arch/arm/mach-omap2/cpuidle34xx.c

   1 /*
   2  * linux/arch/arm/mach-omap2/cpuidle34xx.c
   3  *
   4  * OMAP3 CPU IDLE Routines
   5  *
   6  * Copyright (C) 2008 Texas Instruments, Inc.
   7  * Rajendra Nayak <rnayak@ti.com>
   8  *
   9  * Copyright (C) 2007 Texas Instruments, Inc.
  10  * Karthik Dasu <karthik-dp@ti.com>
  11  *
  12  * Copyright (C) 2006 Nokia Corporation
  13  * Tony Lindgren <tony@atomide.com>
  14  *
  15  * Copyright (C) 2005 Texas Instruments, Inc.
  16  * Richard Woodruff <r-woodruff2@ti.com>
  17  *
  18  * Based on pm.c for omap2
  19  *
  20  * This program is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License version 2 as
  22  * published by the Free Software Foundation.
  23  */
  24
  25 #include <linux/sched.h>
  26 #include <linux/cpuidle.h>
  27
  28 #include <plat/prcm.h>
  29 #include <plat/irqs.h>
  30 #include <plat/powerdomain.h>
  31 #include <plat/clockdomain.h>
  32 #include <plat/serial.h>
  33
  34 #include "pm.h"
  35 #include "control.h"
  36
  37 #ifdef CONFIG_CPU_IDLE
  38
  39 #define OMAP3_MAX_STATES 7
  40 #define OMAP3_STATE_C1 0 /* C1 - MPU WFI + Core active */
  41 #define OMAP3_STATE_C2 1 /* C2 - MPU WFI + Core inactive */
  42 #define OMAP3_STATE_C3 2 /* C3 - MPU CSWR + Core inactive */
  43 #define OMAP3_STATE_C4 3 /* C4 - MPU OFF + Core iactive */
  44 #define OMAP3_STATE_C5 4 /* C5 - MPU RET + Core RET */
  45 #define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
  46 #define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */
  47
  48 #define OMAP3_STATE_MAX OMAP3_STATE_C7
  49
  50 #define CPUIDLE_FLAG_CHECK_BM   0x10000 /* use omap3_enter_idle_bm() */
  51
  52 struct omap3_processor_cx {
  53         u8 valid;
  54         u8 type;
  55         u32 sleep_latency;
  56         u32 wakeup_latency;
  57         u32 mpu_state;
  58         u32 core_state;
  59         u32 threshold;
  60         u32 flags;
  61 };
  62
  63 struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
  64 struct omap3_processor_cx current_cx_state;
  65 struct powerdomain *mpu_pd, *core_pd, *per_pd;
  66 struct powerdomain *cam_pd;
  67
  68 /*
  69  * The latencies/thresholds for various C states have
  70  * to be configured from the respective board files.
  71  * These are some default values (which might not provide
  72  * the best power savings) used on boards which do not
  73  * pass these details from the board file.
  74  */
  75 static struct cpuidle_params cpuidle_params_table[] = {
  76         /* C1 */
  77         {1, 2, 2, 5},
  78         /* C2 */
  79         {1, 10, 10, 30},
  80         /* C3 */
  81         {1, 50, 50, 300},
  82         /* C4 */
  83         {1, 1500, 1800, 4000},
  84         /* C5 */
  85         {1, 2500, 7500, 12000},
  86         /* C6 */
  87         {1, 3000, 8500, 15000},
  88         /* C7 */
  89         {1, 10000, 30000, 300000},
  90 };
  91
  92 static int omap3_idle_bm_check(void)
  93 {
  94         if (!omap3_can_sleep())
  95                 return 1;
  96         return 0;
  97 }
  98
  99 static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
 100                                 struct clockdomain *clkdm)
 101 {
 102         omap2_clkdm_allow_idle(clkdm);
 103         return 0;
 104 }
 105
 106 static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
 107                                 struct clockdomain *clkdm)
 108 {
 109         omap2_clkdm_deny_idle(clkdm);
 110         return 0;
 111 }
 112
 113 /**
 114  * omap3_enter_idle - Programs OMAP3 to enter the specified state
 115  * @dev: cpuidle device
 116  * @state: The target state to be programmed
 117  *
 118  * Called from the CPUidle framework to program the device to the
 119  * specified target state selected by the governor.
 120  */
 121 static int omap3_enter_idle(struct cpuidle_device *dev,
 122                         struct cpuidle_state *state)
 123 {
 124         struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
 125         struct timespec ts_preidle, ts_postidle, ts_idle;
 126         u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
 127
 128         current_cx_state = *cx;
 129
 130         /* Used to keep track of the total time in idle */
 131         getnstimeofday(&ts_preidle);
 132
 133         local_irq_disable();
 134         local_fiq_disable();
 135
 136         pwrdm_set_next_pwrst(mpu_pd, mpu_state);
 137         pwrdm_set_next_pwrst(core_pd, core_state);
 138
 139         if (omap_irq_pending() || need_resched())
 140                 goto return_sleep_time;
 141
 142         if (cx->type == OMAP3_STATE_C1) {
 143                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
 144                 pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
 145         }
 146
 147         /* Execute ARM wfi */
 148         omap_sram_idle();
 149
 150         if (cx->type == OMAP3_STATE_C1) {
 151                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
 152                 pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
 153         }
 154
 155 return_sleep_time:
 156         getnstimeofday(&ts_postidle);
 157         ts_idle = timespec_sub(ts_postidle, ts_preidle);
 158
 159         local_irq_enable();
 160         local_fiq_enable();
 161
 162         return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
 163 }
 164
 165 /**
 166  * next_valid_state - Find next valid c-state
 167  * @dev: cpuidle device
 168  * @state: Currently selected c-state
 169  *
 170  * If the current state is valid, it is returned back to the caller.
 171  * Else, this function searches for a lower c-state which is still
 172  * valid (as defined in omap3_power_states[]).
 173  */
 174 static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
 175                                                 struct cpuidle_state *curr)
 176 {
 177         struct cpuidle_state *next = NULL;
 178         struct omap3_processor_cx *cx;
 179
 180         cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);
 181
 182         /* Check if current state is valid */
 183         if (cx->valid) {
 184                 return curr;
 185         } else {
 186                 u8 idx = OMAP3_STATE_MAX;
 187
 188                 /*
 189                  * Reach the current state starting at highest C-state
 190                  */
 191                 for (; idx >= OMAP3_STATE_C1; idx--) {
 192                         if (&dev->states[idx] == curr) {
 193                                 next = &dev->states[idx];
 194                                 break;
 195                         }
 196                 }
 197
 198                 /*
 199                  * Should never hit this condition.
 200                  */
 201                 WARN_ON(next == NULL);
 202
 203                 /*
 204                  * Drop to next valid state.
 205                  * Start search from the next (lower) state.
 206                  */
 207                 idx--;
 208                 for (; idx >= OMAP3_STATE_C1; idx--) {
 209                         struct omap3_processor_cx *cx;
 210
 211                         cx = cpuidle_get_statedata(&dev->states[idx]);
 212                         if (cx->valid) {
 213                                 next = &dev->states[idx];
 214                                 break;
 215                         }
 216                 }
 217                 /*
 218                  * C1 and C2 are always valid.
 219                  * So, no need to check for 'next==NULL' outside this loop.
 220                  */
 221         }
 222
 223         return next;
 224 }
 225
 226 /**
 227  * omap3_enter_idle_bm - Checks for any bus activity
 228  * @dev: cpuidle device
 229  * @state: The target state to be programmed
 230  *
 231  * Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. This
 232  * function checks for any pending activity and then programs the
 233  * device to the specified or a safer state.
 234  */
 235 static int omap3_enter_idle_bm(struct cpuidle_device *dev,
 236                                struct cpuidle_state *state)
 237 {
 238         struct cpuidle_state *new_state = next_valid_state(dev, state);
 239         u32 core_next_state, per_next_state = 0, per_saved_state = 0;
 240         u32 cam_state;
 241         struct omap3_processor_cx *cx;
 242         int ret;
 243
 244         if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
 245                 BUG_ON(!dev->safe_state);
 246                 new_state = dev->safe_state;
 247                 goto select_state;
 248         }
 249
 250         cx = cpuidle_get_statedata(state);
 251         core_next_state = cx->core_state;
 252
 253         /*
 254          * FIXME: we currently manage device-specific idle states
 255          *        for PER and CORE in combination with CPU-specific
 256          *        idle states.  This is wrong, and device-specific
 257          *        idle managment needs to be separated out into
 258          *        its own code.
 259          */
 260
 261         /*
 262          * Prevent idle completely if CAM is active.
 263          * CAM does not have wakeup capability in OMAP3.
 264          */
 265         cam_state = pwrdm_read_pwrst(cam_pd);
 266         if (cam_state == PWRDM_POWER_ON) {
 267                 new_state = dev->safe_state;
 268                 goto select_state;
 269         }
 270
 271         /*
 272          * Prevent PER off if CORE is not in retention or off as this
 273          * would disable PER wakeups completely.
 274          */
 275         per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
 276         if ((per_next_state == PWRDM_POWER_OFF) &&
 277             (core_next_state > PWRDM_POWER_RET))
 278                 per_next_state = PWRDM_POWER_RET;
 279
 280         /* Are we changing PER target state? */
 281         if (per_next_state != per_saved_state)
 282                 pwrdm_set_next_pwrst(per_pd, per_next_state);
 283
 284 select_state:
 285         dev->last_state = new_state;
 286         ret = omap3_enter_idle(dev, new_state);
 287
 288         /* Restore original PER state if it was modified */
 289         if (per_next_state != per_saved_state)
 290                 pwrdm_set_next_pwrst(per_pd, per_saved_state);
 291
 292         return ret;
 293 }
 294
 295 DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
 296
 297 /**
 298  * omap3_cpuidle_update_states - Update the cpuidle states.
 299  *
 300  * Currently, this function toggles the validity of idle states based upon
 301  * the flag 'enable_off_mode'. When the flag is set all states are valid.
 302  * Else, states leading to OFF state set to be invalid.
 303  */
 304 void omap3_cpuidle_update_states(void)
 305 {
 306         int i;
 307
 308         for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
 309                 struct omap3_processor_cx *cx = &omap3_power_states[i];
 310
 311                 if (enable_off_mode) {
 312                         cx->valid = 1;
 313                 } else {
 314                         if ((cx->mpu_state == PWRDM_POWER_OFF) ||
 315                                 (cx->core_state == PWRDM_POWER_OFF))
 316                                 cx->valid = 0;
 317                 }
 318         }
 319 }
 320
 321 void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
 322 {
 323         int i;
 324
 325         if (!cpuidle_board_params)
 326                 return;
 327
 328         for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
 329                 cpuidle_params_table[i].valid =
 330                         cpuidle_board_params[i].valid;
 331                 cpuidle_params_table[i].sleep_latency =
 332                         cpuidle_board_params[i].sleep_latency;
 333                 cpuidle_params_table[i].wake_latency =
 334                         cpuidle_board_params[i].wake_latency;
 335                 cpuidle_params_table[i].threshold =
 336                         cpuidle_board_params[i].threshold;
 337         }
 338         return;
 339 }
 340
 341 /* omap3_init_power_states - Initialises the OMAP3 specific C states.
 342  *
 343  * Below is the desciption of each C state.
 344  *      C1 . MPU WFI + Core active
 345  *      C2 . MPU WFI + Core inactive
 346  *      C3 . MPU CSWR + Core inactive
 347  *      C4 . MPU OFF + Core inactive
 348  *      C5 . MPU CSWR + Core CSWR
 349  *      C6 . MPU OFF + Core CSWR
 350  *      C7 . MPU OFF + Core OFF
 351  */
 352 void omap_init_power_states(void)
 353 {
 354         /* C1 . MPU WFI + Core active */
 355         omap3_power_states[OMAP3_STATE_C1].valid =
 356                         cpuidle_params_table[OMAP3_STATE_C1].valid;
 357         omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
 358         omap3_power_states[OMAP3_STATE_C1].sleep_latency =
 359                         cpuidle_params_table[OMAP3_STATE_C1].sleep_latency;
 360         omap3_power_states[OMAP3_STATE_C1].wakeup_latency =
 361                         cpuidle_params_table[OMAP3_STATE_C1].wake_latency;
 362         omap3_power_states[OMAP3_STATE_C1].threshold =
 363                         cpuidle_params_table[OMAP3_STATE_C1].threshold;
 364         omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
 365         omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
 366         omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
 367
 368         /* C2 . MPU WFI + Core inactive */
 369         omap3_power_states[OMAP3_STATE_C2].valid =
 370                         cpuidle_params_table[OMAP3_STATE_C2].valid;
 371         omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
 372         omap3_power_states[OMAP3_STATE_C2].sleep_latency =
 373                         cpuidle_params_table[OMAP3_STATE_C2].sleep_latency;
 374         omap3_power_states[OMAP3_STATE_C2].wakeup_latency =
 375                         cpuidle_params_table[OMAP3_STATE_C2].wake_latency;
 376         omap3_power_states[OMAP3_STATE_C2].threshold =
 377                         cpuidle_params_table[OMAP3_STATE_C2].threshold;
 378         omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
 379         omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
 380         omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
 381                                 CPUIDLE_FLAG_CHECK_BM;
 382
 383         /* C3 . MPU CSWR + Core inactive */
 384         omap3_power_states[OMAP3_STATE_C3].valid =
 385                         cpuidle_params_table[OMAP3_STATE_C3].valid;
 386         omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
 387         omap3_power_states[OMAP3_STATE_C3].sleep_latency =
 388                         cpuidle_params_table[OMAP3_STATE_C3].sleep_latency;
 389         omap3_power_states[OMAP3_STATE_C3].wakeup_latency =
 390                         cpuidle_params_table[OMAP3_STATE_C3].wake_latency;
 391         omap3_power_states[OMAP3_STATE_C3].threshold =
 392                         cpuidle_params_table[OMAP3_STATE_C3].threshold;
 393         omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
 394         omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
 395         omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
 396                                 CPUIDLE_FLAG_CHECK_BM;
 397
 398         /* C4 . MPU OFF + Core inactive */
 399         omap3_power_states[OMAP3_STATE_C4].valid =
 400                         cpuidle_params_table[OMAP3_STATE_C4].valid;
 401         omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
 402         omap3_power_states[OMAP3_STATE_C4].sleep_latency =
 403                         cpuidle_params_table[OMAP3_STATE_C4].sleep_latency;
 404         omap3_power_states[OMAP3_STATE_C4].wakeup_latency =
 405                         cpuidle_params_table[OMAP3_STATE_C4].wake_latency;
 406         omap3_power_states[OMAP3_STATE_C4].threshold =
 407                         cpuidle_params_table[OMAP3_STATE_C4].threshold;
 408         omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
 409         omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
 410         omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
 411                                 CPUIDLE_FLAG_CHECK_BM;
 412
 413         /* C5 . MPU CSWR + Core CSWR*/
 414         omap3_power_states[OMAP3_STATE_C5].valid =
 415                         cpuidle_params_table[OMAP3_STATE_C5].valid;
 416         omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
 417         omap3_power_states[OMAP3_STATE_C5].sleep_latency =
 418                         cpuidle_params_table[OMAP3_STATE_C5].sleep_latency;
 419         omap3_power_states[OMAP3_STATE_C5].wakeup_latency =
 420                         cpuidle_params_table[OMAP3_STATE_C5].wake_latency;
 421         omap3_power_states[OMAP3_STATE_C5].threshold =
 422                         cpuidle_params_table[OMAP3_STATE_C5].threshold;
 423         omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
 424         omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
 425         omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
 426                                 CPUIDLE_FLAG_CHECK_BM;
 427
 428         /* C6 . MPU OFF + Core CSWR */
 429         omap3_power_states[OMAP3_STATE_C6].valid =
 430                         cpuidle_params_table[OMAP3_STATE_C6].valid;
 431         omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
 432         omap3_power_states[OMAP3_STATE_C6].sleep_latency =
 433                         cpuidle_params_table[OMAP3_STATE_C6].sleep_latency;
 434         omap3_power_states[OMAP3_STATE_C6].wakeup_latency =
 435                         cpuidle_params_table[OMAP3_STATE_C6].wake_latency;
 436         omap3_power_states[OMAP3_STATE_C6].threshold =
 437                         cpuidle_params_table[OMAP3_STATE_C6].threshold;
 438         omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
 439         omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
 440         omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
 441                                 CPUIDLE_FLAG_CHECK_BM;
 442
 443         /* C7 . MPU OFF + Core OFF */
 444         omap3_power_states[OMAP3_STATE_C7].valid =
 445                         cpuidle_params_table[OMAP3_STATE_C7].valid;
 446         omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
 447         omap3_power_states[OMAP3_STATE_C7].sleep_latency =
 448                         cpuidle_params_table[OMAP3_STATE_C7].sleep_latency;
 449         omap3_power_states[OMAP3_STATE_C7].wakeup_latency =
 450                         cpuidle_params_table[OMAP3_STATE_C7].wake_latency;
 451         omap3_power_states[OMAP3_STATE_C7].threshold =
 452                         cpuidle_params_table[OMAP3_STATE_C7].threshold;
 453         omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
 454         omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
 455         omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
 456                                 CPUIDLE_FLAG_CHECK_BM;
 457 }
 458
 459 struct cpuidle_driver omap3_idle_driver = {
 460         .name =         "omap3_idle",
 461         .owner =        THIS_MODULE,
 462 };
 463
 464 /**
 465  * omap3_idle_init - Init routine for OMAP3 idle
 466  *
 467  * Registers the OMAP3 specific cpuidle driver with the cpuidle
 468  * framework with the valid set of states.
 469  */
 470 int __init omap3_idle_init(void)
 471 {
 472         int i, count = 0;
 473         struct omap3_processor_cx *cx;
 474         struct cpuidle_state *state;
 475         struct cpuidle_device *dev;
 476
 477         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 478         core_pd = pwrdm_lookup("core_pwrdm");
 479         per_pd = pwrdm_lookup("per_pwrdm");
 480         cam_pd = pwrdm_lookup("cam_pwrdm");
 481
 482         omap_init_power_states();
 483         cpuidle_register_driver(&omap3_idle_driver);
 484
 485         dev = &per_cpu(omap3_idle_dev, smp_processor_id());
 486
 487         for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
 488                 cx = &omap3_power_states[i];
 489                 state = &dev->states[count];
 490
 491                 if (!cx->valid)
 492                         continue;
 493                 cpuidle_set_statedata(state, cx);
 494                 state->exit_latency = cx->sleep_latency + cx->wakeup_latency;
 495                 state->target_residency = cx->threshold;
 496                 state->flags = cx->flags;
 497                 state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
 498                         omap3_enter_idle_bm : omap3_enter_idle;
 499                 if (cx->type == OMAP3_STATE_C1)
 500                         dev->safe_state = state;
 501                 sprintf(state->name, "C%d", count+1);
 502                 count++;
 503         }
 504
 505         if (!count)
 506                 return -EINVAL;
 507         dev->state_count = count;
 508
 509         omap3_cpuidle_update_states();
 510
 511         if (cpuidle_register_device(dev)) {
 512                 printk(KERN_ERR "%s: CPUidle register device failed\n",
 513                        __func__);
 514                 return -EIO;
 515         }
 516
 517         return 0;
 518 }
 519 #else
 520 int __init omap3_idle_init(void)
 521 {
 522         return 0;
 523 }
 524 #endif /* CONFIG_CPU_IDLE */