1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
6 #include <linux/cpuidle.h>
7 #include <linux/module.h>
8 #include <asm/cpuidle.h>
10 #include <soc/imx/cpuidle.h>
16 static int num_idle_cpus = 0;
17 static DEFINE_RAW_SPINLOCK(cpuidle_lock);
19 static int imx6q_enter_wait(struct cpuidle_device *dev,
20 struct cpuidle_driver *drv, int index)
22 raw_spin_lock(&cpuidle_lock);
23 if (++num_idle_cpus == num_online_cpus())
24 imx6_set_lpm(WAIT_UNCLOCKED);
25 raw_spin_unlock(&cpuidle_lock);
31 raw_spin_lock(&cpuidle_lock);
32 if (num_idle_cpus-- == num_online_cpus())
33 imx6_set_lpm(WAIT_CLOCKED);
34 raw_spin_unlock(&cpuidle_lock);
39 static struct cpuidle_driver imx6q_cpuidle_driver = {
40 .name = "imx6q_cpuidle",
44 ARM_CPUIDLE_WFI_STATE,
48 .target_residency = 75,
49 .flags = CPUIDLE_FLAG_TIMER_STOP | CPUIDLE_FLAG_RCU_IDLE,
50 .enter = imx6q_enter_wait,
56 .safe_state_index = 0,
60 * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the
61 * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't
62 * applicable to all boards, disable the deeper idle state when the workaround
63 * isn't present and the FEC is in use.
65 void imx6q_cpuidle_fec_irqs_used(void)
67 cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, true);
69 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
71 void imx6q_cpuidle_fec_irqs_unused(void)
73 cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, false);
75 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
77 int __init imx6q_cpuidle_init(void)
79 /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
80 imx6_set_int_mem_clk_lpm(true);
82 return cpuidle_register(&imx6q_cpuidle_driver, NULL);