summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-u300/regulator.c
blob: c0cc1d82e1b993a70f75575c11680d2096b2aa41 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * arch/arm/mach-u300/regulator.c
 *
 * Copyright (C) 2009 ST-Ericsson AB
 * Handle board-bound regulators and board power not related
 * to any devices.
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 */
#include <linux/device.h>
#include <linux/signal.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/consumer.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

/* Power Management Control 16bit (R/W) */
#define U300_SYSCON_PMCR					(0x50)
#define U300_SYSCON_PMCR_DCON_ENABLE				(0x0002)
#define U300_SYSCON_PMCR_PWR_MGNT_ENABLE			(0x0001)

/*
 * Regulators that power the board and chip and which are
 * not copuled to specific drivers are hogged in these
 * instances.
 */
static struct regulator *main_power_15;

/*
 * This function is used from pm.h to shut down the system by
 * resetting all regulators in turn and then disable regulator
 * LDO D (main power).
 */
void u300_pm_poweroff(void)
{
	sigset_t old, all;

	sigfillset(&all);
	if (!sigprocmask(SIG_BLOCK, &all, &old)) {
		/* Disable LDO D to shut down the system */
		if (main_power_15)
			regulator_disable(main_power_15);
		else
			pr_err("regulator not available to shut down system\n");
		(void) sigprocmask(SIG_SETMASK, &old, NULL);
	}
	return;
}

/*
 * Hog the regulators needed to power up the board.
 */
static int __init __u300_init_boardpower(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct device_node *syscon_np;
	struct regmap *regmap;
	int err;

	pr_info("U300: setting up board power\n");

	syscon_np = of_parse_phandle(np, "syscon", 0);
	if (!syscon_np) {
		pr_crit("U300: no syscon node\n");
		return -ENODEV;
	}
	regmap = syscon_node_to_regmap(syscon_np);
	if (IS_ERR(regmap)) {
		pr_crit("U300: could not locate syscon regmap\n");
		return PTR_ERR(regmap);
	}

	main_power_15 = regulator_get(&pdev->dev, "vana15");

	if (IS_ERR(main_power_15)) {
		pr_err("could not get vana15");
		return PTR_ERR(main_power_15);
	}
	err = regulator_enable(main_power_15);
	if (err) {
		pr_err("could not enable vana15\n");
		return err;
	}

	/*
	 * On U300 a special system controller register pulls up the DC
	 * until the vana15 (LDO D) regulator comes up. At this point, all
	 * regulators are set and we do not need power control via
	 * DC ON anymore. This function will likely be moved whenever
	 * the rest of the U300 power management is implemented.
	 */
	pr_info("U300: disable system controller pull-up\n");
	regmap_update_bits(regmap, U300_SYSCON_PMCR,
			   U300_SYSCON_PMCR_DCON_ENABLE, 0);

	/* Register globally exported PM poweroff hook */
	pm_power_off = u300_pm_poweroff;

	return 0;
}

static int __init s365_board_probe(struct platform_device *pdev)
{
	return __u300_init_boardpower(pdev);
}

static const struct of_device_id s365_board_match[] = {
	{ .compatible = "stericsson,s365" },
	{},
};

static struct platform_driver s365_board_driver = {
	.driver		= {
		.name   = "s365-board",
		.of_match_table = s365_board_match,
	},
};

/*
 * So at module init time we hog the regulator!
 */
static int __init u300_init_boardpower(void)
{
	return platform_driver_probe(&s365_board_driver,
				     s365_board_probe);
}

device_initcall(u300_init_boardpower);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Linus Walleij");