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         .type           = PORT_SCIF,
  79         .mapbase        = CONFIG_EARLY_SCIF_CONSOLE_PORT,
  80         .membase        = (char __iomem *)CONFIG_EARLY_SCIF_CONSOLE_PORT,
  81 };
  82
  83 static void scif_sercon_putc(int c)
  84 {
  85         while (((sci_in(&scif_port, SCFDR) & EPK_FIFO_BITS) >= EPK_FIFO_SIZE))
  86                 ;
  87
  88         sci_in(&scif_port, SCxSR);
  89         sci_out(&scif_port, SCxSR, 0xf3 & ~(0x20 | 0x40));
  90         sci_out(&scif_port, SCxTDR, c);
  91
  92         while ((sci_in(&scif_port, SCxSR) & 0x40) == 0)
  93                 ;
  94
  95         if (c == '\n')
  96                 scif_sercon_putc('\r');
  97 }
  98
  99 static void scif_sercon_write(struct console *con, const char *s,
 100                               unsigned count)
 101 {
 102         while (count-- > 0)
 103                 scif_sercon_putc(*s++);
 104 }
 105
 106 static int __init scif_sercon_setup(struct console *con, char *options)
 107 {
 108         con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
 109
 110         return 0;
 111 }
 112
 113 static struct console scif_console = {
 114         .name           = "sercon",
 115         .write          = scif_sercon_write,
 116         .setup          = scif_sercon_setup,
 117         .flags          = CON_PRINTBUFFER,
 118         .index          = -1,
 119 };
 120
 121 #if !defined(CONFIG_SH_STANDARD_BIOS)
 122 #if defined(CONFIG_CPU_SUBTYPE_SH7720) || \
 123     defined(CONFIG_CPU_SUBTYPE_SH7721)
 124 static void scif_sercon_init(char *s)
 125 {
 126         sci_out(&scif_port, SCSCR, 0x0000);     /* clear TE and RE */
 127         sci_out(&scif_port, SCFCR, 0x4006);     /* reset */
 128         sci_out(&scif_port, SCSCR, 0x0000);     /* select internal clock */
 129         sci_out(&scif_port, SCSMR, EPK_SCSMR_VALUE);
 130         sci_out(&scif_port, SCBRR, EPK_SCBRR_VALUE);
 131
 132         mdelay(1);      /* wait 1-bit time */
 133
 134         sci_out(&scif_port, SCFCR, 0x0030);     /* TTRG=b'11 */
 135         sci_out(&scif_port, SCSCR, 0x0030);     /* TE, RE */
 136 }
 137 #elif defined(CONFIG_CPU_SH4)
 138 #define DEFAULT_BAUD 115200
 139 /*
 140  * Simple SCIF init, primarily aimed at SH7750 and other similar SH-4
 141  * devices that aren't using sh-ipl+g.
 142  */
 143 static void scif_sercon_init(char *s)
 144 {
 145         struct uart_port *port = &scif_port;
 146         unsigned baud = DEFAULT_BAUD;
 147         unsigned int status;
 148         char *e;
 149
 150         if (*s == ',')
 151                 ++s;
 152
 153         if (*s) {
 154                 /* ignore ioport/device name */
 155                 s += strcspn(s, ",");
 156                 if (*s == ',')
 157                         s++;
 158         }
 159
 160         if (*s) {
 161                 baud = simple_strtoul(s, &e, 0);
 162                 if (baud == 0 || s == e)
 163                         baud = DEFAULT_BAUD;
 164         }
 165
 166         do {
 167                 status = sci_in(port, SCxSR);
 168         } while (!(status & SCxSR_TEND(port)));
 169
 170         sci_out(port, SCSCR, 0);         /* TE=0, RE=0 */
 171         sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
 172         sci_out(port, SCSMR, 0);
 173
 174         /* Set baud rate */
 175         sci_out(port, SCBRR, (CONFIG_SH_PCLK_FREQ + 16 * baud) /
 176                 (32 * baud) - 1);
 177         udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
 178
 179         sci_out(port, SCSPTR, 0);
 180         sci_out(port, SCxSR, 0x60);
 181         sci_out(port, SCLSR, 0);
 182
 183         sci_out(port, SCFCR, 0);
 184         sci_out(port, SCSCR, 0x30);      /* TE=1, RE=1 */
 185 }
 186 #endif /* defined(CONFIG_CPU_SUBTYPE_SH7720) */
 187 #endif /* !defined(CONFIG_SH_STANDARD_BIOS) */
 188 #endif /* CONFIG_EARLY_SCIF_CONSOLE */
 189
 190 /*
 191  * Setup a default console, if more than one is compiled in, rely on the
 192  * earlyprintk= parsing to give priority.
 193  */
 194 static struct console *early_console =
 195 #ifdef CONFIG_SH_STANDARD_BIOS
 196         &bios_console
 197 #elif defined(CONFIG_EARLY_SCIF_CONSOLE)
 198         &scif_console
 199 #else
 200         NULL
 201 #endif
 202         ;
 203
 204 static int __init setup_early_printk(char *buf)
 205 {
 206         int keep_early = 0;
 207
 208         if (!buf)
 209                 return 0;
 210
 211         if (strstr(buf, "keep"))
 212                 keep_early = 1;
 213
 214 #ifdef CONFIG_SH_STANDARD_BIOS
 215         if (!strncmp(buf, "bios", 4))
 216                 early_console = &bios_console;
 217 #endif
 218 #if defined(CONFIG_EARLY_SCIF_CONSOLE)
 219         if (!strncmp(buf, "serial", 6)) {
 220                 early_console = &scif_console;
 221
 222 #if !defined(CONFIG_SH_STANDARD_BIOS)
 223 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_CPU_SUBTYPE_SH7720) || \
 224     defined(CONFIG_CPU_SUBTYPE_SH7721)
 225                 scif_sercon_init(buf + 6);
 226 #endif
 227 #endif
 228         }
 229 #endif
 230
 231         if (likely(early_console)) {
 232                 if (keep_early)
 233                         early_console->flags &= ~CON_BOOT;
 234                 else
 235                         early_console->flags |= CON_BOOT;
 236                 register_console(early_console);
 237         }
 238
 239         return 0;
 240 }
 241 early_param("earlyprintk", setup_early_printk);