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	dev_set_drvdata(dev, scmi_pd_data);
116
117	return of_genpd_add_provider_onecell(np, scmi_pd_data);
118}
119
120static void scmi_pm_domain_remove(struct scmi_device *sdev)
121{
122	int i;
123	struct genpd_onecell_data *scmi_pd_data;
124	struct device *dev = &sdev->dev;
125	struct device_node *np = dev->of_node;
126
127	of_genpd_del_provider(np);
128
129	scmi_pd_data = dev_get_drvdata(dev);
130	for (i = 0; i < scmi_pd_data->num_domains; i++) {
131		if (!scmi_pd_data->domains[i])
132			continue;
133		pm_genpd_remove(scmi_pd_data->domains[i]);
134	}
135}
136
137static const struct scmi_device_id scmi_id_table[] = {
138	{ SCMI_PROTOCOL_POWER, "genpd" },
139	{ },
140};
141MODULE_DEVICE_TABLE(scmi, scmi_id_table);
142
143static struct scmi_driver scmi_power_domain_driver = {
144	.name = "scmi-power-domain",
145	.probe = scmi_pm_domain_probe,
146	.remove = scmi_pm_domain_remove,
147	.id_table = scmi_id_table,
148};
149module_scmi_driver(scmi_power_domain_driver);
150
151MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
152MODULE_DESCRIPTION("ARM SCMI power domain driver");
153MODULE_LICENSE("GPL v2");
154