arch/mips/cobalt/promcon.c

   1 /*
   2  * PROM console for Cobalt Raq2
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 1995, 1996, 1997 by Ralf Baechle
   9  * Copyright (C) 2001 by Liam Davies (ldavies@agile.tv)
  10  *
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/console.h>
  15 #include <linux/kdev_t.h>
  16 #include <linux/serial_reg.h>
  17
  18 #include <asm/delay.h>
  19 #include <asm/serial.h>
  20 #include <asm/io.h>
  21
  22 static unsigned long port = 0xc800000;
  23
  24 static __inline__ void ns16550_cons_put_char(char ch, unsigned long ioaddr)
  25 {
  26         char lsr;
  27
  28         do {
  29                 lsr = inb(ioaddr + UART_LSR);
  30         } while ((lsr & (UART_LSR_TEMT | UART_LSR_THRE)) != (UART_LSR_TEMT | UART_LSR_THRE));
  31         outb(ch, ioaddr + UART_TX);
  32 }
  33
  34 static __inline__ char ns16550_cons_get_char(unsigned long ioaddr)
  35 {
  36         while ((inb(ioaddr + UART_LSR) & UART_LSR_DR) == 0)
  37                 udelay(1);
  38         return inb(ioaddr + UART_RX);
  39 }
  40
  41 void ns16550_console_write(struct console *co, const char *s, unsigned count)
  42 {
  43         char lsr, ier;
  44         unsigned i;
  45
  46         ier = inb(port + UART_IER);
  47         outb(0x00, port + UART_IER);
  48         for (i=0; i < count; i++, s++) {
  49
  50                 if(*s == '\n')
  51                         ns16550_cons_put_char('\r', port);
  52                 ns16550_cons_put_char(*s, port);
  53         }
  54
  55         do {
  56                 lsr = inb(port + UART_LSR);
  57         } while ((lsr & (UART_LSR_TEMT | UART_LSR_THRE)) != (UART_LSR_TEMT | UART_LSR_THRE));
  58
  59         outb(ier, port + UART_IER);
  60 }
  61
  62 char getDebugChar(void)
  63 {
  64         return ns16550_cons_get_char(port);
  65 }
  66
  67 void putDebugChar(char kgdb_char)
  68 {
  69         ns16550_cons_put_char(kgdb_char, port);
  70 }
  71
  72 static struct console ns16550_console = {
  73     .name       = "prom",
  74     .setup      = NULL,
  75     .write      = ns16550_console_write,
  76     .flags      = CON_PRINTBUFFER,
  77     .index      = -1,
  78 };
  79
  80 static int __init ns16550_setup_console(void)
  81 {
  82         register_console(&ns16550_console);
  83
  84         return 0;
  85 }
  86
  87 console_initcall(ns16550_setup_console);