1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SCMI Generic power domain support. 4 * 5 * Copyright (C) 2018-2021 ARM Ltd. 6 */ 7 8 #include <linux/err.h> 9 #include <linux/io.h> 10 #include <linux/module.h> 11 #include <linux/pm_domain.h> 12 #include <linux/scmi_protocol.h> 13 14 static const struct scmi_power_proto_ops *power_ops; 15 16 struct scmi_pm_domain { 17 struct generic_pm_domain genpd; 18 const struct scmi_protocol_handle *ph; 19 const char *name; 20 u32 domain; 21 }; 22 23 #define to_scmi_pd(gpd) container_of(gpd, struct scmi_pm_domain, genpd) 24 25 static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on) 26 { 27 u32 state; 28 struct scmi_pm_domain *pd = to_scmi_pd(domain); 29 30 if (power_on) 31 state = SCMI_POWER_STATE_GENERIC_ON; 32 else 33 state = SCMI_POWER_STATE_GENERIC_OFF; 34 35 return power_ops->state_set(pd->ph, pd->domain, state); 36 } 37 38 static int scmi_pd_power_on(struct generic_pm_domain *domain) 39 { 40 return scmi_pd_power(domain, true); 41 } 42 43 static int scmi_pd_power_off(struct generic_pm_domain *domain) 44 { 45 return scmi_pd_power(domain, false); 46 } 47 48 static int scmi_pm_domain_probe(struct scmi_device *sdev) 49 { 50 int num_domains, i; 51 struct device *dev = &sdev->dev; 52 struct device_node *np = dev->of_node; 53 struct scmi_pm_domain *scmi_pd; 54 struct genpd_onecell_data *scmi_pd_data; 55 struct generic_pm_domain **domains; 56 const struct scmi_handle *handle = sdev->handle; 57 struct scmi_protocol_handle *ph; 58 59 if (!handle) 60 return -ENODEV; 61 62 power_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWER, &ph); 63 if (IS_ERR(power_ops)) 64 return PTR_ERR(power_ops); 65 66 num_domains = power_ops->num_domains_get(ph); 67 if (num_domains < 0) { 68 dev_err(dev, "number of domains not found\n"); 69 return num_domains; 70 } 71 72 scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL); 73 if (!scmi_pd) 74 return -ENOMEM; 75 76 scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL); 77 if (!scmi_pd_data) 78 return -ENOMEM; 79 80 domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL); 81 if (!domains) 82 return -ENOMEM; 83 84 for (i = 0; i < num_domains; i++, scmi_pd++) { 85 u32 state; 86 87 if (power_ops->state_get(ph, i, &state)) { 88 dev_warn(dev, "failed to get state for domain %d\n", i); 89 continue; 90 } 91 92 /* 93 * Register the explicit power on request to the firmware so 94 * that it is tracked as used by OSPM agent and not 95 * accidentally turned off with OSPM's knowledge 96 */ 97 if (state == SCMI_POWER_STATE_GENERIC_ON) 98 power_ops->state_set(ph, i, state); 99 100 scmi_pd->domain = i; 101 scmi_pd->ph = ph; 102 scmi_pd->name = power_ops->name_get(ph, i); 103 scmi_pd->genpd.name = scmi_pd->name; 104 scmi_pd->genpd.power_off = scmi_pd_power_off; 105 scmi_pd->genpd.power_on = scmi_pd_power_on; 106 scmi_pd->genpd.flags = GENPD_FLAG_ACTIVE_WAKEUP; 107 108 pm_genpd_init(&scmi_pd->genpd, NULL, 109 state == SCMI_POWER_STATE_GENERIC_OFF); 110 111 domains[i] = &scmi_pd->genpd; 112 } 113 114 scmi_pd_data->domains = domains; 115 scmi_pd_data->num_domains = num_domains; 116 117 dev_set_drvdata(dev, scmi_pd_data); 118 119 return of_genpd_add_provider_onecell(np, scmi_pd_data); 120 } 121 122 static void scmi_pm_domain_remove(struct scmi_device *sdev) 123 { 124 int i; 125 struct genpd_onecell_data *scmi_pd_data; 126 struct device *dev = &sdev->dev; 127 struct device_node *np = dev->of_node; 128 129 of_genpd_del_provider(np); 130 131 scmi_pd_data = dev_get_drvdata(dev); 132 for (i = 0; i < scmi_pd_data->num_domains; i++) { 133 if (!scmi_pd_data->domains[i]) 134 continue; 135 pm_genpd_remove(scmi_pd_data->domains[i]); 136 } 137 } 138 139 static const struct scmi_device_id scmi_id_table[] = { 140 { SCMI_PROTOCOL_POWER, "genpd" }, 141 { }, 142 }; 143 MODULE_DEVICE_TABLE(scmi, scmi_id_table); 144 145 static struct scmi_driver scmi_power_domain_driver = { 146 .name = "scmi-power-domain", 147 .probe = scmi_pm_domain_probe, 148 .remove = scmi_pm_domain_remove, 149 .id_table = scmi_id_table, 150 }; 151 module_scmi_driver(scmi_power_domain_driver); 152 153 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); 154 MODULE_DESCRIPTION("ARM SCMI power domain driver"); 155 MODULE_LICENSE("GPL v2"); 156