1/*
2 * Suspend/resume support
3 *
4 * Copyright 2009  MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/errno.h>
17#include <linux/export.h>
18#include <linux/suspend.h>
19#include <linux/delay.h>
20#include <linux/device.h>
21#include <linux/of_address.h>
22#include <linux/of_platform.h>
23
24struct pmc_regs {
25	__be32 devdisr;
26	__be32 devdisr2;
27	__be32 :32;
28	__be32 :32;
29	__be32 pmcsr;
30#define PMCSR_SLP	(1 << 17)
31};
32
33static struct device *pmc_dev;
34static struct pmc_regs __iomem *pmc_regs;
35
36static int pmc_suspend_enter(suspend_state_t state)
37{
38	int ret;
39
40	setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
41	/* At this point, the CPU is asleep. */
42
43	/* Upon resume, wait for SLP bit to be clear. */
44	ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
45				 10000, 10) ? 0 : -ETIMEDOUT;
46	if (ret)
47		dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
48	return ret;
49}
50
51static int pmc_suspend_valid(suspend_state_t state)
52{
53	if (state != PM_SUSPEND_STANDBY)
54		return 0;
55	return 1;
56}
57
58static const struct platform_suspend_ops pmc_suspend_ops = {
59	.valid = pmc_suspend_valid,
60	.enter = pmc_suspend_enter,
61};
62
63static int pmc_probe(struct platform_device *ofdev)
64{
65	pmc_regs = of_iomap(ofdev->dev.of_node, 0);
66	if (!pmc_regs)
67		return -ENOMEM;
68
69	pmc_dev = &ofdev->dev;
70	suspend_set_ops(&pmc_suspend_ops);
71	return 0;
72}
73
74static const struct of_device_id pmc_ids[] = {
75	{ .compatible = "fsl,mpc8548-pmc", },
76	{ .compatible = "fsl,mpc8641d-pmc", },
77	{ },
78};
79
80static struct platform_driver pmc_driver = {
81	.driver = {
82		.name = "fsl-pmc",
83		.of_match_table = pmc_ids,
84	},
85	.probe = pmc_probe,
86};
87
88static int __init pmc_init(void)
89{
90	return platform_driver_register(&pmc_driver);
91}
92device_initcall(pmc_init);
93