LXR linux/arch/arm/mach-imx/cpuidle-imx6q.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
   4 */
   5
   6#include <linux/cpuidle.h>
   7#include <linux/module.h>
   8#include <asm/cpuidle.h>
   9
  10#include <soc/imx/cpuidle.h>
  11
  12#include "common.h"
  13#include "cpuidle.h"
  14#include "hardware.h"
  15
  16static int num_idle_cpus = 0;
  17static DEFINE_RAW_SPINLOCK(cpuidle_lock);
  18
  19static int imx6q_enter_wait(struct cpuidle_device *dev,
  20                            struct cpuidle_driver *drv, int index)
  21{
  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);
  26
  27        rcu_idle_enter();
  28        cpu_do_idle();
  29        rcu_idle_exit();
  30
  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);
  35
  36        return index;
  37}
  38
  39static struct cpuidle_driver imx6q_cpuidle_driver = {
  40        .name = "imx6q_cpuidle",
  41        .owner = THIS_MODULE,
  42        .states = {
  43                /* WFI */
  44                ARM_CPUIDLE_WFI_STATE,
  45                /* WAIT */
  46                {
  47                        .exit_latency = 50,
  48                        .target_residency = 75,
  49                        .flags = CPUIDLE_FLAG_TIMER_STOP | CPUIDLE_FLAG_RCU_IDLE,
  50                        .enter = imx6q_enter_wait,
  51                        .name = "WAIT",
  52                        .desc = "Clock off",
  53                },
  54        },
  55        .state_count = 2,
  56        .safe_state_index = 0,
  57};
  58
  59/*
  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.
  64 */
  65void imx6q_cpuidle_fec_irqs_used(void)
  66{
  67        cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, true);
  68}
  69EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
  70
  71void imx6q_cpuidle_fec_irqs_unused(void)
  72{
  73        cpuidle_driver_state_disabled(&imx6q_cpuidle_driver, 1, false);
  74}
  75EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
  76
  77int __init imx6q_cpuidle_init(void)
  78{
  79        /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
  80        imx6_set_int_mem_clk_lpm(true);
  81
  82        return cpuidle_register(&imx6q_cpuidle_driver, NULL);
  83}
  84