arm/mach-imx/cpuidle-imx6q.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2012 Freescale Semiconductor, Inc.
0004  */
0005
0006 #include <linux/context_tracking.h>
0007 #include <linux/cpuidle.h>
0008 #include <linux/module.h>
0009 #include <asm/cpuidle.h>
0010
0011 #include <soc/imx/cpuidle.h>
0012
0013 #include "common.h"
0014 #include "cpuidle.h"
0015 #include "hardware.h"
0016
0017 static int num_idle_cpus = 0;
0018 static DEFINE_RAW_SPINLOCK(cpuidle_lock);
0019
0020 static int imx6q_enter_wait(struct cpuidle_device *dev,
0021                 struct cpuidle_driver *drv, int index)
0022 {
0023     raw_spin_lock(&cpuidle_lock);
0024     if (++num_idle_cpus == num_online_cpus())
0025         imx6_set_lpm(WAIT_UNCLOCKED);
0026     raw_spin_unlock(&cpuidle_lock);
0027
0028     ct_idle_enter();
0029     cpu_do_idle();
0030     ct_idle_exit();
0031
0032     raw_spin_lock(&cpuidle_lock);
0033     if (num_idle_cpus-- == num_online_cpus())
0034         imx6_set_lpm(WAIT_CLOCKED);
0035     raw_spin_unlock(&cpuidle_lock);
0036
0037     return index;
0038 }
0039
0040 static struct cpuidle_driver imx6q_cpuidle_driver = {
0041     .name = "imx6q_cpuidle",
0042     .owner = THIS_MODULE,
0043     .states = {
0044         /* WFI */
0045         ARM_CPUIDLE_WFI_STATE,
0046         /* WAIT */
0047         {
0048             .exit_latency = 50,
0049             .target_residency = 75,
0050             .flags = CPUIDLE_FLAG_TIMER_STOP | CPUIDLE_FLAG_RCU_IDLE,
0051             .enter = imx6q_enter_wait,
0052             .name = "WAIT",
0053             .desc = "Clock off",
0054         },
0055     },
0056     .state_count = 2,
0057     .safe_state_index = 0,
0058 };
0059
0060 /*
0061  * i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the
0062  * CPUs when they are in wait(unclocked) state. As the hardware workaround isn't
0063  * applicable to all boards, disable the deeper idle state when the workaround
0064  * isn't present and the FEC is in use.
0065  */
0066 void imx6q_cpuidle_fec_irqs_used(void)
0067 {
0068     cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, true);
0069 }
0070 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
0071
0072 void imx6q_cpuidle_fec_irqs_unused(void)
0073 {
0074     cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, false);
0075 }
0076 EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
0077
0078 int __init imx6q_cpuidle_init(void)
0079 {
0080     /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
0081     imx6_set_int_mem_clk_lpm(true);
0082
0083     return cpuidle_register(&imx6q_cpuidle_driver, NULL);
0084 }