arch/sh64/kernel/early_printk.c

   1 /*
   2  * arch/sh64/kernel/early_printk.c
   3  *
   4  * SH-5 Early SCIF console (cloned and hacked from sh implementation)
   5  *
   6  * Copyright (C) 2003, 2004  Paul Mundt <lethal@linux-sh.org>
   7  * Copyright (C) 2002  M. R. Brown <mrbrown@0xd6.org>
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/console.h>
  14 #include <linux/tty.h>
  15 #include <linux/init.h>
  16 #include <asm/io.h>
  17 #include <asm/hardware.h>
  18
  19 #define SCIF_BASE_ADDR  0x01030000
  20 #define SCIF_ADDR_SH5   PHYS_PERIPHERAL_BLOCK+SCIF_BASE_ADDR
  21
  22 /*
  23  * Fixed virtual address where SCIF is mapped (should already be done
  24  * in arch/sh64/kernel/head.S!).
  25  */
  26 #define SCIF_REG        0xfa030000
  27
  28 enum {
  29         SCIF_SCSMR2     = SCIF_REG + 0x00,
  30         SCIF_SCBRR2     = SCIF_REG + 0x04,
  31         SCIF_SCSCR2     = SCIF_REG + 0x08,
  32         SCIF_SCFTDR2    = SCIF_REG + 0x0c,
  33         SCIF_SCFSR2     = SCIF_REG + 0x10,
  34         SCIF_SCFRDR2    = SCIF_REG + 0x14,
  35         SCIF_SCFCR2     = SCIF_REG + 0x18,
  36         SCIF_SCFDR2     = SCIF_REG + 0x1c,
  37         SCIF_SCSPTR2    = SCIF_REG + 0x20,
  38         SCIF_SCLSR2     = SCIF_REG + 0x24,
  39 };
  40
  41 static void sh_console_putc(int c)
  42 {
  43         while (!(ctrl_inw(SCIF_SCFSR2) & 0x20))
  44                 cpu_relax();
  45
  46         ctrl_outb(c, SCIF_SCFTDR2);
  47         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0x9f), SCIF_SCFSR2);
  48
  49         if (c == '\n')
  50                 sh_console_putc('\r');
  51 }
  52
  53 static void sh_console_flush(void)
  54 {
  55         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0xbf), SCIF_SCFSR2);
  56
  57         while (!(ctrl_inw(SCIF_SCFSR2) & 0x40))
  58                 cpu_relax();
  59
  60         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0xbf), SCIF_SCFSR2);
  61 }
  62
  63 static void sh_console_write(struct console *con, const char *s, unsigned count)
  64 {
  65         while (count-- > 0)
  66                 sh_console_putc(*s++);
  67
  68         sh_console_flush();
  69 }
  70
  71 static int __init sh_console_setup(struct console *con, char *options)
  72 {
  73         con->cflag = CREAD | HUPCL | CLOCAL | B19200 | CS8;
  74
  75         return 0;
  76 }
  77
  78 static struct console sh_console = {
  79         .name           = "scifcon",
  80         .write          = sh_console_write,
  81         .setup          = sh_console_setup,
  82         .flags          = CON_PRINTBUFFER,
  83         .index          = -1,
  84 };
  85
  86 void __init enable_early_printk(void)
  87 {
  88         ctrl_outb(0x2a, SCIF_SCBRR2);   /* 19200bps */
  89
  90         ctrl_outw(0x04, SCIF_SCFCR2);   /* Reset TFRST */
  91         ctrl_outw(0x10, SCIF_SCFCR2);   /* TTRG0=1 */
  92
  93         ctrl_outw(0, SCIF_SCSPTR2);
  94         ctrl_outw(0x60, SCIF_SCFSR2);
  95         ctrl_outw(0, SCIF_SCLSR2);
  96         ctrl_outw(0x30, SCIF_SCSCR2);
  97
  98         register_console(&sh_console);
  99 }
 100
 101 void disable_early_printk(void)
 102 {
 103         unregister_console(&sh_console);
 104 }
 105