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); 196