summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-exynos/pm_domains.c
blob: fe6570ebbdde961de10602f3e77ad5a7bc09fa8c (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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*
 * 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.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#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/sched.h>

#include "regs-pmu.h"

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

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 ? S5P_INT_LOCAL_PWR_EN : 0;
	__raw_writel(pwr, base);

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

	while ((__raw_readl(base + 0x4) & S5P_INT_LOCAL_PWR_EN)	!= 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 void exynos_add_device_to_domain(struct exynos_pm_domain *pd,
					 struct device *dev)
{
	int ret;

	dev_dbg(dev, "adding to power domain %s\n", pd->pd.name);

	while (1) {
		ret = pm_genpd_add_device(&pd->pd, dev);
		if (ret != -EAGAIN)
			break;
		cond_resched();
	}

	pm_genpd_dev_need_restore(dev, true);
}

static void exynos_remove_device_from_domain(struct device *dev)
{
	struct generic_pm_domain *genpd = dev_to_genpd(dev);
	int ret;

	dev_dbg(dev, "removing from power domain %s\n", genpd->name);

	while (1) {
		ret = pm_genpd_remove_device(genpd, dev);
		if (ret != -EAGAIN)
			break;
		cond_resched();
	}
}

static void exynos_read_domain_from_dt(struct device *dev)
{
	struct platform_device *pd_pdev;
	struct exynos_pm_domain *pd;
	struct device_node *node;

	node = of_parse_phandle(dev->of_node, "samsung,power-domain", 0);
	if (!node)
		return;
	pd_pdev = of_find_device_by_node(node);
	if (!pd_pdev)
		return;
	pd = platform_get_drvdata(pd_pdev);
	exynos_add_device_to_domain(pd, dev);
}

static int exynos_pm_notifier_call(struct notifier_block *nb,
				    unsigned long event, void *data)
{
	struct device *dev = data;

	switch (event) {
	case BUS_NOTIFY_BIND_DRIVER:
		if (dev->of_node)
			exynos_read_domain_from_dt(dev);

		break;

	case BUS_NOTIFY_UNBOUND_DRIVER:
		exynos_remove_device_from_domain(dev);

		break;
	}
	return NOTIFY_DONE;
}

static struct notifier_block platform_nb = {
	.notifier_call = exynos_pm_notifier_call,
};

static __init int exynos4_pm_init_power_domain(void)
{
	struct platform_device *pdev;
	struct device_node *np;

	for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
		struct exynos_pm_domain *pd;
		int on;

		pdev = of_find_device_by_node(np);

		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
		if (!pd) {
			pr_err("%s: failed to allocate memory for domain\n",
					__func__);
			return -ENOMEM;
		}

		pd->pd.name = kstrdup(np->name, GFP_KERNEL);
		pd->name = pd->pd.name;
		pd->base = of_iomap(np, 0);
		pd->pd.power_off = exynos_pd_power_off;
		pd->pd.power_on = exynos_pd_power_on;
		pd->pd.of_node = np;

		platform_set_drvdata(pdev, pd);

		on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;

		pm_genpd_init(&pd->pd, NULL, !on);
	}

	bus_register_notifier(&platform_bus_type, &platform_nb);

	return 0;
}
arch_initcall(exynos4_pm_init_power_domain);
OpenPOWER on IntegriCloud