arch/m68k/mac/debug.c

   1 /*
   2  * linux/arch/m68k/mac/debug.c
   3  *
   4  * Shamelessly stolen (SCC code and general framework) from:
   5  *
   6  * linux/arch/m68k/atari/debug.c
   7  *
   8  * Atari debugging and serial console stuff
   9  *
  10  * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
  11  *
  12  * This file is subject to the terms and conditions of the GNU General Public
  13  * License.  See the file COPYING in the main directory of this archive
  14  * for more details.
  15  */
  16
  17 #include <linux/types.h>
  18 #include <linux/sched.h>
  19 #include <linux/tty.h>
  20 #include <linux/console.h>
  21 #include <linux/init.h>
  22 #include <linux/delay.h>
  23
  24 #define BOOTINFO_COMPAT_1_0
  25 #include <asm/setup.h>
  26 #include <asm/bootinfo.h>
  27 #include <asm/machw.h>
  28 #include <asm/macints.h>
  29
  30 extern unsigned long mac_videobase;
  31 extern unsigned long mac_videodepth;
  32 extern unsigned long mac_rowbytes;
  33
  34 extern void mac_serial_print(const char *);
  35
  36 #define DEBUG_HEADS
  37 #undef DEBUG_SCREEN
  38 #define DEBUG_SERIAL
  39
  40 /*
  41  * These two auxiliary debug functions should go away ASAP. Only usage:
  42  * before the console output is up (after head.S come some other crucial
  43  * setup routines :-) it permits writing 'data' to the screen as bit patterns
  44  * (good luck reading those). Helped to figure that the bootinfo contained
  45  * garbage data on the amount and size of memory chunks ...
  46  *
  47  * The 'pos' argument now simply means 'linefeed after print' ...
  48  */
  49
  50 #ifdef DEBUG_SCREEN
  51 static int peng, line;
  52 #endif
  53
  54 void mac_debugging_short(int pos, short num)
  55 {
  56 #ifdef DEBUG_SCREEN
  57         unsigned char *pengoffset;
  58         unsigned char *pptr;
  59         int i;
  60 #endif
  61
  62 #ifdef DEBUG_SERIAL
  63         printk("debug: %d !\n", num);
  64 #endif
  65
  66 #ifdef DEBUG_SCREEN
  67         if (!MACH_IS_MAC) {
  68                 /* printk("debug: %d !\n", num); */
  69                 return;
  70         }
  71
  72         /* calculate current offset */
  73         pengoffset = (unsigned char *)mac_videobase +
  74                 (150+line*2) * mac_rowbytes + 80 * peng;
  75
  76         pptr = pengoffset;
  77
  78         for (i = 0; i < 8 * sizeof(short); i++) { /* # of bits */
  79                 /*        value        mask for bit i, reverse order */
  80                 *pptr++ = (num & (1 << (8*sizeof(short)-i-1)) ? 0xFF : 0x00);
  81         }
  82
  83         peng++;
  84
  85         if (pos) {
  86                 line++;
  87                 peng = 0;
  88         }
  89 #endif
  90 }
  91
  92 void mac_debugging_long(int pos, long addr)
  93 {
  94 #ifdef DEBUG_SCREEN
  95         unsigned char *pengoffset;
  96         unsigned char *pptr;
  97         int i;
  98 #endif
  99
 100 #ifdef DEBUG_SERIAL
 101         printk("debug: #%ld !\n", addr);
 102 #endif
 103
 104 #ifdef DEBUG_SCREEN
 105         if (!MACH_IS_MAC) {
 106                 /* printk("debug: #%ld !\n", addr); */
 107                 return;
 108         }
 109
 110         pengoffset=(unsigned char *)(mac_videobase+(150+line*2)*mac_rowbytes)
 111                     +80*peng;
 112
 113         pptr = pengoffset;
 114
 115         for (i = 0; i < 8 * sizeof(long); i++) { /* # of bits */
 116                 *pptr++ = (addr & (1 << (8*sizeof(long)-i-1)) ? 0xFF : 0x00);
 117         }
 118
 119         peng++;
 120
 121         if (pos) {
 122                 line++;
 123                 peng = 0;
 124         }
 125 #endif
 126 }
 127
 128 #ifdef DEBUG_SERIAL
 129 /*
 130  * TODO: serial debug code
 131  */
 132
 133 struct mac_SCC {
 134         u_char cha_b_ctrl;
 135         u_char char_dummy1;
 136         u_char cha_a_ctrl;
 137         u_char char_dummy2;
 138         u_char cha_b_data;
 139         u_char char_dummy3;
 140         u_char cha_a_data;
 141 };
 142
 143 # define scc (*((volatile struct mac_SCC*)mac_bi_data.sccbase))
 144
 145 /* Flag that serial port is already initialized and used */
 146 int mac_SCC_init_done;
 147 /* Can be set somewhere, if a SCC master reset has already be done and should
 148  * not be repeated; used by kgdb */
 149 int mac_SCC_reset_done;
 150
 151 static int scc_port = -1;
 152
 153 static struct console mac_console_driver = {
 154         .name   = "debug",
 155         .flags  = CON_PRINTBUFFER,
 156         .index  = -1,
 157 };
 158
 159 /*
 160  * Crude hack to get console output to the screen before the framebuffer
 161  * is initialized (happens a lot later in 2.1!).
 162  * We just use the console routines declared in head.S, this will interfere
 163  * with regular framebuffer console output and should be used exclusively
 164  * to debug kernel problems manifesting before framebuffer init (aka WSOD)
 165  *
 166  * To keep this hack from interfering with the regular console driver, either
 167  * deregister this driver before/on framebuffer console init, or silence this
 168  * function after the fbcon driver is running (will lose console messages!?).
 169  * To debug real early bugs, need to write a 'mac_register_console_hack()'
 170  * that is called from start_kernel() before setup_arch() and just registers
 171  * this driver if Mac.
 172  */
 173
 174 void mac_debug_console_write(struct console *co, const char *str,
 175                              unsigned int count)
 176 {
 177         mac_serial_print(str);
 178 }
 179
 180
 181
 182 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
 183
 184 #define uSEC 1
 185
 186 static inline void mac_sccb_out(char c)
 187 {
 188         int i;
 189
 190         do {
 191                 for (i = uSEC; i > 0; --i)
 192                         barrier();
 193         } while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
 194         for (i = uSEC; i > 0; --i)
 195                 barrier();
 196         scc.cha_b_data = c;
 197 }
 198
 199 static inline void mac_scca_out(char c)
 200 {
 201         int i;
 202
 203         do {
 204                 for (i = uSEC; i > 0; --i)
 205                         barrier();
 206         } while (!(scc.cha_a_ctrl & 0x04)); /* wait for tx buf empty */
 207         for (i = uSEC; i > 0; --i)
 208                 barrier();
 209         scc.cha_a_data = c;
 210 }
 211
 212 void mac_sccb_console_write(struct console *co, const char *str,
 213                             unsigned int count)
 214 {
 215         while (count--) {
 216                 if (*str == '\n')
 217                         mac_sccb_out('\r');
 218                 mac_sccb_out(*str++);
 219         }
 220 }
 221
 222 void mac_scca_console_write(struct console *co, const char *str,
 223                             unsigned int count)
 224 {
 225         while (count--) {
 226                 if (*str == '\n')
 227                         mac_scca_out('\r');
 228                 mac_scca_out(*str++);
 229         }
 230 }
 231
 232
 233 /* The following two functions do a quick'n'dirty initialization of the MFP or
 234  * SCC serial ports. They're used by the debugging interface, kgdb, and the
 235  * serial console code. */
 236 #define SCCB_WRITE(reg,val)                             \
 237         do {                                            \
 238                 int i;                                  \
 239                 scc.cha_b_ctrl = (reg);                 \
 240                 for (i = uSEC; i > 0; --i)              \
 241                         barrier();                      \
 242                 scc.cha_b_ctrl = (val);                 \
 243                 for (i = uSEC; i > 0; --i)              \
 244                         barrier();                      \
 245         } while(0)
 246
 247 #define SCCA_WRITE(reg,val)                             \
 248         do {                                            \
 249                 int i;                                  \
 250                 scc.cha_a_ctrl = (reg);                 \
 251                 for (i = uSEC; i > 0; --i)              \
 252                         barrier();                      \
 253                 scc.cha_a_ctrl = (val);                 \
 254                 for (i = uSEC; i > 0; --i)              \
 255                         barrier();                      \
 256         } while(0)
 257
 258 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
 259  * delay of ~ 60us. */
 260 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
 261 #define LONG_DELAY()                                    \
 262         do {                                            \
 263                 int i;                                  \
 264                 for (i = 60*uSEC; i > 0; --i)           \
 265                     barrier();                          \
 266         } while(0)
 267
 268 #ifndef CONFIG_SERIAL_CONSOLE
 269 static void __init mac_init_scc_port(int cflag, int port)
 270 #else
 271 void mac_init_scc_port(int cflag, int port)
 272 #endif
 273 {
 274         extern int mac_SCC_reset_done;
 275
 276         /*
 277          * baud rates: 1200, 1800, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, 115.2k
 278          */
 279
 280         static int clksrc_table[9] =
 281                 /* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
 282                 { 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
 283         static int clkmode_table[9] =
 284                 /* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
 285                 { 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
 286         static int div_table[9] =
 287                 /* reg12 (BRG low) */
 288                 { 94, 62, 46, 22, 10, 4, 1, 0, 0 };
 289
 290         int baud = cflag & CBAUD;
 291         int clksrc, clkmode, div, reg3, reg5;
 292
 293         if (cflag & CBAUDEX)
 294                 baud += B38400;
 295         if (baud < B1200 || baud > B38400+2)
 296                 baud = B9600; /* use default 9600bps for non-implemented rates */
 297         baud -= B1200; /* tables starts at 1200bps */
 298
 299         clksrc  = clksrc_table[baud];
 300         clkmode = clkmode_table[baud];
 301         div     = div_table[baud];
 302
 303         reg3 = (((cflag & CSIZE) == CS8) ? 0xc0 : 0x40);
 304         reg5 = (((cflag & CSIZE) == CS8) ? 0x60 : 0x20) | 0x82 /* assert DTR/RTS */;
 305
 306         if (port == 1) {
 307                 (void)scc.cha_b_ctrl;   /* reset reg pointer */
 308                 SCCB_WRITE(9, 0xc0);    /* reset */
 309                 LONG_DELAY();           /* extra delay after WR9 access */
 310                 SCCB_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
 311                            0x04 /* 1 stopbit */ |
 312                            clkmode);
 313                 SCCB_WRITE(3, reg3);
 314                 SCCB_WRITE(5, reg5);
 315                 SCCB_WRITE(9, 0);       /* no interrupts */
 316                 LONG_DELAY();           /* extra delay after WR9 access */
 317                 SCCB_WRITE(10, 0);      /* NRZ mode */
 318                 SCCB_WRITE(11, clksrc); /* main clock source */
 319                 SCCB_WRITE(12, div);    /* BRG value */
 320                 SCCB_WRITE(13, 0);      /* BRG high byte */
 321                 SCCB_WRITE(14, 1);
 322                 SCCB_WRITE(3, reg3 | 1);
 323                 SCCB_WRITE(5, reg5 | 8);
 324         } else if (port == 0) {
 325                 (void)scc.cha_a_ctrl;   /* reset reg pointer */
 326                 SCCA_WRITE(9, 0xc0);    /* reset */
 327                 LONG_DELAY();           /* extra delay after WR9 access */
 328                 SCCA_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
 329                           0x04 /* 1 stopbit */ |
 330                           clkmode);
 331                 SCCA_WRITE(3, reg3);
 332                 SCCA_WRITE(5, reg5);
 333                 SCCA_WRITE(9, 0);       /* no interrupts */
 334                 LONG_DELAY();           /* extra delay after WR9 access */
 335                 SCCA_WRITE(10, 0);      /* NRZ mode */
 336                 SCCA_WRITE(11, clksrc); /* main clock source */
 337                 SCCA_WRITE(12, div);    /* BRG value */
 338                 SCCA_WRITE(13, 0);      /* BRG high byte */
 339                 SCCA_WRITE(14, 1);
 340                 SCCA_WRITE(3, reg3 | 1);
 341                 SCCA_WRITE(5, reg5 | 8);
 342         }
 343
 344         mac_SCC_reset_done = 1;
 345         mac_SCC_init_done = 1;
 346 }
 347 #endif /* DEBUG_SERIAL */
 348
 349 void mac_init_scca_port(int cflag)
 350 {
 351         mac_init_scc_port(cflag, 0);
 352 }
 353
 354 void mac_init_sccb_port(int cflag)
 355 {
 356         mac_init_scc_port(cflag, 1);
 357 }
 358
 359 static int __init mac_debug_setup(char *arg)
 360 {
 361         if (!MACH_IS_MAC)
 362                 return 0;
 363
 364 #ifdef DEBUG_SERIAL
 365         if (!strcmp(arg, "ser") || !strcmp(arg, "ser1")) {
 366                 /* Mac modem port */
 367                 mac_init_scc_port(B9600|CS8, 0);
 368                 mac_console_driver.write = mac_scca_console_write;
 369                 scc_port = 0;
 370         } else if (!strcmp(arg, "ser2")) {
 371                 /* Mac printer port */
 372                 mac_init_scc_port(B9600|CS8, 1);
 373                 mac_console_driver.write = mac_sccb_console_write;
 374                 scc_port = 1;
 375         }
 376 #endif
 377 #ifdef DEBUG_HEADS
 378         if (!strcmp(arg, "scn") || !strcmp(arg, "con")) {
 379                 /* display, using head.S console routines */
 380                 mac_console_driver.write = mac_debug_console_write;
 381         }
 382 #endif
 383         if (mac_console_driver.write)
 384                 register_console(&mac_console_driver);
 385         return 0;
 386 }
 387
 388 early_param("debug", mac_debug_setup);