diff options
Diffstat (limited to 'arch/arm/mach-omap2/cpuidle44xx.c')
| -rw-r--r-- | arch/arm/mach-omap2/cpuidle44xx.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c new file mode 100644 index 00000000000..cfdbb86bc84 --- /dev/null +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -0,0 +1,245 @@ +/* + * OMAP4 CPU idle Routines + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Santosh Shilimkar <santosh.shilimkar@ti.com> + * Rajendra Nayak <rnayak@ti.com> + * + * 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 <linux/sched.h> +#include <linux/cpuidle.h> +#include <linux/cpu_pm.h> +#include <linux/export.h> +#include <linux/clockchips.h> + +#include <asm/proc-fns.h> + +#include "common.h" +#include "pm.h" +#include "prm.h" + +#ifdef CONFIG_CPU_IDLE + +/* Machine specific information to be recorded in the C-state driver_data */ +struct omap4_idle_statedata { + u32 cpu_state; + u32 mpu_logic_state; + u32 mpu_state; + u8 valid; +}; + +static struct cpuidle_params cpuidle_params_table[] = { + /* C1 - CPU0 ON + CPU1 ON + MPU ON */ + {.exit_latency = 2 + 2 , .target_residency = 5, .valid = 1}, + /* C2- CPU0 OFF + CPU1 OFF + MPU CSWR */ + {.exit_latency = 328 + 440 , .target_residency = 960, .valid = 1}, + /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ + {.exit_latency = 460 + 518 , .target_residency = 1100, .valid = 1}, +}; + +#define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table) + +struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES]; +static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd; + +/** + * omap4_enter_idle - Programs OMAP4 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 low power state selected by the governor. + * Returns the amount of time spent in the low power state. + */ +static int omap4_enter_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + struct omap4_idle_statedata *cx = + cpuidle_get_statedata(&dev->states_usage[index]); + struct timespec ts_preidle, ts_postidle, ts_idle; + u32 cpu1_state; + int idle_time; + int new_state_idx; + int cpu_id = smp_processor_id(); + + /* Used to keep track of the total time in idle */ + getnstimeofday(&ts_preidle); + + local_irq_disable(); + local_fiq_disable(); + + /* + * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state. + * This is necessary to honour hardware recommondation + * of triggeing all the possible low power modes once CPU1 is + * out of coherency and in OFF mode. + * Update dev->last_state so that governor stats reflects right + * data. + */ + cpu1_state = pwrdm_read_pwrst(cpu1_pd); + if (cpu1_state != PWRDM_POWER_OFF) { + new_state_idx = drv->safe_state_index; + cx = cpuidle_get_statedata(&dev->states_usage[new_state_idx]); + } + + if (index > 0) + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id); + + /* + * Call idle CPU PM enter notifier chain so that + * VFP and per CPU interrupt context is saved. + */ + if (cx->cpu_state == PWRDM_POWER_OFF) + cpu_pm_enter(); + + pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); + omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + + /* + * Call idle CPU cluster PM enter notifier chain + * to save GIC and wakeupgen context. + */ + if ((cx->mpu_state == PWRDM_POWER_RET) && + (cx->mpu_logic_state == PWRDM_POWER_OFF)) + cpu_cluster_pm_enter(); + + omap4_enter_lowpower(dev->cpu, cx->cpu_state); + + /* + * Call idle CPU PM exit notifier chain to restore + * VFP and per CPU IRQ context. Only CPU0 state is + * considered since CPU1 is managed by CPU hotplug. + */ + if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF) + cpu_pm_exit(); + + /* + * Call idle CPU cluster PM exit notifier chain + * to restore GIC and wakeupgen context. + */ + if (omap4_mpuss_read_prev_context_state()) + cpu_cluster_pm_exit(); + + if (index > 0) + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id); + + getnstimeofday(&ts_postidle); + ts_idle = timespec_sub(ts_postidle, ts_preidle); + + local_irq_enable(); + local_fiq_enable(); + + idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \ + USEC_PER_SEC; + + /* Update cpuidle counters */ + dev->last_residency = idle_time; + + return index; +} + +DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev); + +struct cpuidle_driver omap4_idle_driver = { + .name = "omap4_idle", + .owner = THIS_MODULE, +}; + +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 = omap4_enter_idle; + sprintf(state->name, "C%d", idx + 1); + strncpy(state->desc, descr, CPUIDLE_DESC_LEN); +} + +static inline struct omap4_idle_statedata *_fill_cstate_usage( + struct cpuidle_device *dev, + int idx) +{ + struct omap4_idle_statedata *cx = &omap4_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; +} + + + +/** + * omap4_idle_init - Init routine for OMAP4 idle + * + * Registers the OMAP4 specific cpuidle driver to the cpuidle + * framework with the valid set of states. + */ +int __init omap4_idle_init(void) +{ + struct omap4_idle_statedata *cx; + struct cpuidle_device *dev; + struct cpuidle_driver *drv = &omap4_idle_driver; + unsigned int cpu_id = 0; + + mpu_pd = pwrdm_lookup("mpu_pwrdm"); + cpu0_pd = pwrdm_lookup("cpu0_pwrdm"); + cpu1_pd = pwrdm_lookup("cpu1_pwrdm"); + if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd)) + return -ENODEV; + + + drv->safe_state_index = -1; + dev = &per_cpu(omap4_idle_dev, cpu_id); + dev->cpu = cpu_id; + + /* C1 - CPU0 ON + CPU1 ON + MPU ON */ + _fill_cstate(drv, 0, "MPUSS ON"); + drv->safe_state_index = 0; + cx = _fill_cstate_usage(dev, 0); + cx->valid = 1; /* C1 is always valid */ + cx->cpu_state = PWRDM_POWER_ON; + cx->mpu_state = PWRDM_POWER_ON; + cx->mpu_logic_state = PWRDM_POWER_RET; + + /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */ + _fill_cstate(drv, 1, "MPUSS CSWR"); + cx = _fill_cstate_usage(dev, 1); + cx->cpu_state = PWRDM_POWER_OFF; + cx->mpu_state = PWRDM_POWER_RET; + cx->mpu_logic_state = PWRDM_POWER_RET; + + /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ + _fill_cstate(drv, 2, "MPUSS OSWR"); + cx = _fill_cstate_usage(dev, 2); + cx->cpu_state = PWRDM_POWER_OFF; + cx->mpu_state = PWRDM_POWER_RET; + cx->mpu_logic_state = PWRDM_POWER_OFF; + + drv->state_count = OMAP4_NUM_STATES; + cpuidle_register_driver(&omap4_idle_driver); + + dev->state_count = OMAP4_NUM_STATES; + if (cpuidle_register_device(dev)) { + pr_err("%s: CPUidle register device failed\n", __func__); + return -EIO; + } + + return 0; +} +#else +int __init omap4_idle_init(void) +{ + return 0; +} +#endif /* CONFIG_CPU_IDLE */ |