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 - 2007  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 #include <linux/delay.h>
  17
  18 #ifdef CONFIG_SH_STANDARD_BIOS
  19 #include <asm/sh_bios.h>
  20
  21 /*
  22  *      Print a string through the BIOS
  23  */
  24 static void sh_console_write(struct console *co, const char *s,
  25                                  unsigned count)
  26 {
  27         sh_bios_console_write(s, count);
  28 }
  29
  30 /*
  31  *      Setup initial baud/bits/parity. We do two things here:
  32  *      - construct a cflag setting for the first rs_open()
  33  *      - initialize the serial port
  34  *      Return non-zero if we didn't find a serial port.
  35  */
  36 static int __init sh_console_setup(struct console *co, char *options)
  37 {
  38         int     cflag = CREAD | HUPCL | CLOCAL;
  39
  40         /*
  41          *      Now construct a cflag setting.
  42          *      TODO: this is a totally bogus cflag, as we have
  43          *      no idea what serial settings the BIOS is using, or
  44          *      even if its using the serial port at all.
  45          */
  46         cflag |= B115200 | CS8 | /*no parity*/0;
  47
  48         co->cflag = cflag;
  49
  50         return 0;
  51 }
  52
  53 static struct console bios_console = {
  54         .name           = "bios",
  55         .write          = sh_console_write,
  56         .setup          = sh_console_setup,
  57         .flags          = CON_PRINTBUFFER,
  58         .index          = -1,
  59 };
  60 #endif
  61
  62 #ifdef CONFIG_EARLY_SCIF_CONSOLE
  63 #include <linux/serial_core.h>
  64 #include "../../../drivers/serial/sh-sci.h"
  65
  66 #if defined(CONFIG_CPU_SUBTYPE_SH7720) || \
  67     defined(CONFIG_CPU_SUBTYPE_SH7721)
  68 #define EPK_SCSMR_VALUE 0x000
  69 #define EPK_SCBRR_VALUE 0x00C
  70 #define EPK_FIFO_SIZE 64
  71 #define EPK_FIFO_BITS (0x7f00 >> 8)
  72 #else
  73 #define EPK_FIFO_SIZE 16
  74 #define EPK_FIFO_BITS (0x1f00 >> 8)
  75 #endif
  76
  77 static struct uart_port scif_port = {
  78         .mapbase        = CONFIG_EARLY_SCIF_CONSOLE_PORT,
  79         .membase        = (char __iomem *)CONFIG_EARLY_SCIF_CONSOLE_PORT,
  80 };
  81
  82 static void scif_sercon_putc(int c)
  83 {
  84         while (((sci_in(&scif_port, SCFDR) & EPK_FIFO_BITS) >= EPK_FIFO_SIZE))
  85                 ;
  86
  87         sci_out(&scif_port, SCxTDR, c);
  88         sci_in(&scif_port, SCxSR);
  89         sci_out(&scif_port, SCxSR, 0xf3 & ~(0x20 | 0x40));
  90
  91         while ((sci_in(&scif_port, SCxSR) & 0x40) == 0)
  92                 ;
  93
  94         if (c == '\n')
  95                 scif_sercon_putc('\r');
  96 }
  97
  98 static void scif_sercon_write(struct console *con, const char *s,
  99                               unsigned count)
 100 {
 101         while (count-- > 0)
 102                 scif_sercon_putc(*s++);
 103 }
 104
 105 static int __init scif_sercon_setup(struct console *con, char *options)
 106 {
 107         con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
 108
 109         return 0;
 110 }
 111
 112 static struct console scif_console = {
 113         .name           = "sercon",
 114         .write          = scif_sercon_write,
 115         .setup          = scif_sercon_setup,
 116         .flags          = CON_PRINTBUFFER,
 117         .index          = -1,
 118 };
 119
 120 #if !defined(CONFIG_SH_STANDARD_BIOS)
 121 #if defined(CONFIG_CPU_SUBTYPE_SH7720) || \
 122     defined(CONFIG_CPU_SUBTYPE_SH7721)
 123 static void scif_sercon_init(char *s)
 124 {
 125         sci_out(&scif_port, SCSCR, 0x0000);     /* clear TE and RE */
 126         sci_out(&scif_port, SCFCR, 0x4006);     /* reset */
 127         sci_out(&scif_port, SCSCR, 0x0000);     /* select internal clock */
 128         sci_out(&scif_port, SCSMR, EPK_SCSMR_VALUE);
 129         sci_out(&scif_port, SCBRR, EPK_SCBRR_VALUE);
 130
 131         mdelay(1);      /* wait 1-bit time */
 132
 133         sci_out(&scif_port, SCFCR, 0x0030);     /* TTRG=b'11 */
 134         sci_out(&scif_port, SCSCR, 0x0030);     /* TE, RE */
 135 }
 136 #elif defined(CONFIG_CPU_SH4)
 137 #define DEFAULT_BAUD 115200
 138 /*
 139  * Simple SCIF init, primarily aimed at SH7750 and other similar SH-4
 140  * devices that aren't using sh-ipl+g.
 141  */
 142 static void scif_sercon_init(char *s)
 143 {
 144         struct uart_port *port = &scif_port;
 145         unsigned baud = DEFAULT_BAUD;
 146         unsigned int status;
 147         char *e;
 148
 149         if (*s == ',')
 150                 ++s;
 151
 152         if (*s) {
 153                 /* ignore ioport/device name */
 154                 s += strcspn(s, ",");
 155                 if (*s == ',')
 156                         s++;
 157         }
 158
 159         if (*s) {
 160                 baud = simple_strtoul(s, &e, 0);
 161                 if (baud == 0 || s == e)
 162                         baud = DEFAULT_BAUD;
 163         }
 164
 165         do {
 166                 status = sci_in(port, SCxSR);
 167         } while (!(status & SCxSR_TEND(port)));
 168
 169         sci_out(port, SCSCR, 0);         /* TE=0, RE=0 */
 170         sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
 171         sci_out(port, SCSMR, 0);
 172
 173         /* Set baud rate */
 174         sci_out(port, SCBRR, (CONFIG_SH_PCLK_FREQ + 16 * baud) /
 175                 (32 * baud) - 1);
 176         udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
 177
 178         sci_out(port, SCSPTR, 0);
 179         sci_out(port, SCxSR, 0x60);
 180         sci_out(port, SCLSR, 0);
 181
 182         sci_out(port, SCFCR, 0);
 183         sci_out(port, SCSCR, 0x30);      /* TE=1, RE=1 */
 184 }
 185 #endif /* defined(CONFIG_CPU_SUBTYPE_SH7720) */
 186 #endif /* !defined(CONFIG_SH_STANDARD_BIOS) */
 187 #endif /* CONFIG_EARLY_SCIF_CONSOLE */
 188
 189 /*
 190  * Setup a default console, if more than one is compiled in, rely on the
 191  * earlyprintk= parsing to give priority.
 192  */
 193 static struct console *early_console =
 194 #ifdef CONFIG_SH_STANDARD_BIOS
 195         &bios_console
 196 #elif defined(CONFIG_EARLY_SCIF_CONSOLE)
 197         &scif_console
 198 #else
 199         NULL
 200 #endif
 201         ;
 202
 203 static int __init setup_early_printk(char *buf)
 204 {
 205         int keep_early = 0;
 206
 207         if (!buf)
 208                 return 0;
 209
 210         if (strstr(buf, "keep"))
 211                 keep_early = 1;
 212
 213 #ifdef CONFIG_SH_STANDARD_BIOS
 214         if (!strncmp(buf, "bios", 4))
 215                 early_console = &bios_console;
 216 #endif
 217 #if defined(CONFIG_EARLY_SCIF_CONSOLE)
 218         if (!strncmp(buf, "serial", 6)) {
 219                 early_console = &scif_console;
 220
 221 #if !defined(CONFIG_SH_STANDARD_BIOS)
 222 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_CPU_SUBTYPE_SH7720) || \
 223     defined(CONFIG_CPU_SUBTYPE_SH7721)
 224                 scif_sercon_init(buf + 6);
 225 #endif
 226 #endif
 227         }
 228 #endif
 229
 230         if (likely(early_console)) {
 231                 if (keep_early)
 232                         early_console->flags &= ~CON_BOOT;
 233                 else
 234                         early_console->flags |= CON_BOOT;
 235                 register_console(early_console);
 236         }
 237
 238         return 0;
 239 }
 240 early_param("earlyprintk", setup_early_printk);