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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.4 * Copyright (c) 2014,2015, Linaro Ltd.5 *6 * SAW power controller driver7 */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 27struct cpuidle_qcom_spm_data {28 struct cpuidle_driver cpuidle_driver;29 struct spm_driver_data *spm;30};31 32static 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 not38 * power down as a result.39 */40 return -1;41}42 43static 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 and51 * if the SPM mode is not reset, then we may accidently power down the52 * 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 60static __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 69static 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 82static const struct of_device_id qcom_idle_state_match[] = {83 { .compatible = "qcom,idle-state-spc", .data = spm_enter_idle_state },84 { },85};86 87static 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 127static 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 149static 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 157static 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 173static 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}195device_initcall(qcom_spm_cpuidle_init);196