RM9000 serial driver

Add support for the integrated serial ports of the MIPS RM9122 processor
and its relatives.

The patch also does some whitespace cleanup.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/Kconfig

@@ -1042,6 +1042,9 @@ config SOC_AU1X00
 	select SYS_SUPPORTS_APM_EMULATION
 	select SYS_SUPPORTS_KGDB
 
+config SERIAL_RM9000
+	bool
+
 config PNX8550
 	bool
 	select SOC_PNX8550

drivers/serial/8250.c

@@ -251,9 +251,16 @@ static const struct serial8250_config uart_config[] = {
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
 		.flags		= UART_CAP_FIFO | UART_CAP_UUE,
 	},
+	[PORT_RM9000] = {
+		.name		= "RM9000",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO,
+	},
 };
 
-#ifdef CONFIG_SERIAL_8250_AU1X00
+#if defined (CONFIG_SERIAL_8250_AU1X00)
 
 /* Au1x00 UART hardware has a weird register layout */
 static const u8 au_io_in_map[] = {
@@ -289,6 +296,44 @@ static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
 	return au_io_out_map[offset];
 }
 
+#elif defined (CONFIG_SERIAL_8250_RM9K)
+
+static const u8
+	regmap_in[8] = {
+		[UART_RX]	= 0x00,
+		[UART_IER]	= 0x0c,
+		[UART_IIR]	= 0x14,
+		[UART_LCR]	= 0x1c,
+		[UART_MCR]	= 0x20,
+		[UART_LSR]	= 0x24,
+		[UART_MSR]	= 0x28,
+		[UART_SCR]	= 0x2c
+	},
+	regmap_out[8] = {
+		[UART_TX] 	= 0x04,
+		[UART_IER]	= 0x0c,
+		[UART_FCR]	= 0x18,
+		[UART_LCR]	= 0x1c,
+		[UART_MCR]	= 0x20,
+		[UART_LSR]	= 0x24,
+		[UART_MSR]	= 0x28,
+		[UART_SCR]	= 0x2c
+	};
+
+static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
+{
+	if (up->port.iotype != UPIO_RM9000)
+		return offset;
+	return regmap_in[offset];
+}
+
+static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
+{
+	if (up->port.iotype != UPIO_RM9000)
+		return offset;
+	return regmap_out[offset];
+}
+
 #else
 
 /* sane hardware needs no mapping */
@@ -311,6 +356,7 @@ static unsigned int serial_in(struct uart_8250_port *up, int offset)
 	case UPIO_DWAPB:
 		return readb(up->port.membase + offset);
 
+	case UPIO_RM9000:
 	case UPIO_MEM32:
 		return readl(up->port.membase + offset);
 
@@ -348,6 +394,7 @@ serial_out(struct uart_8250_port *up, int offset, int value)
 		writeb(value, up->port.membase + offset);
 		break;
 
+	case UPIO_RM9000:
 	case UPIO_MEM32:
 		writel(value, up->port.membase + offset);
 		break;
@@ -419,7 +466,7 @@ static inline void _serial_dl_write(struct uart_8250_port *up, int value)
 	serial_outp(up, UART_DLM, value >> 8 & 0xff);
 }
 
-#ifdef CONFIG_SERIAL_8250_AU1X00
+#if defined (CONFIG_SERIAL_8250_AU1X00)
 /* Au1x00 haven't got a standard divisor latch */
 static int serial_dl_read(struct uart_8250_port *up)
 {
@@ -436,6 +483,24 @@ static void serial_dl_write(struct uart_8250_port *up, int value)
 	else
 		_serial_dl_write(up, value);
 }
+#elif defined (CONFIG_SERIAL_8250_RM9K)
+static int serial_dl_read(struct uart_8250_port *up)
+{
+	return	(up->port.iotype == UPIO_RM9000) ?
+		(((__raw_readl(up->port.membase + 0x10) << 8) |
+		(__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
+		_serial_dl_read(up);
+}
+
+static void serial_dl_write(struct uart_8250_port *up, int value)
+{
+	if (up->port.iotype == UPIO_RM9000) {
+		__raw_writel(value, up->port.membase + 0x08);
+		__raw_writel(value >> 8, up->port.membase + 0x10);
+	} else {
+		_serial_dl_write(up, value);
+	}
+}
 #else
 #define serial_dl_read(up) _serial_dl_read(up)
 #define serial_dl_write(up, value) _serial_dl_write(up, value)
@@ -1175,8 +1240,11 @@ static void serial8250_start_tx(struct uart_port *port)
 		if (up->bugs & UART_BUG_TXEN) {
 			unsigned char lsr, iir;
 			lsr = serial_in(up, UART_LSR);
-			iir = serial_in(up, UART_IIR);
-			if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
+			iir = serial_in(up, UART_IIR) & 0x0f;
+			if ((up->port.type == PORT_RM9000) ?
+				(lsr & UART_LSR_THRE &&
+				(iir == UART_IIR_NO_INT || iir == UART_IIR_THRI)) :
+				(lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT))
 				transmit_chars(up);
 		}
 	}

drivers/serial/Kconfig

@@ -254,6 +254,15 @@ config SERIAL_8250_AU1X00
 	  to this option.  The driver can handle 1 or 2 serial ports.
 	  If unsure, say N.
 
+config SERIAL_8250_RM9K
+	bool "Support for MIPS RM9xxx integrated serial port"
+	depends on SERIAL_8250 != n && SERIAL_RM9000
+	select SERIAL_8250_SHARE_IRQ
+	help
+	  Selecting this option will add support for the integrated serial
+	  port hardware found on MIPS RM9122 and similar processors.
+	  If unsure, say N.
+
 comment "Non-8250 serial port support"
 
 config SERIAL_AMBA_PL010

include/linux/serial_core.h

@@ -39,7 +39,8 @@
 #define PORT_RSA	13
 #define PORT_NS16550A	14
 #define PORT_XSCALE	15
-#define PORT_MAX_8250	15	/* max port ID */
+#define PORT_RM9000	16	/* PMC-Sierra RM9xxx internal UART */
+#define PORT_MAX_8250	16	/* max port ID */
 
 /*
  * ARM specific type numbers.  These are not currently guaranteed
@@ -231,6 +232,7 @@ struct uart_port {
 #define UPIO_AU			(4)			/* Au1x00 type IO */
 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
+#define UPIO_RM9000		(7)			/* RM9000 type IO */
 
 	unsigned int		read_status_mask;	/* driver specific */
 	unsigned int		ignore_status_mask;	/* driver specific */