Commit b6911bba authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle

MIPS: Malta: add suspend state entry code

This patch introduces code which will enter a suspend state via the
PIIX4. This can only be done when PCI support is enabled since it
requires access to PCI I/O space and the generation of a special cycle
on the PCI bus. In cases where PCI is disabled the mips_pm_suspend
function will simply always return an error.
Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6905/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 643c5705
......@@ -1671,6 +1671,12 @@ config SYS_HAS_CPU_XLR
config SYS_HAS_CPU_XLP
bool
config MIPS_MALTA_PM
depends on MIPS_MALTA
depends on PCI
bool
default y
#
# CPU may reorder R->R, R->W, W->R, W->W
# Reordering beyond LL and SC is handled in WEAK_REORDERING_BEYOND_LLSC
......
/*
* Copyright (C) 2014 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.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.
*/
#ifndef __ASM_MIPS_MACH_MALTA_PM_H__
#define __ASM_MIPS_MACH_MALTA_PM_H__
#include <asm/mips-boards/piix4.h>
#ifdef CONFIG_MIPS_MALTA_PM
/**
* mips_pm_suspend - enter a suspend state
* @state: the state to enter, one of PIIX4_FUNC3IO_PMCNTRL_SUS_TYP_*
*
* Enters a suspend state via the Malta's PIIX4. If the state to be entered
* is one which loses context (eg. SOFF) then this function will never
* return.
*/
extern int mips_pm_suspend(unsigned state);
#else /* !CONFIG_MIPS_MALTA_PM */
static inline int mips_pm_suspend(unsigned state)
{
return -EINVAL;
}
#endif /* !CONFIG_MIPS_MALTA_PM */
#endif /* __ASM_MIPS_MACH_MALTA_PM_H__ */
......@@ -8,3 +8,5 @@
obj-y := malta-amon.o malta-display.o malta-init.o \
malta-int.o malta-memory.o malta-platform.o \
malta-reset.o malta-setup.o malta-time.o
obj-$(CONFIG_MIPS_MALTA_PM) += malta-pm.o
/*
* Copyright (C) 2014 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.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/init.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <asm/mach-malta/malta-pm.h>
static struct pci_bus *pm_pci_bus;
static resource_size_t pm_io_offset;
int mips_pm_suspend(unsigned state)
{
int spec_devid;
u16 sts;
if (!pm_pci_bus || !pm_io_offset)
return -ENODEV;
/* Ensure the power button status is clear */
while (1) {
sts = inw(pm_io_offset + PIIX4_FUNC3IO_PMSTS);
if (!(sts & PIIX4_FUNC3IO_PMSTS_PWRBTN_STS))
break;
outw(sts, pm_io_offset + PIIX4_FUNC3IO_PMSTS);
}
/* Enable entry to suspend */
outw(state | PIIX4_FUNC3IO_PMCNTRL_SUS_EN,
pm_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_pci_bus, spec_devid, 0,
PIIX4_SUSPEND_MAGIC);
/* Give the system some time to power down */
mdelay(1000);
return 0;
}
static int __init malta_pm_setup(void)
{
struct pci_dev *dev;
int res, io_region = PCI_BRIDGE_RESOURCES;
/* Find a reference to the PCI bus */
pm_pci_bus = pci_find_next_bus(NULL);
if (!pm_pci_bus) {
pr_warn("malta-pm: failed to find reference to PCI bus\n");
return -ENODEV;
}
/* Find the PIIX4 PM device */
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
PCI_ANY_ID, NULL);
if (!dev) {
pr_warn("malta-pm: failed to find PIIX4 PM\n");
return -ENODEV;
}
/* Request access to the PIIX4 PM IO registers */
res = pci_request_region(dev, io_region, "PIIX4 PM IO registers");
if (res) {
pr_warn("malta-pm: failed to request PM IO registers (%d)\n",
res);
pci_dev_put(dev);
return -ENODEV;
}
/* Find the offset to the PIIX4 PM IO registers */
pm_io_offset = pci_resource_start(dev, io_region);
pci_dev_put(dev);
return 0;
}
late_initcall(malta_pm_setup);
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment