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/suspend.h>
18 #include <linux/delay.h>
19 #include <linux/device.h>
20 #include <linux/of_platform.h>
21
22 struct pmc_regs {
23 __be32 devdisr;
24 __be32 devdisr2;
25 __be32 :32;
26 __be32 :32;
27 __be32 pmcsr;
28 #define PMCSR_SLP (1 << 17)
29 };
30
31 static struct device *pmc_dev;
32 static struct pmc_regs __iomem *pmc_regs;
33
pmc_suspend_enter(suspend_state_t state)34 static int pmc_suspend_enter(suspend_state_t state)
35 {
36 int ret;
37
38 setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
39 /* At this point, the CPU is asleep. */
40
41 /* Upon resume, wait for SLP bit to be clear. */
42 ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
43 10000, 10) ? 0 : -ETIMEDOUT;
44 if (ret)
45 dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
46 return ret;
47 }
48
pmc_suspend_valid(suspend_state_t state)49 static int pmc_suspend_valid(suspend_state_t state)
50 {
51 if (state != PM_SUSPEND_STANDBY)
52 return 0;
53 return 1;
54 }
55
56 static const struct platform_suspend_ops pmc_suspend_ops = {
57 .valid = pmc_suspend_valid,
58 .enter = pmc_suspend_enter,
59 };
60
pmc_probe(struct platform_device * ofdev)61 static int pmc_probe(struct platform_device *ofdev)
62 {
63 pmc_regs = of_iomap(ofdev->dev.of_node, 0);
64 if (!pmc_regs)
65 return -ENOMEM;
66
67 pmc_dev = &ofdev->dev;
68 suspend_set_ops(&pmc_suspend_ops);
69 return 0;
70 }
71
72 static const struct of_device_id pmc_ids[] = {
73 { .compatible = "fsl,mpc8548-pmc", },
74 { .compatible = "fsl,mpc8641d-pmc", },
75 { },
76 };
77
78 static struct platform_driver pmc_driver = {
79 .driver = {
80 .name = "fsl-pmc",
81 .owner = THIS_MODULE,
82 .of_match_table = pmc_ids,
83 },
84 .probe = pmc_probe,
85 };
86
pmc_init(void)87 static int __init pmc_init(void)
88 {
89 return platform_driver_register(&pmc_driver);
90 }
91 device_initcall(pmc_init);
92