/* * 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 "powerdomain.h" #include "clockdomain.h" #include "pm.h" #include "control.h" #include "common.h" /* Mach specific information to be recorded in the C-state driver_data */ struct omap3_idle_statedata { u8 mpu_state; u8 core_state; u8 per_min_state; u8 flags; }; static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd; /* * Possible flag bits for struct omap3_idle_statedata.flags: * * OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go * inactive. This in turn prevents the MPU DPLL from entering autoidle * mode, so wakeup latency is greatly reduced, at the cost of additional * energy consumption. This also prevents the CORE clockdomain from * entering idle. */ #define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE BIT(0) /* * Prevent PER OFF if CORE is not in RETention or OFF as this would * disable PER wakeups completely. */ static struct omap3_idle_statedata omap3_idle_data[] = { { .mpu_state = PWRDM_POWER_ON, .core_state = PWRDM_POWER_ON, /* In C1 do not allow PER state lower than CORE state */ .per_min_state = PWRDM_POWER_ON, .flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE, }, { .mpu_state = PWRDM_POWER_ON, .core_state = PWRDM_POWER_ON, .per_min_state = PWRDM_POWER_RET, }, { .mpu_state = PWRDM_POWER_RET, .core_state = PWRDM_POWER_ON, .per_min_state = PWRDM_POWER_RET, }, { .mpu_state = PWRDM_POWER_OFF, .core_state = PWRDM_POWER_ON, .per_min_state = PWRDM_POWER_RET, }, { .mpu_state = PWRDM_POWER_RET, .core_state = PWRDM_POWER_RET, .per_min_state = PWRDM_POWER_OFF, }, { .mpu_state = PWRDM_POWER_OFF, .core_state = PWRDM_POWER_RET, .per_min_state = PWRDM_POWER_OFF, }, { .mpu_state = PWRDM_POWER_OFF, .core_state = PWRDM_POWER_OFF, .per_min_state = PWRDM_POWER_OFF, }, }; /** * omap3_enter_idle - Programs OMAP3 to enter the specified state * @dev: cpuidle device * @drv: cpuidle driver * @index: the index of state to be entered */ static int omap3_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct omap3_idle_statedata *cx = &omap3_idle_data[index]; if (omap_irq_pending() || need_resched()) goto return_sleep_time; /* Deny idle for C1 */ if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) { clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]); } else { pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state); pwrdm_set_next_pwrst(core_pd, cx->core_state); } /* * Call idle CPU PM enter notifier chain so that * VFP context is saved. */ if (cx->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 (cx->mpu_state == PWRDM_POWER_OFF && pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF) cpu_pm_exit(); /* Re-allow idle for C1 */ if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]); return_sleep_time: return index; } /** * 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 omap3_idle_statedata *cx = &omap3_idle_data[index]; u32 mpu_deepest_state = PWRDM_POWER_RET; u32 core_deepest_state = PWRDM_POWER_RET; int idx; int next_index = 0; /* C1 is the default value */ 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->mpu_state >= mpu_deepest_state) && (cx->core_state >= core_deepest_state)) return index; /* * Drop to next valid state. * Start search from the next (lower) state. */ for (idx = index - 1; idx >= 0; idx--) { cx = &omap3_idle_data[idx]; if ((cx->mpu_state >= mpu_deepest_state) && (cx->core_state >= core_deepest_state)) { next_index = idx; break; } } 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, ret; u8 per_next_state, per_saved_state; struct omap3_idle_statedata *cx; /* * Use only C1 if CAM is active. * CAM does not have wakeup capability in OMAP3. */ if (pwrdm_read_pwrst(cam_pd) == PWRDM_POWER_ON) new_state_idx = drv->safe_state_index; else new_state_idx = next_valid_state(dev, drv, index); /* * 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. */ /* Program PER state */ cx = &omap3_idle_data[new_state_idx]; per_next_state = pwrdm_read_next_pwrst(per_pd); per_saved_state = per_next_state; if (per_next_state < cx->per_min_state) { per_next_state = cx->per_min_state; pwrdm_set_next_pwrst(per_pd, per_next_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; } static struct cpuidle_driver omap3_idle_driver = { .name = "omap3_idle", .owner = THIS_MODULE, .states = { { .enter = omap3_enter_idle_bm, .exit_latency = 2 + 2, .target_residency = 5, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C1", .desc = "MPU ON + CORE ON", }, { .enter = omap3_enter_idle_bm, .exit_latency = 10 + 10, .target_residency = 30, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C2", .desc = "MPU ON + CORE ON", }, { .enter = omap3_enter_idle_bm, .exit_latency = 50 + 50, .target_residency = 300, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C3", .desc = "MPU RET + CORE ON", }, { .enter = omap3_enter_idle_bm, .exit_latency = 1500 + 1800, .target_residency = 4000, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C4", .desc = "MPU OFF + CORE ON", }, { .enter = omap3_enter_idle_bm, .exit_latency = 2500 + 7500, .target_residency = 12000, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C5", .desc = "MPU RET + CORE RET", }, { .enter = omap3_enter_idle_bm, .exit_latency = 3000 + 8500, .target_residency = 15000, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C6", .desc = "MPU OFF + CORE RET", }, { .enter = omap3_enter_idle_bm, .exit_latency = 10000 + 30000, .target_residency = 30000, .flags = CPUIDLE_FLAG_TIME_VALID, .name = "C7", .desc = "MPU OFF + CORE OFF", }, }, .state_count = ARRAY_SIZE(omap3_idle_data), .safe_state_index = 0, }; /* Public functions */ /** * 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) { mpu_pd = pwrdm_lookup("mpu_pwrdm"); core_pd = pwrdm_lookup("core_pwrdm"); per_pd = pwrdm_lookup("per_pwrdm"); cam_pd = pwrdm_lookup("cam_pwrdm"); if (!mpu_pd || !core_pd || !per_pd || !cam_pd) return -ENODEV; return cpuidle_register(&omap3_idle_driver, NULL); }