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 #include <linux/export.h>
  28 #include <linux/cpu_pm.h>
  29 #include <asm/cpuidle.h>
  30
  31 #include "powerdomain.h"
  32 #include "clockdomain.h"
  33
  34 #include "pm.h"
  35 #include "control.h"
  36 #include "common.h"
  37 #include "soc.h"
  38
  39 /* Mach specific information to be recorded in the C-state driver_data */
  40 struct omap3_idle_statedata {
  41         u8 mpu_state;
  42         u8 core_state;
  43         u8 per_min_state;
  44         u8 flags;
  45 };
  46
  47 static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
  48
  49 /*
  50  * Possible flag bits for struct omap3_idle_statedata.flags:
  51  *
  52  * OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go
  53  *    inactive.  This in turn prevents the MPU DPLL from entering autoidle
  54  *    mode, so wakeup latency is greatly reduced, at the cost of additional
  55  *    energy consumption.  This also prevents the CORE clockdomain from
  56  *    entering idle.
  57  */
  58 #define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE           BIT(0)
  59
  60 /*
  61  * Prevent PER OFF if CORE is not in RETention or OFF as this would
  62  * disable PER wakeups completely.
  63  */
  64 static struct omap3_idle_statedata omap3_idle_data[] = {
  65         {
  66                 .mpu_state = PWRDM_POWER_ON,
  67                 .core_state = PWRDM_POWER_ON,
  68                 /* In C1 do not allow PER state lower than CORE state */
  69                 .per_min_state = PWRDM_POWER_ON,
  70                 .flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE,
  71         },
  72         {
  73                 .mpu_state = PWRDM_POWER_ON,
  74                 .core_state = PWRDM_POWER_ON,
  75                 .per_min_state = PWRDM_POWER_RET,
  76         },
  77         {
  78                 .mpu_state = PWRDM_POWER_RET,
  79                 .core_state = PWRDM_POWER_ON,
  80                 .per_min_state = PWRDM_POWER_RET,
  81         },
  82         {
  83                 .mpu_state = PWRDM_POWER_OFF,
  84                 .core_state = PWRDM_POWER_ON,
  85                 .per_min_state = PWRDM_POWER_RET,
  86         },
  87         {
  88                 .mpu_state = PWRDM_POWER_RET,
  89                 .core_state = PWRDM_POWER_RET,
  90                 .per_min_state = PWRDM_POWER_OFF,
  91         },
  92         {
  93                 .mpu_state = PWRDM_POWER_OFF,
  94                 .core_state = PWRDM_POWER_RET,
  95                 .per_min_state = PWRDM_POWER_OFF,
  96         },
  97         {
  98                 .mpu_state = PWRDM_POWER_OFF,
  99                 .core_state = PWRDM_POWER_OFF,
 100                 .per_min_state = PWRDM_POWER_OFF,
 101         },
 102 };
 103
 104 /**
 105  * omap3_enter_idle - Programs OMAP3 to enter the specified state
 106  * @dev: cpuidle device
 107  * @drv: cpuidle driver
 108  * @index: the index of state to be entered
 109  */
 110 static int omap3_enter_idle(struct cpuidle_device *dev,
 111                             struct cpuidle_driver *drv,
 112                             int index)
 113 {
 114         struct omap3_idle_statedata *cx = &omap3_idle_data[index];
 115
 116         if (omap_irq_pending() || need_resched())
 117                 goto return_sleep_time;
 118
 119         /* Deny idle for C1 */
 120         if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) {
 121                 clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]);
 122         } else {
 123                 pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
 124                 pwrdm_set_next_pwrst(core_pd, cx->core_state);
 125         }
 126
 127         /*
 128          * Call idle CPU PM enter notifier chain so that
 129          * VFP context is saved.
 130          */
 131         if (cx->mpu_state == PWRDM_POWER_OFF)
 132                 cpu_pm_enter();
 133
 134         /* Execute ARM wfi */
 135         omap_sram_idle();
 136
 137         /*
 138          * Call idle CPU PM enter notifier chain to restore
 139          * VFP context.
 140          */
 141         if (cx->mpu_state == PWRDM_POWER_OFF &&
 142             pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
 143                 cpu_pm_exit();
 144
 145         /* Re-allow idle for C1 */
 146         if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
 147                 clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);
 148
 149 return_sleep_time:
 150
 151         return index;
 152 }
 153
 154 /**
 155  * next_valid_state - Find next valid C-state
 156  * @dev: cpuidle device
 157  * @drv: cpuidle driver
 158  * @index: Index of currently selected c-state
 159  *
 160  * If the state corresponding to index is valid, index is returned back
 161  * to the caller. Else, this function searches for a lower c-state which is
 162  * still valid (as defined in omap3_power_states[]) and returns its index.
 163  *
 164  * A state is valid if the 'valid' field is enabled and
 165  * if it satisfies the enable_off_mode condition.
 166  */
 167 static int next_valid_state(struct cpuidle_device *dev,
 168                             struct cpuidle_driver *drv, int index)
 169 {
 170         struct omap3_idle_statedata *cx = &omap3_idle_data[index];
 171         u32 mpu_deepest_state = PWRDM_POWER_RET;
 172         u32 core_deepest_state = PWRDM_POWER_RET;
 173         int idx;
 174         int next_index = 0; /* C1 is the default value */
 175
 176         if (enable_off_mode) {
 177                 mpu_deepest_state = PWRDM_POWER_OFF;
 178                 /*
 179                  * Erratum i583: valable for ES rev < Es1.2 on 3630.
 180                  * CORE OFF mode is not supported in a stable form, restrict
 181                  * instead the CORE state to RET.
 182                  */
 183                 if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
 184                         core_deepest_state = PWRDM_POWER_OFF;
 185         }
 186
 187         /* Check if current state is valid */
 188         if ((cx->mpu_state >= mpu_deepest_state) &&
 189             (cx->core_state >= core_deepest_state))
 190                 return index;
 191
 192         /*
 193          * Drop to next valid state.
 194          * Start search from the next (lower) state.
 195          */
 196         for (idx = index - 1; idx >= 0; idx--) {
 197                 cx = &omap3_idle_data[idx];
 198                 if ((cx->mpu_state >= mpu_deepest_state) &&
 199                     (cx->core_state >= core_deepest_state)) {
 200                         next_index = idx;
 201                         break;
 202                 }
 203         }
 204
 205         return next_index;
 206 }
 207
 208 /**
 209  * omap3_enter_idle_bm - Checks for any bus activity
 210  * @dev: cpuidle device
 211  * @drv: cpuidle driver
 212  * @index: array index of target state to be programmed
 213  *
 214  * This function checks for any pending activity and then programs
 215  * the device to the specified or a safer state.
 216  */
 217 static int omap3_enter_idle_bm(struct cpuidle_device *dev,
 218                                struct cpuidle_driver *drv,
 219                                int index)
 220 {
 221         int new_state_idx, ret;
 222         u8 per_next_state, per_saved_state;
 223         struct omap3_idle_statedata *cx;
 224
 225         /*
 226          * Use only C1 if CAM is active.
 227          * CAM does not have wakeup capability in OMAP3.
 228          */
 229         if (pwrdm_read_pwrst(cam_pd) == PWRDM_POWER_ON)
 230                 new_state_idx = drv->safe_state_index;
 231         else
 232                 new_state_idx = next_valid_state(dev, drv, index);
 233
 234         /*
 235          * FIXME: we currently manage device-specific idle states
 236          *        for PER and CORE in combination with CPU-specific
 237          *        idle states.  This is wrong, and device-specific
 238          *        idle management needs to be separated out into
 239          *        its own code.
 240          */
 241
 242         /* Program PER state */
 243         cx = &omap3_idle_data[new_state_idx];
 244
 245         per_next_state = pwrdm_read_next_pwrst(per_pd);
 246         per_saved_state = per_next_state;
 247         if (per_next_state < cx->per_min_state) {
 248                 per_next_state = cx->per_min_state;
 249                 pwrdm_set_next_pwrst(per_pd, per_next_state);
 250         }
 251
 252         ret = omap3_enter_idle(dev, drv, new_state_idx);
 253
 254         /* Restore original PER state if it was modified */
 255         if (per_next_state != per_saved_state)
 256                 pwrdm_set_next_pwrst(per_pd, per_saved_state);
 257
 258         return ret;
 259 }
 260
 261 static struct cpuidle_driver omap3_idle_driver = {
 262         .name             = "omap3_idle",
 263         .owner            = THIS_MODULE,
 264         .states = {
 265                 {
 266                         .enter            = omap3_enter_idle_bm,
 267                         .exit_latency     = 2 + 2,
 268                         .target_residency = 5,
 269                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 270                         .name             = "C1",
 271                         .desc             = "MPU ON + CORE ON",
 272                 },
 273                 {
 274                         .enter            = omap3_enter_idle_bm,
 275                         .exit_latency     = 10 + 10,
 276                         .target_residency = 30,
 277                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 278                         .name             = "C2",
 279                         .desc             = "MPU ON + CORE ON",
 280                 },
 281                 {
 282                         .enter            = omap3_enter_idle_bm,
 283                         .exit_latency     = 50 + 50,
 284                         .target_residency = 300,
 285                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 286                         .name             = "C3",
 287                         .desc             = "MPU RET + CORE ON",
 288                 },
 289                 {
 290                         .enter            = omap3_enter_idle_bm,
 291                         .exit_latency     = 1500 + 1800,
 292                         .target_residency = 4000,
 293                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 294                         .name             = "C4",
 295                         .desc             = "MPU OFF + CORE ON",
 296                 },
 297                 {
 298                         .enter            = omap3_enter_idle_bm,
 299                         .exit_latency     = 2500 + 7500,
 300                         .target_residency = 12000,
 301                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 302                         .name             = "C5",
 303                         .desc             = "MPU RET + CORE RET",
 304                 },
 305                 {
 306                         .enter            = omap3_enter_idle_bm,
 307                         .exit_latency     = 3000 + 8500,
 308                         .target_residency = 15000,
 309                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 310                         .name             = "C6",
 311                         .desc             = "MPU OFF + CORE RET",
 312                 },
 313                 {
 314                         .enter            = omap3_enter_idle_bm,
 315                         .exit_latency     = 10000 + 30000,
 316                         .target_residency = 30000,
 317                         .flags            = CPUIDLE_FLAG_TIME_VALID,
 318                         .name             = "C7",
 319                         .desc             = "MPU OFF + CORE OFF",
 320                 },
 321         },
 322         .state_count = ARRAY_SIZE(omap3_idle_data),
 323         .safe_state_index = 0,
 324 };
 325
 326 /*
 327  * Numbers based on measurements made in October 2009 for PM optimized kernel
 328  * with CPU freq enabled on device Nokia N900. Assumes OPP2 (main idle OPP,
 329  * and worst case latencies).
 330  */
 331 static struct cpuidle_driver omap3430_idle_driver = {
 332         .name             = "omap3430_idle",
 333         .owner            = THIS_MODULE,
 334         .states = {
 335                 {
 336                         .enter            = omap3_enter_idle_bm,
 337                         .exit_latency     = 110 + 162,
 338                         .target_residency = 5,
 339                         .name             = "C1",
 340                         .desc             = "MPU ON + CORE ON",
 341                 },
 342                 {
 343                         .enter            = omap3_enter_idle_bm,
 344                         .exit_latency     = 106 + 180,
 345                         .target_residency = 309,
 346                         .name             = "C2",
 347                         .desc             = "MPU ON + CORE ON",
 348                 },
 349                 {
 350                         .enter            = omap3_enter_idle_bm,
 351                         .exit_latency     = 107 + 410,
 352                         .target_residency = 46057,
 353                         .name             = "C3",
 354                         .desc             = "MPU RET + CORE ON",
 355                 },
 356                 {
 357                         .enter            = omap3_enter_idle_bm,
 358                         .exit_latency     = 121 + 3374,
 359                         .target_residency = 46057,
 360                         .name             = "C4",
 361                         .desc             = "MPU OFF + CORE ON",
 362                 },
 363                 {
 364                         .enter            = omap3_enter_idle_bm,
 365                         .exit_latency     = 855 + 1146,
 366                         .target_residency = 46057,
 367                         .name             = "C5",
 368                         .desc             = "MPU RET + CORE RET",
 369                 },
 370                 {
 371                         .enter            = omap3_enter_idle_bm,
 372                         .exit_latency     = 7580 + 4134,
 373                         .target_residency = 484329,
 374                         .name             = "C6",
 375                         .desc             = "MPU OFF + CORE RET",
 376                 },
 377                 {
 378                         .enter            = omap3_enter_idle_bm,
 379                         .exit_latency     = 7505 + 15274,
 380                         .target_residency = 484329,
 381                         .name             = "C7",
 382                         .desc             = "MPU OFF + CORE OFF",
 383                 },
 384         },
 385         .state_count = ARRAY_SIZE(omap3_idle_data),
 386         .safe_state_index = 0,
 387 };
 388
 389 /* Public functions */
 390
 391 /**
 392  * omap3_idle_init - Init routine for OMAP3 idle
 393  *
 394  * Registers the OMAP3 specific cpuidle driver to the cpuidle
 395  * framework with the valid set of states.
 396  */
 397 int __init omap3_idle_init(void)
 398 {
 399         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 400         core_pd = pwrdm_lookup("core_pwrdm");
 401         per_pd = pwrdm_lookup("per_pwrdm");
 402         cam_pd = pwrdm_lookup("cam_pwrdm");
 403
 404         if (!mpu_pd || !core_pd || !per_pd || !cam_pd)
 405                 return -ENODEV;
 406
 407         if (cpu_is_omap3430())
 408                 return cpuidle_register(&omap3430_idle_driver, NULL);
 409         else
 410                 return cpuidle_register(&omap3_idle_driver, NULL);
 411 }