ARM: sunxi: Add support for using R_UART as console

The A23 only has UART0 muxed with MMC0. Some of the boards we
encountered expose R_UART as a set of pads.

Add support for R_UART so we can have a console while using mmc.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

arch/arm/cpu/armv7/sunxi/board.c

@@ -75,6 +75,10 @@ int gpio_init(void)
 	sunxi_gpio_set_cfgpin(SUNXI_GPG(3), SUN5I_GPG3_UART1_TX);
 	sunxi_gpio_set_cfgpin(SUNXI_GPG(4), SUN5I_GPG4_UART1_RX);
 	sunxi_gpio_set_pull(SUNXI_GPG(4), SUNXI_GPIO_PULL_UP);
+#elif CONFIG_CONS_INDEX == 5 && defined(CONFIG_SUN8I)
+	sunxi_gpio_set_cfgpin(SUNXI_GPL(2), SUN8I_GPL2_R_UART_TX);
+	sunxi_gpio_set_cfgpin(SUNXI_GPL(3), SUN8I_GPL3_R_UART_RX);
+	sunxi_gpio_set_pull(SUNXI_GPL(3), SUNXI_GPIO_PULL_UP);
 #else
 #error Unsupported console port number. Please fix pin mux settings in board.c
 #endif

arch/arm/cpu/armv7/sunxi/clock_sun6i.c

@@ -13,6 +13,7 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
+#include <asm/arch/prcm.h>
 #include <asm/arch/sys_proto.h>
 
 void clock_init_uart(void)
@@ -20,6 +21,7 @@ void clock_init_uart(void)
 	struct sunxi_ccm_reg *const ccm =
 		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
 
+#if CONFIG_CONS_INDEX < 5
 	/* uart clock source is apb2 */
 	writel(APB2_CLK_SRC_OSC24M|
 	       APB2_CLK_RATE_N_1|
@@ -35,6 +37,10 @@ void clock_init_uart(void)
 	setbits_le32(&ccm->apb2_reset_cfg,
 		     1 << (APB2_RESET_UART_SHIFT +
 			   CONFIG_CONS_INDEX - 1));
+#else
+	/* enable R_PIO and R_UART clocks, and de-assert resets */
+	prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_UART);
+#endif
 
 	/* Dup with clock_init_safe(), drop once sun6i SPL support lands */
 	writel(PLL6_CFG_DEFAULT, &ccm->pll6_cfg);

arch/arm/include/asm/arch-sunxi/cpu.h

@@ -111,6 +111,7 @@
 #define SUNXI_AVG_BASE			0x01ea0000
 
 #define SUNXI_PRCM_BASE			0x01f01400
+#define SUNXI_R_UART_BASE		0x01f02800
 #define SUNXI_R_PIO_BASE		0x01f02c00
 #define SUNXI_P2WI_BASE			0x01f03400
 

arch/arm/include/asm/arch-sunxi/gpio.h

@@ -172,6 +172,9 @@ enum sunxi_gpio_number {
 
 #define SUN4I_GPI4_SDC3		2
 
+#define SUN8I_GPL2_R_UART_TX	2
+#define SUN8I_GPL3_R_UART_RX	2
+
 /* GPIO pin pull-up/down config */
 #define SUNXI_GPIO_PULL_DISABLE	0
 #define SUNXI_GPIO_PULL_UP	1

include/configs/sunxi-common.h

@@ -42,6 +42,7 @@
 #define CONFIG_SYS_NS16550_COM2		SUNXI_UART1_BASE
 #define CONFIG_SYS_NS16550_COM3		SUNXI_UART2_BASE
 #define CONFIG_SYS_NS16550_COM4		SUNXI_UART3_BASE
+#define CONFIG_SYS_NS16550_COM5		SUNXI_R_UART_BASE
 
 /* DRAM Base */
 #define CONFIG_SYS_SDRAM_BASE		0x40000000