1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SCMI performance domain support.
4 *
5 * Copyright (C) 2023 Linaro Ltd.
6 */
7
8 #include <linux/err.h>
9 #include <linux/device.h>
10 #include <linux/module.h>
11 #include <linux/pm_domain.h>
12 #include <linux/pm_opp.h>
13 #include <linux/scmi_protocol.h>
14 #include <linux/slab.h>
15
16 struct scmi_perf_domain {
17 struct generic_pm_domain genpd;
18 const struct scmi_perf_proto_ops *perf_ops;
19 const struct scmi_protocol_handle *ph;
20 const struct scmi_perf_domain_info *info;
21 u32 domain_id;
22 };
23
24 #define to_scmi_pd(pd) container_of(pd, struct scmi_perf_domain, genpd)
25
26 static int
scmi_pd_set_perf_state(struct generic_pm_domain * genpd,unsigned int state)27 scmi_pd_set_perf_state(struct generic_pm_domain *genpd, unsigned int state)
28 {
29 struct scmi_perf_domain *pd = to_scmi_pd(genpd);
30 int ret;
31
32 if (!pd->info->set_perf)
33 return 0;
34
35 if (!state)
36 return -EINVAL;
37
38 ret = pd->perf_ops->level_set(pd->ph, pd->domain_id, state, false);
39 if (ret)
40 dev_warn(&genpd->dev, "Failed with %d when trying to set %d perf level",
41 ret, state);
42
43 return ret;
44 }
45
46 static int
scmi_pd_attach_dev(struct generic_pm_domain * genpd,struct device * dev)47 scmi_pd_attach_dev(struct generic_pm_domain *genpd, struct device *dev)
48 {
49 struct scmi_perf_domain *pd = to_scmi_pd(genpd);
50 int ret;
51
52 /*
53 * Allow the device to be attached, but don't add the OPP table unless
54 * the performance level can be changed.
55 */
56 if (!pd->info->set_perf)
57 return 0;
58
59 ret = pd->perf_ops->device_opps_add(pd->ph, dev, pd->domain_id);
60 if (ret)
61 dev_warn(dev, "failed to add OPPs for the device\n");
62
63 return ret;
64 }
65
66 static void
scmi_pd_detach_dev(struct generic_pm_domain * genpd,struct device * dev)67 scmi_pd_detach_dev(struct generic_pm_domain *genpd, struct device *dev)
68 {
69 struct scmi_perf_domain *pd = to_scmi_pd(genpd);
70
71 if (!pd->info->set_perf)
72 return;
73
74 dev_pm_opp_remove_all_dynamic(dev);
75 }
76
scmi_perf_domain_probe(struct scmi_device * sdev)77 static int scmi_perf_domain_probe(struct scmi_device *sdev)
78 {
79 struct device *dev = &sdev->dev;
80 const struct scmi_handle *handle = sdev->handle;
81 const struct scmi_perf_proto_ops *perf_ops;
82 struct scmi_protocol_handle *ph;
83 struct scmi_perf_domain *scmi_pd;
84 struct genpd_onecell_data *scmi_pd_data;
85 struct generic_pm_domain **domains;
86 int num_domains, i, ret = 0;
87
88 if (!handle)
89 return -ENODEV;
90
91 /* The OF node must specify us as a power-domain provider. */
92 if (!of_find_property(dev->of_node, "#power-domain-cells", NULL))
93 return 0;
94
95 perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
96 if (IS_ERR(perf_ops))
97 return PTR_ERR(perf_ops);
98
99 num_domains = perf_ops->num_domains_get(ph);
100 if (num_domains < 0) {
101 dev_warn(dev, "Failed with %d when getting num perf domains\n",
102 num_domains);
103 return num_domains;
104 } else if (!num_domains) {
105 return 0;
106 }
107
108 scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL);
109 if (!scmi_pd)
110 return -ENOMEM;
111
112 scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL);
113 if (!scmi_pd_data)
114 return -ENOMEM;
115
116 domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL);
117 if (!domains)
118 return -ENOMEM;
119
120 for (i = 0; i < num_domains; i++, scmi_pd++) {
121 scmi_pd->info = perf_ops->info_get(ph, i);
122
123 scmi_pd->domain_id = i;
124 scmi_pd->perf_ops = perf_ops;
125 scmi_pd->ph = ph;
126 scmi_pd->genpd.name = scmi_pd->info->name;
127 scmi_pd->genpd.flags = GENPD_FLAG_ALWAYS_ON |
128 GENPD_FLAG_OPP_TABLE_FW;
129 scmi_pd->genpd.set_performance_state = scmi_pd_set_perf_state;
130 scmi_pd->genpd.attach_dev = scmi_pd_attach_dev;
131 scmi_pd->genpd.detach_dev = scmi_pd_detach_dev;
132
133 ret = pm_genpd_init(&scmi_pd->genpd, NULL, false);
134 if (ret)
135 goto err;
136
137 domains[i] = &scmi_pd->genpd;
138 }
139
140 scmi_pd_data->domains = domains;
141 scmi_pd_data->num_domains = num_domains;
142
143 ret = of_genpd_add_provider_onecell(dev->of_node, scmi_pd_data);
144 if (ret)
145 goto err;
146
147 dev_set_drvdata(dev, scmi_pd_data);
148 dev_info(dev, "Initialized %d performance domains", num_domains);
149 return 0;
150 err:
151 for (i--; i >= 0; i--)
152 pm_genpd_remove(domains[i]);
153 return ret;
154 }
155
scmi_perf_domain_remove(struct scmi_device * sdev)156 static void scmi_perf_domain_remove(struct scmi_device *sdev)
157 {
158 struct device *dev = &sdev->dev;
159 struct genpd_onecell_data *scmi_pd_data = dev_get_drvdata(dev);
160 int i;
161
162 if (!scmi_pd_data)
163 return;
164
165 of_genpd_del_provider(dev->of_node);
166
167 for (i = 0; i < scmi_pd_data->num_domains; i++)
168 pm_genpd_remove(scmi_pd_data->domains[i]);
169 }
170
171 static const struct scmi_device_id scmi_id_table[] = {
172 { SCMI_PROTOCOL_PERF, "perf" },
173 { },
174 };
175 MODULE_DEVICE_TABLE(scmi, scmi_id_table);
176
177 static struct scmi_driver scmi_perf_domain_driver = {
178 .name = "scmi-perf-domain",
179 .probe = scmi_perf_domain_probe,
180 .remove = scmi_perf_domain_remove,
181 .id_table = scmi_id_table,
182 };
183 module_scmi_driver(scmi_perf_domain_driver);
184
185 MODULE_AUTHOR("Ulf Hansson <ulf.hansson@linaro.org>");
186 MODULE_DESCRIPTION("ARM SCMI perf domain driver");
187 MODULE_LICENSE("GPL v2");
188