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