drivers/cpuidle/cpuidle-qcom-spm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
   4  * Copyright (c) 2014,2015, Linaro Ltd.
   5  *
   6  * SAW power controller driver
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12 #include <linux/slab.h>
  13 #include <linux/of.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/err.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/cpuidle.h>
  18 #include <linux/cpu_pm.h>
  19 #include <linux/firmware/qcom/qcom_scm.h>
  20 #include <soc/qcom/spm.h>
  21
  22 #include <asm/proc-fns.h>
  23 #include <asm/suspend.h>
  24
  25 #include "dt_idle_states.h"
  26
  27 struct cpuidle_qcom_spm_data {
  28         struct cpuidle_driver cpuidle_driver;
  29         struct spm_driver_data *spm;
  30 };
  31
  32 static int qcom_pm_collapse(unsigned long int unused)
  33 {
  34         qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
  35
  36         /*
  37          * Returns here only if there was a pending interrupt and we did not
  38          * power down as a result.
  39          */
  40         return -1;
  41 }
  42
  43 static int qcom_cpu_spc(struct spm_driver_data *drv)
  44 {
  45         int ret;
  46
  47         spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
  48         ret = cpu_suspend(0, qcom_pm_collapse);
  49         /*
  50          * ARM common code executes WFI without calling into our driver and
  51          * if the SPM mode is not reset, then we may accidently power down the
  52          * cpu when we intended only to gate the cpu clock.
  53          * Ensure the state is set to standby before returning.
  54          */
  55         spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
  56
  57         return ret;
  58 }
  59
  60 static __cpuidle int spm_enter_idle_state(struct cpuidle_device *dev,
  61                                           struct cpuidle_driver *drv, int idx)
  62 {
  63         struct cpuidle_qcom_spm_data *data = container_of(drv, struct cpuidle_qcom_spm_data,
  64                                                           cpuidle_driver);
  65
  66         return CPU_PM_CPU_IDLE_ENTER_PARAM(qcom_cpu_spc, idx, data->spm);
  67 }
  68
  69 static struct cpuidle_driver qcom_spm_idle_driver = {
  70         .name = "qcom_spm",
  71         .owner = THIS_MODULE,
  72         .states[0] = {
  73                 .enter                  = spm_enter_idle_state,
  74                 .exit_latency           = 1,
  75                 .target_residency       = 1,
  76                 .power_usage            = UINT_MAX,
  77                 .name                   = "WFI",
  78                 .desc                   = "ARM WFI",
  79         }
  80 };
  81
  82 static const struct of_device_id qcom_idle_state_match[] = {
  83         { .compatible = "qcom,idle-state-spc", .data = spm_enter_idle_state },
  84         { },
  85 };
  86
  87 static int spm_cpuidle_register(struct device *cpuidle_dev, int cpu)
  88 {
  89         struct platform_device *pdev = NULL;
  90         struct device_node *cpu_node, *saw_node;
  91         struct cpuidle_qcom_spm_data *data = NULL;
  92         int ret;
  93
  94         cpu_node = of_cpu_device_node_get(cpu);
  95         if (!cpu_node)
  96                 return -ENODEV;
  97
  98         saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
  99         if (!saw_node)
 100                 return -ENODEV;
 101
 102         pdev = of_find_device_by_node(saw_node);
 103         of_node_put(saw_node);
 104         of_node_put(cpu_node);
 105         if (!pdev)
 106                 return -ENODEV;
 107
 108         data = devm_kzalloc(cpuidle_dev, sizeof(*data), GFP_KERNEL);
 109         if (!data)
 110                 return -ENOMEM;
 111
 112         data->spm = dev_get_drvdata(&pdev->dev);
 113         if (!data->spm)
 114                 return -EINVAL;
 115
 116         data->cpuidle_driver = qcom_spm_idle_driver;
 117         data->cpuidle_driver.cpumask = (struct cpumask *)cpumask_of(cpu);
 118
 119         ret = dt_init_idle_driver(&data->cpuidle_driver,
 120                                   qcom_idle_state_match, 1);
 121         if (ret <= 0)
 122                 return ret ? : -ENODEV;
 123
 124         return cpuidle_register(&data->cpuidle_driver, NULL);
 125 }
 126
 127 static int spm_cpuidle_drv_probe(struct platform_device *pdev)
 128 {
 129         int cpu, ret;
 130
 131         if (!qcom_scm_is_available())
 132                 return -EPROBE_DEFER;
 133
 134         ret = qcom_scm_set_warm_boot_addr(cpu_resume_arm);
 135         if (ret)
 136                 return dev_err_probe(&pdev->dev, ret, "set warm boot addr failed");
 137
 138         for_each_possible_cpu(cpu) {
 139                 ret = spm_cpuidle_register(&pdev->dev, cpu);
 140                 if (ret && ret != -ENODEV) {
 141                         dev_err(&pdev->dev,
 142                                 "Cannot register for CPU%d: %d\n", cpu, ret);
 143                 }
 144         }
 145
 146         return 0;
 147 }
 148
 149 static struct platform_driver spm_cpuidle_driver = {
 150         .probe = spm_cpuidle_drv_probe,
 151         .driver = {
 152                 .name = "qcom-spm-cpuidle",
 153                 .suppress_bind_attrs = true,
 154         },
 155 };
 156
 157 static bool __init qcom_spm_find_any_cpu(void)
 158 {
 159         struct device_node *cpu_node, *saw_node;
 160
 161         for_each_of_cpu_node(cpu_node) {
 162                 saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
 163                 if (of_device_is_available(saw_node)) {
 164                         of_node_put(saw_node);
 165                         of_node_put(cpu_node);
 166                         return true;
 167                 }
 168                 of_node_put(saw_node);
 169         }
 170         return false;
 171 }
 172
 173 static int __init qcom_spm_cpuidle_init(void)
 174 {
 175         struct platform_device *pdev;
 176         int ret;
 177
 178         ret = platform_driver_register(&spm_cpuidle_driver);
 179         if (ret)
 180                 return ret;
 181
 182         /* Make sure there is actually any CPU managed by the SPM */
 183         if (!qcom_spm_find_any_cpu())
 184                 return 0;
 185
 186         pdev = platform_device_register_simple("qcom-spm-cpuidle",
 187                                                -1, NULL, 0);
 188         if (IS_ERR(pdev)) {
 189                 platform_driver_unregister(&spm_cpuidle_driver);
 190                 return PTR_ERR(pdev);
 191         }
 192
 193         return 0;
 194 }
 195 device_initcall(qcom_spm_cpuidle_init);