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
 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, u32 state)
 26{
 27	struct scmi_pm_domain *pd = to_scmi_pd(domain);
 28
 29	return power_ops->state_set(pd->ph, pd->domain, state);
 30}
 31
 32static int scmi_pd_power_on(struct generic_pm_domain *domain)
 33{
 34	return scmi_pd_power(domain, SCMI_POWER_STATE_GENERIC_ON);
 35}
 36
 37static int scmi_pd_power_off(struct generic_pm_domain *domain)
 38{
 39	return scmi_pd_power(domain, SCMI_POWER_STATE_GENERIC_OFF);
 40}
 41
 42static int scmi_pm_domain_probe(struct scmi_device *sdev)
 43{
 44	int num_domains, i, ret;
 45	struct device *dev = &sdev->dev;
 46	struct device_node *np = dev->of_node;
 47	struct scmi_pm_domain *scmi_pd;
 48	struct genpd_onecell_data *scmi_pd_data;
 49	struct generic_pm_domain **domains;
 50	const struct scmi_handle *handle = sdev->handle;
 51	struct scmi_protocol_handle *ph;
 52
 53	if (!handle)
 54		return -ENODEV;
 55
 56	power_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWER, &ph);
 57	if (IS_ERR(power_ops))
 58		return PTR_ERR(power_ops);
 59
 60	num_domains = power_ops->num_domains_get(ph);
 61	if (num_domains < 0) {
 62		dev_err(dev, "number of domains not found\n");
 63		return num_domains;
 64	}
 65
 66	scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL);
 67	if (!scmi_pd)
 68		return -ENOMEM;
 69
 70	scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL);
 71	if (!scmi_pd_data)
 72		return -ENOMEM;
 73
 74	domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL);
 75	if (!domains)
 76		return -ENOMEM;
 77
 78	for (i = 0; i < num_domains; i++, scmi_pd++) {
 79		u32 state;
 80
 81		if (power_ops->state_get(ph, i, &state)) {
 82			dev_warn(dev, "failed to get state for domain %d\n", i);
 83			continue;
 84		}
 85
 86		/*
 87		 * Register the explicit power on request to the firmware so
 88		 * that it is tracked as used by OSPM agent and not
 89		 * accidentally turned off with OSPM's knowledge
 90		 */
 91		if (state == SCMI_POWER_STATE_GENERIC_ON)
 92			power_ops->state_set(ph, i, state);
 93
 94		scmi_pd->domain = i;
 95		scmi_pd->ph = ph;
 96		scmi_pd->name = power_ops->name_get(ph, i);
 97		scmi_pd->genpd.name = scmi_pd->name;
 98		scmi_pd->genpd.power_off = scmi_pd_power_off;
 99		scmi_pd->genpd.power_on = scmi_pd_power_on;
100		scmi_pd->genpd.flags = GENPD_FLAG_ACTIVE_WAKEUP;
101
102		pm_genpd_init(&scmi_pd->genpd, NULL,
103			      state == SCMI_POWER_STATE_GENERIC_OFF);
104
105		domains[i] = &scmi_pd->genpd;
106	}
107
108	scmi_pd_data->domains = domains;
109	scmi_pd_data->num_domains = num_domains;
110
111	ret = of_genpd_add_provider_onecell(np, scmi_pd_data);
112	if (ret)
113		goto err_rm_genpds;
114
115	dev_set_drvdata(dev, scmi_pd_data);
116
117	return 0;
118err_rm_genpds:
119	for (i = num_domains - 1; i >= 0; i--)
120		pm_genpd_remove(domains[i]);
121
122	return ret;
123}
124
125static void scmi_pm_domain_remove(struct scmi_device *sdev)
126{
127	int i;
128	struct genpd_onecell_data *scmi_pd_data;
129	struct device *dev = &sdev->dev;
130	struct device_node *np = dev->of_node;
131
132	of_genpd_del_provider(np);
133
134	scmi_pd_data = dev_get_drvdata(dev);
135	for (i = 0; i < scmi_pd_data->num_domains; i++) {
136		if (!scmi_pd_data->domains[i])
137			continue;
138		pm_genpd_remove(scmi_pd_data->domains[i]);
139	}
140}
141
142static const struct scmi_device_id scmi_id_table[] = {
143	{ SCMI_PROTOCOL_POWER, "genpd" },
144	{ },
145};
146MODULE_DEVICE_TABLE(scmi, scmi_id_table);
147
148static struct scmi_driver scmi_power_domain_driver = {
149	.name = "scmi-power-domain",
150	.probe = scmi_pm_domain_probe,
151	.remove = scmi_pm_domain_remove,
152	.id_table = scmi_id_table,
153};
154module_scmi_driver(scmi_power_domain_driver);
155
156MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
157MODULE_DESCRIPTION("ARM SCMI power domain driver");
158MODULE_LICENSE("GPL v2");