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29676833 PB |
1 | /* |
2 | * Copyright (C) 2016 Imagination Technologies | |
fb615d61 | 3 | * Author: Paul Burton <paul.burton@mips.com> |
29676833 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/io.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/pci.h> | |
15 | #include <linux/pm.h> | |
16 | ||
17 | static struct pci_dev *pm_dev; | |
18 | static resource_size_t io_offset; | |
19 | ||
20 | enum piix4_pm_io_reg { | |
21 | PIIX4_FUNC3IO_PMSTS = 0x00, | |
22 | #define PIIX4_FUNC3IO_PMSTS_PWRBTN_STS BIT(8) | |
23 | PIIX4_FUNC3IO_PMCNTRL = 0x04, | |
24 | #define PIIX4_FUNC3IO_PMCNTRL_SUS_EN BIT(13) | |
25 | #define PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF (0x0 << 10) | |
26 | }; | |
27 | ||
28 | #define PIIX4_SUSPEND_MAGIC 0x00120002 | |
29 | ||
30 | static const int piix4_pm_io_region = PCI_BRIDGE_RESOURCES; | |
31 | ||
32 | static void piix4_poweroff(void) | |
33 | { | |
34 | int spec_devid; | |
35 | u16 sts; | |
36 | ||
37 | /* Ensure the power button status is clear */ | |
38 | while (1) { | |
39 | sts = inw(io_offset + PIIX4_FUNC3IO_PMSTS); | |
40 | if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS)) | |
41 | break; | |
42 | outw(sts, io_offset + PIIX4_FUNC3IO_PMSTS); | |
43 | } | |
44 | ||
45 | /* Enable entry to suspend */ | |
46 | outw(PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF | PIIX4_FUNC3IO_PMCNTRL_SUS_EN, | |
47 | io_offset + PIIX4_FUNC3IO_PMCNTRL); | |
48 | ||
49 | /* If the special cycle occurs too soon this doesn't work... */ | |
50 | mdelay(10); | |
51 | ||
52 | /* | |
53 | * The PIIX4 will enter the suspend state only after seeing a special | |
54 | * cycle with the correct magic data on the PCI bus. Generate that | |
55 | * cycle now. | |
56 | */ | |
57 | spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7)); | |
58 | pci_bus_write_config_dword(pm_dev->bus, spec_devid, 0, | |
59 | PIIX4_SUSPEND_MAGIC); | |
60 | ||
61 | /* Give the system some time to power down, then error */ | |
62 | mdelay(1000); | |
63 | pr_emerg("Unable to poweroff system\n"); | |
64 | } | |
65 | ||
66 | static int piix4_poweroff_probe(struct pci_dev *dev, | |
67 | const struct pci_device_id *id) | |
68 | { | |
69 | int res; | |
70 | ||
71 | if (pm_dev) | |
72 | return -EINVAL; | |
73 | ||
74 | /* Request access to the PIIX4 PM IO registers */ | |
75 | res = pci_request_region(dev, piix4_pm_io_region, | |
76 | "PIIX4 PM IO registers"); | |
77 | if (res) { | |
78 | dev_err(&dev->dev, "failed to request PM IO registers: %d\n", | |
79 | res); | |
80 | return res; | |
81 | } | |
82 | ||
83 | pm_dev = dev; | |
84 | io_offset = pci_resource_start(dev, piix4_pm_io_region); | |
85 | pm_power_off = piix4_poweroff; | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | static void piix4_poweroff_remove(struct pci_dev *dev) | |
91 | { | |
92 | if (pm_power_off == piix4_poweroff) | |
93 | pm_power_off = NULL; | |
94 | ||
95 | pci_release_region(dev, piix4_pm_io_region); | |
96 | pm_dev = NULL; | |
97 | } | |
98 | ||
99 | static const struct pci_device_id piix4_poweroff_ids[] = { | |
100 | { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) }, | |
101 | { 0 }, | |
102 | }; | |
103 | ||
104 | static struct pci_driver piix4_poweroff_driver = { | |
105 | .name = "piix4-poweroff", | |
106 | .id_table = piix4_poweroff_ids, | |
107 | .probe = piix4_poweroff_probe, | |
108 | .remove = piix4_poweroff_remove, | |
109 | }; | |
110 | ||
111 | module_pci_driver(piix4_poweroff_driver); | |
fb615d61 | 112 | MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>"); |
29676833 | 113 | MODULE_LICENSE("GPL"); |