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/platform_device.h>
15#include <linux/slab.h>
16#include <linux/pm_domain.h>
17#include <linux/delay.h>
18#include <linux/of.h>
19#include <linux/of_address.h>
20#include <linux/pm_runtime.h>
21
22struct exynos_pm_domain_config {
23	/* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
24	u32 local_pwr_cfg;
25};
26
27/*
28 * Exynos specific wrapper around the generic power domain
29 */
30struct exynos_pm_domain {
31	void __iomem *base;
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 = {
77	.local_pwr_cfg		= 0x7,
78};
79
80static const struct exynos_pm_domain_config exynos5433_cfg = {
81	.local_pwr_cfg		= 0xf,
82};
83
84static const struct of_device_id exynos_pm_domain_of_match[] = {
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 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 int exynos_pd_probe(struct platform_device *pdev)
105{
106	const struct exynos_pm_domain_config *pm_domain_cfg;
107	struct device *dev = &pdev->dev;
108	struct device_node *np = dev->of_node;
109	struct of_phandle_args child, parent;
110	struct exynos_pm_domain *pd;
111	int on, ret;
112
113	pm_domain_cfg = of_device_get_match_data(dev);
114	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
115	if (!pd)
116		return -ENOMEM;
117
118	pd->pd.name = exynos_get_domain_name(np);
119	if (!pd->pd.name)
120		return -ENOMEM;
121
122	pd->base = of_iomap(np, 0);
123	if (!pd->base) {
124		kfree_const(pd->pd.name);
125		return -ENODEV;
126	}
127
128	pd->pd.power_off = exynos_pd_power_off;
129	pd->pd.power_on = exynos_pd_power_on;
130	pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg;
131
132	on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;
133
134	pm_genpd_init(&pd->pd, NULL, !on);
135	ret = of_genpd_add_provider_simple(np, &pd->pd);
136
137	if (ret == 0 && of_parse_phandle_with_args(np, "power-domains",
138				      "#power-domain-cells", 0, &parent) == 0) {
139		child.np = np;
140		child.args_count = 0;
141
142		if (of_genpd_add_subdomain(&parent, &child))
143			pr_warn("%pOF failed to add subdomain: %pOF\n",
144				parent.np, child.np);
145		else
146			pr_info("%pOF has as child subdomain: %pOF.\n",
147				parent.np, child.np);
148	}
149
150	pm_runtime_enable(dev);
151	return ret;
152}
153
154static struct platform_driver exynos_pd_driver = {
155	.probe	= exynos_pd_probe,
156	.driver	= {
157		.name		= "exynos-pd",
158		.of_match_table	= exynos_pm_domain_of_match,
159		.suppress_bind_attrs = true,
160	}
161};
162
163static __init int exynos4_pm_init_power_domain(void)
164{
165	return platform_driver_register(&exynos_pd_driver);
166}
167core_initcall(exynos4_pm_init_power_domain);
168