arch/x86/platform/olpc/olpc-xo1-pm.c

Source file repositories/reference/linux-study-clean/arch/x86/platform/olpc/olpc-xo1-pm.c

File Facts

System
Linux kernel
Corpus path
arch/x86/platform/olpc/olpc-xo1-pm.c
Extension
.c
Size
4435 bytes
Lines
188
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Support for power management features of the OLPC XO-1 laptop
 *
 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
 * Copyright (C) 2010 One Laptop per Child
 * Copyright (C) 2006 Red Hat, Inc.
 * Copyright (C) 2006 Advanced Micro Devices, Inc.
 */

#include <linux/cs5535.h>
#include <linux/platform_device.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/olpc-ec.h>

#include <asm/io.h>
#include <asm/olpc.h>

#define DRV_NAME "olpc-xo1-pm"

static unsigned long acpi_base;
static unsigned long pms_base;

static u16 wakeup_mask = CS5536_PM_PWRBTN;

static struct {
	unsigned long address;
	unsigned short segment;
} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };

/* Set bits in the wakeup mask */
void olpc_xo1_pm_wakeup_set(u16 value)
{
	wakeup_mask |= value;
}
EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);

/* Clear bits in the wakeup mask */
void olpc_xo1_pm_wakeup_clear(u16 value)
{
	wakeup_mask &= ~value;
}
EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);

static int xo1_power_state_enter(suspend_state_t pm_state)
{
	unsigned long saved_sci_mask;

	/* Only STR is supported */
	if (pm_state != PM_SUSPEND_MEM)
		return -EINVAL;

	/*
	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
	 * wakeup events, which is not necessarily the same event set)
	 */
	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
	saved_sci_mask &= 0xffff0000;

	/* Save CPU state */
	do_olpc_suspend_lowlevel();

	/* Resume path starts here */

	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);

	return 0;
}

asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
{
	void *pgd_addr = __va(read_cr3_pa());

	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);

	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
	__asm__("call *(%%edi); cld"
		: : "D" (&ofw_bios_entry));
	__asm__("movb $0x34, %al\n\t"
		"outb %al, $0x70\n\t"
		"movb $0x30, %al\n\t"
		"outb %al, $0x71\n\t");
	return 0;
}

static void xo1_power_off(void)

Annotation

Implementation Notes