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/macints.h>
  28
  29 extern unsigned long mac_videobase;
  30 extern unsigned long mac_rowbytes;
  31
  32 extern void mac_serial_print(const char *);
  33
  34 #define DEBUG_HEADS
  35 #undef DEBUG_SCREEN
  36 #define DEBUG_SERIAL
  37
  38 /*
  39  * These two auxiliary debug functions should go away ASAP. Only usage:
  40  * before the console output is up (after head.S come some other crucial
  41  * setup routines :-) it permits writing 'data' to the screen as bit patterns
  42  * (good luck reading those). Helped to figure that the bootinfo contained
  43  * garbage data on the amount and size of memory chunks ...
  44  *
  45  * The 'pos' argument now simply means 'linefeed after print' ...
  46  */
  47
  48 #ifdef DEBUG_SCREEN
  49 static int peng, line;
  50 #endif
  51
  52 #if 0
  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 #endif  /*  0  */
 129
 130 #ifdef DEBUG_SERIAL
 131 /*
 132  * TODO: serial debug code
 133  */
 134
 135 struct mac_SCC {
 136         u_char cha_b_ctrl;
 137         u_char char_dummy1;
 138         u_char cha_a_ctrl;
 139         u_char char_dummy2;
 140         u_char cha_b_data;
 141         u_char char_dummy3;
 142         u_char cha_a_data;
 143 };
 144
 145 # define scc (*((volatile struct mac_SCC*)mac_bi_data.sccbase))
 146
 147 static int scc_port = -1;
 148
 149 static struct console mac_console_driver = {
 150         .name   = "debug",
 151         .flags  = CON_PRINTBUFFER,
 152         .index  = -1,
 153 };
 154
 155 /*
 156  * Crude hack to get console output to the screen before the framebuffer
 157  * is initialized (happens a lot later in 2.1!).
 158  * We just use the console routines declared in head.S, this will interfere
 159  * with regular framebuffer console output and should be used exclusively
 160  * to debug kernel problems manifesting before framebuffer init (aka WSOD)
 161  *
 162  * To keep this hack from interfering with the regular console driver, either
 163  * deregister this driver before/on framebuffer console init, or silence this
 164  * function after the fbcon driver is running (will lose console messages!?).
 165  * To debug real early bugs, need to write a 'mac_register_console_hack()'
 166  * that is called from start_kernel() before setup_arch() and just registers
 167  * this driver if Mac.
 168  */
 169
 170 static void mac_debug_console_write(struct console *co, const char *str,
 171                                     unsigned int count)
 172 {
 173         mac_serial_print(str);
 174 }
 175
 176
 177
 178 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
 179
 180 #define uSEC 1
 181
 182 static inline void mac_sccb_out(char c)
 183 {
 184         int i;
 185
 186         do {
 187                 for (i = uSEC; i > 0; --i)
 188                         barrier();
 189         } while (!(scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
 190         for (i = uSEC; i > 0; --i)
 191                 barrier();
 192         scc.cha_b_data = c;
 193 }
 194
 195 static inline void mac_scca_out(char c)
 196 {
 197         int i;
 198
 199         do {
 200                 for (i = uSEC; i > 0; --i)
 201                         barrier();
 202         } while (!(scc.cha_a_ctrl & 0x04)); /* wait for tx buf empty */
 203         for (i = uSEC; i > 0; --i)
 204                 barrier();
 205         scc.cha_a_data = c;
 206 }
 207
 208 static void mac_sccb_console_write(struct console *co, const char *str,
 209                                    unsigned int count)
 210 {
 211         while (count--) {
 212                 if (*str == '\n')
 213                         mac_sccb_out('\r');
 214                 mac_sccb_out(*str++);
 215         }
 216 }
 217
 218 static void mac_scca_console_write(struct console *co, const char *str,
 219                                    unsigned int count)
 220 {
 221         while (count--) {
 222                 if (*str == '\n')
 223                         mac_scca_out('\r');
 224                 mac_scca_out(*str++);
 225         }
 226 }
 227
 228
 229 /* The following two functions do a quick'n'dirty initialization of the MFP or
 230  * SCC serial ports. They're used by the debugging interface, kgdb, and the
 231  * serial console code. */
 232 #define SCCB_WRITE(reg,val)                             \
 233         do {                                            \
 234                 int i;                                  \
 235                 scc.cha_b_ctrl = (reg);                 \
 236                 for (i = uSEC; i > 0; --i)              \
 237                         barrier();                      \
 238                 scc.cha_b_ctrl = (val);                 \
 239                 for (i = uSEC; i > 0; --i)              \
 240                         barrier();                      \
 241         } while(0)
 242
 243 #define SCCA_WRITE(reg,val)                             \
 244         do {                                            \
 245                 int i;                                  \
 246                 scc.cha_a_ctrl = (reg);                 \
 247                 for (i = uSEC; i > 0; --i)              \
 248                         barrier();                      \
 249                 scc.cha_a_ctrl = (val);                 \
 250                 for (i = uSEC; i > 0; --i)              \
 251                         barrier();                      \
 252         } while(0)
 253
 254 /* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
 255  * delay of ~ 60us. */
 256 /* Mac: loops_per_jiffy min. 19000 ^= .5 us; MFPDELAY was 0.6 us*/
 257 #define LONG_DELAY()                                    \
 258         do {                                            \
 259                 int i;                                  \
 260                 for (i = 60*uSEC; i > 0; --i)           \
 261                     barrier();                          \
 262         } while(0)
 263
 264 static void __init mac_init_scc_port(int cflag, int port)
 265 {
 266         /*
 267          * baud rates: 1200, 1800, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, 115.2k
 268          */
 269
 270         static int clksrc_table[9] =
 271                 /* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
 272                 { 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
 273         static int clkmode_table[9] =
 274                 /* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
 275                 { 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
 276         static int div_table[9] =
 277                 /* reg12 (BRG low) */
 278                 { 94, 62, 46, 22, 10, 4, 1, 0, 0 };
 279
 280         int baud = cflag & CBAUD;
 281         int clksrc, clkmode, div, reg3, reg5;
 282
 283         if (cflag & CBAUDEX)
 284                 baud += B38400;
 285         if (baud < B1200 || baud > B38400+2)
 286                 baud = B9600; /* use default 9600bps for non-implemented rates */
 287         baud -= B1200; /* tables starts at 1200bps */
 288
 289         clksrc  = clksrc_table[baud];
 290         clkmode = clkmode_table[baud];
 291         div     = div_table[baud];
 292
 293         reg3 = (((cflag & CSIZE) == CS8) ? 0xc0 : 0x40);
 294         reg5 = (((cflag & CSIZE) == CS8) ? 0x60 : 0x20) | 0x82 /* assert DTR/RTS */;
 295
 296         if (port == 1) {
 297                 (void)scc.cha_b_ctrl;   /* reset reg pointer */
 298                 SCCB_WRITE(9, 0xc0);    /* reset */
 299                 LONG_DELAY();           /* extra delay after WR9 access */
 300                 SCCB_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
 301                            0x04 /* 1 stopbit */ |
 302                            clkmode);
 303                 SCCB_WRITE(3, reg3);
 304                 SCCB_WRITE(5, reg5);
 305                 SCCB_WRITE(9, 0);       /* no interrupts */
 306                 LONG_DELAY();           /* extra delay after WR9 access */
 307                 SCCB_WRITE(10, 0);      /* NRZ mode */
 308                 SCCB_WRITE(11, clksrc); /* main clock source */
 309                 SCCB_WRITE(12, div);    /* BRG value */
 310                 SCCB_WRITE(13, 0);      /* BRG high byte */
 311                 SCCB_WRITE(14, 1);
 312                 SCCB_WRITE(3, reg3 | 1);
 313                 SCCB_WRITE(5, reg5 | 8);
 314         } else if (port == 0) {
 315                 (void)scc.cha_a_ctrl;   /* reset reg pointer */
 316                 SCCA_WRITE(9, 0xc0);    /* reset */
 317                 LONG_DELAY();           /* extra delay after WR9 access */
 318                 SCCA_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03) : 0 |
 319                           0x04 /* 1 stopbit */ |
 320                           clkmode);
 321                 SCCA_WRITE(3, reg3);
 322                 SCCA_WRITE(5, reg5);
 323                 SCCA_WRITE(9, 0);       /* no interrupts */
 324                 LONG_DELAY();           /* extra delay after WR9 access */
 325                 SCCA_WRITE(10, 0);      /* NRZ mode */
 326                 SCCA_WRITE(11, clksrc); /* main clock source */
 327                 SCCA_WRITE(12, div);    /* BRG value */
 328                 SCCA_WRITE(13, 0);      /* BRG high byte */
 329                 SCCA_WRITE(14, 1);
 330                 SCCA_WRITE(3, reg3 | 1);
 331                 SCCA_WRITE(5, reg5 | 8);
 332         }
 333 }
 334 #endif /* DEBUG_SERIAL */
 335
 336 static int __init mac_debug_setup(char *arg)
 337 {
 338         if (!MACH_IS_MAC)
 339                 return 0;
 340
 341 #ifdef DEBUG_SERIAL
 342         if (!strcmp(arg, "ser") || !strcmp(arg, "ser1")) {
 343                 /* Mac modem port */
 344                 mac_init_scc_port(B9600|CS8, 0);
 345                 mac_console_driver.write = mac_scca_console_write;
 346                 scc_port = 0;
 347         } else if (!strcmp(arg, "ser2")) {
 348                 /* Mac printer port */
 349                 mac_init_scc_port(B9600|CS8, 1);
 350                 mac_console_driver.write = mac_sccb_console_write;
 351                 scc_port = 1;
 352         }
 353 #endif
 354 #ifdef DEBUG_HEADS
 355         if (!strcmp(arg, "scn") || !strcmp(arg, "con")) {
 356                 /* display, using head.S console routines */
 357                 mac_console_driver.write = mac_debug_console_write;
 358         }
 359 #endif
 360         if (mac_console_driver.write)
 361                 register_console(&mac_console_driver);
 362         return 0;
 363 }
 364
 365 early_param("debug", mac_debug_setup);