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