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