arch/ppc/xmon/start.c

   1 /*
   2  * Copyright (C) 1996 Paul Mackerras.
   3  */
   4 #include <linux/string.h>
   5 #include <asm/machdep.h>
   6 #include <asm/io.h>
   7 #include <asm/page.h>
   8 #include <linux/kernel.h>
   9 #include <linux/errno.h>
  10 #include <linux/sysrq.h>
  11 #include <linux/bitops.h>
  12 #include <asm/xmon.h>
  13 #include <asm/machdep.h>
  14 #include <asm/errno.h>
  15 #include <asm/processor.h>
  16 #include <asm/delay.h>
  17 #include <asm/btext.h>
  18 #include <asm/ibm4xx.h>
  19
  20 static volatile unsigned char *sccc, *sccd;
  21 unsigned int TXRDY, RXRDY, DLAB;
  22 static int xmon_expect(const char *str, unsigned int timeout);
  23
  24 static int via_modem;
  25
  26 #define TB_SPEED        25000000
  27
  28 static inline unsigned int readtb(void)
  29 {
  30         unsigned int ret;
  31
  32         asm volatile("mftb %0" : "=r" (ret) :);
  33         return ret;
  34 }
  35
  36 void buf_access(void)
  37 {
  38         if (DLAB)
  39                 sccd[3] &= ~DLAB;       /* reset DLAB */
  40 }
  41
  42
  43 #ifdef CONFIG_MAGIC_SYSRQ
  44 static void sysrq_handle_xmon(int key, struct pt_regs *regs,
  45                               struct tty_struct *tty)
  46 {
  47         xmon(regs);
  48 }
  49
  50 static struct sysrq_key_op sysrq_xmon_op =
  51 {
  52         .handler =      sysrq_handle_xmon,
  53         .help_msg =     "Xmon",
  54         .action_msg =   "Entering xmon",
  55 };
  56 #endif
  57
  58 void
  59 xmon_map_scc(void)
  60 {
  61 #if defined(CONFIG_405GP)
  62         sccd = (volatile unsigned char *)0xef600300;
  63 #elif defined(CONFIG_440EP)
  64         sccd = (volatile unsigned char *) ioremap(PPC440EP_UART0_ADDR, 8);
  65 #elif defined(CONFIG_440SP)
  66         sccd = (volatile unsigned char *) ioremap64(PPC440SP_UART0_ADDR, 8);
  67 #elif defined(CONFIG_440SPE)
  68         sccd = (volatile unsigned char *) ioremap64(PPC440SPE_UART0_ADDR, 8);
  69 #elif defined(CONFIG_44x)
  70         /* This is the default for 44x platforms.  Any boards that have a
  71            different UART address need to be put in cases before this or the
  72            port will be mapped incorrectly */
  73         sccd = (volatile unsigned char *) ioremap64(PPC440GP_UART0_ADDR, 8);
  74 #endif /* platform */
  75
  76 #ifndef CONFIG_PPC_PREP
  77         sccc = sccd + 5;
  78         TXRDY = 0x20;
  79         RXRDY = 1;
  80         DLAB = 0x80;
  81 #endif
  82
  83         register_sysrq_key('x', &sysrq_xmon_op);
  84 }
  85
  86 static int scc_initialized;
  87
  88 void xmon_init_scc(void);
  89
  90 int
  91 xmon_write(void *handle, void *ptr, int nb)
  92 {
  93         char *p = ptr;
  94         int i, c, ct;
  95
  96 #ifdef CONFIG_SMP
  97         static unsigned long xmon_write_lock;
  98         int lock_wait = 1000000;
  99         int locked;
 100
 101         while ((locked = test_and_set_bit(0, &xmon_write_lock)) != 0)
 102                 if (--lock_wait == 0)
 103                         break;
 104 #endif
 105
 106         if (!scc_initialized)
 107                 xmon_init_scc();
 108         ct = 0;
 109         for (i = 0; i < nb; ++i) {
 110                 while ((*sccc & TXRDY) == 0)
 111                         ;
 112                 c = p[i];
 113                 if (c == '\n' && !ct) {
 114                         c = '\r';
 115                         ct = 1;
 116                         --i;
 117                 } else {
 118                         ct = 0;
 119                 }
 120                 buf_access();
 121                 *sccd = c;
 122                 eieio();
 123         }
 124
 125 #ifdef CONFIG_SMP
 126         if (!locked)
 127                 clear_bit(0, &xmon_write_lock);
 128 #endif
 129         return nb;
 130 }
 131
 132 int xmon_wants_key;
 133
 134
 135 int
 136 xmon_read(void *handle, void *ptr, int nb)
 137 {
 138     char *p = ptr;
 139     int i;
 140
 141     if (!scc_initialized)
 142         xmon_init_scc();
 143     for (i = 0; i < nb; ++i) {
 144         while ((*sccc & RXRDY) == 0)
 145             ;
 146         buf_access();
 147         *p++ = *sccd;
 148     }
 149     return i;
 150 }
 151
 152 int
 153 xmon_read_poll(void)
 154 {
 155         if ((*sccc & RXRDY) == 0) {
 156                 ;
 157                 return -1;
 158         }
 159         buf_access();
 160         return *sccd;
 161 }
 162
 163 void
 164 xmon_init_scc(void)
 165 {
 166         scc_initialized = 1;
 167         if (via_modem) {
 168                 for (;;) {
 169                         xmon_write(NULL, "ATE1V1\r", 7);
 170                         if (xmon_expect("OK", 5)) {
 171                                 xmon_write(NULL, "ATA\r", 4);
 172                                 if (xmon_expect("CONNECT", 40))
 173                                         break;
 174                         }
 175                         xmon_write(NULL, "+++", 3);
 176                         xmon_expect("OK", 3);
 177                 }
 178         }
 179 }
 180
 181
 182 void *xmon_stdin;
 183 void *xmon_stdout;
 184 void *xmon_stderr;
 185
 186 void
 187 xmon_init(int arg)
 188 {
 189         xmon_map_scc();
 190 }
 191
 192 int
 193 xmon_putc(int c, void *f)
 194 {
 195     char ch = c;
 196
 197     if (c == '\n')
 198         xmon_putc('\r', f);
 199     return xmon_write(f, &ch, 1) == 1? c: -1;
 200 }
 201
 202 int
 203 xmon_putchar(int c)
 204 {
 205     return xmon_putc(c, xmon_stdout);
 206 }
 207
 208 int
 209 xmon_fputs(char *str, void *f)
 210 {
 211     int n = strlen(str);
 212
 213     return xmon_write(f, str, n) == n? 0: -1;
 214 }
 215
 216 int
 217 xmon_readchar(void)
 218 {
 219     char ch;
 220
 221     for (;;) {
 222         switch (xmon_read(xmon_stdin, &ch, 1)) {
 223         case 1:
 224             return ch;
 225         case -1:
 226             xmon_printf("read(stdin) returned -1\r\n", 0, 0);
 227             return -1;
 228         }
 229     }
 230 }
 231
 232 static char line[256];
 233 static char *lineptr;
 234 static int lineleft;
 235
 236 int xmon_expect(const char *str, unsigned int timeout)
 237 {
 238         int c;
 239         unsigned int t0;
 240
 241         timeout *= TB_SPEED;
 242         t0 = readtb();
 243         do {
 244                 lineptr = line;
 245                 for (;;) {
 246                         c = xmon_read_poll();
 247                         if (c == -1) {
 248                                 if (readtb() - t0 > timeout)
 249                                         return 0;
 250                                 continue;
 251                         }
 252                         if (c == '\n')
 253                                 break;
 254                         if (c != '\r' && lineptr < &line[sizeof(line) - 1])
 255                                 *lineptr++ = c;
 256                 }
 257                 *lineptr = 0;
 258         } while (strstr(line, str) == NULL);
 259         return 1;
 260 }
 261
 262 int
 263 xmon_getchar(void)
 264 {
 265     int c;
 266
 267     if (lineleft == 0) {
 268         lineptr = line;
 269         for (;;) {
 270             c = xmon_readchar();
 271             if (c == -1 || c == 4)
 272                 break;
 273             if (c == '\r' || c == '\n') {
 274                 *lineptr++ = '\n';
 275                 xmon_putchar('\n');
 276                 break;
 277             }
 278             switch (c) {
 279             case 0177:
 280             case '\b':
 281                 if (lineptr > line) {
 282                     xmon_putchar('\b');
 283                     xmon_putchar(' ');
 284                     xmon_putchar('\b');
 285                     --lineptr;
 286                 }
 287                 break;
 288             case 'U' & 0x1F:
 289                 while (lineptr > line) {
 290                     xmon_putchar('\b');
 291                     xmon_putchar(' ');
 292                     xmon_putchar('\b');
 293                     --lineptr;
 294                 }
 295                 break;
 296             default:
 297                 if (lineptr >= &line[sizeof(line) - 1])
 298                     xmon_putchar('\a');
 299                 else {
 300                     xmon_putchar(c);
 301                     *lineptr++ = c;
 302                 }
 303             }
 304         }
 305         lineleft = lineptr - line;
 306         lineptr = line;
 307     }
 308     if (lineleft == 0)
 309         return -1;
 310     --lineleft;
 311     return *lineptr++;
 312 }
 313
 314 char *
 315 xmon_fgets(char *str, int nb, void *f)
 316 {
 317     char *p;
 318     int c;
 319
 320     for (p = str; p < str + nb - 1; ) {
 321         c = xmon_getchar();
 322         if (c == -1) {
 323             if (p == str)
 324                 return NULL;
 325             break;
 326         }
 327         *p++ = c;
 328         if (c == '\n')
 329             break;
 330     }
 331     *p = 0;
 332     return str;
 333 }
 334
 335 void
 336 xmon_enter(void)
 337 {
 338 }
 339
 340 void
 341 xmon_leave(void)
 342 {
 343 }