drivers/firmware/arm_scmi/scmi_pm_domain.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SCMI Generic power domain support.
   4  *
   5  * Copyright (C) 2018 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 struct scmi_pm_domain {
  15         struct generic_pm_domain genpd;
  16         const struct scmi_handle *handle;
  17         const char *name;
  18         u32 domain;
  19 };
  20
  21 #define to_scmi_pd(gpd) container_of(gpd, struct scmi_pm_domain, genpd)
  22
  23 static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
  24 {
  25         int ret;
  26         u32 state, ret_state;
  27         struct scmi_pm_domain *pd = to_scmi_pd(domain);
  28         const struct scmi_power_ops *ops = pd->handle->power_ops;
  29
  30         if (power_on)
  31                 state = SCMI_POWER_STATE_GENERIC_ON;
  32         else
  33                 state = SCMI_POWER_STATE_GENERIC_OFF;
  34
  35         ret = ops->state_set(pd->handle, pd->domain, state);
  36         if (!ret)
  37                 ret = ops->state_get(pd->handle, pd->domain, &ret_state);
  38         if (!ret && state != ret_state)
  39                 return -EIO;
  40
  41         return ret;
  42 }
  43
  44 static int scmi_pd_power_on(struct generic_pm_domain *domain)
  45 {
  46         return scmi_pd_power(domain, true);
  47 }
  48
  49 static int scmi_pd_power_off(struct generic_pm_domain *domain)
  50 {
  51         return scmi_pd_power(domain, false);
  52 }
  53
  54 static int scmi_pm_domain_probe(struct scmi_device *sdev)
  55 {
  56         int num_domains, i;
  57         struct device *dev = &sdev->dev;
  58         struct device_node *np = dev->of_node;
  59         struct scmi_pm_domain *scmi_pd;
  60         struct genpd_onecell_data *scmi_pd_data;
  61         struct generic_pm_domain **domains;
  62         const struct scmi_handle *handle = sdev->handle;
  63
  64         if (!handle || !handle->power_ops)
  65                 return -ENODEV;
  66
  67         num_domains = handle->power_ops->num_domains_get(handle);
  68         if (num_domains < 0) {
  69                 dev_err(dev, "number of domains not found\n");
  70                 return num_domains;
  71         }
  72
  73         scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL);
  74         if (!scmi_pd)
  75                 return -ENOMEM;
  76
  77         scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL);
  78         if (!scmi_pd_data)
  79                 return -ENOMEM;
  80
  81         domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL);
  82         if (!domains)
  83                 return -ENOMEM;
  84
  85         for (i = 0; i < num_domains; i++, scmi_pd++) {
  86                 u32 state;
  87
  88                 domains[i] = &scmi_pd->genpd;
  89
  90                 scmi_pd->domain = i;
  91                 scmi_pd->handle = handle;
  92                 scmi_pd->name = handle->power_ops->name_get(handle, i);
  93                 scmi_pd->genpd.name = scmi_pd->name;
  94                 scmi_pd->genpd.power_off = scmi_pd_power_off;
  95                 scmi_pd->genpd.power_on = scmi_pd_power_on;
  96
  97                 if (handle->power_ops->state_get(handle, i, &state)) {
  98                         dev_warn(dev, "failed to get state for domain %d\n", i);
  99                         continue;
 100                 }
 101
 102                 pm_genpd_init(&scmi_pd->genpd, NULL,
 103                               state == SCMI_POWER_STATE_GENERIC_OFF);
 104         }
 105
 106         scmi_pd_data->domains = domains;
 107         scmi_pd_data->num_domains = num_domains;
 108
 109         of_genpd_add_provider_onecell(np, scmi_pd_data);
 110
 111         return 0;
 112 }
 113
 114 static const struct scmi_device_id scmi_id_table[] = {
 115         { SCMI_PROTOCOL_POWER },
 116         { },
 117 };
 118 MODULE_DEVICE_TABLE(scmi, scmi_id_table);
 119
 120 static struct scmi_driver scmi_power_domain_driver = {
 121         .name = "scmi-power-domain",
 122         .probe = scmi_pm_domain_probe,
 123         .id_table = scmi_id_table,
 124 };
 125 module_scmi_driver(scmi_power_domain_driver);
 126
 127 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 128 MODULE_DESCRIPTION("ARM SCMI power domain driver");
 129 MODULE_LICENSE("GPL v2");