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(node: ofdev->dev.of_node, index: 0); |
62 | if (!pmc_regs) |
63 | return -ENOMEM; |
64 | |
65 | pmc_dev = &ofdev->dev; |
66 | suspend_set_ops(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 | |