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