1// SPDX-License-Identifier: GPL-2.0
2//
3// Exynos Generic power domain support.
4//
5// Copyright (c) 2012 Samsung Electronics Co., Ltd.
6// http://www.samsung.com
7//
8// Implementation of Exynos specific power domain control which is used in
9// conjunction with runtime-pm. Support for both device-tree and non-device-tree
10// based power domain support is included.
11
12#include <linux/io.h>
13#include <linux/err.h>
14#include <linux/slab.h>
15#include <linux/pm_domain.h>
16#include <linux/delay.h>
17#include <linux/of_address.h>
18#include <linux/of_platform.h>
19#include <linux/sched.h>
20
21struct exynos_pm_domain_config {
22 /* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
23 u32 local_pwr_cfg;
24};
25
26/*
27 * Exynos specific wrapper around the generic power domain
28 */
29struct exynos_pm_domain {
30 void __iomem *base;
31 bool is_off;
32 struct generic_pm_domain pd;
33 u32 local_pwr_cfg;
34};
35
36static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
37{
38 struct exynos_pm_domain *pd;
39 void __iomem *base;
40 u32 timeout, pwr;
41 char *op;
42
43 pd = container_of(domain, struct exynos_pm_domain, pd);
44 base = pd->base;
45
46 pwr = power_on ? pd->local_pwr_cfg : 0;
47 writel_relaxed(pwr, base);
48
49 /* Wait max 1ms */
50 timeout = 10;
51
52 while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) {
53 if (!timeout) {
54 op = (power_on) ? "enable" : "disable";
55 pr_err("Power domain %s %s failed\n", domain->name, op);
56 return -ETIMEDOUT;
57 }
58 timeout--;
59 cpu_relax();
60 usleep_range(80, 100);
61 }
62
63 return 0;
64}
65
66static int exynos_pd_power_on(struct generic_pm_domain *domain)
67{
68 return exynos_pd_power(domain, true);
69}
70
71static int exynos_pd_power_off(struct generic_pm_domain *domain)
72{
73 return exynos_pd_power(domain, false);
74}
75
76static const struct exynos_pm_domain_config exynos4210_cfg __initconst = {
77 .local_pwr_cfg = 0x7,
78};
79
80static const struct exynos_pm_domain_config exynos5433_cfg __initconst = {
81 .local_pwr_cfg = 0xf,
82};
83
84static const struct of_device_id exynos_pm_domain_of_match[] __initconst = {
85 {
86 .compatible = "samsung,exynos4210-pd",
87 .data = &exynos4210_cfg,
88 }, {
89 .compatible = "samsung,exynos5433-pd",
90 .data = &exynos5433_cfg,
91 },
92 { },
93};
94
95static __init const char *exynos_get_domain_name(struct device_node *node)
96{
97 const char *name;
98
99 if (of_property_read_string(node, "label", &name) < 0)
100 name = kbasename(node->full_name);
101 return kstrdup_const(name, GFP_KERNEL);
102}
103
104static __init int exynos4_pm_init_power_domain(void)
105{
106 struct device_node *np;
107 const struct of_device_id *match;
108
109 for_each_matching_node_and_match(np, exynos_pm_domain_of_match, &match) {
110 const struct exynos_pm_domain_config *pm_domain_cfg;
111 struct exynos_pm_domain *pd;
112 int on;
113
114 pm_domain_cfg = match->data;
115
116 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
117 if (!pd) {
118 of_node_put(np);
119 return -ENOMEM;
120 }
121 pd->pd.name = exynos_get_domain_name(np);
122 if (!pd->pd.name) {
123 kfree(pd);
124 of_node_put(np);
125 return -ENOMEM;
126 }
127
128 pd->base = of_iomap(np, 0);
129 if (!pd->base) {
130 pr_warn("%s: failed to map memory\n", __func__);
131 kfree_const(pd->pd.name);
132 kfree(pd);
133 continue;
134 }
135
136 pd->pd.power_off = exynos_pd_power_off;
137 pd->pd.power_on = exynos_pd_power_on;
138 pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg;
139
140 on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;
141
142 pm_genpd_init(&pd->pd, NULL, !on);
143 of_genpd_add_provider_simple(np, &pd->pd);
144 }
145
146 /* Assign the child power domains to their parents */
147 for_each_matching_node(np, exynos_pm_domain_of_match) {
148 struct of_phandle_args child, parent;
149
150 child.np = np;
151 child.args_count = 0;
152
153 if (of_parse_phandle_with_args(np, "power-domains",
154 "#power-domain-cells", 0,
155 &parent) != 0)
156 continue;
157
158 if (of_genpd_add_subdomain(&parent, &child))
159 pr_warn("%pOF failed to add subdomain: %pOF\n",
160 parent.np, child.np);
161 else
162 pr_info("%pOF has as child subdomain: %pOF.\n",
163 parent.np, child.np);
164 }
165
166 return 0;
167}
168core_initcall(exynos4_pm_init_power_domain);
169