK_STP		(1 << 8)
 #define CPU1_CLK_STP		(1 << 9)
 
+#define CPCON			(1 << 8)
+
 #endif	/* CLK_RST_H */
-- 
1.7.4.3



More information about the U-Boot mailing list