release/src-rt-6.x/linux/linux-2.6/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 - 2006  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 <linux/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 bios_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 #include <linux/serial_core.h>
  63 #include "../../../drivers/serial/sh-sci.h"
  64
  65 static struct uart_port scif_port = {
  66         .mapbase        = CONFIG_EARLY_SCIF_CONSOLE_PORT,
  67         .membase        = (char __iomem *)CONFIG_EARLY_SCIF_CONSOLE_PORT,
  68 };
  69
  70 static void scif_sercon_putc(int c)
  71 {
  72         while (((sci_in(&scif_port, SCFDR) & 0x1f00 >> 8) == 16))
  73                 ;
  74
  75         sci_out(&scif_port, SCxTDR, c);
  76         sci_in(&scif_port, SCxSR);
  77         sci_out(&scif_port, SCxSR, 0xf3 & ~(0x20 | 0x40));
  78
  79         while ((sci_in(&scif_port, SCxSR) & 0x40) == 0);
  80                 ;
  81
  82         if (c == '\n')
  83                 scif_sercon_putc('\r');
  84 }
  85
  86 static void scif_sercon_write(struct console *con, const char *s,
  87                               unsigned count)
  88 {
  89         while (count-- > 0)
  90                 scif_sercon_putc(*s++);
  91 }
  92
  93 static int __init scif_sercon_setup(struct console *con, char *options)
  94 {
  95         con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
  96
  97         return 0;
  98 }
  99
 100 static struct console scif_console = {
 101         .name           = "sercon",
 102         .write          = scif_sercon_write,
 103         .setup          = scif_sercon_setup,
 104         .flags          = CON_PRINTBUFFER,
 105         .index          = -1,
 106 };
 107
 108 #if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_STANDARD_BIOS)
 109 #define DEFAULT_BAUD 115200
 110 /*
 111  * Simple SCIF init, primarily aimed at SH7750 and other similar SH-4
 112  * devices that aren't using sh-ipl+g.
 113  */
 114 static void scif_sercon_init(char *s)
 115 {
 116         unsigned baud = DEFAULT_BAUD;
 117         char *e;
 118
 119         if (*s == ',')
 120                 ++s;
 121
 122         if (*s) {
 123                 /* ignore ioport/device name */
 124                 s += strcspn(s, ",");
 125                 if (*s == ',')
 126                         s++;
 127         }
 128
 129         if (*s) {
 130                 baud = simple_strtoul(s, &e, 0);
 131                 if (baud == 0 || s == e)
 132                         baud = DEFAULT_BAUD;
 133         }
 134
 135         ctrl_outw(0, scif_port.mapbase + 8);
 136         ctrl_outw(0, scif_port.mapbase);
 137
 138         /* Set baud rate */
 139         ctrl_outb((CONFIG_SH_PCLK_FREQ + 16 * baud) /
 140                   (32 * baud) - 1, scif_port.mapbase + 4);
 141
 142         ctrl_outw(12, scif_port.mapbase + 24);
 143         ctrl_outw(8, scif_port.mapbase + 24);
 144         ctrl_outw(0, scif_port.mapbase + 32);
 145         ctrl_outw(0x60, scif_port.mapbase + 16);
 146         ctrl_outw(0, scif_port.mapbase + 36);
 147         ctrl_outw(0x30, scif_port.mapbase + 8);
 148 }
 149 #endif /* CONFIG_CPU_SH4 && !CONFIG_SH_STANDARD_BIOS */
 150 #endif /* CONFIG_EARLY_SCIF_CONSOLE */
 151
 152 /*
 153  * Setup a default console, if more than one is compiled in, rely on the
 154  * earlyprintk= parsing to give priority.
 155  */
 156 static struct console *early_console =
 157 #ifdef CONFIG_SH_STANDARD_BIOS
 158         &bios_console
 159 #elif defined(CONFIG_EARLY_SCIF_CONSOLE)
 160         &scif_console
 161 #else
 162         NULL
 163 #endif
 164         ;
 165
 166 static int __initdata keep_early;
 167 static int early_console_initialized;
 168
 169 int __init setup_early_printk(char *buf)
 170 {
 171         if (!buf)
 172                 return 0;
 173
 174         if (early_console_initialized)
 175                 return 0;
 176         early_console_initialized = 1;
 177
 178         if (strstr(buf, "keep"))
 179                 keep_early = 1;
 180
 181 #ifdef CONFIG_SH_STANDARD_BIOS
 182         if (!strncmp(buf, "bios", 4))
 183                 early_console = &bios_console;
 184 #endif
 185 #if defined(CONFIG_EARLY_SCIF_CONSOLE)
 186         if (!strncmp(buf, "serial", 6)) {
 187                 early_console = &scif_console;
 188
 189 #if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_STANDARD_BIOS)
 190                 scif_sercon_init(buf + 6);
 191 #endif
 192         }
 193 #endif
 194
 195         if (likely(early_console)) {
 196                 if (keep_early)
 197                         early_console->flags &= ~CON_BOOT;
 198                 else
 199                         early_console->flags |= CON_BOOT;
 200                 register_console(early_console);
 201         }
 202
 203         return 0;
 204 }
 205 early_param("earlyprintk", setup_early_printk);