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 extern void cpu_relax(void);
  20
  21 #define SCIF_BASE_ADDR  0x01030000
  22 #define SCIF_ADDR_SH5   PHYS_PERIPHERAL_BLOCK+SCIF_BASE_ADDR
  23
  24 /*
  25  * Fixed virtual address where SCIF is mapped (should already be done
  26  * in arch/sh64/kernel/head.S!).
  27  */
  28 #define SCIF_REG        0xfa030000
  29
  30 enum {
  31         SCIF_SCSMR2     = SCIF_REG + 0x00,
  32         SCIF_SCBRR2     = SCIF_REG + 0x04,
  33         SCIF_SCSCR2     = SCIF_REG + 0x08,
  34         SCIF_SCFTDR2    = SCIF_REG + 0x0c,
  35         SCIF_SCFSR2     = SCIF_REG + 0x10,
  36         SCIF_SCFRDR2    = SCIF_REG + 0x14,
  37         SCIF_SCFCR2     = SCIF_REG + 0x18,
  38         SCIF_SCFDR2     = SCIF_REG + 0x1c,
  39         SCIF_SCSPTR2    = SCIF_REG + 0x20,
  40         SCIF_SCLSR2     = SCIF_REG + 0x24,
  41 };
  42
  43 static void sh_console_putc(int c)
  44 {
  45         while (!(ctrl_inw(SCIF_SCFSR2) & 0x20))
  46                 cpu_relax();
  47
  48         ctrl_outb(c, SCIF_SCFTDR2);
  49         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0x9f), SCIF_SCFSR2);
  50
  51         if (c == '\n')
  52                 sh_console_putc('\r');
  53 }
  54
  55 static void sh_console_flush(void)
  56 {
  57         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0xbf), SCIF_SCFSR2);
  58
  59         while (!(ctrl_inw(SCIF_SCFSR2) & 0x40))
  60                 cpu_relax();
  61
  62         ctrl_outw((ctrl_inw(SCIF_SCFSR2) & 0xbf), SCIF_SCFSR2);
  63 }
  64
  65 static void sh_console_write(struct console *con, const char *s, unsigned count)
  66 {
  67         while (count-- > 0)
  68                 sh_console_putc(*s++);
  69
  70         sh_console_flush();
  71 }
  72
  73 static int __init sh_console_setup(struct console *con, char *options)
  74 {
  75         con->cflag = CREAD | HUPCL | CLOCAL | B19200 | CS8;
  76
  77         return 0;
  78 }
  79
  80 static struct console sh_console = {
  81         .name           = "scifcon",
  82         .write          = sh_console_write,
  83         .setup          = sh_console_setup,
  84         .flags          = CON_PRINTBUFFER,
  85         .index          = -1,
  86 };
  87
  88 void __init enable_early_printk(void)
  89 {
  90         ctrl_outb(0x2a, SCIF_SCBRR2);   /* 19200bps */
  91
  92         ctrl_outw(0x04, SCIF_SCFCR2);   /* Reset TFRST */
  93         ctrl_outw(0x10, SCIF_SCFCR2);   /* TTRG0=1 */
  94
  95         ctrl_outw(0, SCIF_SCSPTR2);
  96         ctrl_outw(0x60, SCIF_SCFSR2);
  97         ctrl_outw(0, SCIF_SCLSR2);
  98         ctrl_outw(0x30, SCIF_SCSCR2);
  99
 100         register_console(&sh_console);
 101 }
 102
 103 void disable_early_printk(void)
 104 {
 105         unregister_console(&sh_console);
 106 }
 107