[RFC][PATCH 11/26] MIPS: JZ4740: Add serial support

Lars-Peter Clausen
2010-06-02T19:12:10Z

This patch adds support for serials on a JZ4740 SoC.

The JZ4740 UART interface is almost 16550A 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>
---
arch/mips/jz4740/serial.c | 33 +++++++++++++++++++++++++++++++++
arch/mips/jz4740/serial.h | 21 +++++++++++++++++++++
2 files changed, 54 insertions(+), 0 deletions(-)
create mode 100644 arch/mips/jz4740/serial.c
create mode 100644 arch/mips/jz4740/serial.h

diff --git a/arch/mips/jz4740/serial.c b/arch/mips/jz4740/serial.c
new file mode 100644
index 0000000..d23de45
--- /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 0000000..247a7d8
--- /dev/null
+++ b/arch/mips/jz4740/serial.h
@@ -0,0 +1,21 @@
+/*
+ * 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
+
--
1.5.6.5