| /* |
| * Copyright (C) 2016 Imagination Technologies |
| * Author: Paul Burton <paul.burton@mips.com> |
| * |
| * 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. |
| */ |
| |
| #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"); |