| Paul Burton | b6911bb | 2014-05-07 12:20:57 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 Imagination Technologies |
| 3 | * Author: Paul Burton <paul.burton@imgtec.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/init.h> |
| 13 | #include <linux/io.h> |
| 14 | #include <linux/pci.h> |
| 15 | |
| 16 | #include <asm/mach-malta/malta-pm.h> |
| 17 | |
| 18 | static struct pci_bus *pm_pci_bus; |
| 19 | static resource_size_t pm_io_offset; |
| 20 | |
| 21 | int mips_pm_suspend(unsigned state) |
| 22 | { |
| 23 | int spec_devid; |
| 24 | u16 sts; |
| 25 | |
| 26 | if (!pm_pci_bus || !pm_io_offset) |
| 27 | return -ENODEV; |
| 28 | |
| 29 | /* Ensure the power button status is clear */ |
| 30 | while (1) { |
| 31 | sts = inw(pm_io_offset + PIIX4_FUNC3IO_PMSTS); |
| 32 | if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS)) |
| 33 | break; |
| 34 | outw(sts, pm_io_offset + PIIX4_FUNC3IO_PMSTS); |
| 35 | } |
| 36 | |
| 37 | /* Enable entry to suspend */ |
| 38 | outw(state | PIIX4_FUNC3IO_PMCNTRL_SUS_EN, |
| 39 | pm_io_offset + PIIX4_FUNC3IO_PMCNTRL); |
| 40 | |
| 41 | /* If the special cycle occurs too soon this doesn't work... */ |
| 42 | mdelay(10); |
| 43 | |
| 44 | /* |
| 45 | * The PIIX4 will enter the suspend state only after seeing a special |
| 46 | * cycle with the correct magic data on the PCI bus. Generate that |
| 47 | * cycle now. |
| 48 | */ |
| 49 | spec_devid = PCI_DEVID(0, PCI_DEVFN(0x1f, 0x7)); |
| 50 | pci_bus_write_config_dword(pm_pci_bus, spec_devid, 0, |
| 51 | PIIX4_SUSPEND_MAGIC); |
| 52 | |
| 53 | /* Give the system some time to power down */ |
| 54 | mdelay(1000); |
| 55 | |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | static int __init malta_pm_setup(void) |
| 60 | { |
| 61 | struct pci_dev *dev; |
| 62 | int res, io_region = PCI_BRIDGE_RESOURCES; |
| 63 | |
| 64 | /* Find a reference to the PCI bus */ |
| 65 | pm_pci_bus = pci_find_next_bus(NULL); |
| 66 | if (!pm_pci_bus) { |
| 67 | pr_warn("malta-pm: failed to find reference to PCI bus\n"); |
| 68 | return -ENODEV; |
| 69 | } |
| 70 | |
| 71 | /* Find the PIIX4 PM device */ |
| 72 | dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, |
| 73 | PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID, |
| 74 | PCI_ANY_ID, NULL); |
| 75 | if (!dev) { |
| 76 | pr_warn("malta-pm: failed to find PIIX4 PM\n"); |
| 77 | return -ENODEV; |
| 78 | } |
| 79 | |
| 80 | /* Request access to the PIIX4 PM IO registers */ |
| 81 | res = pci_request_region(dev, io_region, "PIIX4 PM IO registers"); |
| 82 | if (res) { |
| 83 | pr_warn("malta-pm: failed to request PM IO registers (%d)\n", |
| 84 | res); |
| 85 | pci_dev_put(dev); |
| 86 | return -ENODEV; |
| 87 | } |
| 88 | |
| 89 | /* Find the offset to the PIIX4 PM IO registers */ |
| 90 | pm_io_offset = pci_resource_start(dev, io_region); |
| 91 | |
| 92 | pci_dev_put(dev); |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | late_initcall(malta_pm_setup); |