1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Suspend/resume support
4 *
5 * Copyright 2009  MontaVista Software, Inc.
6 *
7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
8 */
9
10#include <linux/init.h>
11#include <linux/types.h>
12#include <linux/errno.h>
13#include <linux/export.h>
14#include <linux/suspend.h>
15#include <linux/delay.h>
16#include <linux/mod_devicetable.h>
17#include <linux/of_address.h>
18#include <linux/platform_device.h>
19
20struct pmc_regs {
21	__be32 devdisr;
22	__be32 devdisr2;
23	__be32 :32;
24	__be32 :32;
25	__be32 pmcsr;
26#define PMCSR_SLP	(1 << 17)
27};
28
29static struct device *pmc_dev;
30static struct pmc_regs __iomem *pmc_regs;
31
32static int pmc_suspend_enter(suspend_state_t state)
33{
34	int ret;
35
36	setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
37	/* At this point, the CPU is asleep. */
38
39	/* Upon resume, wait for SLP bit to be clear. */
40	ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
41				 10000, 10) ? 0 : -ETIMEDOUT;
42	if (ret)
43		dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
44	return ret;
45}
46
47static int pmc_suspend_valid(suspend_state_t state)
48{
49	if (state != PM_SUSPEND_STANDBY)
50		return 0;
51	return 1;
52}
53
54static const struct platform_suspend_ops pmc_suspend_ops = {
55	.valid = pmc_suspend_valid,
56	.enter = pmc_suspend_enter,
57};
58
59static int pmc_probe(struct platform_device *ofdev)
60{
61	pmc_regs = of_iomap(ofdev->dev.of_node, 0);
62	if (!pmc_regs)
63		return -ENOMEM;
64
65	pmc_dev = &ofdev->dev;
66	suspend_set_ops(&pmc_suspend_ops);
67	return 0;
68}
69
70static const struct of_device_id pmc_ids[] = {
71	{ .compatible = "fsl,mpc8548-pmc", },
72	{ .compatible = "fsl,mpc8641d-pmc", },
73	{ },
74};
75
76static struct platform_driver pmc_driver = {
77	.driver = {
78		.name = "fsl-pmc",
79		.of_match_table = pmc_ids,
80	},
81	.probe = pmc_probe,
82};
83
84builtin_platform_driver(pmc_driver);
85