1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2016 Imagination Technologies
4*4882a593Smuzhiyun * Author: Paul Burton <paul.burton@mips.com>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/delay.h>
8*4882a593Smuzhiyun #include <linux/io.h>
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/pci.h>
11*4882a593Smuzhiyun #include <linux/pm.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun static struct pci_dev *pm_dev;
14*4882a593Smuzhiyun static resource_size_t io_offset;
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun enum piix4_pm_io_reg {
17*4882a593Smuzhiyun PIIX4_FUNC3IO_PMSTS = 0x00,
18*4882a593Smuzhiyun #define PIIX4_FUNC3IO_PMSTS_PWRBTN_STS BIT(8)
19*4882a593Smuzhiyun PIIX4_FUNC3IO_PMCNTRL = 0x04,
20*4882a593Smuzhiyun #define PIIX4_FUNC3IO_PMCNTRL_SUS_EN BIT(13)
21*4882a593Smuzhiyun #define PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF (0x0 << 10)
22*4882a593Smuzhiyun };
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun #define PIIX4_SUSPEND_MAGIC 0x00120002
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun static const int piix4_pm_io_region = PCI_BRIDGE_RESOURCES;
27*4882a593Smuzhiyun
piix4_poweroff(void)28*4882a593Smuzhiyun static void piix4_poweroff(void)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun int spec_devid;
31*4882a593Smuzhiyun u16 sts;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun /* Ensure the power button status is clear */
34*4882a593Smuzhiyun while (1) {
35*4882a593Smuzhiyun sts = inw(io_offset + PIIX4_FUNC3IO_PMSTS);
36*4882a593Smuzhiyun if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS))
37*4882a593Smuzhiyun break;
38*4882a593Smuzhiyun outw(sts, io_offset + PIIX4_FUNC3IO_PMSTS);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun /* Enable entry to suspend */
42*4882a593Smuzhiyun outw(PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF | PIIX4_FUNC3IO_PMCNTRL_SUS_EN,
43*4882a593Smuzhiyun io_offset + PIIX4_FUNC3IO_PMCNTRL);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun /* If the special cycle occurs too soon this doesn't work... */
46*4882a593Smuzhiyun mdelay(10);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun /*
49*4882a593Smuzhiyun * The PIIX4 will enter the suspend state only after seeing a special
50*4882a593Smuzhiyun * cycle with the correct magic data on the PCI bus. Generate that
51*4882a593Smuzhiyun * cycle now.
52*4882a593Smuzhiyun */
53*4882a593Smuzhiyun spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7));
54*4882a593Smuzhiyun pci_bus_write_config_dword(pm_dev->bus, spec_devid, 0,
55*4882a593Smuzhiyun PIIX4_SUSPEND_MAGIC);
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun /* Give the system some time to power down, then error */
58*4882a593Smuzhiyun mdelay(1000);
59*4882a593Smuzhiyun pr_emerg("Unable to poweroff system\n");
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
piix4_poweroff_probe(struct pci_dev * dev,const struct pci_device_id * id)62*4882a593Smuzhiyun static int piix4_poweroff_probe(struct pci_dev *dev,
63*4882a593Smuzhiyun const struct pci_device_id *id)
64*4882a593Smuzhiyun {
65*4882a593Smuzhiyun int res;
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun if (pm_dev)
68*4882a593Smuzhiyun return -EINVAL;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun /* Request access to the PIIX4 PM IO registers */
71*4882a593Smuzhiyun res = pci_request_region(dev, piix4_pm_io_region,
72*4882a593Smuzhiyun "PIIX4 PM IO registers");
73*4882a593Smuzhiyun if (res) {
74*4882a593Smuzhiyun dev_err(&dev->dev, "failed to request PM IO registers: %d\n",
75*4882a593Smuzhiyun res);
76*4882a593Smuzhiyun return res;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun pm_dev = dev;
80*4882a593Smuzhiyun io_offset = pci_resource_start(dev, piix4_pm_io_region);
81*4882a593Smuzhiyun pm_power_off = piix4_poweroff;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun return 0;
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun
piix4_poweroff_remove(struct pci_dev * dev)86*4882a593Smuzhiyun static void piix4_poweroff_remove(struct pci_dev *dev)
87*4882a593Smuzhiyun {
88*4882a593Smuzhiyun if (pm_power_off == piix4_poweroff)
89*4882a593Smuzhiyun pm_power_off = NULL;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun pci_release_region(dev, piix4_pm_io_region);
92*4882a593Smuzhiyun pm_dev = NULL;
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun static const struct pci_device_id piix4_poweroff_ids[] = {
96*4882a593Smuzhiyun { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
97*4882a593Smuzhiyun { 0 },
98*4882a593Smuzhiyun };
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun static struct pci_driver piix4_poweroff_driver = {
101*4882a593Smuzhiyun .name = "piix4-poweroff",
102*4882a593Smuzhiyun .id_table = piix4_poweroff_ids,
103*4882a593Smuzhiyun .probe = piix4_poweroff_probe,
104*4882a593Smuzhiyun .remove = piix4_poweroff_remove,
105*4882a593Smuzhiyun };
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun module_pci_driver(piix4_poweroff_driver);
108*4882a593Smuzhiyun MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
109*4882a593Smuzhiyun MODULE_LICENSE("GPL");
110