MIPS: Loongson 3: Add serial port support

Loongson family machines has three types of serial port: PCI UART, LPC
UART and CPU internal UART. Loongson-2E and parts of Loongson-2F based
machines use PCI UART; most Loongson-2F based machines use LPC UART;
Loongson-2G/3A has both LPC and CPU UART but usually use CPU UART.

Port address of UARTs:
CPU UART: REG_BASE + OFFSET;
LPC UART: LIO1_BASE + OFFSET;
PCI UART: PCIIO_BASE + OFFSET.

Since LPC UART are linked in "Local Bus", both CPU UART and LPC UART
are called "CPU provided serial port".

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Tested-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Alex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6635
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/loongson/common/serial.c

@@ -19,19 +19,19 @@
 #include <loongson.h>
 #include <machine.h>
 
-#define PORT(int)			\
+#define PORT(int, clk)			\
 {								\
 	.irq		= int,					\
-	.uartclk	= 1843200,				\
+	.uartclk	= clk,					\
 	.iotype		= UPIO_PORT,				\
 	.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,	\
 	.regshift	= 0,					\
 }
 
-#define PORT_M(int)				\
+#define PORT_M(int, clk)				\
 {								\
 	.irq		= MIPS_CPU_IRQ_BASE + (int),		\
-	.uartclk	= 3686400,				\
+	.uartclk	= clk,					\
 	.iotype		= UPIO_MEM,				\
 	.membase	= (void __iomem *)NULL,			\
 	.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,	\
@@ -40,13 +40,17 @@
 
 static struct plat_serial8250_port uart8250_data[][2] = {
 	[MACH_LOONGSON_UNKNOWN]		{},
-	[MACH_LEMOTE_FL2E]		{PORT(4), {} },
-	[MACH_LEMOTE_FL2F]		{PORT(3), {} },
-	[MACH_LEMOTE_ML2F7]		{PORT_M(3), {} },
-	[MACH_LEMOTE_YL2F89]		{PORT_M(3), {} },
-	[MACH_DEXXON_GDIUM2F10]		{PORT_M(3), {} },
-	[MACH_LEMOTE_NAS]		{PORT_M(3), {} },
-	[MACH_LEMOTE_LL2F]		{PORT(3), {} },
+	[MACH_LEMOTE_FL2E]              {PORT(4, 1843200), {} },
+	[MACH_LEMOTE_FL2F]              {PORT(3, 1843200), {} },
+	[MACH_LEMOTE_ML2F7]             {PORT_M(3, 3686400), {} },
+	[MACH_LEMOTE_YL2F89]            {PORT_M(3, 3686400), {} },
+	[MACH_DEXXON_GDIUM2F10]         {PORT_M(3, 3686400), {} },
+	[MACH_LEMOTE_NAS]               {PORT_M(3, 3686400), {} },
+	[MACH_LEMOTE_LL2F]              {PORT(3, 1843200), {} },
+	[MACH_LEMOTE_A1004]             {PORT_M(2, 33177600), {} },
+	[MACH_LEMOTE_A1101]             {PORT_M(2, 25000000), {} },
+	[MACH_LEMOTE_A1201]             {PORT_M(2, 25000000), {} },
+	[MACH_LEMOTE_A1205]             {PORT_M(2, 25000000), {} },
 	[MACH_LOONGSON_END]		{},
 };
 

arch/mips/loongson/common/uart_base.c

@@ -35,9 +35,16 @@ void prom_init_loongson_uart_base(void)
 	case MACH_DEXXON_GDIUM2F10:
 	case MACH_LEMOTE_NAS:
 	default:
-		/* The CPU provided serial port */
+		/* The CPU provided serial port (LPC) */
 		loongson_uart_base = LOONGSON_LIO1_BASE + 0x3f8;
 		break;
+	case MACH_LEMOTE_A1004:
+	case MACH_LEMOTE_A1101:
+	case MACH_LEMOTE_A1201:
+	case MACH_LEMOTE_A1205:
+		/* The CPU provided serial port (CPU) */
+		loongson_uart_base = LOONGSON_REG_BASE + 0x1e0;
+		break;
 	}
 
 	_loongson_uart_base =