diff options
Diffstat (limited to 'arch/arm/mach-imx/cpuidle-imx6sx.c')
-rw-r--r-- | arch/arm/mach-imx/cpuidle-imx6sx.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c new file mode 100644 index 000000000..3708a71f3 --- /dev/null +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c @@ -0,0 +1,118 @@ +/* + * Copyright (C) 2014 Freescale Semiconductor, Inc. + * + * 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/cpuidle.h> +#include <linux/cpu_pm.h> +#include <linux/module.h> +#include <asm/cacheflush.h> +#include <asm/cpuidle.h> +#include <asm/suspend.h> + +#include "common.h" +#include "cpuidle.h" +#include "hardware.h" + +static int imx6sx_idle_finish(unsigned long val) +{ + /* + * for Cortex-A7 which has an internal L2 + * cache, need to flush it before powering + * down ARM platform, since flushing L1 cache + * here again has very small overhead, compared + * to adding conditional code for L2 cache type, + * just call flush_cache_all() is fine. + */ + flush_cache_all(); + cpu_do_idle(); + + return 0; +} + +static int imx6sx_enter_wait(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + imx6_set_lpm(WAIT_UNCLOCKED); + + switch (index) { + case 1: + cpu_do_idle(); + break; + case 2: + imx6_enable_rbc(true); + imx_gpc_set_arm_power_in_lpm(true); + imx_set_cpu_jump(0, v7_cpu_resume); + /* Need to notify there is a cpu pm operation. */ + cpu_pm_enter(); + cpu_cluster_pm_enter(); + + cpu_suspend(0, imx6sx_idle_finish); + + cpu_cluster_pm_exit(); + cpu_pm_exit(); + imx_gpc_set_arm_power_in_lpm(false); + imx6_enable_rbc(false); + break; + default: + break; + } + + imx6_set_lpm(WAIT_CLOCKED); + + return index; +} + +static struct cpuidle_driver imx6sx_cpuidle_driver = { + .name = "imx6sx_cpuidle", + .owner = THIS_MODULE, + .states = { + /* WFI */ + ARM_CPUIDLE_WFI_STATE, + /* WAIT */ + { + .exit_latency = 50, + .target_residency = 75, + .flags = CPUIDLE_FLAG_TIMER_STOP, + .enter = imx6sx_enter_wait, + .name = "WAIT", + .desc = "Clock off", + }, + /* WAIT + ARM power off */ + { + /* + * ARM gating 31us * 5 + RBC clear 65us + * and some margin for SW execution, here set it + * to 300us. + */ + .exit_latency = 300, + .target_residency = 500, + .flags = CPUIDLE_FLAG_TIMER_STOP, + .enter = imx6sx_enter_wait, + .name = "LOW-POWER-IDLE", + .desc = "ARM power off", + }, + }, + .state_count = 3, + .safe_state_index = 0, +}; + +int __init imx6sx_cpuidle_init(void) +{ + imx6_set_int_mem_clk_lpm(true); + imx6_enable_rbc(false); + imx_gpc_set_l2_mem_power_in_lpm(false); + /* + * set ARM power up/down timing to the fastest, + * sw2iso and sw can be set to one 32K cycle = 31us + * except for power up sw2iso which need to be + * larger than LDO ramp up time. + */ + imx_gpc_set_arm_power_up_timing(cpu_is_imx6sx() ? 0xf : 0x2, 1); + imx_gpc_set_arm_power_down_timing(1, 1); + + return cpuidle_register(&imx6sx_cpuidle_driver, NULL); +} |