1 // SPDX-License-Identifier: GPL-2.0-only
3 * PM domains for CPUs via genpd.
5 * Copyright (C) 2019 Linaro Ltd.
6 * Author: Ulf Hansson <ulf.hansson@linaro.org>
8 * Copyright (c) 2021 Western Digital Corporation or its affiliates.
9 * Copyright (c) 2022 Ventana Micro Systems Inc.
12 #define pr_fmt(fmt) "dt-idle-genpd: " fmt
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>
22 #include "dt_idle_genpd.h"
24 static int pd_parse_state_nodes(
25 int (*parse_state)(struct device_node *, u32 *),
26 struct genpd_power_state *states, int state_count)
29 u32 state, *state_buf;
31 for (i = 0; i < state_count; i++) {
32 ret = parse_state(to_of_node(states[i].fwnode), &state);
36 state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
42 states[i].data = state_buf;
50 kfree(states[i].data);
54 static int pd_parse_states(struct device_node *np,
55 int (*parse_state)(struct device_node *, u32 *),
56 struct genpd_power_state **states,
61 /* Parse the domain idle states. */
62 ret = of_genpd_parse_idle_states(np, states, state_count);
66 /* Fill out the dt specifics for each found state. */
67 ret = pd_parse_state_nodes(parse_state, *states, *state_count);
74 static void pd_free_states(struct genpd_power_state *states,
75 unsigned int state_count)
79 for (i = 0; i < state_count; i++)
80 kfree(states[i].data);
84 void dt_idle_pd_free(struct generic_pm_domain *pd)
86 pd_free_states(pd->states, pd->state_count);
91 struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np,
92 int (*parse_state)(struct device_node *, u32 *))
94 struct generic_pm_domain *pd;
95 struct genpd_power_state *states = NULL;
96 int ret, state_count = 0;
98 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
102 pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
107 * Parse the domain idle states and let genpd manage the state selection
108 * for those being compatible with "domain-idle-state".
110 ret = pd_parse_states(np, parse_state, &states, &state_count);
114 pd->free_states = pd_free_states;
115 pd->name = kbasename(pd->name);
117 pd->state_count = state_count;
119 pr_debug("alloc PM domain %s\n", pd->name);
127 pr_err("failed to alloc PM domain %pOF\n", np);
131 int dt_idle_pd_init_topology(struct device_node *np)
133 struct device_node *node;
134 struct of_phandle_args child, parent;
137 for_each_child_of_node(np, node) {
138 if (of_parse_phandle_with_args(node, "power-domains",
139 "#power-domain-cells", 0, &parent))
143 child.args_count = 0;
144 ret = of_genpd_add_subdomain(&parent, &child);
145 of_node_put(parent.np);
155 struct device *dt_idle_attach_cpu(int cpu, const char *name)
159 dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
160 if (IS_ERR_OR_NULL(dev))
163 pm_runtime_irq_safe(dev);
165 pm_runtime_get_sync(dev);
167 dev_pm_syscore_device(dev, true);
172 void dt_idle_detach_cpu(struct device *dev)
174 if (IS_ERR_OR_NULL(dev))
177 dev_pm_domain_detach(dev, false);