summaryrefslogtreecommitdiffstats
path: root/drivers/soc/samsung/pm_domains.c
blob: 5ec0c13f0aafdc02aea3e5abda79db511818adbc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
// SPDX-License-Identifier: GPL-2.0
//
// Exynos Generic power domain support.
//
// Copyright (c) 2012 Samsung Electronics Co., Ltd.
//		http://www.samsung.com
//
// Implementation of Exynos specific power domain control which is used in
// conjunction with runtime-pm. Support for both device-tree and non-device-tree
// based power domain support is included.

#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_domain.h>
#include <linux/delay.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>

struct exynos_pm_domain_config {
	/* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
	u32 local_pwr_cfg;
};

/*
 * Exynos specific wrapper around the generic power domain
 */
struct exynos_pm_domain {
	void __iomem *base;
	bool is_off;
	struct generic_pm_domain pd;
	u32 local_pwr_cfg;
};

static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
{
	struct exynos_pm_domain *pd;
	void __iomem *base;
	u32 timeout, pwr;
	char *op;

	pd = container_of(domain, struct exynos_pm_domain, pd);
	base = pd->base;

	pwr = power_on ? pd->local_pwr_cfg : 0;
	writel_relaxed(pwr, base);

	/* Wait max 1ms */
	timeout = 10;

	while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) {
		if (!timeout) {
			op = (power_on) ? "enable" : "disable";
			pr_err("Power domain %s %s failed\n", domain->name, op);
			return -ETIMEDOUT;
		}
		timeout--;
		cpu_relax();
		usleep_range(80, 100);
	}

	return 0;
}

static int exynos_pd_power_on(struct generic_pm_domain *domain)
{
	return exynos_pd_power(domain, true);
}

static int exynos_pd_power_off(struct generic_pm_domain *domain)
{
	return exynos_pd_power(domain, false);
}

static const struct exynos_pm_domain_config exynos4210_cfg = {
	.local_pwr_cfg		= 0x7,
};

static const struct exynos_pm_domain_config exynos5433_cfg = {
	.local_pwr_cfg		= 0xf,
};

static const struct of_device_id exynos_pm_domain_of_match[] = {
	{
		.compatible = "samsung,exynos4210-pd",
		.data = &exynos4210_cfg,
	}, {
		.compatible = "samsung,exynos5433-pd",
		.data = &exynos5433_cfg,
	},
	{ },
};

static const char *exynos_get_domain_name(struct device_node *node)
{
	const char *name;

	if (of_property_read_string(node, "label", &name) < 0)
		name = kbasename(node->full_name);
	return kstrdup_const(name, GFP_KERNEL);
}

static int exynos_pd_probe(struct platform_device *pdev)
{
	const struct exynos_pm_domain_config *pm_domain_cfg;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct of_phandle_args child, parent;
	struct exynos_pm_domain *pd;
	int on, ret;

	pm_domain_cfg = of_device_get_match_data(dev);
	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
	if (!pd)
		return -ENOMEM;

	pd->pd.name = exynos_get_domain_name(np);
	if (!pd->pd.name)
		return -ENOMEM;

	pd->base = of_iomap(np, 0);
	if (!pd->base) {
		kfree_const(pd->pd.name);
		return -ENODEV;
	}

	pd->pd.power_off = exynos_pd_power_off;
	pd->pd.power_on = exynos_pd_power_on;
	pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg;

	on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;

	pm_genpd_init(&pd->pd, NULL, !on);
	ret = of_genpd_add_provider_simple(np, &pd->pd);

	if (ret == 0 && of_parse_phandle_with_args(np, "power-domains",
				      "#power-domain-cells", 0, &parent) == 0) {
		child.np = np;
		child.args_count = 0;

		if (of_genpd_add_subdomain(&parent, &child))
			pr_warn("%pOF failed to add subdomain: %pOF\n",
				parent.np, child.np);
		else
			pr_info("%pOF has as child subdomain: %pOF.\n",
				parent.np, child.np);
	}

	pm_runtime_enable(dev);
	return ret;
}

static struct platform_driver exynos_pd_driver = {
	.probe	= exynos_pd_probe,
	.driver	= {
		.name		= "exynos-pd",
		.of_match_table	= exynos_pm_domain_of_match,
		.suppress_bind_attrs = true,
	}
};

static __init int exynos4_pm_init_power_domain(void)
{
	return platform_driver_register(&exynos_pd_driver);
}
core_initcall(exynos4_pm_init_power_domain);