drivers/staging/android/fiq_debugger/fiq_debugger.c

   1 /*
   2  * drivers/staging/android/fiq_debugger.c
   3  *
   4  * Serial Debugger Interface accessed through an FIQ interrupt.
   5  *
   6  * Copyright (C) 2008 Google, Inc.
   7  *
   8  * This software is licensed under the terms of the GNU General Public
   9  * License version 2, as published by the Free Software Foundation, and
  10  * may be copied, distributed, and modified under those terms.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <stdarg.h>
  19 #include <linux/module.h>
  20 #include <linux/io.h>
  21 #include <linux/console.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/clk.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/kmsg_dump.h>
  27 #include <linux/irq.h>
  28 #include <linux/delay.h>
  29 #include <linux/reboot.h>
  30 #include <linux/sched.h>
  31 #include <linux/slab.h>
  32 #include <linux/smp.h>
  33 #include <linux/timer.h>
  34 #include <linux/tty.h>
  35 #include <linux/tty_flip.h>
  36 #include <linux/wakelock.h>
  37
  38 #ifdef CONFIG_FIQ_GLUE
  39 #include <asm/fiq_glue.h>
  40 #endif
  41
  42 #include <linux/uaccess.h>
  43
  44 #include "fiq_debugger.h"
  45 #include "fiq_debugger_priv.h"
  46 #include "fiq_debugger_ringbuf.h"
  47
  48 #define DEBUG_MAX 64
  49 #define MAX_UNHANDLED_FIQ_COUNT 1000000
  50
  51 #define MAX_FIQ_DEBUGGER_PORTS 4
  52
  53 struct fiq_debugger_state {
  54 #ifdef CONFIG_FIQ_GLUE
  55         struct fiq_glue_handler handler;
  56 #endif
  57         struct fiq_debugger_output output;
  58
  59         int fiq;
  60         int uart_irq;
  61         int signal_irq;
  62         int wakeup_irq;
  63         bool wakeup_irq_no_set_wake;
  64         struct clk *clk;
  65         struct fiq_debugger_pdata *pdata;
  66         struct platform_device *pdev;
  67
  68         char debug_cmd[DEBUG_MAX];
  69         int debug_busy;
  70         int debug_abort;
  71
  72         char debug_buf[DEBUG_MAX];
  73         int debug_count;
  74
  75         bool no_sleep;
  76         bool debug_enable;
  77         bool ignore_next_wakeup_irq;
  78         struct timer_list sleep_timer;
  79         spinlock_t sleep_timer_lock;
  80         bool uart_enabled;
  81         struct wake_lock debugger_wake_lock;
  82         bool console_enable;
  83         int current_cpu;
  84         atomic_t unhandled_fiq_count;
  85         bool in_fiq;
  86
  87         struct work_struct work;
  88         spinlock_t work_lock;
  89         char work_cmd[DEBUG_MAX];
  90
  91 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
  92         spinlock_t console_lock;
  93         struct console console;
  94         struct tty_port tty_port;
  95         struct fiq_debugger_ringbuf *tty_rbuf;
  96         bool syslog_dumping;
  97 #endif
  98
  99         unsigned int last_irqs[NR_IRQS];
 100         unsigned int last_local_timer_irqs[NR_CPUS];
 101 };
 102
 103 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 104 struct tty_driver *fiq_tty_driver;
 105 #endif
 106
 107 #ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
 108 static bool initial_no_sleep = true;
 109 #else
 110 static bool initial_no_sleep;
 111 #endif
 112
 113 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
 114 static bool initial_debug_enable = true;
 115 static bool initial_console_enable = true;
 116 #else
 117 static bool initial_debug_enable;
 118 static bool initial_console_enable;
 119 #endif
 120
 121 static bool fiq_kgdb_enable;
 122
 123 module_param_named(no_sleep, initial_no_sleep, bool, 0644);
 124 module_param_named(debug_enable, initial_debug_enable, bool, 0644);
 125 module_param_named(console_enable, initial_console_enable, bool, 0644);
 126 module_param_named(kgdb_enable, fiq_kgdb_enable, bool, 0644);
 127
 128 #ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
 129 static inline
 130 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state) {}
 131 static inline
 132 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state) {}
 133 #else
 134 static inline
 135 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state)
 136 {
 137         if (state->wakeup_irq < 0)
 138                 return;
 139         enable_irq(state->wakeup_irq);
 140         if (!state->wakeup_irq_no_set_wake)
 141                 enable_irq_wake(state->wakeup_irq);
 142 }
 143 static inline
 144 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state)
 145 {
 146         if (state->wakeup_irq < 0)
 147                 return;
 148         disable_irq_nosync(state->wakeup_irq);
 149         if (!state->wakeup_irq_no_set_wake)
 150                 disable_irq_wake(state->wakeup_irq);
 151 }
 152 #endif
 153
 154 static inline bool fiq_debugger_have_fiq(struct fiq_debugger_state *state)
 155 {
 156         return (state->fiq >= 0);
 157 }
 158
 159 #ifdef CONFIG_FIQ_GLUE
 160 static void fiq_debugger_force_irq(struct fiq_debugger_state *state)
 161 {
 162         unsigned int irq = state->signal_irq;
 163
 164         if (WARN_ON(!fiq_debugger_have_fiq(state)))
 165                 return;
 166         if (state->pdata->force_irq) {
 167                 state->pdata->force_irq(state->pdev, irq);
 168         } else {
 169                 struct irq_chip *chip = irq_get_chip(irq);
 170                 if (chip && chip->irq_retrigger)
 171                         chip->irq_retrigger(irq_get_irq_data(irq));
 172         }
 173 }
 174 #endif
 175
 176 static void fiq_debugger_uart_enable(struct fiq_debugger_state *state)
 177 {
 178         if (state->clk)
 179                 clk_enable(state->clk);
 180         if (state->pdata->uart_enable)
 181                 state->pdata->uart_enable(state->pdev);
 182 }
 183
 184 static void fiq_debugger_uart_disable(struct fiq_debugger_state *state)
 185 {
 186         if (state->pdata->uart_disable)
 187                 state->pdata->uart_disable(state->pdev);
 188         if (state->clk)
 189                 clk_disable(state->clk);
 190 }
 191
 192 static void fiq_debugger_uart_flush(struct fiq_debugger_state *state)
 193 {
 194         if (state->pdata->uart_flush)
 195                 state->pdata->uart_flush(state->pdev);
 196 }
 197
 198 static void fiq_debugger_putc(struct fiq_debugger_state *state, char c)
 199 {
 200         state->pdata->uart_putc(state->pdev, c);
 201 }
 202
 203 static void fiq_debugger_puts(struct fiq_debugger_state *state, char *s)
 204 {
 205         unsigned c;
 206         while ((c = *s++)) {
 207                 if (c == '\n')
 208                         fiq_debugger_putc(state, '\r');
 209                 fiq_debugger_putc(state, c);
 210         }
 211 }
 212
 213 static void fiq_debugger_prompt(struct fiq_debugger_state *state)
 214 {
 215         fiq_debugger_puts(state, "debug> ");
 216 }
 217
 218 static void fiq_debugger_dump_kernel_log(struct fiq_debugger_state *state)
 219 {
 220         char buf[512];
 221         size_t len;
 222         struct kmsg_dumper dumper = { .active = true };
 223
 224
 225         kmsg_dump_rewind_nolock(&dumper);
 226         while (kmsg_dump_get_line_nolock(&dumper, true, buf,
 227                                          sizeof(buf) - 1, &len)) {
 228                 buf[len] = 0;
 229                 fiq_debugger_puts(state, buf);
 230         }
 231 }
 232
 233 static void fiq_debugger_printf(struct fiq_debugger_output *output,
 234                                const char *fmt, ...)
 235 {
 236         struct fiq_debugger_state *state;
 237         char buf[256];
 238         va_list ap;
 239
 240         state = container_of(output, struct fiq_debugger_state, output);
 241         va_start(ap, fmt);
 242         vsnprintf(buf, sizeof(buf), fmt, ap);
 243         va_end(ap);
 244
 245         fiq_debugger_puts(state, buf);
 246 }
 247
 248 /* Safe outside fiq context */
 249 static int fiq_debugger_printf_nfiq(void *cookie, const char *fmt, ...)
 250 {
 251         struct fiq_debugger_state *state = cookie;
 252         char buf[256];
 253         va_list ap;
 254         unsigned long irq_flags;
 255
 256         va_start(ap, fmt);
 257         vsnprintf(buf, 128, fmt, ap);
 258         va_end(ap);
 259
 260         local_irq_save(irq_flags);
 261         fiq_debugger_puts(state, buf);
 262         fiq_debugger_uart_flush(state);
 263         local_irq_restore(irq_flags);
 264         return state->debug_abort;
 265 }
 266
 267 static void fiq_debugger_dump_irqs(struct fiq_debugger_state *state)
 268 {
 269         int n;
 270         struct irq_desc *desc;
 271
 272         fiq_debugger_printf(&state->output,
 273                         "irqnr       total  since-last   status  name\n");
 274         for_each_irq_desc(n, desc) {
 275                 struct irqaction *act = desc->action;
 276                 if (!act && !kstat_irqs(n))
 277                         continue;
 278                 fiq_debugger_printf(&state->output, "%5d: %10u %11u %8x  %s\n", n,
 279                         kstat_irqs(n),
 280                         kstat_irqs(n) - state->last_irqs[n],
 281                         desc->status_use_accessors,
 282                         (act && act->name) ? act->name : "???");
 283                 state->last_irqs[n] = kstat_irqs(n);
 284         }
 285 }
 286
 287 static void fiq_debugger_do_ps(struct fiq_debugger_state *state)
 288 {
 289         struct task_struct *g;
 290         struct task_struct *p;
 291         unsigned task_state;
 292         static const char stat_nam[] = "RSDTtZX";
 293
 294         fiq_debugger_printf(&state->output, "pid   ppid  prio task            pc\n");
 295         read_lock(&tasklist_lock);
 296         do_each_thread(g, p) {
 297                 task_state = p->state ? __ffs(p->state) + 1 : 0;
 298                 fiq_debugger_printf(&state->output,
 299                              "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
 300                 fiq_debugger_printf(&state->output, "%-13.13s %c", p->comm,
 301                              task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
 302                 if (task_state == TASK_RUNNING)
 303                         fiq_debugger_printf(&state->output, " running\n");
 304                 else
 305                         fiq_debugger_printf(&state->output, " %08lx\n",
 306                                         thread_saved_pc(p));
 307         } while_each_thread(g, p);
 308         read_unlock(&tasklist_lock);
 309 }
 310
 311 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 312 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 313 {
 314         state->syslog_dumping = true;
 315 }
 316
 317 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 318 {
 319         state->syslog_dumping = false;
 320 }
 321 #else
 322 extern int do_syslog(int type, char __user *bug, int count);
 323 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 324 {
 325         do_syslog(5 /* clear */, NULL, 0);
 326 }
 327
 328 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 329 {
 330         fiq_debugger_dump_kernel_log(state);
 331 }
 332 #endif
 333
 334 static void fiq_debugger_do_sysrq(struct fiq_debugger_state *state, char rq)
 335 {
 336         if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {
 337                 fiq_debugger_printf(&state->output, "sysrq-g blocked\n");
 338                 return;
 339         }
 340         fiq_debugger_begin_syslog_dump(state);
 341         handle_sysrq(rq);
 342         fiq_debugger_end_syslog_dump(state);
 343 }
 344
 345 #ifdef CONFIG_KGDB
 346 static void fiq_debugger_do_kgdb(struct fiq_debugger_state *state)
 347 {
 348         if (!fiq_kgdb_enable) {
 349                 fiq_debugger_printf(&state->output, "kgdb through fiq debugger not enabled\n");
 350                 return;
 351         }
 352
 353         fiq_debugger_printf(&state->output, "enabling console and triggering kgdb\n");
 354         state->console_enable = true;
 355         handle_sysrq('g');
 356 }
 357 #endif
 358
 359 static void fiq_debugger_schedule_work(struct fiq_debugger_state *state,
 360                 char *cmd)
 361 {
 362         unsigned long flags;
 363
 364         spin_lock_irqsave(&state->work_lock, flags);
 365         if (state->work_cmd[0] != '\0') {
 366                 fiq_debugger_printf(&state->output, "work command processor busy\n");
 367                 spin_unlock_irqrestore(&state->work_lock, flags);
 368                 return;
 369         }
 370
 371         strlcpy(state->work_cmd, cmd, sizeof(state->work_cmd));
 372         spin_unlock_irqrestore(&state->work_lock, flags);
 373
 374         schedule_work(&state->work);
 375 }
 376
 377 static void fiq_debugger_work(struct work_struct *work)
 378 {
 379         struct fiq_debugger_state *state;
 380         char work_cmd[DEBUG_MAX];
 381         char *cmd;
 382         unsigned long flags;
 383
 384         state = container_of(work, struct fiq_debugger_state, work);
 385
 386         spin_lock_irqsave(&state->work_lock, flags);
 387
 388         strlcpy(work_cmd, state->work_cmd, sizeof(work_cmd));
 389         state->work_cmd[0] = '\0';
 390
 391         spin_unlock_irqrestore(&state->work_lock, flags);
 392
 393         cmd = work_cmd;
 394         if (!strncmp(cmd, "reboot", 6)) {
 395                 cmd += 6;
 396                 while (*cmd == ' ')
 397                         cmd++;
 398                 if (cmd != '\0')
 399                         kernel_restart(cmd);
 400                 else
 401                         kernel_restart(NULL);
 402         } else {
 403                 fiq_debugger_printf(&state->output, "unknown work command '%s'\n",
 404                                 work_cmd);
 405         }
 406 }
 407
 408 /* This function CANNOT be called in FIQ context */
 409 static void fiq_debugger_irq_exec(struct fiq_debugger_state *state, char *cmd)
 410 {
 411         if (!strcmp(cmd, "ps"))
 412                 fiq_debugger_do_ps(state);
 413         if (!strcmp(cmd, "sysrq"))
 414                 fiq_debugger_do_sysrq(state, 'h');
 415         if (!strncmp(cmd, "sysrq ", 6))
 416                 fiq_debugger_do_sysrq(state, cmd[6]);
 417 #ifdef CONFIG_KGDB
 418         if (!strcmp(cmd, "kgdb"))
 419                 fiq_debugger_do_kgdb(state);
 420 #endif
 421         if (!strncmp(cmd, "reboot", 6))
 422                 fiq_debugger_schedule_work(state, cmd);
 423 }
 424
 425 static void fiq_debugger_help(struct fiq_debugger_state *state)
 426 {
 427         fiq_debugger_printf(&state->output,
 428                                 "FIQ Debugger commands:\n"
 429                                 " pc            PC status\n"
 430                                 " regs          Register dump\n"
 431                                 " allregs       Extended Register dump\n"
 432                                 " bt            Stack trace\n"
 433                                 " reboot [<c>]  Reboot with command <c>\n"
 434                                 " reset [<c>]   Hard reset with command <c>\n"
 435                                 " irqs          Interupt status\n"
 436                                 " kmsg          Kernel log\n"
 437                                 " version       Kernel version\n");
 438         fiq_debugger_printf(&state->output,
 439                                 " sleep         Allow sleep while in FIQ\n"
 440                                 " nosleep       Disable sleep while in FIQ\n"
 441                                 " console       Switch terminal to console\n"
 442                                 " cpu           Current CPU\n"
 443                                 " cpu <number>  Switch to CPU<number>\n");
 444         fiq_debugger_printf(&state->output,
 445                                 " ps            Process list\n"
 446                                 " sysrq         sysrq options\n"
 447                                 " sysrq <param> Execute sysrq with <param>\n");
 448 #ifdef CONFIG_KGDB
 449         fiq_debugger_printf(&state->output,
 450                                 " kgdb          Enter kernel debugger\n");
 451 #endif
 452 }
 453
 454 static void fiq_debugger_take_affinity(void *info)
 455 {
 456         struct fiq_debugger_state *state = info;
 457         struct cpumask cpumask;
 458
 459         cpumask_clear(&cpumask);
 460         cpumask_set_cpu(get_cpu(), &cpumask);
 461
 462         irq_set_affinity(state->uart_irq, &cpumask);
 463 }
 464
 465 static void fiq_debugger_switch_cpu(struct fiq_debugger_state *state, int cpu)
 466 {
 467         if (!fiq_debugger_have_fiq(state))
 468                 smp_call_function_single(cpu, fiq_debugger_take_affinity, state,
 469                                 false);
 470         state->current_cpu = cpu;
 471 }
 472
 473 static bool fiq_debugger_fiq_exec(struct fiq_debugger_state *state,
 474                         const char *cmd, const struct pt_regs *regs,
 475                         void *svc_sp)
 476 {
 477         bool signal_helper = false;
 478
 479         if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
 480                 fiq_debugger_help(state);
 481         } else if (!strcmp(cmd, "pc")) {
 482                 fiq_debugger_dump_pc(&state->output, regs);
 483         } else if (!strcmp(cmd, "regs")) {
 484                 fiq_debugger_dump_regs(&state->output, regs);
 485         } else if (!strcmp(cmd, "allregs")) {
 486                 fiq_debugger_dump_allregs(&state->output, regs);
 487         } else if (!strcmp(cmd, "bt")) {
 488                 fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
 489         } else if (!strncmp(cmd, "reset", 5)) {
 490                 cmd += 5;
 491                 while (*cmd == ' ')
 492                         cmd++;
 493                 if (*cmd) {
 494                         char tmp_cmd[32];
 495                         strlcpy(tmp_cmd, cmd, sizeof(tmp_cmd));
 496                         machine_restart(tmp_cmd);
 497                 } else {
 498                         machine_restart(NULL);
 499                 }
 500         } else if (!strcmp(cmd, "irqs")) {
 501                 fiq_debugger_dump_irqs(state);
 502         } else if (!strcmp(cmd, "kmsg")) {
 503                 fiq_debugger_dump_kernel_log(state);
 504         } else if (!strcmp(cmd, "version")) {
 505                 fiq_debugger_printf(&state->output, "%s\n", linux_banner);
 506         } else if (!strcmp(cmd, "sleep")) {
 507                 state->no_sleep = false;
 508                 fiq_debugger_printf(&state->output, "enabling sleep\n");
 509         } else if (!strcmp(cmd, "nosleep")) {
 510                 state->no_sleep = true;
 511                 fiq_debugger_printf(&state->output, "disabling sleep\n");
 512         } else if (!strcmp(cmd, "console")) {
 513                 fiq_debugger_printf(&state->output, "console mode\n");
 514                 fiq_debugger_uart_flush(state);
 515                 state->console_enable = true;
 516         } else if (!strcmp(cmd, "cpu")) {
 517                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 518         } else if (!strncmp(cmd, "cpu ", 4)) {
 519                 unsigned long cpu = 0;
 520                 if (strict_strtoul(cmd + 4, 10, &cpu) == 0)
 521                         fiq_debugger_switch_cpu(state, cpu);
 522                 else
 523                         fiq_debugger_printf(&state->output, "invalid cpu\n");
 524                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 525         } else {
 526                 if (state->debug_busy) {
 527                         fiq_debugger_printf(&state->output,
 528                                 "command processor busy. trying to abort.\n");
 529                         state->debug_abort = -1;
 530                 } else {
 531                         strcpy(state->debug_cmd, cmd);
 532                         state->debug_busy = 1;
 533                 }
 534
 535                 return true;
 536         }
 537         if (!state->console_enable)
 538                 fiq_debugger_prompt(state);
 539
 540         return signal_helper;
 541 }
 542
 543 static void fiq_debugger_sleep_timer_expired(unsigned long data)
 544 {
 545         struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
 546         unsigned long flags;
 547
 548         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 549         if (state->uart_enabled && !state->no_sleep) {
 550                 if (state->debug_enable && !state->console_enable) {
 551                         state->debug_enable = false;
 552                         fiq_debugger_printf_nfiq(state,
 553                                         "suspending fiq debugger\n");
 554                 }
 555                 state->ignore_next_wakeup_irq = true;
 556                 fiq_debugger_uart_disable(state);
 557                 state->uart_enabled = false;
 558                 fiq_debugger_enable_wakeup_irq(state);
 559         }
 560         wake_unlock(&state->debugger_wake_lock);
 561         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 562 }
 563
 564 static void fiq_debugger_handle_wakeup(struct fiq_debugger_state *state)
 565 {
 566         unsigned long flags;
 567
 568         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 569         if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
 570                 state->ignore_next_wakeup_irq = false;
 571         } else if (!state->uart_enabled) {
 572                 wake_lock(&state->debugger_wake_lock);
 573                 fiq_debugger_uart_enable(state);
 574                 state->uart_enabled = true;
 575                 fiq_debugger_disable_wakeup_irq(state);
 576                 mod_timer(&state->sleep_timer, jiffies + HZ / 2);
 577         }
 578         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 579 }
 580
 581 static irqreturn_t fiq_debugger_wakeup_irq_handler(int irq, void *dev)
 582 {
 583         struct fiq_debugger_state *state = dev;
 584
 585         if (!state->no_sleep)
 586                 fiq_debugger_puts(state, "WAKEUP\n");
 587         fiq_debugger_handle_wakeup(state);
 588
 589         return IRQ_HANDLED;
 590 }
 591
 592 static
 593 void fiq_debugger_handle_console_irq_context(struct fiq_debugger_state *state)
 594 {
 595 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 596         if (state->tty_port.ops) {
 597                 int i;
 598                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 599                 for (i = 0; i < count; i++) {
 600                         int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 601                         tty_insert_flip_char(&state->tty_port, c, TTY_NORMAL);
 602                         if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
 603                                 pr_warn("fiq tty failed to consume byte\n");
 604                 }
 605                 tty_flip_buffer_push(&state->tty_port);
 606         }
 607 #endif
 608 }
 609
 610 static void fiq_debugger_handle_irq_context(struct fiq_debugger_state *state)
 611 {
 612         if (!state->no_sleep) {
 613                 unsigned long flags;
 614
 615                 spin_lock_irqsave(&state->sleep_timer_lock, flags);
 616                 wake_lock(&state->debugger_wake_lock);
 617                 mod_timer(&state->sleep_timer, jiffies + HZ * 5);
 618                 spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 619         }
 620         fiq_debugger_handle_console_irq_context(state);
 621         if (state->debug_busy) {
 622                 fiq_debugger_irq_exec(state, state->debug_cmd);
 623                 if (!state->console_enable)
 624                         fiq_debugger_prompt(state);
 625                 state->debug_busy = 0;
 626         }
 627 }
 628
 629 static int fiq_debugger_getc(struct fiq_debugger_state *state)
 630 {
 631         return state->pdata->uart_getc(state->pdev);
 632 }
 633
 634 static bool fiq_debugger_handle_uart_interrupt(struct fiq_debugger_state *state,
 635                         int this_cpu, const struct pt_regs *regs, void *svc_sp)
 636 {
 637         int c;
 638         static int last_c;
 639         int count = 0;
 640         bool signal_helper = false;
 641
 642         if (this_cpu != state->current_cpu) {
 643                 if (state->in_fiq)
 644                         return false;
 645
 646                 if (atomic_inc_return(&state->unhandled_fiq_count) !=
 647                                         MAX_UNHANDLED_FIQ_COUNT)
 648                         return false;
 649
 650                 fiq_debugger_printf(&state->output,
 651                         "fiq_debugger: cpu %d not responding, "
 652                         "reverting to cpu %d\n", state->current_cpu,
 653                         this_cpu);
 654
 655                 atomic_set(&state->unhandled_fiq_count, 0);
 656                 fiq_debugger_switch_cpu(state, this_cpu);
 657                 return false;
 658         }
 659
 660         state->in_fiq = true;
 661
 662         while ((c = fiq_debugger_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
 663                 count++;
 664                 if (!state->debug_enable) {
 665                         if ((c == 13) || (c == 10)) {
 666                                 state->debug_enable = true;
 667                                 state->debug_count = 0;
 668                                 fiq_debugger_prompt(state);
 669                         }
 670                 } else if (c == FIQ_DEBUGGER_BREAK) {
 671                         state->console_enable = false;
 672                         fiq_debugger_puts(state, "fiq debugger mode\n");
 673                         state->debug_count = 0;
 674                         fiq_debugger_prompt(state);
 675 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 676                 } else if (state->console_enable && state->tty_rbuf) {
 677                         fiq_debugger_ringbuf_push(state->tty_rbuf, c);
 678                         signal_helper = true;
 679 #endif
 680                 } else if ((c >= ' ') && (c < 127)) {
 681                         if (state->debug_count < (DEBUG_MAX - 1)) {
 682                                 state->debug_buf[state->debug_count++] = c;
 683                                 fiq_debugger_putc(state, c);
 684                         }
 685                 } else if ((c == 8) || (c == 127)) {
 686                         if (state->debug_count > 0) {
 687                                 state->debug_count--;
 688                                 fiq_debugger_putc(state, 8);
 689                                 fiq_debugger_putc(state, ' ');
 690                                 fiq_debugger_putc(state, 8);
 691                         }
 692                 } else if ((c == 13) || (c == 10)) {
 693                         if (c == '\r' || (c == '\n' && last_c != '\r')) {
 694                                 fiq_debugger_putc(state, '\r');
 695                                 fiq_debugger_putc(state, '\n');
 696                         }
 697                         if (state->debug_count) {
 698                                 state->debug_buf[state->debug_count] = 0;
 699                                 state->debug_count = 0;
 700                                 signal_helper |=
 701                                         fiq_debugger_fiq_exec(state,
 702                                                         state->debug_buf,
 703                                                         regs, svc_sp);
 704                         } else {
 705                                 fiq_debugger_prompt(state);
 706                         }
 707                 }
 708                 last_c = c;
 709         }
 710         if (!state->console_enable)
 711                 fiq_debugger_uart_flush(state);
 712         if (state->pdata->fiq_ack)
 713                 state->pdata->fiq_ack(state->pdev, state->fiq);
 714
 715         /* poke sleep timer if necessary */
 716         if (state->debug_enable && !state->no_sleep)
 717                 signal_helper = true;
 718
 719         atomic_set(&state->unhandled_fiq_count, 0);
 720         state->in_fiq = false;
 721
 722         return signal_helper;
 723 }
 724
 725 #ifdef CONFIG_FIQ_GLUE
 726 static void fiq_debugger_fiq(struct fiq_glue_handler *h,
 727                 const struct pt_regs *regs, void *svc_sp)
 728 {
 729         struct fiq_debugger_state *state =
 730                 container_of(h, struct fiq_debugger_state, handler);
 731         unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
 732         bool need_irq;
 733
 734         need_irq = fiq_debugger_handle_uart_interrupt(state, this_cpu, regs,
 735                         svc_sp);
 736         if (need_irq)
 737                 fiq_debugger_force_irq(state);
 738 }
 739 #endif
 740
 741 /*
 742  * When not using FIQs, we only use this single interrupt as an entry point.
 743  * This just effectively takes over the UART interrupt and does all the work
 744  * in this context.
 745  */
 746 static irqreturn_t fiq_debugger_uart_irq(int irq, void *dev)
 747 {
 748         struct fiq_debugger_state *state = dev;
 749         bool not_done;
 750
 751         fiq_debugger_handle_wakeup(state);
 752
 753         /* handle the debugger irq in regular context */
 754         not_done = fiq_debugger_handle_uart_interrupt(state, smp_processor_id(),
 755                                               get_irq_regs(),
 756                                               current_thread_info());
 757         if (not_done)
 758                 fiq_debugger_handle_irq_context(state);
 759
 760         return IRQ_HANDLED;
 761 }
 762
 763 /*
 764  * If FIQs are used, not everything can happen in fiq context.
 765  * FIQ handler does what it can and then signals this interrupt to finish the
 766  * job in irq context.
 767  */
 768 static irqreturn_t fiq_debugger_signal_irq(int irq, void *dev)
 769 {
 770         struct fiq_debugger_state *state = dev;
 771
 772         if (state->pdata->force_irq_ack)
 773                 state->pdata->force_irq_ack(state->pdev, state->signal_irq);
 774
 775         fiq_debugger_handle_irq_context(state);
 776
 777         return IRQ_HANDLED;
 778 }
 779
 780 #ifdef CONFIG_FIQ_GLUE
 781 static void fiq_debugger_resume(struct fiq_glue_handler *h)
 782 {
 783         struct fiq_debugger_state *state =
 784                 container_of(h, struct fiq_debugger_state, handler);
 785         if (state->pdata->uart_resume)
 786                 state->pdata->uart_resume(state->pdev);
 787 }
 788 #endif
 789
 790 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 791 struct tty_driver *fiq_debugger_console_device(struct console *co, int *index)
 792 {
 793         *index = co->index;
 794         return fiq_tty_driver;
 795 }
 796
 797 static void fiq_debugger_console_write(struct console *co,
 798                                 const char *s, unsigned int count)
 799 {
 800         struct fiq_debugger_state *state;
 801         unsigned long flags;
 802
 803         state = container_of(co, struct fiq_debugger_state, console);
 804
 805         if (!state->console_enable && !state->syslog_dumping)
 806                 return;
 807
 808         fiq_debugger_uart_enable(state);
 809         spin_lock_irqsave(&state->console_lock, flags);
 810         while (count--) {
 811                 if (*s == '\n')
 812                         fiq_debugger_putc(state, '\r');
 813                 fiq_debugger_putc(state, *s++);
 814         }
 815         fiq_debugger_uart_flush(state);
 816         spin_unlock_irqrestore(&state->console_lock, flags);
 817         fiq_debugger_uart_disable(state);
 818 }
 819
 820 static struct console fiq_debugger_console = {
 821         .name = "ttyFIQ",
 822         .device = fiq_debugger_console_device,
 823         .write = fiq_debugger_console_write,
 824         .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
 825 };
 826
 827 int fiq_tty_open(struct tty_struct *tty, struct file *filp)
 828 {
 829         int line = tty->index;
 830         struct fiq_debugger_state **states = tty->driver->driver_state;
 831         struct fiq_debugger_state *state = states[line];
 832
 833         return tty_port_open(&state->tty_port, tty, filp);
 834 }
 835
 836 void fiq_tty_close(struct tty_struct *tty, struct file *filp)
 837 {
 838         tty_port_close(tty->port, tty, filp);
 839 }
 840
 841 int  fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 842 {
 843         int i;
 844         int line = tty->index;
 845         struct fiq_debugger_state **states = tty->driver->driver_state;
 846         struct fiq_debugger_state *state = states[line];
 847
 848         if (!state->console_enable)
 849                 return count;
 850
 851         fiq_debugger_uart_enable(state);
 852         spin_lock_irq(&state->console_lock);
 853         for (i = 0; i < count; i++)
 854                 fiq_debugger_putc(state, *buf++);
 855         spin_unlock_irq(&state->console_lock);
 856         fiq_debugger_uart_disable(state);
 857
 858         return count;
 859 }
 860
 861 int  fiq_tty_write_room(struct tty_struct *tty)
 862 {
 863         return 16;
 864 }
 865
 866 #ifdef CONFIG_CONSOLE_POLL
 867 static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)
 868 {
 869         return 0;
 870 }
 871
 872 static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)
 873 {
 874         struct fiq_debugger_state **states = driver->driver_state;
 875         struct fiq_debugger_state *state = states[line];
 876         int c = NO_POLL_CHAR;
 877
 878         fiq_debugger_uart_enable(state);
 879         if (fiq_debugger_have_fiq(state)) {
 880                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 881                 if (count > 0) {
 882                         c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 883                         fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);
 884                 }
 885         } else {
 886                 c = fiq_debugger_getc(state);
 887                 if (c == FIQ_DEBUGGER_NO_CHAR)
 888                         c = NO_POLL_CHAR;
 889         }
 890         fiq_debugger_uart_disable(state);
 891
 892         return c;
 893 }
 894
 895 static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
 896 {
 897         struct fiq_debugger_state **states = driver->driver_state;
 898         struct fiq_debugger_state *state = states[line];
 899         fiq_debugger_uart_enable(state);
 900         fiq_debugger_putc(state, ch);
 901         fiq_debugger_uart_disable(state);
 902 }
 903 #endif
 904
 905 static const struct tty_port_operations fiq_tty_port_ops;
 906
 907 static const struct tty_operations fiq_tty_driver_ops = {
 908         .write = fiq_tty_write,
 909         .write_room = fiq_tty_write_room,
 910         .open = fiq_tty_open,
 911         .close = fiq_tty_close,
 912 #ifdef CONFIG_CONSOLE_POLL
 913         .poll_init = fiq_tty_poll_init,
 914         .poll_get_char = fiq_tty_poll_get_char,
 915         .poll_put_char = fiq_tty_poll_put_char,
 916 #endif
 917 };
 918
 919 static int fiq_debugger_tty_init(void)
 920 {
 921         int ret;
 922         struct fiq_debugger_state **states = NULL;
 923
 924         states = kzalloc(sizeof(*states) * MAX_FIQ_DEBUGGER_PORTS, GFP_KERNEL);
 925         if (!states) {
 926                 pr_err("Failed to allocate fiq debugger state structres\n");
 927                 return -ENOMEM;
 928         }
 929
 930         fiq_tty_driver = alloc_tty_driver(MAX_FIQ_DEBUGGER_PORTS);
 931         if (!fiq_tty_driver) {
 932                 pr_err("Failed to allocate fiq debugger tty\n");
 933                 ret = -ENOMEM;
 934                 goto err_free_state;
 935         }
 936
 937         fiq_tty_driver->owner           = THIS_MODULE;
 938         fiq_tty_driver->driver_name     = "fiq-debugger";
 939         fiq_tty_driver->name            = "ttyFIQ";
 940         fiq_tty_driver->type            = TTY_DRIVER_TYPE_SERIAL;
 941         fiq_tty_driver->subtype         = SERIAL_TYPE_NORMAL;
 942         fiq_tty_driver->init_termios    = tty_std_termios;
 943         fiq_tty_driver->flags           = TTY_DRIVER_REAL_RAW |
 944                                           TTY_DRIVER_DYNAMIC_DEV;
 945         fiq_tty_driver->driver_state    = states;
 946
 947         fiq_tty_driver->init_termios.c_cflag =
 948                                         B115200 | CS8 | CREAD | HUPCL | CLOCAL;
 949         fiq_tty_driver->init_termios.c_ispeed = 115200;
 950         fiq_tty_driver->init_termios.c_ospeed = 115200;
 951
 952         tty_set_operations(fiq_tty_driver, &fiq_tty_driver_ops);
 953
 954         ret = tty_register_driver(fiq_tty_driver);
 955         if (ret) {
 956                 pr_err("Failed to register fiq tty: %d\n", ret);
 957                 goto err_free_tty;
 958         }
 959
 960         pr_info("Registered FIQ tty driver\n");
 961         return 0;
 962
 963 err_free_tty:
 964         put_tty_driver(fiq_tty_driver);
 965         fiq_tty_driver = NULL;
 966 err_free_state:
 967         kfree(states);
 968         return ret;
 969 }
 970
 971 static int fiq_debugger_tty_init_one(struct fiq_debugger_state *state)
 972 {
 973         int ret;
 974         struct device *tty_dev;
 975         struct fiq_debugger_state **states = fiq_tty_driver->driver_state;
 976
 977         states[state->pdev->id] = state;
 978
 979         state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
 980         if (!state->tty_rbuf) {
 981                 pr_err("Failed to allocate fiq debugger ringbuf\n");
 982                 ret = -ENOMEM;
 983                 goto err;
 984         }
 985
 986         tty_port_init(&state->tty_port);
 987         state->tty_port.ops = &fiq_tty_port_ops;
 988
 989         tty_dev = tty_port_register_device(&state->tty_port, fiq_tty_driver,
 990                                            state->pdev->id, &state->pdev->dev);
 991         if (IS_ERR(tty_dev)) {
 992                 pr_err("Failed to register fiq debugger tty device\n");
 993                 ret = PTR_ERR(tty_dev);
 994                 goto err;
 995         }
 996
 997         device_set_wakeup_capable(tty_dev, 1);
 998
 999         pr_info("Registered fiq debugger ttyFIQ%d\n", state->pdev->id);
1000
1001         return 0;
1002
1003 err:
1004         fiq_debugger_ringbuf_free(state->tty_rbuf);
1005         state->tty_rbuf = NULL;
1006         return ret;
1007 }
1008 #endif
1009
1010 static int fiq_debugger_dev_suspend(struct device *dev)
1011 {
1012         struct platform_device *pdev = to_platform_device(dev);
1013         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1014
1015         if (state->pdata->uart_dev_suspend)
1016                 return state->pdata->uart_dev_suspend(pdev);
1017         return 0;
1018 }
1019
1020 static int fiq_debugger_dev_resume(struct device *dev)
1021 {
1022         struct platform_device *pdev = to_platform_device(dev);
1023         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1024
1025         if (state->pdata->uart_dev_resume)
1026                 return state->pdata->uart_dev_resume(pdev);
1027         return 0;
1028 }
1029
1030 static int fiq_debugger_probe(struct platform_device *pdev)
1031 {
1032         int ret;
1033         struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
1034         struct fiq_debugger_state *state;
1035         int fiq;
1036         int uart_irq;
1037
1038         if (pdev->id >= MAX_FIQ_DEBUGGER_PORTS)
1039                 return -EINVAL;
1040
1041         if (!pdata->uart_getc || !pdata->uart_putc)
1042                 return -EINVAL;
1043         if ((pdata->uart_enable && !pdata->uart_disable) ||
1044             (!pdata->uart_enable && pdata->uart_disable))
1045                 return -EINVAL;
1046
1047         fiq = platform_get_irq_byname(pdev, "fiq");
1048         uart_irq = platform_get_irq_byname(pdev, "uart_irq");
1049
1050         /* uart_irq mode and fiq mode are mutually exclusive, but one of them
1051          * is required */
1052         if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
1053                 return -EINVAL;
1054         if (fiq >= 0 && !pdata->fiq_enable)
1055                 return -EINVAL;
1056
1057         state = kzalloc(sizeof(*state), GFP_KERNEL);
1058         state->output.printf = fiq_debugger_printf;
1059         setup_timer(&state->sleep_timer, fiq_debugger_sleep_timer_expired,
1060                     (unsigned long)state);
1061         state->pdata = pdata;
1062         state->pdev = pdev;
1063         state->no_sleep = initial_no_sleep;
1064         state->debug_enable = initial_debug_enable;
1065         state->console_enable = initial_console_enable;
1066
1067         state->fiq = fiq;
1068         state->uart_irq = uart_irq;
1069         state->signal_irq = platform_get_irq_byname(pdev, "signal");
1070         state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
1071
1072         INIT_WORK(&state->work, fiq_debugger_work);
1073         spin_lock_init(&state->work_lock);
1074
1075         platform_set_drvdata(pdev, state);
1076
1077         spin_lock_init(&state->sleep_timer_lock);
1078
1079         if (state->wakeup_irq < 0 && fiq_debugger_have_fiq(state))
1080                 state->no_sleep = true;
1081         state->ignore_next_wakeup_irq = !state->no_sleep;
1082
1083         wake_lock_init(&state->debugger_wake_lock,
1084                         WAKE_LOCK_SUSPEND, "serial-debug");
1085
1086         state->clk = clk_get(&pdev->dev, NULL);
1087         if (IS_ERR(state->clk))
1088                 state->clk = NULL;
1089
1090         /* do not call pdata->uart_enable here since uart_init may still
1091          * need to do some initialization before uart_enable can work.
1092          * So, only try to manage the clock during init.
1093          */
1094         if (state->clk)
1095                 clk_enable(state->clk);
1096
1097         if (pdata->uart_init) {
1098                 ret = pdata->uart_init(pdev);
1099                 if (ret)
1100                         goto err_uart_init;
1101         }
1102
1103         fiq_debugger_printf_nfiq(state,
1104                                 "<hit enter %sto activate fiq debugger>\n",
1105                                 state->no_sleep ? "" : "twice ");
1106
1107 #ifdef CONFIG_FIQ_GLUE
1108         if (fiq_debugger_have_fiq(state)) {
1109                 state->handler.fiq = fiq_debugger_fiq;
1110                 state->handler.resume = fiq_debugger_resume;
1111                 ret = fiq_glue_register_handler(&state->handler);
1112                 if (ret) {
1113                         pr_err("%s: could not install fiq handler\n", __func__);
1114                         goto err_register_irq;
1115                 }
1116
1117                 pdata->fiq_enable(pdev, state->fiq, 1);
1118         } else
1119 #endif
1120         {
1121                 ret = request_irq(state->uart_irq, fiq_debugger_uart_irq,
1122                                   IRQF_NO_SUSPEND, "debug", state);
1123                 if (ret) {
1124                         pr_err("%s: could not install irq handler\n", __func__);
1125                         goto err_register_irq;
1126                 }
1127
1128                 /* for irq-only mode, we want this irq to wake us up, if it
1129                  * can.
1130                  */
1131                 enable_irq_wake(state->uart_irq);
1132         }
1133
1134         if (state->clk)
1135                 clk_disable(state->clk);
1136
1137         if (state->signal_irq >= 0) {
1138                 ret = request_irq(state->signal_irq, fiq_debugger_signal_irq,
1139                           IRQF_TRIGGER_RISING, "debug-signal", state);
1140                 if (ret)
1141                         pr_err("serial_debugger: could not install signal_irq");
1142         }
1143
1144         if (state->wakeup_irq >= 0) {
1145                 ret = request_irq(state->wakeup_irq,
1146                                   fiq_debugger_wakeup_irq_handler,
1147                                   IRQF_TRIGGER_FALLING | IRQF_DISABLED,
1148                                   "debug-wakeup", state);
1149                 if (ret) {
1150                         pr_err("serial_debugger: "
1151                                 "could not install wakeup irq\n");
1152                         state->wakeup_irq = -1;
1153                 } else {
1154                         ret = enable_irq_wake(state->wakeup_irq);
1155                         if (ret) {
1156                                 pr_err("serial_debugger: "
1157                                         "could not enable wakeup\n");
1158                                 state->wakeup_irq_no_set_wake = true;
1159                         }
1160                 }
1161         }
1162         if (state->no_sleep)
1163                 fiq_debugger_handle_wakeup(state);
1164
1165 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1166         spin_lock_init(&state->console_lock);
1167         state->console = fiq_debugger_console;
1168         state->console.index = pdev->id;
1169         if (!console_set_on_cmdline)
1170                 add_preferred_console(state->console.name,
1171                         state->console.index, NULL);
1172         register_console(&state->console);
1173         fiq_debugger_tty_init_one(state);
1174 #endif
1175         return 0;
1176
1177 err_register_irq:
1178         if (pdata->uart_free)
1179                 pdata->uart_free(pdev);
1180 err_uart_init:
1181         if (state->clk)
1182                 clk_disable(state->clk);
1183         if (state->clk)
1184                 clk_put(state->clk);
1185         wake_lock_destroy(&state->debugger_wake_lock);
1186         platform_set_drvdata(pdev, NULL);
1187         kfree(state);
1188         return ret;
1189 }
1190
1191 static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
1192         .suspend        = fiq_debugger_dev_suspend,
1193         .resume         = fiq_debugger_dev_resume,
1194 };
1195
1196 static struct platform_driver fiq_debugger_driver = {
1197         .probe  = fiq_debugger_probe,
1198         .driver = {
1199                 .name   = "fiq_debugger",
1200                 .pm     = &fiq_debugger_dev_pm_ops,
1201         },
1202 };
1203
1204 static int __init fiq_debugger_init(void)
1205 {
1206 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1207         fiq_debugger_tty_init();
1208 #endif
1209         return platform_driver_register(&fiq_debugger_driver);
1210 }
1211
1212 postcore_initcall(fiq_debugger_init);