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_platform.h>
22
23 struct pmc_regs {
24 __be32 devdisr;
25 __be32 devdisr2;
26 __be32 :32;
27 __be32 :32;
28 __be32 pmcsr;
29 #define PMCSR_SLP (1 << 17)
30 };
31
32 static struct device *pmc_dev;
33 static struct pmc_regs __iomem *pmc_regs;
34
pmc_suspend_enter(suspend_state_t state)35 static int pmc_suspend_enter(suspend_state_t state)
36 {
37 int ret;
38
39 setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
40 /* At this point, the CPU is asleep. */
41
42 /* Upon resume, wait for SLP bit to be clear. */
43 ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
44 10000, 10) ? 0 : -ETIMEDOUT;
45 if (ret)
46 dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
47 return ret;
48 }
49
pmc_suspend_valid(suspend_state_t state)50 static int pmc_suspend_valid(suspend_state_t state)
51 {
52 if (state != PM_SUSPEND_STANDBY)
53 return 0;
54 return 1;
55 }
56
57 static const struct platform_suspend_ops pmc_suspend_ops = {
58 .valid = pmc_suspend_valid,
59 .enter = pmc_suspend_enter,
60 };
61
pmc_probe(struct platform_device * ofdev)62 static int pmc_probe(struct platform_device *ofdev)
63 {
64 pmc_regs = of_iomap(ofdev->dev.of_node, 0);
65 if (!pmc_regs)
66 return -ENOMEM;
67
68 pmc_dev = &ofdev->dev;
69 suspend_set_ops(&pmc_suspend_ops);
70 return 0;
71 }
72
73 static const struct of_device_id pmc_ids[] = {
74 { .compatible = "fsl,mpc8548-pmc", },
75 { .compatible = "fsl,mpc8641d-pmc", },
76 { },
77 };
78
79 static struct platform_driver pmc_driver = {
80 .driver = {
81 .name = "fsl-pmc",
82 .owner = THIS_MODULE,
83 .of_match_table = pmc_ids,
84 },
85 .probe = pmc_probe,
86 };
87
pmc_init(void)88 static int __init pmc_init(void)
89 {
90 return platform_driver_register(&pmc_driver);
91 }
92 device_initcall(pmc_init);
93