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 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
  14struct 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
  23static 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
  44static int scmi_pd_power_on(struct generic_pm_domain *domain)
  45{
  46        return scmi_pd_power(domain, true);
  47}
  48
  49static int scmi_pd_power_off(struct generic_pm_domain *domain)
  50{
  51        return scmi_pd_power(domain, false);
  52}
  53
  54static 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
 114static const struct scmi_device_id scmi_id_table[] = {
 115        { SCMI_PROTOCOL_POWER },
 116        { },
 117};
 118MODULE_DEVICE_TABLE(scmi, scmi_id_table);
 119
 120static 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};
 125module_scmi_driver(scmi_power_domain_driver);
 126
 127MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 128MODULE_DESCRIPTION("ARM SCMI power domain driver");
 129MODULE_LICENSE("GPL v2");
 130