/* * linux/arch/arm/mach-omap2/cpuidle34xx.c * * OMAP3 CPU IDLE Routines * * Copyright (C) 2008 Texas Instruments, Inc. * Rajendra Nayak * * Copyright (C) 2007 Texas Instruments, Inc. * Karthik Dasu * * Copyright (C) 2006 Nokia Corporation * Tony Lindgren * * Copyright (C) 2005 Texas Instruments, Inc. * Richard Woodruff * * Based on pm.c for omap2 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include "powerdomain.h" #include "clockdomain.h" #include "pm.h" #include "control.h" #include "common.h" #ifdef CONFIG_CPU_IDLE /* * The latencies/thresholds for various C states have * to be configured from the respective board files. * These are some default values (which might not provide * the best power savings) used on boards which do not * pass these details from the board file. */ static struct cpuidle_params cpuidle_params_table[] = { /* C1 */ {2 + 2, 5, 1}, /* C2 */ {10 + 10, 30, 1}, /* C3 */ {50 + 50, 300, 1}, /* C4 */ {1500 + 1800, 4000, 1}, /* C5 */ {2500 + 7500, 12000, 1}, /* C6 */ {3000 + 8500, 15000, 1}, /* C7 */ {10000 + 30000, 300000, 1}, }; #define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table) /* Mach specific information to be recorded in the C-state driver_data */ struct omap3_idle_statedata { u32 mpu_state; u32 core_state; u8 valid; }; struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES]; struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd; static int _cpuidle_allow_idle(struct powerdomain *pwrdm, struct clockdomain *clkdm) { clkdm_allow_idle(clkdm); return 0; } static int _cpuidle_deny_idle(struct powerdomain *pwrdm, struct clockdomain *clkdm) { clkdm_deny_idle(clkdm); return 0; } static int __omap3_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct omap3_idle_statedata *cx = cpuidle_get_statedata(&dev->states_usage[index]); u32 mpu_state = cx->mpu_state, core_state = cx->core_state; local_fiq_disable(); pwrdm_set_next_pwrst(mpu_pd, mpu_state); pwrdm_set_next_pwrst(core_pd, core_state); if (omap_irq_pending() || need_resched()) goto return_sleep_time; /* Deny idle for C1 */ if (index == 0) { pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle); pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle); } /* * Call idle CPU PM enter notifier chain so that * VFP context is saved. */ if (mpu_state == PWRDM_POWER_OFF) cpu_pm_enter(); /* Execute ARM wfi */ omap_sram_idle(); /* * Call idle CPU PM enter notifier chain to restore * VFP context. */ if (pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF) cpu_pm_exit(); /* Re-allow idle for C1 */ if (index == 0) { pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle); pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle); } return_sleep_time: local_fiq_enable(); return index; } /** * omap3_enter_idle - Programs OMAP3 to enter the specified state * @dev: cpuidle device * @drv: cpuidle driver * @index: the index of state to be entered * * Called from the CPUidle framework to program the device to the * specified target state selected by the governor. */ static inline int omap3_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { return cpuidle_wrap_enter(dev, drv, index, __omap3_enter_idle); } /** * next_valid_state - Find next valid C-state * @dev: cpuidle device * @drv: cpuidle driver * @index: Index of currently selected c-state * * If the state corresponding to index is valid, index is returned back * to the caller. Else, this function searches for a lower c-state which is * still valid (as defined in omap3_power_states[]) and returns its index. * * A state is valid if the 'valid' field is enabled and * if it satisfies the enable_off_mode condition. */ static int next_valid_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct cpuidle_state_usage *curr_usage = &dev->states_usage[index]; struct cpuidle_state *curr = &drv->states[index]; struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr_usage); u32 mpu_deepest_state = PWRDM_POWER_RET; u32 core_deepest_state = PWRDM_POWER_RET; int next_index = -1; if (enable_off_mode) { mpu_deepest_state = PWRDM_POWER_OFF; /* * Erratum i583: valable for ES rev < Es1.2 on 3630. * CORE OFF mode is not supported in a stable form, restrict * instead the CORE state to RET. */ if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) core_deepest_state = PWRDM_POWER_OFF; } /* Check if current state is valid */ if ((cx->valid) && (cx->mpu_state >= mpu_deepest_state) && (cx->core_state >= core_deepest_state)) { return index; } else { int idx = OMAP3_NUM_STATES - 1; /* Reach the current state starting at highest C-state */ for (; idx >= 0; idx--) { if (&drv->states[idx] == curr) { next_index = idx; break; } } /* Should never hit this condition */ WARN_ON(next_index == -1); /* * Drop to next valid state. * Start search from the next (lower) state. */ idx--; for (; idx >= 0; idx--) { cx = cpuidle_get_statedata(&dev->states_usage[idx]); if ((cx->valid) && (cx->mpu_state >= mpu_deepest_state) && (cx->core_state >= core_deepest_state)) { next_index = idx; break; } } /* * C1 is always valid. * So, no need to check for 'next_index == -1' outside * this loop. */ } return next_index; } /** * omap3_enter_idle_bm - Checks for any bus activity * @dev: cpuidle device * @drv: cpuidle driver * @index: array index of target state to be programmed * * This function checks for any pending activity and then programs * the device to the specified or a safer state. */ static int omap3_enter_idle_bm(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { int new_state_idx; u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state; struct omap3_idle_statedata *cx; int ret; /* * Prevent idle completely if CAM is active. * CAM does not have wakeup capability in OMAP3. */ cam_state = pwrdm_read_pwrst(cam_pd); if (cam_state == PWRDM_POWER_ON) { new_state_idx = drv->safe_state_index; goto select_state; } /* * FIXME: we currently manage device-specific idle states * for PER and CORE in combination with CPU-specific * idle states. This is wrong, and device-specific * idle management needs to be separated out into * its own code. */ /* * Prevent PER off if CORE is not in retention or off as this * would disable PER wakeups completely. */ cx = cpuidle_get_statedata(&dev->states_usage[index]); core_next_state = cx->core_state; per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd); if ((per_next_state == PWRDM_POWER_OFF) && (core_next_state > PWRDM_POWER_RET)) per_next_state = PWRDM_POWER_RET; /* Are we changing PER target state? */ if (per_next_state != per_saved_state) pwrdm_set_next_pwrst(per_pd, per_next_state); new_state_idx = next_valid_state(dev, drv, index); select_state: ret = omap3_enter_idle(dev, drv, new_state_idx); /* Restore original PER state if it was modified */ if (per_next_state != per_saved_state) pwrdm_set_next_pwrst(per_pd, per_saved_state); return ret; } DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev); struct cpuidle_driver omap3_idle_driver = { .name = "omap3_idle", .owner = THIS_MODULE, }; /* Helper to fill the C-state common data*/ static inline void _fill_cstate(struct cpuidle_driver *drv, int idx, const char *descr) { struct cpuidle_state *state = &drv->states[idx]; state->exit_latency = cpuidle_params_table[idx].exit_latency; state->target_residency = cpuidle_params_table[idx].target_residency; state->flags = CPUIDLE_FLAG_TIME_VALID; state->enter = omap3_enter_idle_bm; sprintf(state->name, "C%d", idx + 1); strncpy(state->desc, descr, CPUIDLE_DESC_LEN); } /* Helper to register the driver_data */ static inline struct omap3_idle_statedata *_fill_cstate_usage( struct cpuidle_device *dev, int idx) { struct omap3_idle_statedata *cx = &omap3_idle_data[idx]; struct cpuidle_state_usage *state_usage = &dev->states_usage[idx]; cx->valid = cpuidle_params_table[idx].valid; cpuidle_set_statedata(state_usage, cx); return cx; } /** * omap3_idle_init - Init routine for OMAP3 idle * * Registers the OMAP3 specific cpuidle driver to the cpuidle * framework with the valid set of states. */ int __init omap3_idle_init(void) { struct cpuidle_device *dev; struct cpuidle_driver *drv = &omap3_idle_driver; struct omap3_idle_statedata *cx; mpu_pd = pwrdm_lookup("mpu_pwrdm"); core_pd = pwrdm_lookup("core_pwrdm"); per_pd = pwrdm_lookup("per_pwrdm"); cam_pd = pwrdm_lookup("cam_pwrdm"); drv->safe_state_index = -1; dev = &per_cpu(omap3_idle_dev, smp_processor_id()); /* C1 . MPU WFI + Core active */ _fill_cstate(drv, 0, "MPU ON + CORE ON"); (&drv->states[0])->enter = omap3_enter_idle; drv->safe_state_index = 0; cx = _fill_cstate_usage(dev, 0); cx->valid = 1; /* C1 is always valid */ cx->mpu_state = PWRDM_POWER_ON; cx->core_state = PWRDM_POWER_ON; /* C2 . MPU WFI + Core inactive */ _fill_cstate(drv, 1, "MPU ON + CORE ON"); cx = _fill_cstate_usage(dev, 1); cx->mpu_state = PWRDM_POWER_ON; cx->core_state = PWRDM_POWER_ON; /* C3 . MPU CSWR + Core inactive */ _fill_cstate(drv, 2, "MPU RET + CORE ON"); cx = _fill_cstate_usage(dev, 2); cx->mpu_state = PWRDM_POWER_RET; cx->core_state = PWRDM_POWER_ON; /* C4 . MPU OFF + Core inactive */ _fill_cstate(drv, 3, "MPU OFF + CORE ON"); cx = _fill_cstate_usage(dev, 3); cx->mpu_state = PWRDM_POWER_OFF; cx->core_state = PWRDM_POWER_ON; /* C5 . MPU RET + Core RET */ _fill_cstate(drv, 4, "MPU RET + CORE RET"); cx = _fill_cstate_usage(dev, 4); cx->mpu_state = PWRDM_POWER_RET; cx->core_state = PWRDM_POWER_RET; /* C6 . MPU OFF + Core RET */ _fill_cstate(drv, 5, "MPU OFF + CORE RET"); cx = _fill_cstate_usage(dev, 5); cx->mpu_state = PWRDM_POWER_OFF; cx->core_state = PWRDM_POWER_RET; /* C7 . MPU OFF + Core OFF */ _fill_cstate(drv, 6, "MPU OFF + CORE OFF"); cx = _fill_cstate_usage(dev, 6); /* * Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot * enable OFF mode in a stable form for previous revisions. * We disable C7 state as a result. */ if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) { cx->valid = 0; pr_warn("%s: core off state C7 disabled due to i583\n", __func__); } cx->mpu_state = PWRDM_POWER_OFF; cx->core_state = PWRDM_POWER_OFF; drv->state_count = OMAP3_NUM_STATES; cpuidle_register_driver(&omap3_idle_driver); dev->state_count = OMAP3_NUM_STATES; if (cpuidle_register_device(dev)) { printk(KERN_ERR "%s: CPUidle register device failed\n", __func__); return -EIO; } return 0; } #else int __init omap3_idle_init(void) { return 0; } #endif /* CONFIG_CPU_IDLE */