From d9d3dc9a5a28b2bbb82fedca63aadae8ca540e94 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Sat, 19 Jun 2010 04:08:16 +0000 Subject: [PATCH] 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 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 --- arch/mips/jz4740/serial.c | 33 +++++++++++++++++++++++++++++++++ arch/mips/jz4740/serial.h | 20 ++++++++++++++++++++ 2 files changed, 53 insertions(+), 0 deletions(-) create mode 100644 arch/mips/jz4740/serial.c create mode 100644 arch/mips/jz4740/serial.h --- /dev/null +++ b/arch/mips/jz4740/serial.c @@ -0,0 +1,33 @@ +/* + * Copyright (C) 2010, Lars-Peter Clausen + * 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 +#include +#include + +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)); +} --- /dev/null +++ b/arch/mips/jz4740/serial.h @@ -0,0 +1,20 @@ +/* + * Copyright (C) 2010, Lars-Peter Clausen + * 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