LXR linux/drivers/cpuidle/cpuidle-exynos.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
   4 *              http://www.samsung.com
   5 *
   6 * Coupled cpuidle support based on the work of:
   7 *      Colin Cross <ccross@android.com>
   8 *      Daniel Lezcano <daniel.lezcano@linaro.org>
   9*/
  10
  11#include <linux/cpuidle.h>
  12#include <linux/cpu_pm.h>
  13#include <linux/export.h>
  14#include <linux/init.h>
  15#include <linux/platform_device.h>
  16#include <linux/of.h>
  17#include <linux/platform_data/cpuidle-exynos.h>
  18
  19#include <asm/suspend.h>
  20#include <asm/cpuidle.h>
  21
  22static atomic_t exynos_idle_barrier;
  23
  24static struct cpuidle_exynos_data *exynos_cpuidle_pdata;
  25static void (*exynos_enter_aftr)(void);
  26
  27static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
  28                                         struct cpuidle_driver *drv,
  29                                         int index)
  30{
  31        int ret;
  32
  33        exynos_cpuidle_pdata->pre_enter_aftr();
  34
  35        /*
  36         * Waiting all cpus to reach this point at the same moment
  37         */
  38        cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
  39
  40        /*
  41         * Both cpus will reach this point at the same time
  42         */
  43        ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
  44                       : exynos_cpuidle_pdata->cpu0_enter_aftr();
  45        if (ret)
  46                index = ret;
  47
  48        /*
  49         * Waiting all cpus to finish the power sequence before going further
  50         */
  51        cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
  52
  53        exynos_cpuidle_pdata->post_enter_aftr();
  54
  55        return index;
  56}
  57
  58static int exynos_enter_lowpower(struct cpuidle_device *dev,
  59                                struct cpuidle_driver *drv,
  60                                int index)
  61{
  62        int new_index = index;
  63
  64        /* AFTR can only be entered when cores other than CPU0 are offline */
  65        if (num_online_cpus() > 1 || dev->cpu != 0)
  66                new_index = drv->safe_state_index;
  67
  68        if (new_index == 0)
  69                return arm_cpuidle_simple_enter(dev, drv, new_index);
  70
  71        exynos_enter_aftr();
  72
  73        return new_index;
  74}
  75
  76static struct cpuidle_driver exynos_idle_driver = {
  77        .name                   = "exynos_idle",
  78        .owner                  = THIS_MODULE,
  79        .states = {
  80                [0] = ARM_CPUIDLE_WFI_STATE,
  81                [1] = {
  82                        .enter                  = exynos_enter_lowpower,
  83                        .exit_latency           = 300,
  84                        .target_residency       = 10000,
  85                        .name                   = "C1",
  86                        .desc                   = "ARM power down",
  87                },
  88        },
  89        .state_count = 2,
  90        .safe_state_index = 0,
  91};
  92
  93static struct cpuidle_driver exynos_coupled_idle_driver = {
  94        .name                   = "exynos_coupled_idle",
  95        .owner                  = THIS_MODULE,
  96        .states = {
  97                [0] = ARM_CPUIDLE_WFI_STATE,
  98                [1] = {
  99                        .enter                  = exynos_enter_coupled_lowpower,
 100                        .exit_latency           = 5000,
 101                        .target_residency       = 10000,
 102                        .flags                  = CPUIDLE_FLAG_COUPLED |
 103                                                  CPUIDLE_FLAG_TIMER_STOP,
 104                        .name                   = "C1",
 105                        .desc                   = "ARM power down",
 106                },
 107        },
 108        .state_count = 2,
 109        .safe_state_index = 0,
 110};
 111
 112static int exynos_cpuidle_probe(struct platform_device *pdev)
 113{
 114        int ret;
 115
 116        if (IS_ENABLED(CONFIG_SMP) &&
 117            (of_machine_is_compatible("samsung,exynos4210") ||
 118             of_machine_is_compatible("samsung,exynos3250"))) {
 119                exynos_cpuidle_pdata = pdev->dev.platform_data;
 120
 121                ret = cpuidle_register(&exynos_coupled_idle_driver,
 122                                       cpu_possible_mask);
 123        } else {
 124                exynos_enter_aftr = (void *)(pdev->dev.platform_data);
 125
 126                ret = cpuidle_register(&exynos_idle_driver, NULL);
 127        }
 128
 129        if (ret) {
 130                dev_err(&pdev->dev, "failed to register cpuidle driver\n");
 131                return ret;
 132        }
 133
 134        return 0;
 135}
 136
 137static struct platform_driver exynos_cpuidle_driver = {
 138        .probe  = exynos_cpuidle_probe,
 139        .driver = {
 140                .name = "exynos_cpuidle",
 141        },
 142};
 143builtin_platform_driver(exynos_cpuidle_driver);
 144