drivers/pmdomain/arm/scmi_pm_domain.c

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