1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * PM domains for CPUs via genpd.
4 *
5 * Copyright (C) 2019 Linaro Ltd.
6 * Author: Ulf Hansson <ulf.hansson@linaro.org>
7 *
8 * Copyright (c) 2021 Western Digital Corporation or its affiliates.
9 * Copyright (c) 2022 Ventana Micro Systems Inc.
10 */
11
12 #define pr_fmt(fmt) "dt-idle-genpd: " fmt
13
14 #include <linux/cpu.h>
15 #include <linux/device.h>
16 #include <linux/kernel.h>
17 #include <linux/pm_domain.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/slab.h>
20 #include <linux/string.h>
21
22 #include "dt_idle_genpd.h"
23
pd_parse_state_nodes(int (* parse_state)(struct device_node *,u32 *),struct genpd_power_state * states,int state_count)24 static int pd_parse_state_nodes(
25 int (*parse_state)(struct device_node *, u32 *),
26 struct genpd_power_state *states, int state_count)
27 {
28 int i, ret;
29 u32 state, *state_buf;
30
31 for (i = 0; i < state_count; i++) {
32 ret = parse_state(to_of_node(states[i].fwnode), &state);
33 if (ret)
34 goto free_state;
35
36 state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
37 if (!state_buf) {
38 ret = -ENOMEM;
39 goto free_state;
40 }
41 *state_buf = state;
42 states[i].data = state_buf;
43 }
44
45 return 0;
46
47 free_state:
48 i--;
49 for (; i >= 0; i--)
50 kfree(states[i].data);
51 return ret;
52 }
53
pd_parse_states(struct device_node * np,int (* parse_state)(struct device_node *,u32 *),struct genpd_power_state ** states,int * state_count)54 static int pd_parse_states(struct device_node *np,
55 int (*parse_state)(struct device_node *, u32 *),
56 struct genpd_power_state **states,
57 int *state_count)
58 {
59 int ret;
60
61 /* Parse the domain idle states. */
62 ret = of_genpd_parse_idle_states(np, states, state_count);
63 if (ret)
64 return ret;
65
66 /* Fill out the dt specifics for each found state. */
67 ret = pd_parse_state_nodes(parse_state, *states, *state_count);
68 if (ret)
69 kfree(*states);
70
71 return ret;
72 }
73
pd_free_states(struct genpd_power_state * states,unsigned int state_count)74 static void pd_free_states(struct genpd_power_state *states,
75 unsigned int state_count)
76 {
77 int i;
78
79 for (i = 0; i < state_count; i++)
80 kfree(states[i].data);
81 kfree(states);
82 }
83
dt_idle_pd_free(struct generic_pm_domain * pd)84 void dt_idle_pd_free(struct generic_pm_domain *pd)
85 {
86 pd_free_states(pd->states, pd->state_count);
87 kfree(pd->name);
88 kfree(pd);
89 }
90
dt_idle_pd_alloc(struct device_node * np,int (* parse_state)(struct device_node *,u32 *))91 struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np,
92 int (*parse_state)(struct device_node *, u32 *))
93 {
94 struct generic_pm_domain *pd;
95 struct genpd_power_state *states = NULL;
96 int ret, state_count = 0;
97
98 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
99 if (!pd)
100 goto out;
101
102 pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
103 if (!pd->name)
104 goto free_pd;
105
106 /*
107 * Parse the domain idle states and let genpd manage the state selection
108 * for those being compatible with "domain-idle-state".
109 */
110 ret = pd_parse_states(np, parse_state, &states, &state_count);
111 if (ret)
112 goto free_name;
113
114 pd->free_states = pd_free_states;
115 pd->name = kbasename(pd->name);
116 pd->states = states;
117 pd->state_count = state_count;
118
119 pr_debug("alloc PM domain %s\n", pd->name);
120 return pd;
121
122 free_name:
123 kfree(pd->name);
124 free_pd:
125 kfree(pd);
126 out:
127 pr_err("failed to alloc PM domain %pOF\n", np);
128 return NULL;
129 }
130
dt_idle_pd_init_topology(struct device_node * np)131 int dt_idle_pd_init_topology(struct device_node *np)
132 {
133 struct device_node *node;
134 struct of_phandle_args child, parent;
135 int ret;
136
137 for_each_child_of_node(np, node) {
138 if (of_parse_phandle_with_args(node, "power-domains",
139 "#power-domain-cells", 0, &parent))
140 continue;
141
142 child.np = node;
143 child.args_count = 0;
144 ret = of_genpd_add_subdomain(&parent, &child);
145 of_node_put(parent.np);
146 if (ret) {
147 of_node_put(node);
148 return ret;
149 }
150 }
151
152 return 0;
153 }
154
dt_idle_pd_remove_topology(struct device_node * np)155 int dt_idle_pd_remove_topology(struct device_node *np)
156 {
157 struct device_node *node;
158 struct of_phandle_args child, parent;
159 int ret;
160
161 for_each_child_of_node(np, node) {
162 if (of_parse_phandle_with_args(node, "power-domains",
163 "#power-domain-cells", 0, &parent))
164 continue;
165
166 child.np = node;
167 child.args_count = 0;
168 ret = of_genpd_remove_subdomain(&parent, &child);
169 of_node_put(parent.np);
170 if (ret) {
171 of_node_put(node);
172 return ret;
173 }
174 }
175
176 return 0;
177 }
178
dt_idle_attach_cpu(int cpu,const char * name)179 struct device *dt_idle_attach_cpu(int cpu, const char *name)
180 {
181 struct device *dev;
182
183 dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
184 if (IS_ERR_OR_NULL(dev))
185 return dev;
186
187 pm_runtime_irq_safe(dev);
188 if (cpu_online(cpu))
189 pm_runtime_get_sync(dev);
190
191 dev_pm_syscore_device(dev, true);
192
193 return dev;
194 }
195
dt_idle_detach_cpu(struct device * dev)196 void dt_idle_detach_cpu(struct device *dev)
197 {
198 if (IS_ERR_OR_NULL(dev))
199 return;
200
201 dev_pm_domain_detach(dev, false);
202 }
203
