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b6911bba PB |
1 | /* |
2 | * Copyright (C) 2014 Imagination Technologies | |
48c834be | 3 | * Author: Paul Burton <paul.burton@mips.com> |
b6911bba PB |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the | |
7 | * Free Software Foundation; either version 2 of the License, or (at your | |
8 | * option) any later version. | |
9 | */ | |
10 | ||
11 | #include <linux/delay.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/io.h> | |
14 | #include <linux/pci.h> | |
15 | ||
16 | #include <asm/mach-malta/malta-pm.h> | |
17 | ||
18 | static struct pci_bus *pm_pci_bus; | |
19 | static resource_size_t pm_io_offset; | |
20 | ||
21 | int mips_pm_suspend(unsigned state) | |
22 | { | |
23 | int spec_devid; | |
24 | u16 sts; | |
25 | ||
26 | if (!pm_pci_bus || !pm_io_offset) | |
27 | return -ENODEV; | |
28 | ||
29 | /* Ensure the power button status is clear */ | |
30 | while (1) { | |
31 | sts = inw(pm_io_offset + PIIX4_FUNC3IO_PMSTS); | |
32 | if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS)) | |
33 | break; | |
34 | outw(sts, pm_io_offset + PIIX4_FUNC3IO_PMSTS); | |
35 | } | |
36 | ||
37 | /* Enable entry to suspend */ | |
38 | outw(state | PIIX4_FUNC3IO_PMCNTRL_SUS_EN, | |
39 | pm_io_offset + PIIX4_FUNC3IO_PMCNTRL); | |
40 | ||
41 | /* If the special cycle occurs too soon this doesn't work... */ | |
42 | mdelay(10); | |
43 | ||
44 | /* | |
45 | * The PIIX4 will enter the suspend state only after seeing a special | |
46 | * cycle with the correct magic data on the PCI bus. Generate that | |
47 | * cycle now. | |
48 | */ | |
49 | spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7)); | |
50 | pci_bus_write_config_dword(pm_pci_bus, spec_devid, 0, | |
51 | PIIX4_SUSPEND_MAGIC); | |
52 | ||
53 | /* Give the system some time to power down */ | |
54 | mdelay(1000); | |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | static int __init malta_pm_setup(void) | |
60 | { | |
61 | struct pci_dev *dev; | |
62 | int res, io_region = PCI_BRIDGE_RESOURCES; | |
63 | ||
64 | /* Find a reference to the PCI bus */ | |
65 | pm_pci_bus = pci_find_next_bus(NULL); | |
66 | if (!pm_pci_bus) { | |
67 | pr_warn("malta-pm: failed to find reference to PCI bus\n"); | |
68 | return -ENODEV; | |
69 | } | |
70 | ||
71 | /* Find the PIIX4 PM device */ | |
72 | dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, | |
73 | PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID, | |
74 | PCI_ANY_ID, NULL); | |
75 | if (!dev) { | |
76 | pr_warn("malta-pm: failed to find PIIX4 PM\n"); | |
77 | return -ENODEV; | |
78 | } | |
79 | ||
80 | /* Request access to the PIIX4 PM IO registers */ | |
81 | res = pci_request_region(dev, io_region, "PIIX4 PM IO registers"); | |
82 | if (res) { | |
83 | pr_warn("malta-pm: failed to request PM IO registers (%d)\n", | |
84 | res); | |
85 | pci_dev_put(dev); | |
86 | return -ENODEV; | |
87 | } | |
88 | ||
89 | /* Find the offset to the PIIX4 PM IO registers */ | |
90 | pm_io_offset = pci_resource_start(dev, io_region); | |
91 | ||
92 | pci_dev_put(dev); | |
93 | return 0; | |
94 | } | |
95 | ||
96 | late_initcall(malta_pm_setup); |