arch/sh/kernel/early_printk.c

   1 /*
   2  * arch/sh/kernel/early_printk.c
   3  *
   4  *  Copyright (C) 1999, 2000  Niibe Yutaka
   5  *  Copyright (C) 2002  M. R. Brown
   6  *  Copyright (C) 2004  Paul Mundt
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/console.h>
  13 #include <linux/tty.h>
  14 #include <linux/init.h>
  15 #include <asm/io.h>
  16
  17 #ifdef CONFIG_SH_STANDARD_BIOS
  18 #include <asm/sh_bios.h>
  19
  20 /*
  21  *      Print a string through the BIOS
  22  */
  23 static void sh_console_write(struct console *co, const char *s,
  24                                  unsigned count)
  25 {
  26         sh_bios_console_write(s, count);
  27 }
  28
  29 /*
  30  *      Setup initial baud/bits/parity. We do two things here:
  31  *      - construct a cflag setting for the first rs_open()
  32  *      - initialize the serial port
  33  *      Return non-zero if we didn't find a serial port.
  34  */
  35 static int __init sh_console_setup(struct console *co, char *options)
  36 {
  37         int     cflag = CREAD | HUPCL | CLOCAL;
  38
  39         /*
  40          *      Now construct a cflag setting.
  41          *      TODO: this is a totally bogus cflag, as we have
  42          *      no idea what serial settings the BIOS is using, or
  43          *      even if its using the serial port at all.
  44          */
  45         cflag |= B115200 | CS8 | /*no parity*/0;
  46
  47         co->cflag = cflag;
  48
  49         return 0;
  50 }
  51
  52 static struct console early_console = {
  53         .name           = "bios",
  54         .write          = sh_console_write,
  55         .setup          = sh_console_setup,
  56         .flags          = CON_PRINTBUFFER,
  57         .index          = -1,
  58 };
  59 #endif
  60
  61 #ifdef CONFIG_EARLY_SCIF_CONSOLE
  62 #define SCIF_REG        0xffe80000
  63
  64 static void scif_sercon_putc(int c)
  65 {
  66         while (!(ctrl_inw(SCIF_REG + 0x10) & 0x20)) ;
  67
  68         ctrl_outb(c, SCIF_REG + 12);
  69         ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0x9f), SCIF_REG + 0x10);
  70
  71         if (c == '\n')
  72                 scif_sercon_putc('\r');
  73 }
  74
  75 static void scif_sercon_flush(void)
  76 {
  77         ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
  78
  79         while (!(ctrl_inw(SCIF_REG + 0x10) & 0x40)) ;
  80
  81         ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
  82 }
  83
  84 static void scif_sercon_write(struct console *con, const char *s, unsigned count)
  85 {
  86         while (count-- > 0)
  87                 scif_sercon_putc(*s++);
  88
  89         scif_sercon_flush();
  90 }
  91
  92 static int __init scif_sercon_setup(struct console *con, char *options)
  93 {
  94         con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
  95
  96         return 0;
  97 }
  98
  99 static struct console early_console = {
 100         .name           = "sercon",
 101         .write          = scif_sercon_write,
 102         .setup          = scif_sercon_setup,
 103         .flags          = CON_PRINTBUFFER,
 104         .index          = -1,
 105 };
 106
 107 void scif_sercon_init(int baud)
 108 {
 109         ctrl_outw(0, SCIF_REG + 8);
 110         ctrl_outw(0, SCIF_REG);
 111
 112         /* Set baud rate */
 113         ctrl_outb((CONFIG_SH_PCLK_FREQ + 16 * baud) /
 114                   (32 * baud) - 1, SCIF_REG + 4);
 115
 116         ctrl_outw(12, SCIF_REG + 24);
 117         ctrl_outw(8, SCIF_REG + 24);
 118         ctrl_outw(0, SCIF_REG + 32);
 119         ctrl_outw(0x60, SCIF_REG + 16);
 120         ctrl_outw(0, SCIF_REG + 36);
 121         ctrl_outw(0x30, SCIF_REG + 8);
 122 }
 123 #endif
 124
 125 void __init enable_early_printk(void)
 126 {
 127 #ifdef CONFIG_EARLY_SCIF_CONSOLE
 128         scif_sercon_init(115200);
 129 #endif
 130         register_console(&early_console);
 131 }
 132
 133 void disable_early_printk(void)
 134 {
 135         unregister_console(&early_console);
 136 }
 137