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_clock.h> 12 #include <linux/pm_domain.h> 13 #include <linux/scmi_protocol.h> 14 15 static const struct scmi_power_proto_ops *power_ops; 16 17 struct scmi_pm_domain { 18 struct generic_pm_domain genpd; 19 const struct scmi_protocol_handle *ph; 20 const char *name; 21 u32 domain; 22 }; 23 24 #define to_scmi_pd(gpd) container_of(gpd, struct scmi_pm_domain, genpd) 25 26 static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on) 27 { 28 int ret; 29 u32 state, ret_state; 30 struct scmi_pm_domain *pd = to_scmi_pd(domain); 31 32 if (power_on) 33 state = SCMI_POWER_STATE_GENERIC_ON; 34 else 35 state = SCMI_POWER_STATE_GENERIC_OFF; 36 37 ret = power_ops->state_set(pd->ph, pd->domain, state); 38 if (!ret) 39 ret = power_ops->state_get(pd->ph, pd->domain, &ret_state); 40 if (!ret && state != ret_state) 41 return -EIO; 42 43 return ret; 44 } 45 46 static int scmi_pd_power_on(struct generic_pm_domain *domain) 47 { 48 return scmi_pd_power(domain, true); 49 } 50 51 static int scmi_pd_power_off(struct generic_pm_domain *domain) 52 { 53 return scmi_pd_power(domain, false); 54 } 55 56 static int scmi_pd_attach_dev(struct generic_pm_domain *pd, struct device *dev) 57 { 58 int ret; 59 60 ret = pm_clk_create(dev); 61 if (ret) 62 return ret; 63 64 ret = of_pm_clk_add_clks(dev); 65 if (ret >= 0) 66 return 0; 67 68 pm_clk_destroy(dev); 69 return ret; 70 } 71 72 static void scmi_pd_detach_dev(struct generic_pm_domain *pd, struct device *dev) 73 { 74 pm_clk_destroy(dev); 75 } 76 77 static int scmi_pm_domain_probe(struct scmi_device *sdev) 78 { 79 int num_domains, i; 80 struct device *dev = &sdev->dev; 81 struct device_node *np = dev->of_node; 82 struct scmi_pm_domain *scmi_pd; 83 struct genpd_onecell_data *scmi_pd_data; 84 struct generic_pm_domain **domains; 85 const struct scmi_handle *handle = sdev->handle; 86 struct scmi_protocol_handle *ph; 87 88 if (!handle) 89 return -ENODEV; 90 91 power_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWER, &ph); 92 if (IS_ERR(power_ops)) 93 return PTR_ERR(power_ops); 94 95 num_domains = power_ops->num_domains_get(ph); 96 if (num_domains < 0) { 97 dev_err(dev, "number of domains not found\n"); 98 return num_domains; 99 } 100 101 scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL); 102 if (!scmi_pd) 103 return -ENOMEM; 104 105 scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL); 106 if (!scmi_pd_data) 107 return -ENOMEM; 108 109 domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL); 110 if (!domains) 111 return -ENOMEM; 112 113 for (i = 0; i < num_domains; i++, scmi_pd++) { 114 u32 state; 115 116 if (power_ops->state_get(ph, i, &state)) { 117 dev_warn(dev, "failed to get state for domain %d\n", i); 118 continue; 119 } 120 121 scmi_pd->domain = i; 122 scmi_pd->ph = ph; 123 scmi_pd->name = power_ops->name_get(ph, i); 124 scmi_pd->genpd.name = scmi_pd->name; 125 scmi_pd->genpd.power_off = scmi_pd_power_off; 126 scmi_pd->genpd.power_on = scmi_pd_power_on; 127 scmi_pd->genpd.attach_dev = scmi_pd_attach_dev; 128 scmi_pd->genpd.detach_dev = scmi_pd_detach_dev; 129 scmi_pd->genpd.flags = GENPD_FLAG_PM_CLK | 130 GENPD_FLAG_ACTIVE_WAKEUP; 131 132 pm_genpd_init(&scmi_pd->genpd, NULL, 133 state == SCMI_POWER_STATE_GENERIC_OFF); 134 135 domains[i] = &scmi_pd->genpd; 136 } 137 138 scmi_pd_data->domains = domains; 139 scmi_pd_data->num_domains = num_domains; 140 141 of_genpd_add_provider_onecell(np, scmi_pd_data); 142 143 return 0; 144 } 145 146 static const struct scmi_device_id scmi_id_table[] = { 147 { SCMI_PROTOCOL_POWER, "genpd" }, 148 { }, 149 }; 150 MODULE_DEVICE_TABLE(scmi, scmi_id_table); 151 152 static struct scmi_driver scmi_power_domain_driver = { 153 .name = "scmi-power-domain", 154 .probe = scmi_pm_domain_probe, 155 .id_table = scmi_id_table, 156 }; 157 module_scmi_driver(scmi_power_domain_driver); 158 159 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); 160 MODULE_DESCRIPTION("ARM SCMI power domain driver"); 161 MODULE_LICENSE("GPL v2"); 162