| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2016 Imagination Technologies |
| 3 | * Author: Paul Burton <paul.burton@mips.com> |
| 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); |
| 112 | MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>"); |
| 113 | MODULE_LICENSE("GPL"); |