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
14 static const struct scmi_power_proto_ops *power_ops;
15
16 struct 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
scmi_pd_power(struct generic_pm_domain * domain,bool power_on)25 static 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
scmi_pd_power_on(struct generic_pm_domain * domain)45 static int scmi_pd_power_on(struct generic_pm_domain *domain)
46 {
47 return scmi_pd_power(domain, true);
48 }
49
scmi_pd_power_off(struct generic_pm_domain * domain)50 static int scmi_pd_power_off(struct generic_pm_domain *domain)
51 {
52 return scmi_pd_power(domain, false);
53 }
54
scmi_pm_domain_probe(struct scmi_device * sdev)55 static 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
120 static const struct scmi_device_id scmi_id_table[] = {
121 { SCMI_PROTOCOL_POWER, "genpd" },
122 { },
123 };
124 MODULE_DEVICE_TABLE(scmi, scmi_id_table);
125
126 static 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 };
131 module_scmi_driver(scmi_power_domain_driver);
132
133 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
134 MODULE_DESCRIPTION("ARM SCMI power domain driver");
135 MODULE_LICENSE("GPL v2");
136