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authorLars-Peter Clausen <lars@metafoo.de>2010-06-19 04:08:16 +0000
committerRalf Baechle <ralf@linux-mips.org>2010-08-05 13:26:16 +0100
commitc3b9566de89f40557e3a3d041ca08b05978aeb12 (patch)
treeabaf7ae9c47236131fa6e3e387bd369d6d27a485 /arch/mips/jz4740
parenteda0347bf8b449a42b3bf4e0b9754263d853982f (diff)
downloadlinux-c3b9566de89f40557e3a3d041ca08b05978aeb12.tar.gz
MIPS: JZ4740: Add serial support
The JZ4740 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: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1403/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/jz4740')
-rw-r--r--arch/mips/jz4740/serial.c33
-rw-r--r--arch/mips/jz4740/serial.h20
2 files changed, 53 insertions, 0 deletions
diff --git a/arch/mips/jz4740/serial.c b/arch/mips/jz4740/serial.c
new file mode 100644
index 000000000000..d23de45826d1
--- /dev/null
+++ b/arch/mips/jz4740/serial.c
@@ -0,0 +1,33 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 serial support
+ *
+ *  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.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+
+void jz4740_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/jz4740/serial.h b/arch/mips/jz4740/serial.h
new file mode 100644
index 000000000000..b9fe3ade0289
--- /dev/null
+++ b/arch/mips/jz4740/serial.h
@@ -0,0 +1,20 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 serial support
+ *
+ *  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.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __MIPS_JZ4740_SERIAL_H__
+
+void jz4740_serial_out(struct uart_port *p, int offset, int value);
+
+#endif