linux/drivers/firmware/arm_scmi/scmi_pm_domain.c
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   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
  14static const struct scmi_power_proto_ops *power_ops;
  15
  16struct 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
  25static 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
  45static int scmi_pd_power_on(struct generic_pm_domain *domain)
  46{
  47        return scmi_pd_power(domain, true);
  48}
  49
  50static int scmi_pd_power_off(struct generic_pm_domain *domain)
  51{
  52        return scmi_pd_power(domain, false);
  53}
  54
  55static 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
 106                pm_genpd_init(&scmi_pd->genpd, NULL,
 107                              state == SCMI_POWER_STATE_GENERIC_OFF);
 108
 109                domains[i] = &scmi_pd->genpd;
 110        }
 111
 112        scmi_pd_data->domains = domains;
 113        scmi_pd_data->num_domains = num_domains;
 114
 115        of_genpd_add_provider_onecell(np, scmi_pd_data);
 116
 117        return 0;
 118}
 119
 120static const struct scmi_device_id scmi_id_table[] = {
 121        { SCMI_PROTOCOL_POWER, "genpd" },
 122        { },
 123};
 124MODULE_DEVICE_TABLE(scmi, scmi_id_table);
 125
 126static struct scmi_driver scmi_power_domain_driver = {
 127        .name = "scmi-power-domain",
 128        .probe = scmi_pm_domain_probe,
 129        .id_table = scmi_id_table,
 130};
 131module_scmi_driver(scmi_power_domain_driver);
 132
 133MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 134MODULE_DESCRIPTION("ARM SCMI power domain driver");
 135MODULE_LICENSE("GPL v2");
 136