rockchip: rk3328: add board_debug_uart_init()

Add board_debug_uart_init() to make the debug UART work with
correct setting.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/rk3328/rk3328.c b/arch/arm/mach-rockchip/rk3328/rk3328.c
index 222a8d3..afd9de4 100644
--- a/arch/arm/mach-rockchip/rk3328/rk3328.c
+++ b/arch/arm/mach-rockchip/rk3328/rk3328.c
@@ -6,11 +6,17 @@
 #include <common.h>
 #include <asm/arch-rockchip/bootrom.h>
 #include <asm/arch-rockchip/hardware.h>
+#include <asm/arch-rockchip/grf_rk3328.h>
+#include <asm/arch-rockchip/uart.h>
 #include <asm/armv8/mmu.h>
 #include <asm/io.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#define CRU_BASE		0xFF440000
+#define GRF_BASE		0xFF100000
+#define UART2_BASE		0xFF130000
+
 const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
 	[BROM_BOOTSOURCE_EMMC] = "rksdmmc@ff520000",
 	[BROM_BOOTSOURCE_SD] = "rksdmmc@ff500000",
@@ -55,3 +61,46 @@
 
 	return 0;
 }
+
+void board_debug_uart_init(void)
+{
+	struct rk3328_grf_regs * const grf = (void *)GRF_BASE;
+	struct rk_uart * const uart = (void *)UART2_BASE;
+	enum{
+		GPIO2A0_SEL_SHIFT       = 0,
+		GPIO2A0_SEL_MASK        = 3 << GPIO2A0_SEL_SHIFT,
+		GPIO2A0_UART2_TX_M1     = 1,
+
+		GPIO2A1_SEL_SHIFT       = 2,
+		GPIO2A1_SEL_MASK        = 3 << GPIO2A1_SEL_SHIFT,
+		GPIO2A1_UART2_RX_M1     = 1,
+	};
+	enum {
+		IOMUX_SEL_UART2_SHIFT   = 0,
+		IOMUX_SEL_UART2_MASK    = 3 << IOMUX_SEL_UART2_SHIFT,
+		IOMUX_SEL_UART2_M0      = 0,
+		IOMUX_SEL_UART2_M1,
+	};
+
+	/* uart_sel_clk default select 24MHz */
+	writel((3 << (8 + 16)) | (2 << 8), CRU_BASE + 0x148);
+
+	/* init uart baud rate 1500000 */
+	writel(0x83, &uart->lcr);
+	writel(0x1, &uart->rbr);
+	writel(0x3, &uart->lcr);
+
+	/* Enable early UART2 */
+	rk_clrsetreg(&grf->com_iomux,
+		     IOMUX_SEL_UART2_MASK,
+		     IOMUX_SEL_UART2_M1 << IOMUX_SEL_UART2_SHIFT);
+	rk_clrsetreg(&grf->gpio2a_iomux,
+		     GPIO2A0_SEL_MASK,
+		     GPIO2A0_UART2_TX_M1 << GPIO2A0_SEL_SHIFT);
+	rk_clrsetreg(&grf->gpio2a_iomux,
+		     GPIO2A1_SEL_MASK,
+		     GPIO2A1_UART2_RX_M1 << GPIO2A1_SEL_SHIFT);
+
+	/* enable FIFO */
+	writel(0x1, &uart->sfe);
+}