From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001 From: Yuval Adam <_@yuv.al> Date: Wed, 30 Aug 2017 08:25:59 +0000 Subject: Initial file dump from open source release --- arch/arm/mach-imx/cpuidle-imx6q.c | 75 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 arch/arm/mach-imx/cpuidle-imx6q.c (limited to 'arch/arm/mach-imx/cpuidle-imx6q.c') diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c new file mode 100644 index 00000000..23ddfb69 --- /dev/null +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -0,0 +1,75 @@ +/* + * Copyright (C) 2012 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 +#include +#include +#include + +#include "common.h" +#include "cpuidle.h" + +static atomic_t master = ATOMIC_INIT(0); +static DEFINE_SPINLOCK(master_lock); + +static int imx6q_enter_wait(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + if (atomic_inc_return(&master) == num_online_cpus()) { + /* + * With this lock, we prevent other cpu to exit and enter + * this function again and become the master. + */ + if (!spin_trylock(&master_lock)) + goto idle; + imx6q_set_lpm(WAIT_UNCLOCKED); + cpu_do_idle(); + imx6q_set_lpm(WAIT_CLOCKED); + spin_unlock(&master_lock); + goto done; + } + +idle: + cpu_do_idle(); +done: + atomic_dec(&master); + + return index; +} + +static struct cpuidle_driver imx6q_cpuidle_driver = { + .name = "imx6q_cpuidle", + .owner = THIS_MODULE, + .states = { + /* WFI */ + ARM_CPUIDLE_WFI_STATE, + /* WAIT */ + { + .exit_latency = 50, + .target_residency = 75, + .flags = CPUIDLE_FLAG_TIME_VALID | + CPUIDLE_FLAG_TIMER_STOP, + .enter = imx6q_enter_wait, + .name = "WAIT", + .desc = "Clock off", + }, + }, + .state_count = 2, + .safe_state_index = 0, +}; + +int __init imx6q_cpuidle_init(void) +{ + /* Need to enable SCU standby for entering WAIT modes */ + imx_scu_standby_enable(); + + /* Set chicken bit to get a reliable WAIT mode support */ + imx6q_set_chicken_bit(); + + return cpuidle_register(&imx6q_cpuidle_driver, NULL); +} -- cgit v1.3.1