[RFC 08/13] MIPS: JZ4750D: Add serial support

[Antony Pavlov <antonynpavlov@gmail.com>]

The JZ4750D UART interface is almost 16550 compatible.
The UART module needs to be enabled by setting a bit in the FCR register
and it has support for receive timeout interrupts. Instead of adding yet
another machine specific quirk to the 8250 serial driver we provide a
serial_out implementation which sets the required additional flags.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 arch/mips/jz4750d/serial.c |   32 ++++++++++++++++++++++++++++++++
 arch/mips/jz4750d/serial.h |   22 ++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 arch/mips/jz4750d/serial.c
 create mode 100644 arch/mips/jz4750d/serial.h

diff --git a/arch/mips/jz4750d/serial.c b/arch/mips/jz4750d/serial.c
new file mode 100644
index 0000000..e152e64
--- /dev/null
+++ b/arch/mips/jz4750d/serial.c
@@ -0,0 +1,32 @@
+/*
+ *  Copyright (C) 2012, Antony Pavlov <antonynpavlov@gmail.com>
+ *  JZ4750D serial support
+ *
+ *  based on JZ4740 serial support
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+
+void jz4750d_serial_out(struct uart_port *p, int offset, int value)
+{
+	switch (offset) {
+	case UART_FCR:
+		value |= 0x10; /* Enable uart module */
+		break;
+	case UART_IER:
+		value |= (value & 0x4) << 2;
+		break;
+	default:
+		break;
+	}
+	writeb(value, p->membase + (offset << p->regshift));
+}
diff --git a/arch/mips/jz4750d/serial.h b/arch/mips/jz4750d/serial.h
new file mode 100644
index 0000000..d381572
--- /dev/null
+++ b/arch/mips/jz4750d/serial.h
@@ -0,0 +1,22 @@
+/*
+ *  Copyright (C) 2012, Antony Pavlov <antonynpavlov@gmail.com>
+ *  JZ4750D serial support
+ *
+ *  based on JZ4740 serial support
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#ifndef __MIPS_JZ4750D_SERIAL_H__
+#define __MIPS_JZ4750D_SERIAL_H__
+
+struct uart_port;
+
+void jz4750d_serial_out(struct uart_port *p, int offset, int value);
+
+#endif
-- 
1.7.10.4