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         fiq_debugger_printf(&state->output,
 434                                 " reboot [<c>]  Reboot with command <c>\n"
 435                                 " reset [<c>]   Hard reset with command <c>\n"
 436                                 " irqs          Interupt status\n"
 437                                 " kmsg          Kernel log\n"
 438                                 " version       Kernel version\n");
 439         fiq_debugger_printf(&state->output,
 440                                 " sleep         Allow sleep while in FIQ\n"
 441                                 " nosleep       Disable sleep while in FIQ\n"
 442                                 " console       Switch terminal to console\n"
 443                                 " cpu           Current CPU\n"
 444                                 " cpu <number>  Switch to CPU<number>\n");
 445         fiq_debugger_printf(&state->output,
 446                                 " ps            Process list\n"
 447                                 " sysrq         sysrq options\n"
 448                                 " sysrq <param> Execute sysrq with <param>\n");
 449 #ifdef CONFIG_KGDB
 450         fiq_debugger_printf(&state->output,
 451                                 " kgdb          Enter kernel debugger\n");
 452 #endif
 453 }
 454
 455 static void fiq_debugger_take_affinity(void *info)
 456 {
 457         struct fiq_debugger_state *state = info;
 458         struct cpumask cpumask;
 459
 460         cpumask_clear(&cpumask);
 461         cpumask_set_cpu(get_cpu(), &cpumask);
 462
 463         irq_set_affinity(state->uart_irq, &cpumask);
 464 }
 465
 466 static void fiq_debugger_switch_cpu(struct fiq_debugger_state *state, int cpu)
 467 {
 468         if (!fiq_debugger_have_fiq(state))
 469                 smp_call_function_single(cpu, fiq_debugger_take_affinity, state,
 470                                 false);
 471         state->current_cpu = cpu;
 472 }
 473
 474 static bool fiq_debugger_fiq_exec(struct fiq_debugger_state *state,
 475                         const char *cmd, const struct pt_regs *regs,
 476                         void *svc_sp)
 477 {
 478         bool signal_helper = false;
 479
 480         if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
 481                 fiq_debugger_help(state);
 482         } else if (!strcmp(cmd, "pc")) {
 483                 fiq_debugger_dump_pc(&state->output, regs);
 484         } else if (!strcmp(cmd, "regs")) {
 485                 fiq_debugger_dump_regs(&state->output, regs);
 486         } else if (!strcmp(cmd, "allregs")) {
 487                 fiq_debugger_dump_allregs(&state->output, regs);
 488         } else if (!strcmp(cmd, "bt")) {
 489                 fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
 490         } else if (!strncmp(cmd, "reset", 5)) {
 491                 cmd += 5;
 492                 while (*cmd == ' ')
 493                         cmd++;
 494                 if (*cmd) {
 495                         char tmp_cmd[32];
 496                         strlcpy(tmp_cmd, cmd, sizeof(tmp_cmd));
 497                         machine_restart(tmp_cmd);
 498                 } else {
 499                         machine_restart(NULL);
 500                 }
 501         } else if (!strcmp(cmd, "irqs")) {
 502                 fiq_debugger_dump_irqs(state);
 503         } else if (!strcmp(cmd, "kmsg")) {
 504                 fiq_debugger_dump_kernel_log(state);
 505         } else if (!strcmp(cmd, "version")) {
 506                 fiq_debugger_printf(&state->output, "%s\n", linux_banner);
 507         } else if (!strcmp(cmd, "sleep")) {
 508                 state->no_sleep = false;
 509                 fiq_debugger_printf(&state->output, "enabling sleep\n");
 510         } else if (!strcmp(cmd, "nosleep")) {
 511                 state->no_sleep = true;
 512                 fiq_debugger_printf(&state->output, "disabling sleep\n");
 513         } else if (!strcmp(cmd, "console")) {
 514                 fiq_debugger_printf(&state->output, "console mode\n");
 515                 fiq_debugger_uart_flush(state);
 516                 state->console_enable = true;
 517         } else if (!strcmp(cmd, "cpu")) {
 518                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 519         } else if (!strncmp(cmd, "cpu ", 4)) {
 520                 unsigned long cpu = 0;
 521                 if (strict_strtoul(cmd + 4, 10, &cpu) == 0)
 522                         fiq_debugger_switch_cpu(state, cpu);
 523                 else
 524                         fiq_debugger_printf(&state->output, "invalid cpu\n");
 525                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 526         } else {
 527                 if (state->debug_busy) {
 528                         fiq_debugger_printf(&state->output,
 529                                 "command processor busy. trying to abort.\n");
 530                         state->debug_abort = -1;
 531                 } else {
 532                         strcpy(state->debug_cmd, cmd);
 533                         state->debug_busy = 1;
 534                 }
 535
 536                 return true;
 537         }
 538         if (!state->console_enable)
 539                 fiq_debugger_prompt(state);
 540
 541         return signal_helper;
 542 }
 543
 544 static void fiq_debugger_sleep_timer_expired(unsigned long data)
 545 {
 546         struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
 547         unsigned long flags;
 548
 549         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 550         if (state->uart_enabled && !state->no_sleep) {
 551                 if (state->debug_enable && !state->console_enable) {
 552                         state->debug_enable = false;
 553                         fiq_debugger_printf_nfiq(state,
 554                                         "suspending fiq debugger\n");
 555                 }
 556                 state->ignore_next_wakeup_irq = true;
 557                 fiq_debugger_uart_disable(state);
 558                 state->uart_enabled = false;
 559                 fiq_debugger_enable_wakeup_irq(state);
 560         }
 561         wake_unlock(&state->debugger_wake_lock);
 562         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 563 }
 564
 565 static void fiq_debugger_handle_wakeup(struct fiq_debugger_state *state)
 566 {
 567         unsigned long flags;
 568
 569         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 570         if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
 571                 state->ignore_next_wakeup_irq = false;
 572         } else if (!state->uart_enabled) {
 573                 wake_lock(&state->debugger_wake_lock);
 574                 fiq_debugger_uart_enable(state);
 575                 state->uart_enabled = true;
 576                 fiq_debugger_disable_wakeup_irq(state);
 577                 mod_timer(&state->sleep_timer, jiffies + HZ / 2);
 578         }
 579         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 580 }
 581
 582 static irqreturn_t fiq_debugger_wakeup_irq_handler(int irq, void *dev)
 583 {
 584         struct fiq_debugger_state *state = dev;
 585
 586         if (!state->no_sleep)
 587                 fiq_debugger_puts(state, "WAKEUP\n");
 588         fiq_debugger_handle_wakeup(state);
 589
 590         return IRQ_HANDLED;
 591 }
 592
 593 static
 594 void fiq_debugger_handle_console_irq_context(struct fiq_debugger_state *state)
 595 {
 596 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 597         if (state->tty_port.ops) {
 598                 int i;
 599                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 600                 for (i = 0; i < count; i++) {
 601                         int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 602                         tty_insert_flip_char(&state->tty_port, c, TTY_NORMAL);
 603                         if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
 604                                 pr_warn("fiq tty failed to consume byte\n");
 605                 }
 606                 tty_flip_buffer_push(&state->tty_port);
 607         }
 608 #endif
 609 }
 610
 611 static void fiq_debugger_handle_irq_context(struct fiq_debugger_state *state)
 612 {
 613         if (!state->no_sleep) {
 614                 unsigned long flags;
 615
 616                 spin_lock_irqsave(&state->sleep_timer_lock, flags);
 617                 wake_lock(&state->debugger_wake_lock);
 618                 mod_timer(&state->sleep_timer, jiffies + HZ * 5);
 619                 spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 620         }
 621         fiq_debugger_handle_console_irq_context(state);
 622         if (state->debug_busy) {
 623                 fiq_debugger_irq_exec(state, state->debug_cmd);
 624                 if (!state->console_enable)
 625                         fiq_debugger_prompt(state);
 626                 state->debug_busy = 0;
 627         }
 628 }
 629
 630 static int fiq_debugger_getc(struct fiq_debugger_state *state)
 631 {
 632         return state->pdata->uart_getc(state->pdev);
 633 }
 634
 635 static bool fiq_debugger_handle_uart_interrupt(struct fiq_debugger_state *state,
 636                         int this_cpu, const struct pt_regs *regs, void *svc_sp)
 637 {
 638         int c;
 639         static int last_c;
 640         int count = 0;
 641         bool signal_helper = false;
 642
 643         if (this_cpu != state->current_cpu) {
 644                 if (state->in_fiq)
 645                         return false;
 646
 647                 if (atomic_inc_return(&state->unhandled_fiq_count) !=
 648                                         MAX_UNHANDLED_FIQ_COUNT)
 649                         return false;
 650
 651                 fiq_debugger_printf(&state->output,
 652                         "fiq_debugger: cpu %d not responding, "
 653                         "reverting to cpu %d\n", state->current_cpu,
 654                         this_cpu);
 655
 656                 atomic_set(&state->unhandled_fiq_count, 0);
 657                 fiq_debugger_switch_cpu(state, this_cpu);
 658                 return false;
 659         }
 660
 661         state->in_fiq = true;
 662
 663         while ((c = fiq_debugger_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
 664                 count++;
 665                 if (!state->debug_enable) {
 666                         if ((c == 13) || (c == 10)) {
 667                                 state->debug_enable = true;
 668                                 state->debug_count = 0;
 669                                 fiq_debugger_prompt(state);
 670                         }
 671                 } else if (c == FIQ_DEBUGGER_BREAK) {
 672                         state->console_enable = false;
 673                         fiq_debugger_puts(state, "fiq debugger mode\n");
 674                         state->debug_count = 0;
 675                         fiq_debugger_prompt(state);
 676 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 677                 } else if (state->console_enable && state->tty_rbuf) {
 678                         fiq_debugger_ringbuf_push(state->tty_rbuf, c);
 679                         signal_helper = true;
 680 #endif
 681                 } else if ((c >= ' ') && (c < 127)) {
 682                         if (state->debug_count < (DEBUG_MAX - 1)) {
 683                                 state->debug_buf[state->debug_count++] = c;
 684                                 fiq_debugger_putc(state, c);
 685                         }
 686                 } else if ((c == 8) || (c == 127)) {
 687                         if (state->debug_count > 0) {
 688                                 state->debug_count--;
 689                                 fiq_debugger_putc(state, 8);
 690                                 fiq_debugger_putc(state, ' ');
 691                                 fiq_debugger_putc(state, 8);
 692                         }
 693                 } else if ((c == 13) || (c == 10)) {
 694                         if (c == '\r' || (c == '\n' && last_c != '\r')) {
 695                                 fiq_debugger_putc(state, '\r');
 696                                 fiq_debugger_putc(state, '\n');
 697                         }
 698                         if (state->debug_count) {
 699                                 state->debug_buf[state->debug_count] = 0;
 700                                 state->debug_count = 0;
 701                                 signal_helper |=
 702                                         fiq_debugger_fiq_exec(state,
 703                                                         state->debug_buf,
 704                                                         regs, svc_sp);
 705                         } else {
 706                                 fiq_debugger_prompt(state);
 707                         }
 708                 }
 709                 last_c = c;
 710         }
 711         if (!state->console_enable)
 712                 fiq_debugger_uart_flush(state);
 713         if (state->pdata->fiq_ack)
 714                 state->pdata->fiq_ack(state->pdev, state->fiq);
 715
 716         /* poke sleep timer if necessary */
 717         if (state->debug_enable && !state->no_sleep)
 718                 signal_helper = true;
 719
 720         atomic_set(&state->unhandled_fiq_count, 0);
 721         state->in_fiq = false;
 722
 723         return signal_helper;
 724 }
 725
 726 #ifdef CONFIG_FIQ_GLUE
 727 static void fiq_debugger_fiq(struct fiq_glue_handler *h,
 728                 const struct pt_regs *regs, void *svc_sp)
 729 {
 730         struct fiq_debugger_state *state =
 731                 container_of(h, struct fiq_debugger_state, handler);
 732         unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
 733         bool need_irq;
 734
 735         need_irq = fiq_debugger_handle_uart_interrupt(state, this_cpu, regs,
 736                         svc_sp);
 737         if (need_irq)
 738                 fiq_debugger_force_irq(state);
 739 }
 740 #endif
 741
 742 /*
 743  * When not using FIQs, we only use this single interrupt as an entry point.
 744  * This just effectively takes over the UART interrupt and does all the work
 745  * in this context.
 746  */
 747 static irqreturn_t fiq_debugger_uart_irq(int irq, void *dev)
 748 {
 749         struct fiq_debugger_state *state = dev;
 750         bool not_done;
 751
 752         fiq_debugger_handle_wakeup(state);
 753
 754         /* handle the debugger irq in regular context */
 755         not_done = fiq_debugger_handle_uart_interrupt(state, smp_processor_id(),
 756                                               get_irq_regs(),
 757                                               current_thread_info());
 758         if (not_done)
 759                 fiq_debugger_handle_irq_context(state);
 760
 761         return IRQ_HANDLED;
 762 }
 763
 764 /*
 765  * If FIQs are used, not everything can happen in fiq context.
 766  * FIQ handler does what it can and then signals this interrupt to finish the
 767  * job in irq context.
 768  */
 769 static irqreturn_t fiq_debugger_signal_irq(int irq, void *dev)
 770 {
 771         struct fiq_debugger_state *state = dev;
 772
 773         if (state->pdata->force_irq_ack)
 774                 state->pdata->force_irq_ack(state->pdev, state->signal_irq);
 775
 776         fiq_debugger_handle_irq_context(state);
 777
 778         return IRQ_HANDLED;
 779 }
 780
 781 #ifdef CONFIG_FIQ_GLUE
 782 static void fiq_debugger_resume(struct fiq_glue_handler *h)
 783 {
 784         struct fiq_debugger_state *state =
 785                 container_of(h, struct fiq_debugger_state, handler);
 786         if (state->pdata->uart_resume)
 787                 state->pdata->uart_resume(state->pdev);
 788 }
 789 #endif
 790
 791 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 792 struct tty_driver *fiq_debugger_console_device(struct console *co, int *index)
 793 {
 794         *index = co->index;
 795         return fiq_tty_driver;
 796 }
 797
 798 static void fiq_debugger_console_write(struct console *co,
 799                                 const char *s, unsigned int count)
 800 {
 801         struct fiq_debugger_state *state;
 802         unsigned long flags;
 803
 804         state = container_of(co, struct fiq_debugger_state, console);
 805
 806         if (!state->console_enable && !state->syslog_dumping)
 807                 return;
 808
 809         fiq_debugger_uart_enable(state);
 810         spin_lock_irqsave(&state->console_lock, flags);
 811         while (count--) {
 812                 if (*s == '\n')
 813                         fiq_debugger_putc(state, '\r');
 814                 fiq_debugger_putc(state, *s++);
 815         }
 816         fiq_debugger_uart_flush(state);
 817         spin_unlock_irqrestore(&state->console_lock, flags);
 818         fiq_debugger_uart_disable(state);
 819 }
 820
 821 static struct console fiq_debugger_console = {
 822         .name = "ttyFIQ",
 823         .device = fiq_debugger_console_device,
 824         .write = fiq_debugger_console_write,
 825         .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
 826 };
 827
 828 int fiq_tty_open(struct tty_struct *tty, struct file *filp)
 829 {
 830         int line = tty->index;
 831         struct fiq_debugger_state **states = tty->driver->driver_state;
 832         struct fiq_debugger_state *state = states[line];
 833
 834         return tty_port_open(&state->tty_port, tty, filp);
 835 }
 836
 837 void fiq_tty_close(struct tty_struct *tty, struct file *filp)
 838 {
 839         tty_port_close(tty->port, tty, filp);
 840 }
 841
 842 int  fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 843 {
 844         int i;
 845         int line = tty->index;
 846         struct fiq_debugger_state **states = tty->driver->driver_state;
 847         struct fiq_debugger_state *state = states[line];
 848
 849         if (!state->console_enable)
 850                 return count;
 851
 852         fiq_debugger_uart_enable(state);
 853         spin_lock_irq(&state->console_lock);
 854         for (i = 0; i < count; i++)
 855                 fiq_debugger_putc(state, *buf++);
 856         spin_unlock_irq(&state->console_lock);
 857         fiq_debugger_uart_disable(state);
 858
 859         return count;
 860 }
 861
 862 int  fiq_tty_write_room(struct tty_struct *tty)
 863 {
 864         return 16;
 865 }
 866
 867 #ifdef CONFIG_CONSOLE_POLL
 868 static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)
 869 {
 870         return 0;
 871 }
 872
 873 static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)
 874 {
 875         struct fiq_debugger_state **states = driver->driver_state;
 876         struct fiq_debugger_state *state = states[line];
 877         int c = NO_POLL_CHAR;
 878
 879         fiq_debugger_uart_enable(state);
 880         if (fiq_debugger_have_fiq(state)) {
 881                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 882                 if (count > 0) {
 883                         c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 884                         fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);
 885                 }
 886         } else {
 887                 c = fiq_debugger_getc(state);
 888                 if (c == FIQ_DEBUGGER_NO_CHAR)
 889                         c = NO_POLL_CHAR;
 890         }
 891         fiq_debugger_uart_disable(state);
 892
 893         return c;
 894 }
 895
 896 static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
 897 {
 898         struct fiq_debugger_state **states = driver->driver_state;
 899         struct fiq_debugger_state *state = states[line];
 900         fiq_debugger_uart_enable(state);
 901         fiq_debugger_putc(state, ch);
 902         fiq_debugger_uart_disable(state);
 903 }
 904 #endif
 905
 906 static const struct tty_port_operations fiq_tty_port_ops;
 907
 908 static const struct tty_operations fiq_tty_driver_ops = {
 909         .write = fiq_tty_write,
 910         .write_room = fiq_tty_write_room,
 911         .open = fiq_tty_open,
 912         .close = fiq_tty_close,
 913 #ifdef CONFIG_CONSOLE_POLL
 914         .poll_init = fiq_tty_poll_init,
 915         .poll_get_char = fiq_tty_poll_get_char,
 916         .poll_put_char = fiq_tty_poll_put_char,
 917 #endif
 918 };
 919
 920 static int fiq_debugger_tty_init(void)
 921 {
 922         int ret;
 923         struct fiq_debugger_state **states = NULL;
 924
 925         states = kzalloc(sizeof(*states) * MAX_FIQ_DEBUGGER_PORTS, GFP_KERNEL);
 926         if (!states) {
 927                 pr_err("Failed to allocate fiq debugger state structres\n");
 928                 return -ENOMEM;
 929         }
 930
 931         fiq_tty_driver = alloc_tty_driver(MAX_FIQ_DEBUGGER_PORTS);
 932         if (!fiq_tty_driver) {
 933                 pr_err("Failed to allocate fiq debugger tty\n");
 934                 ret = -ENOMEM;
 935                 goto err_free_state;
 936         }
 937
 938         fiq_tty_driver->owner           = THIS_MODULE;
 939         fiq_tty_driver->driver_name     = "fiq-debugger";
 940         fiq_tty_driver->name            = "ttyFIQ";
 941         fiq_tty_driver->type            = TTY_DRIVER_TYPE_SERIAL;
 942         fiq_tty_driver->subtype         = SERIAL_TYPE_NORMAL;
 943         fiq_tty_driver->init_termios    = tty_std_termios;
 944         fiq_tty_driver->flags           = TTY_DRIVER_REAL_RAW |
 945                                           TTY_DRIVER_DYNAMIC_DEV;
 946         fiq_tty_driver->driver_state    = states;
 947
 948         fiq_tty_driver->init_termios.c_cflag =
 949                                         B115200 | CS8 | CREAD | HUPCL | CLOCAL;
 950         fiq_tty_driver->init_termios.c_ispeed = 115200;
 951         fiq_tty_driver->init_termios.c_ospeed = 115200;
 952
 953         tty_set_operations(fiq_tty_driver, &fiq_tty_driver_ops);
 954
 955         ret = tty_register_driver(fiq_tty_driver);
 956         if (ret) {
 957                 pr_err("Failed to register fiq tty: %d\n", ret);
 958                 goto err_free_tty;
 959         }
 960
 961         pr_info("Registered FIQ tty driver\n");
 962         return 0;
 963
 964 err_free_tty:
 965         put_tty_driver(fiq_tty_driver);
 966         fiq_tty_driver = NULL;
 967 err_free_state:
 968         kfree(states);
 969         return ret;
 970 }
 971
 972 static int fiq_debugger_tty_init_one(struct fiq_debugger_state *state)
 973 {
 974         int ret;
 975         struct device *tty_dev;
 976         struct fiq_debugger_state **states = fiq_tty_driver->driver_state;
 977
 978         states[state->pdev->id] = state;
 979
 980         state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
 981         if (!state->tty_rbuf) {
 982                 pr_err("Failed to allocate fiq debugger ringbuf\n");
 983                 ret = -ENOMEM;
 984                 goto err;
 985         }
 986
 987         tty_port_init(&state->tty_port);
 988         state->tty_port.ops = &fiq_tty_port_ops;
 989
 990         tty_dev = tty_port_register_device(&state->tty_port, fiq_tty_driver,
 991                                            state->pdev->id, &state->pdev->dev);
 992         if (IS_ERR(tty_dev)) {
 993                 pr_err("Failed to register fiq debugger tty device\n");
 994                 ret = PTR_ERR(tty_dev);
 995                 goto err;
 996         }
 997
 998         device_set_wakeup_capable(tty_dev, 1);
 999
1000         pr_info("Registered fiq debugger ttyFIQ%d\n", state->pdev->id);
1001
1002         return 0;
1003
1004 err:
1005         fiq_debugger_ringbuf_free(state->tty_rbuf);
1006         state->tty_rbuf = NULL;
1007         return ret;
1008 }
1009 #endif
1010
1011 static int fiq_debugger_dev_suspend(struct device *dev)
1012 {
1013         struct platform_device *pdev = to_platform_device(dev);
1014         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1015
1016         if (state->pdata->uart_dev_suspend)
1017                 return state->pdata->uart_dev_suspend(pdev);
1018         return 0;
1019 }
1020
1021 static int fiq_debugger_dev_resume(struct device *dev)
1022 {
1023         struct platform_device *pdev = to_platform_device(dev);
1024         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1025
1026         if (state->pdata->uart_dev_resume)
1027                 return state->pdata->uart_dev_resume(pdev);
1028         return 0;
1029 }
1030
1031 static int fiq_debugger_probe(struct platform_device *pdev)
1032 {
1033         int ret;
1034         struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
1035         struct fiq_debugger_state *state;
1036         int fiq;
1037         int uart_irq;
1038
1039         if (pdev->id >= MAX_FIQ_DEBUGGER_PORTS)
1040                 return -EINVAL;
1041
1042         if (!pdata->uart_getc || !pdata->uart_putc)
1043                 return -EINVAL;
1044         if ((pdata->uart_enable && !pdata->uart_disable) ||
1045             (!pdata->uart_enable && pdata->uart_disable))
1046                 return -EINVAL;
1047
1048         fiq = platform_get_irq_byname(pdev, "fiq");
1049         uart_irq = platform_get_irq_byname(pdev, "uart_irq");
1050
1051         /* uart_irq mode and fiq mode are mutually exclusive, but one of them
1052          * is required */
1053         if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
1054                 return -EINVAL;
1055         if (fiq >= 0 && !pdata->fiq_enable)
1056                 return -EINVAL;
1057
1058         state = kzalloc(sizeof(*state), GFP_KERNEL);
1059         state->output.printf = fiq_debugger_printf;
1060         setup_timer(&state->sleep_timer, fiq_debugger_sleep_timer_expired,
1061                     (unsigned long)state);
1062         state->pdata = pdata;
1063         state->pdev = pdev;
1064         state->no_sleep = initial_no_sleep;
1065         state->debug_enable = initial_debug_enable;
1066         state->console_enable = initial_console_enable;
1067
1068         state->fiq = fiq;
1069         state->uart_irq = uart_irq;
1070         state->signal_irq = platform_get_irq_byname(pdev, "signal");
1071         state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
1072
1073         INIT_WORK(&state->work, fiq_debugger_work);
1074         spin_lock_init(&state->work_lock);
1075
1076         platform_set_drvdata(pdev, state);
1077
1078         spin_lock_init(&state->sleep_timer_lock);
1079
1080         if (state->wakeup_irq < 0 && fiq_debugger_have_fiq(state))
1081                 state->no_sleep = true;
1082         state->ignore_next_wakeup_irq = !state->no_sleep;
1083
1084         wake_lock_init(&state->debugger_wake_lock,
1085                         WAKE_LOCK_SUSPEND, "serial-debug");
1086
1087         state->clk = clk_get(&pdev->dev, NULL);
1088         if (IS_ERR(state->clk))
1089                 state->clk = NULL;
1090
1091         /* do not call pdata->uart_enable here since uart_init may still
1092          * need to do some initialization before uart_enable can work.
1093          * So, only try to manage the clock during init.
1094          */
1095         if (state->clk)
1096                 clk_enable(state->clk);
1097
1098         if (pdata->uart_init) {
1099                 ret = pdata->uart_init(pdev);
1100                 if (ret)
1101                         goto err_uart_init;
1102         }
1103
1104         fiq_debugger_printf_nfiq(state,
1105                                 "<hit enter %sto activate fiq debugger>\n",
1106                                 state->no_sleep ? "" : "twice ");
1107
1108 #ifdef CONFIG_FIQ_GLUE
1109         if (fiq_debugger_have_fiq(state)) {
1110                 state->handler.fiq = fiq_debugger_fiq;
1111                 state->handler.resume = fiq_debugger_resume;
1112                 ret = fiq_glue_register_handler(&state->handler);
1113                 if (ret) {
1114                         pr_err("%s: could not install fiq handler\n", __func__);
1115                         goto err_register_irq;
1116                 }
1117
1118                 pdata->fiq_enable(pdev, state->fiq, 1);
1119         } else
1120 #endif
1121         {
1122                 ret = request_irq(state->uart_irq, fiq_debugger_uart_irq,
1123                                   IRQF_NO_SUSPEND, "debug", state);
1124                 if (ret) {
1125                         pr_err("%s: could not install irq handler\n", __func__);
1126                         goto err_register_irq;
1127                 }
1128
1129                 /* for irq-only mode, we want this irq to wake us up, if it
1130                  * can.
1131                  */
1132                 enable_irq_wake(state->uart_irq);
1133         }
1134
1135         if (state->clk)
1136                 clk_disable(state->clk);
1137
1138         if (state->signal_irq >= 0) {
1139                 ret = request_irq(state->signal_irq, fiq_debugger_signal_irq,
1140                           IRQF_TRIGGER_RISING, "debug-signal", state);
1141                 if (ret)
1142                         pr_err("serial_debugger: could not install signal_irq");
1143         }
1144
1145         if (state->wakeup_irq >= 0) {
1146                 ret = request_irq(state->wakeup_irq,
1147                                   fiq_debugger_wakeup_irq_handler,
1148                                   IRQF_TRIGGER_FALLING | IRQF_DISABLED,
1149                                   "debug-wakeup", state);
1150                 if (ret) {
1151                         pr_err("serial_debugger: "
1152                                 "could not install wakeup irq\n");
1153                         state->wakeup_irq = -1;
1154                 } else {
1155                         ret = enable_irq_wake(state->wakeup_irq);
1156                         if (ret) {
1157                                 pr_err("serial_debugger: "
1158                                         "could not enable wakeup\n");
1159                                 state->wakeup_irq_no_set_wake = true;
1160                         }
1161                 }
1162         }
1163         if (state->no_sleep)
1164                 fiq_debugger_handle_wakeup(state);
1165
1166 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1167         spin_lock_init(&state->console_lock);
1168         state->console = fiq_debugger_console;
1169         state->console.index = pdev->id;
1170         if (!console_set_on_cmdline)
1171                 add_preferred_console(state->console.name,
1172                         state->console.index, NULL);
1173         register_console(&state->console);
1174         fiq_debugger_tty_init_one(state);
1175 #endif
1176         return 0;
1177
1178 err_register_irq:
1179         if (pdata->uart_free)
1180                 pdata->uart_free(pdev);
1181 err_uart_init:
1182         if (state->clk)
1183                 clk_disable(state->clk);
1184         if (state->clk)
1185                 clk_put(state->clk);
1186         wake_lock_destroy(&state->debugger_wake_lock);
1187         platform_set_drvdata(pdev, NULL);
1188         kfree(state);
1189         return ret;
1190 }
1191
1192 static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
1193         .suspend        = fiq_debugger_dev_suspend,
1194         .resume         = fiq_debugger_dev_resume,
1195 };
1196
1197 static struct platform_driver fiq_debugger_driver = {
1198         .probe  = fiq_debugger_probe,
1199         .driver = {
1200                 .name   = "fiq_debugger",
1201                 .pm     = &fiq_debugger_dev_pm_ops,
1202         },
1203 };
1204
1205 static int __init fiq_debugger_init(void)
1206 {
1207 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1208         fiq_debugger_tty_init();
1209 #endif
1210         return platform_driver_register(&fiq_debugger_driver);
1211 }
1212
1213 postcore_initcall(fiq_debugger_init);