1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SCMI performance domain support. 4 * 5 * Copyright (C) 2023 Linaro Ltd. 6 */ 7 8 #include <linux/err.h> 9 #include <linux/device.h> 10 #include <linux/module.h> 11 #include <linux/pm_domain.h> 12 #include <linux/pm_opp.h> 13 #include <linux/scmi_protocol.h> 14 #include <linux/slab.h> 15 16 struct scmi_perf_domain { 17 struct generic_pm_domain genpd; 18 const struct scmi_perf_proto_ops *perf_ops; 19 const struct scmi_protocol_handle *ph; 20 const struct scmi_perf_domain_info *info; 21 u32 domain_id; 22 }; 23 24 #define to_scmi_pd(pd) container_of(pd, struct scmi_perf_domain, genpd) 25 26 static int 27 scmi_pd_set_perf_state(struct generic_pm_domain *genpd, unsigned int state) 28 { 29 struct scmi_perf_domain *pd = to_scmi_pd(genpd); 30 int ret; 31 32 if (!pd->info->set_perf) 33 return 0; 34 35 if (!state) 36 return -EINVAL; 37 38 ret = pd->perf_ops->level_set(pd->ph, pd->domain_id, state, false); 39 if (ret) 40 dev_warn(&genpd->dev, "Failed with %d when trying to set %d perf level", 41 ret, state); 42 43 return ret; 44 } 45 46 static int 47 scmi_pd_attach_dev(struct generic_pm_domain *genpd, struct device *dev) 48 { 49 struct scmi_perf_domain *pd = to_scmi_pd(genpd); 50 int ret; 51 52 /* 53 * Allow the device to be attached, but don't add the OPP table unless 54 * the performance level can be changed. 55 */ 56 if (!pd->info->set_perf) 57 return 0; 58 59 ret = pd->perf_ops->device_opps_add(pd->ph, dev, pd->domain_id); 60 if (ret) 61 dev_warn(dev, "failed to add OPPs for the device\n"); 62 63 return ret; 64 } 65 66 static void 67 scmi_pd_detach_dev(struct generic_pm_domain *genpd, struct device *dev) 68 { 69 struct scmi_perf_domain *pd = to_scmi_pd(genpd); 70 71 if (!pd->info->set_perf) 72 return; 73 74 dev_pm_opp_remove_all_dynamic(dev); 75 } 76 77 static int scmi_perf_domain_probe(struct scmi_device *sdev) 78 { 79 struct device *dev = &sdev->dev; 80 const struct scmi_handle *handle = sdev->handle; 81 const struct scmi_perf_proto_ops *perf_ops; 82 struct scmi_protocol_handle *ph; 83 struct scmi_perf_domain *scmi_pd; 84 struct genpd_onecell_data *scmi_pd_data; 85 struct generic_pm_domain **domains; 86 int num_domains, i, ret = 0; 87 88 if (!handle) 89 return -ENODEV; 90 91 /* The OF node must specify us as a power-domain provider. */ 92 if (!of_find_property(dev->of_node, "#power-domain-cells", NULL)) 93 return 0; 94 95 perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph); 96 if (IS_ERR(perf_ops)) 97 return PTR_ERR(perf_ops); 98 99 num_domains = perf_ops->num_domains_get(ph); 100 if (num_domains < 0) { 101 dev_warn(dev, "Failed with %d when getting num perf domains\n", 102 num_domains); 103 return num_domains; 104 } else if (!num_domains) { 105 return 0; 106 } 107 108 scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL); 109 if (!scmi_pd) 110 return -ENOMEM; 111 112 scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL); 113 if (!scmi_pd_data) 114 return -ENOMEM; 115 116 domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL); 117 if (!domains) 118 return -ENOMEM; 119 120 for (i = 0; i < num_domains; i++, scmi_pd++) { 121 scmi_pd->info = perf_ops->info_get(ph, i); 122 123 scmi_pd->domain_id = i; 124 scmi_pd->perf_ops = perf_ops; 125 scmi_pd->ph = ph; 126 scmi_pd->genpd.name = scmi_pd->info->name; 127 scmi_pd->genpd.flags = GENPD_FLAG_ALWAYS_ON | 128 GENPD_FLAG_OPP_TABLE_FW; 129 scmi_pd->genpd.set_performance_state = scmi_pd_set_perf_state; 130 scmi_pd->genpd.attach_dev = scmi_pd_attach_dev; 131 scmi_pd->genpd.detach_dev = scmi_pd_detach_dev; 132 133 ret = pm_genpd_init(&scmi_pd->genpd, NULL, false); 134 if (ret) 135 goto err; 136 137 domains[i] = &scmi_pd->genpd; 138 } 139 140 scmi_pd_data->domains = domains; 141 scmi_pd_data->num_domains = num_domains; 142 143 ret = of_genpd_add_provider_onecell(dev->of_node, scmi_pd_data); 144 if (ret) 145 goto err; 146 147 dev_set_drvdata(dev, scmi_pd_data); 148 dev_info(dev, "Initialized %d performance domains", num_domains); 149 return 0; 150 err: 151 for (i--; i >= 0; i--) 152 pm_genpd_remove(domains[i]); 153 return ret; 154 } 155 156 static void scmi_perf_domain_remove(struct scmi_device *sdev) 157 { 158 struct device *dev = &sdev->dev; 159 struct genpd_onecell_data *scmi_pd_data = dev_get_drvdata(dev); 160 int i; 161 162 of_genpd_del_provider(dev->of_node); 163 164 for (i = 0; i < scmi_pd_data->num_domains; i++) 165 pm_genpd_remove(scmi_pd_data->domains[i]); 166 } 167 168 static const struct scmi_device_id scmi_id_table[] = { 169 { SCMI_PROTOCOL_PERF, "perf" }, 170 { }, 171 }; 172 MODULE_DEVICE_TABLE(scmi, scmi_id_table); 173 174 static struct scmi_driver scmi_perf_domain_driver = { 175 .name = "scmi-perf-domain", 176 .probe = scmi_perf_domain_probe, 177 .remove = scmi_perf_domain_remove, 178 .id_table = scmi_id_table, 179 }; 180 module_scmi_driver(scmi_perf_domain_driver); 181 182 MODULE_AUTHOR("Ulf Hansson <ulf.hansson@linaro.org>"); 183 MODULE_DESCRIPTION("ARM SCMI perf domain driver"); 184 MODULE_LICENSE("GPL v2"); 185