linux_dsm_epyc7002/drivers/power/reset/piix4-poweroff.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

110 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Imagination Technologies
* Author: Paul Burton <paul.burton@mips.com>
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm.h>
static struct pci_dev *pm_dev;
static resource_size_t io_offset;
enum piix4_pm_io_reg {
PIIX4_FUNC3IO_PMSTS = 0x00,
#define PIIX4_FUNC3IO_PMSTS_PWRBTN_STS BIT(8)
PIIX4_FUNC3IO_PMCNTRL = 0x04,
#define PIIX4_FUNC3IO_PMCNTRL_SUS_EN BIT(13)
#define PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF (0x0 << 10)
};
#define PIIX4_SUSPEND_MAGIC 0x00120002
static const int piix4_pm_io_region = PCI_BRIDGE_RESOURCES;
static void piix4_poweroff(void)
{
int spec_devid;
u16 sts;
/* Ensure the power button status is clear */
while (1) {
sts = inw(io_offset + PIIX4_FUNC3IO_PMSTS);
if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS))
break;
outw(sts, io_offset + PIIX4_FUNC3IO_PMSTS);
}
/* Enable entry to suspend */
outw(PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_SOFF | PIIX4_FUNC3IO_PMCNTRL_SUS_EN,
io_offset + PIIX4_FUNC3IO_PMCNTRL);
/* If the special cycle occurs too soon this doesn't work... */
mdelay(10);
/*
* The PIIX4 will enter the suspend state only after seeing a special
* cycle with the correct magic data on the PCI bus. Generate that
* cycle now.
*/
spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7));
pci_bus_write_config_dword(pm_dev->bus, spec_devid, 0,
PIIX4_SUSPEND_MAGIC);
/* Give the system some time to power down, then error */
mdelay(1000);
pr_emerg("Unable to poweroff system\n");
}
static int piix4_poweroff_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
int res;
if (pm_dev)
return -EINVAL;
/* Request access to the PIIX4 PM IO registers */
res = pci_request_region(dev, piix4_pm_io_region,
"PIIX4 PM IO registers");
if (res) {
dev_err(&dev->dev, "failed to request PM IO registers: %d\n",
res);
return res;
}
pm_dev = dev;
io_offset = pci_resource_start(dev, piix4_pm_io_region);
pm_power_off = piix4_poweroff;
return 0;
}
static void piix4_poweroff_remove(struct pci_dev *dev)
{
if (pm_power_off == piix4_poweroff)
pm_power_off = NULL;
pci_release_region(dev, piix4_pm_io_region);
pm_dev = NULL;
}
static const struct pci_device_id piix4_poweroff_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
{ 0 },
};
static struct pci_driver piix4_poweroff_driver = {
.name = "piix4-poweroff",
.id_table = piix4_poweroff_ids,
.probe = piix4_poweroff_probe,
.remove = piix4_poweroff_remove,
};
module_pci_driver(piix4_poweroff_driver);
MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
MODULE_LICENSE("GPL");