diff options
Diffstat (limited to 'arch/arm/mach-shmobile/cpuidle.c')
-rw-r--r-- | arch/arm/mach-shmobile/cpuidle.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/cpuidle.c b/arch/arm/mach-shmobile/cpuidle.c new file mode 100644 index 00000000000..2e44f11f592 --- /dev/null +++ b/arch/arm/mach-shmobile/cpuidle.c @@ -0,0 +1,92 @@ +/* + * CPUIdle support code for SH-Mobile ARM + * + * Copyright (C) 2011 Magnus Damm + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/pm.h> +#include <linux/cpuidle.h> +#include <linux/suspend.h> +#include <linux/module.h> +#include <linux/err.h> +#include <asm/system.h> +#include <asm/io.h> + +static void shmobile_enter_wfi(void) +{ + cpu_do_idle(); +} + +void (*shmobile_cpuidle_modes[CPUIDLE_STATE_MAX])(void) = { + shmobile_enter_wfi, /* regular sleep mode */ +}; + +static int shmobile_cpuidle_enter(struct cpuidle_device *dev, + struct cpuidle_state *state) +{ + ktime_t before, after; + int requested_state = state - &dev->states[0]; + + dev->last_state = &dev->states[requested_state]; + before = ktime_get(); + + local_irq_disable(); + local_fiq_disable(); + + shmobile_cpuidle_modes[requested_state](); + + local_irq_enable(); + local_fiq_enable(); + + after = ktime_get(); + return ktime_to_ns(ktime_sub(after, before)) >> 10; +} + +static struct cpuidle_device shmobile_cpuidle_dev; +static struct cpuidle_driver shmobile_cpuidle_driver = { + .name = "shmobile_cpuidle", + .owner = THIS_MODULE, +}; + +void (*shmobile_cpuidle_setup)(struct cpuidle_device *dev); + +static int shmobile_cpuidle_init(void) +{ + struct cpuidle_device *dev = &shmobile_cpuidle_dev; + struct cpuidle_state *state; + int i; + + cpuidle_register_driver(&shmobile_cpuidle_driver); + + for (i = 0; i < CPUIDLE_STATE_MAX; i++) { + dev->states[i].name[0] = '\0'; + dev->states[i].desc[0] = '\0'; + dev->states[i].enter = shmobile_cpuidle_enter; + } + + i = CPUIDLE_DRIVER_STATE_START; + + state = &dev->states[i++]; + snprintf(state->name, CPUIDLE_NAME_LEN, "C1"); + strncpy(state->desc, "WFI", CPUIDLE_DESC_LEN); + state->exit_latency = 1; + state->target_residency = 1 * 2; + state->power_usage = 3; + state->flags = 0; + state->flags |= CPUIDLE_FLAG_TIME_VALID; + + dev->safe_state = state; + dev->state_count = i; + + if (shmobile_cpuidle_setup) + shmobile_cpuidle_setup(dev); + + cpuidle_register_device(dev); + + return 0; +} +late_initcall(shmobile_cpuidle_init); |