Commit | Line | Data |
---|---|---|
8bec4337 SH |
1 | /* |
2 | * SCPI Generic power domain support. | |
3 | * | |
4 | * Copyright (C) 2016 ARM Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms and conditions of the GNU General Public License, | |
8 | * version 2, as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | #include <linux/err.h> | |
20 | #include <linux/io.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/of_platform.h> | |
23 | #include <linux/pm_domain.h> | |
24 | #include <linux/scpi_protocol.h> | |
25 | ||
26 | struct scpi_pm_domain { | |
27 | struct generic_pm_domain genpd; | |
28 | struct scpi_ops *ops; | |
29 | u32 domain; | |
30 | char name[30]; | |
31 | }; | |
32 | ||
33 | /* | |
34 | * These device power state values are not well-defined in the specification. | |
35 | * In case, different implementations use different values, we can make these | |
36 | * specific to compatibles rather than getting these values from device tree. | |
37 | */ | |
38 | enum scpi_power_domain_state { | |
39 | SCPI_PD_STATE_ON = 0, | |
40 | SCPI_PD_STATE_OFF = 3, | |
41 | }; | |
42 | ||
43 | #define to_scpi_pd(gpd) container_of(gpd, struct scpi_pm_domain, genpd) | |
44 | ||
45 | static int scpi_pd_power(struct scpi_pm_domain *pd, bool power_on) | |
46 | { | |
47 | int ret; | |
48 | enum scpi_power_domain_state state; | |
49 | ||
50 | if (power_on) | |
51 | state = SCPI_PD_STATE_ON; | |
52 | else | |
53 | state = SCPI_PD_STATE_OFF; | |
54 | ||
55 | ret = pd->ops->device_set_power_state(pd->domain, state); | |
56 | if (ret) | |
57 | return ret; | |
58 | ||
59 | return !(state == pd->ops->device_get_power_state(pd->domain)); | |
60 | } | |
61 | ||
62 | static int scpi_pd_power_on(struct generic_pm_domain *domain) | |
63 | { | |
64 | struct scpi_pm_domain *pd = to_scpi_pd(domain); | |
65 | ||
66 | return scpi_pd_power(pd, true); | |
67 | } | |
68 | ||
69 | static int scpi_pd_power_off(struct generic_pm_domain *domain) | |
70 | { | |
71 | struct scpi_pm_domain *pd = to_scpi_pd(domain); | |
72 | ||
73 | return scpi_pd_power(pd, false); | |
74 | } | |
75 | ||
76 | static int scpi_pm_domain_probe(struct platform_device *pdev) | |
77 | { | |
78 | struct device *dev = &pdev->dev; | |
79 | struct device_node *np = dev->of_node; | |
80 | struct scpi_pm_domain *scpi_pd; | |
81 | struct genpd_onecell_data *scpi_pd_data; | |
82 | struct generic_pm_domain **domains; | |
83 | struct scpi_ops *scpi_ops; | |
84 | int ret, num_domains, i; | |
85 | ||
86 | scpi_ops = get_scpi_ops(); | |
87 | if (!scpi_ops) | |
88 | return -EPROBE_DEFER; | |
89 | ||
90 | if (!np) { | |
91 | dev_err(dev, "device tree node not found\n"); | |
92 | return -ENODEV; | |
93 | } | |
94 | ||
95 | if (!scpi_ops->device_set_power_state || | |
96 | !scpi_ops->device_get_power_state) { | |
97 | dev_err(dev, "power domains not supported in the firmware\n"); | |
98 | return -ENODEV; | |
99 | } | |
100 | ||
101 | ret = of_property_read_u32(np, "num-domains", &num_domains); | |
102 | if (ret) { | |
103 | dev_err(dev, "number of domains not found\n"); | |
104 | return -EINVAL; | |
105 | } | |
106 | ||
107 | scpi_pd = devm_kcalloc(dev, num_domains, sizeof(*scpi_pd), GFP_KERNEL); | |
108 | if (!scpi_pd) | |
109 | return -ENOMEM; | |
110 | ||
111 | scpi_pd_data = devm_kzalloc(dev, sizeof(*scpi_pd_data), GFP_KERNEL); | |
112 | if (!scpi_pd_data) | |
113 | return -ENOMEM; | |
114 | ||
115 | domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL); | |
116 | if (!domains) | |
117 | return -ENOMEM; | |
118 | ||
119 | for (i = 0; i < num_domains; i++, scpi_pd++) { | |
120 | domains[i] = &scpi_pd->genpd; | |
121 | ||
122 | scpi_pd->domain = i; | |
123 | scpi_pd->ops = scpi_ops; | |
124 | sprintf(scpi_pd->name, "%s.%d", np->name, i); | |
125 | scpi_pd->genpd.name = scpi_pd->name; | |
126 | scpi_pd->genpd.power_off = scpi_pd_power_off; | |
127 | scpi_pd->genpd.power_on = scpi_pd_power_on; | |
128 | ||
129 | /* | |
130 | * Treat all power domains as off at boot. | |
131 | * | |
132 | * The SCP firmware itself may have switched on some domains, | |
133 | * but for reference counting purpose, keep it this way. | |
134 | */ | |
135 | pm_genpd_init(&scpi_pd->genpd, NULL, true); | |
136 | } | |
137 | ||
138 | scpi_pd_data->domains = domains; | |
139 | scpi_pd_data->num_domains = num_domains; | |
140 | ||
141 | of_genpd_add_provider_onecell(np, scpi_pd_data); | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | static const struct of_device_id scpi_power_domain_ids[] = { | |
147 | { .compatible = "arm,scpi-power-domains", }, | |
148 | { /* sentinel */ } | |
149 | }; | |
150 | MODULE_DEVICE_TABLE(of, scpi_power_domain_ids); | |
151 | ||
152 | static struct platform_driver scpi_power_domain_driver = { | |
153 | .driver = { | |
154 | .name = "scpi_power_domain", | |
155 | .of_match_table = scpi_power_domain_ids, | |
156 | }, | |
157 | .probe = scpi_pm_domain_probe, | |
158 | }; | |
159 | module_platform_driver(scpi_power_domain_driver); | |
160 | ||
161 | MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); | |
162 | MODULE_DESCRIPTION("ARM SCPI power domain driver"); | |
163 | MODULE_LICENSE("GPL v2"); |