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); 197