linux/arch/mips/kernel/early_printk_8250.c
Thomas Gleixner 1621633323 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1
Based on 2 normalized pattern(s):

  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 this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details 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
  51 franklin street fifth floor boston ma 02110 1301 usa

  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 [no]_[pad]_[ctrl] any later version this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details 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 51 franklin street fifth floor boston ma
  02110 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 176 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 11:28:39 +02:00

55 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 8250/16550-type serial ports prom_putchar()
*
* Copyright (C) 2010 Yoichi Yuasa <yuasa@linux-mips.org>
*/
#include <linux/io.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <asm/setup.h>
static void __iomem *serial8250_base;
static unsigned int serial8250_reg_shift;
static unsigned int serial8250_tx_timeout;
void setup_8250_early_printk_port(unsigned long base, unsigned int reg_shift,
unsigned int timeout)
{
serial8250_base = (void __iomem *)base;
serial8250_reg_shift = reg_shift;
serial8250_tx_timeout = timeout;
}
static inline u8 serial_in(int offset)
{
return readb(serial8250_base + (offset << serial8250_reg_shift));
}
static inline void serial_out(int offset, char value)
{
writeb(value, serial8250_base + (offset << serial8250_reg_shift));
}
void prom_putchar(char c)
{
unsigned int timeout;
int status, bits;
if (!serial8250_base)
return;
timeout = serial8250_tx_timeout;
bits = UART_LSR_TEMT | UART_LSR_THRE;
do {
status = serial_in(UART_LSR);
if (--timeout == 0)
break;
} while ((status & bits) != bits);
if (timeout)
serial_out(UART_TX, c);
}