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) 2018-2021 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");