diff options
Diffstat (limited to 'drivers/cpuidle/arm_big_little.c')
-rw-r--r-- | drivers/cpuidle/arm_big_little.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/cpuidle/arm_big_little.c b/drivers/cpuidle/arm_big_little.c new file mode 100644 index 000000000000..e5378896a8cb --- /dev/null +++ b/drivers/cpuidle/arm_big_little.c @@ -0,0 +1,183 @@ +/* + * big.LITTLE CPU idle driver. + * + * Copyright (C) 2012 ARM Ltd. + * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.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/arm-cci.h> +#include <linux/bitmap.h> +#include <linux/cpuidle.h> +#include <linux/cpu_pm.h> +#include <linux/clockchips.h> +#include <linux/debugfs.h> +#include <linux/hrtimer.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/tick.h> +#include <linux/vexpress.h> +#include <asm/mcpm.h> +#include <asm/cpuidle.h> +#include <asm/cputype.h> +#include <asm/idmap.h> +#include <asm/proc-fns.h> +#include <asm/suspend.h> +#include <linux/of.h> + +static int bl_cpuidle_simple_enter(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + ktime_t time_start, time_end; + s64 diff; + + time_start = ktime_get(); + + cpu_do_idle(); + + time_end = ktime_get(); + + local_irq_enable(); + + diff = ktime_to_us(ktime_sub(time_end, time_start)); + if (diff > INT_MAX) + diff = INT_MAX; + + dev->last_residency = (int) diff; + + return index; +} + +static int bl_enter_powerdown(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int idx); + +static struct cpuidle_state bl_cpuidle_set[] __initdata = { + [0] = { + .enter = bl_cpuidle_simple_enter, + .exit_latency = 1, + .target_residency = 1, + .power_usage = UINT_MAX, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "WFI", + .desc = "ARM WFI", + }, + [1] = { + .enter = bl_enter_powerdown, + .exit_latency = 300, + .target_residency = 1000, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "C1", + .desc = "ARM power down", + }, +}; + +struct cpuidle_driver bl_idle_driver = { + .name = "bl_idle", + .owner = THIS_MODULE, + .safe_state_index = 0 +}; + +static DEFINE_PER_CPU(struct cpuidle_device, bl_idle_dev); + +static int notrace bl_powerdown_finisher(unsigned long arg) +{ + unsigned int mpidr = read_cpuid_mpidr(); + unsigned int cluster = (mpidr >> 8) & 0xf; + unsigned int cpu = mpidr & 0xf; + + mcpm_set_entry_vector(cpu, cluster, cpu_resume); + mcpm_cpu_suspend(0); /* 0 should be replaced with better value here */ + return 1; +} + +/* + * bl_enter_powerdown - Programs CPU to enter the specified state + * @dev: cpuidle device + * @drv: The target state to be programmed + * @idx: state index + * + * Called from the CPUidle framework to program the device to the + * specified target state selected by the governor. + */ +static int bl_enter_powerdown(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int idx) +{ + struct timespec ts_preidle, ts_postidle, ts_idle; + int ret; + + /* Used to keep track of the total time in idle */ + getnstimeofday(&ts_preidle); + + BUG_ON(!irqs_disabled()); + + cpu_pm_enter(); + + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); + + ret = cpu_suspend((unsigned long) dev, bl_powerdown_finisher); + if (ret) + BUG(); + + mcpm_cpu_powered_up(); + + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); + + cpu_pm_exit(); + + getnstimeofday(&ts_postidle); + local_irq_enable(); + ts_idle = timespec_sub(ts_postidle, ts_preidle); + + dev->last_residency = ts_idle.tv_nsec / NSEC_PER_USEC + + ts_idle.tv_sec * USEC_PER_SEC; + return idx; +} + +/* + * bl_idle_init + * + * Registers the bl specific cpuidle driver with the cpuidle + * framework with the valid set of states. + */ +int __init bl_idle_init(void) +{ + struct cpuidle_device *dev; + int i, cpu_id; + struct cpuidle_driver *drv = &bl_idle_driver; + + if (!of_find_compatible_node(NULL, NULL, "arm,generic")) { + pr_info("%s: No compatible node found\n", __func__); + return -ENODEV; + } + + drv->state_count = (sizeof(bl_cpuidle_set) / + sizeof(struct cpuidle_state)); + + for (i = 0; i < drv->state_count; i++) { + memcpy(&drv->states[i], &bl_cpuidle_set[i], + sizeof(struct cpuidle_state)); + } + + cpuidle_register_driver(drv); + + for_each_cpu(cpu_id, cpu_online_mask) { + pr_err("CPUidle for CPU%d registered\n", cpu_id); + dev = &per_cpu(bl_idle_dev, cpu_id); + dev->cpu = cpu_id; + + dev->state_count = drv->state_count; + + if (cpuidle_register_device(dev)) { + printk(KERN_ERR "%s: Cpuidle register device failed\n", + __func__); + return -EIO; + } + } + + return 0; +} + +device_initcall(bl_idle_init); |