linux_dsm_epyc7002/arch/x86/kernel/pmc_atom.c
Li, Aubrey 93e5eadd1f x86/platform: New Intel Atom SOC power management controller driver
The Power Management Controller (PMC) controls many of the power
management features present in the Atom SoC. This driver provides
a native power off function via PMC PCI IO port.

On some ACPI hardware-reduced platforms(e.g. ASUS-T100), ACPI sleep
registers are not valid so that (*pm_power_off)() is not hooked by
acpi_power_off(). The power off function in this driver is installed
only when pm_power_off is NULL.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Link: http://lkml.kernel.org/r/53B0FEEA.3010805@linux.intel.com
Signed-off-by: Lejun Zhu <lejun.zhu@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-25 14:11:29 -07:00

105 lines
2.6 KiB
C

/*
* Intel Atom SOC Power Management Controller Driver
* Copyright (c) 2014, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/io.h>
#include <asm/pmc_atom.h>
static u32 acpi_base_addr;
static void pmc_power_off(void)
{
u16 pm1_cnt_port;
u32 pm1_cnt_value;
pr_info("Preparing to enter system sleep state S5\n");
pm1_cnt_port = acpi_base_addr + PM1_CNT;
pm1_cnt_value = inl(pm1_cnt_port);
pm1_cnt_value &= SLEEP_TYPE_MASK;
pm1_cnt_value |= SLEEP_TYPE_S5;
pm1_cnt_value |= SLEEP_ENABLE;
outl(pm1_cnt_value, pm1_cnt_port);
}
static int pmc_setup_dev(struct pci_dev *pdev)
{
/* Obtain ACPI base address */
pci_read_config_dword(pdev, ACPI_BASE_ADDR_OFFSET, &acpi_base_addr);
acpi_base_addr &= ACPI_BASE_ADDR_MASK;
/* Install power off function */
if (acpi_base_addr != 0 && pm_power_off == NULL)
pm_power_off = pmc_power_off;
return 0;
}
/*
* Data for PCI driver interface
*
* This data only exists for exporting the supported
* PCI ids via MODULE_DEVICE_TABLE. We do not actually
* register a pci_driver, because lpc_ich will register
* a driver on the same PCI id.
*/
static const struct pci_device_id pmc_pci_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_VLV_PMC) },
{ 0, },
};
MODULE_DEVICE_TABLE(pci, pmc_pci_ids);
static int __init pmc_atom_init(void)
{
int err = -ENODEV;
struct pci_dev *pdev = NULL;
const struct pci_device_id *ent;
/* We look for our device - PCU PMC
* we assume that there is max. one device.
*
* We can't use plain pci_driver mechanism,
* as the device is really a multiple function device,
* main driver that binds to the pci_device is lpc_ich
* and have to find & bind to the device this way.
*/
for_each_pci_dev(pdev) {
ent = pci_match_id(pmc_pci_ids, pdev);
if (ent) {
err = pmc_setup_dev(pdev);
goto out;
}
}
/* Device not found. */
out:
return err;
}
module_init(pmc_atom_init);
/* no module_exit, this driver shouldn't be unloaded */
MODULE_AUTHOR("Aubrey Li <aubrey.li@linux.intel.com>");
MODULE_DESCRIPTION("Intel Atom SOC Power Management Controller Interface");
MODULE_LICENSE("GPL v2");