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
20 struct 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
29 static struct device *pmc_dev;
30 static struct pmc_regs __iomem *pmc_regs;
31
32 static 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
47 static int pmc_suspend_valid(suspend_state_t state)
48 {
49 if (state != PM_SUSPEND_STANDBY)
50 return 0;
51 return 1;
52 }
53
54 static const struct platform_suspend_ops pmc_suspend_ops = {
55 .valid = pmc_suspend_valid,
56 .enter = pmc_suspend_enter,
57 };
58
59 static 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
70 static const struct of_device_id pmc_ids[] = {
71 { .compatible = "fsl,mpc8548-pmc", },
72 { .compatible = "fsl,mpc8641d-pmc", },
73 { },
74 };
75
76 static struct platform_driver pmc_driver = {
77 .driver = {
78 .name = "fsl-pmc",
79 .of_match_table = pmc_ids,
80 },
81 .probe = pmc_probe,
82 };
83
84 builtin_platform_driver(pmc_driver);
85
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