tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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");