Commit 97c4cb71 authored by Daniel Drake's avatar Daniel Drake Committed by H. Peter Anvin

x86, olpc: Add XO-1 suspend/resume support

Add code needed for basic suspend/resume of the XO-1 laptop.
Based on earlier work by Jordan Crouse, Andres Salomon, and others.

This patch incorporates all earlier feedback from Thomas Gleixner. To
clarify a certain point (now more obvious in the code itself):
On resume, OpenFirmware returns execution to Linux in protected mode
with a kernel-compatible GDT already set up. The changes and
simplifications suggested have all been included.
Signed-off-by: default avatarDaniel Drake <>
Link: default avatarAndres Salomon <>
Signed-off-by: default avatarH. Peter Anvin <>
parent a3128588
......@@ -2075,10 +2075,10 @@ config OLPC
config OLPC_XO1_PM
bool "OLPC XO-1 Power Management"
depends on OLPC && MFD_CS5535
depends on OLPC && MFD_CS5535 && PM_SLEEP
select MFD_CORE
Add support for poweroff of the OLPC XO-1 laptop.
Add support for poweroff and suspend of the OLPC XO-1 laptop.
endif # X86_32
......@@ -76,6 +76,12 @@ static inline int olpc_has_dcon(void)
extern void do_olpc_suspend_lowlevel(void);
extern void olpc_xo1_pm_wakeup_set(u16 value);
extern void olpc_xo1_pm_wakeup_clear(u16 value);
extern int pci_olpc_init(void);
/* EC related functions */
......@@ -88,9 +94,12 @@ extern int olpc_ec_mask_unset(uint8_t bits);
/* EC commands */
#define EC_FIRMWARE_REV 0x08
#define EC_WLAN_ENTER_RESET 0x35
#define EC_WLAN_LEAVE_RESET 0x25
#define EC_FIRMWARE_REV 0x08
#define EC_WAKE_UP_WLAN 0x24
#define EC_WLAN_LEAVE_RESET 0x25
#define EC_SET_SCI_INHIBIT 0x32
#define EC_WLAN_ENTER_RESET 0x35
/* SCI source values */
obj-$(CONFIG_OLPC) += olpc.o olpc_ofw.o olpc_dt.o
obj-$(CONFIG_OLPC_XO1_PM) += olpc-xo1-pm.o
obj-$(CONFIG_OLPC_XO1_PM) += olpc-xo1-pm.o xo1-wakeup.o
......@@ -16,6 +16,7 @@
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/mfd/core.h>
#include <linux/suspend.h>
#include <asm/io.h>
#include <asm/olpc.h>
......@@ -25,6 +26,85 @@
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;
/* Clear bits in the wakeup mask */
void olpc_xo1_pm_wakeup_clear(u16 value)
wakeup_mask &= ~value;
static int xo1_power_state_enter(suspend_state_t pm_state)
unsigned long saved_sci_mask;
int r;
/* Only STR is supported */
if (pm_state != PM_SUSPEND_MEM)
return -EINVAL;
r = olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0);
if (r)
return r;
* 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 */
/* Resume path starts here */
/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
/* Tell the EC to stop inhibiting SCIs */
* Tell the wireless module to restart USB communication.
* Must be done twice.
olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
return 0;
asmlinkage int xo1_do_sleep(u8 sleep_state)
void *pgd_addr = __va(read_cr3());
/* 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)
printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
......@@ -43,6 +123,17 @@ static void xo1_power_off(void)
outl(0x00002000, acpi_base + CS5536_PM1_CNT);
static int xo1_power_state_valid(suspend_state_t pm_state)
/* suspend-to-RAM only */
return pm_state == PM_SUSPEND_MEM;
static const struct platform_suspend_ops xo1_suspend_ops = {
.valid = xo1_power_state_valid,
.enter = xo1_power_state_enter,
static int __devinit xo1_pm_probe(struct platform_device *pdev)
struct resource *res;
......@@ -68,6 +159,7 @@ static int __devinit xo1_pm_probe(struct platform_device *pdev)
/* If we have both addresses, we can override the poweroff hook */
if (pms_base && acpi_base) {
pm_power_off = xo1_power_off;
printk(KERN_INFO "OLPC XO-1 support registered\n");
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable_32.h>
.macro writepost,value
movb $0x34, %al
outb %al, $0x70
movb $\value, %al
outb %al, $0x71
# OFW lands us here, running in protected mode, with a
# kernel-compatible GDT already setup.
# Clear any dangerous flags
pushl $0
writepost 0x31
# Set up %cr3
movl $initial_page_table - __PAGE_OFFSET, %eax
movl %eax, %cr3
movl saved_cr4, %eax
movl %eax, %cr4
movl saved_cr0, %eax
movl %eax, %cr0
# Control registers were modified, pipeline resync is needed
jmp 1f
movw $__KERNEL_DS, %ax
movw %ax, %ss
movw %ax, %ds
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
lgdt saved_gdt
lidt saved_idt
lldt saved_ldt
ljmp $(__KERNEL_CS),$1f
movl %cr3, %eax
movl %eax, %cr3
# Go back to the return point
jmp ret_point
sgdt saved_gdt
sidt saved_idt
sldt saved_ldt
pushl %edx
movl %cr4, %edx
movl %edx, saved_cr4
movl %cr0, %edx
movl %edx, saved_cr0
popl %edx
movl %ebx, saved_context_ebx
movl %ebp, saved_context_ebp
movl %esi, saved_context_esi
movl %edi, saved_context_edi
popl saved_context_eflags
movl saved_context_ebp, %ebp
movl saved_context_ebx, %ebx
movl saved_context_esi, %esi
movl saved_context_edi, %edi
pushl saved_context_eflags
call save_processor_state
call save_registers
# This is the stack context we want to remember
movl %esp, saved_context_esp
pushl $3
call xo1_do_sleep
jmp wakeup_start
.p2align 4,,7
movl saved_context_esp, %esp
writepost 0x32
call restore_registers
call restore_processor_state
saved_gdt: .long 0,0
saved_idt: .long 0,0
saved_ldt: .long 0
saved_cr4: .long 0
saved_cr0: .long 0
saved_context_esp: .long 0
saved_context_edi: .long 0
saved_context_esi: .long 0
saved_context_ebx: .long 0
saved_context_ebp: .long 0
saved_context_eflags: .long 0
......@@ -70,6 +70,9 @@
#define CS5536_PM1_CNT 0x08
#define CS5536_PM_GPE0_STS 0x18
/* CS5536_PM1_EN bits */
#define CS5536_PM_PWRBTN (1 << 8)
/* VSA2 magic values */
#define VSA_VRC_INDEX 0xAC1C
#define VSA_VRC_DATA 0xAC1E
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