diff options
Diffstat (limited to 'arch/arm/mach-imx/cpuidle-imx6q.c')
-rw-r--r-- | arch/arm/mach-imx/cpuidle-imx6q.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c new file mode 100644 index 000000000..326e870d7 --- /dev/null +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -0,0 +1,84 @@ +/* + * 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 <linux/cpuidle.h> +#include <linux/module.h> +#include <asm/cpuidle.h> + +#include <soc/imx/cpuidle.h> + +#include "common.h" +#include "cpuidle.h" +#include "hardware.h" + +static int num_idle_cpus = 0; +static DEFINE_SPINLOCK(cpuidle_lock); + +static int imx6q_enter_wait(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + spin_lock(&cpuidle_lock); + if (++num_idle_cpus == num_online_cpus()) + imx6_set_lpm(WAIT_UNCLOCKED); + spin_unlock(&cpuidle_lock); + + cpu_do_idle(); + + spin_lock(&cpuidle_lock); + if (num_idle_cpus-- == num_online_cpus()) + imx6_set_lpm(WAIT_CLOCKED); + spin_unlock(&cpuidle_lock); + + 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_TIMER_STOP, + .enter = imx6q_enter_wait, + .name = "WAIT", + .desc = "Clock off", + }, + }, + .state_count = 2, + .safe_state_index = 0, +}; + +/* + * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the + * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't + * applicable to all boards, disable the deeper idle state when the workaround + * isn't present and the FEC is in use. + */ +void imx6q_cpuidle_fec_irqs_used(void) +{ + imx6q_cpuidle_driver.states[1].disabled = true; +} +EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used); + +void imx6q_cpuidle_fec_irqs_unused(void) +{ + imx6q_cpuidle_driver.states[1].disabled = false; +} +EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused); + +int __init imx6q_cpuidle_init(void) +{ + /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */ + imx6_set_int_mem_clk_lpm(true); + + return cpuidle_register(&imx6q_cpuidle_driver, NULL); +} |