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Commit 97c4cb71 authored by Daniel Drake's avatar Daniel Drake Committed by H. Peter Anvin
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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 <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-5-git-send-email-dsd@laptop.org


Acked-by: default avatarAndres Salomon <dilinger@queued.net>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent a3128588

arch/x86/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -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

	---help---

	  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

arch/x86/include/asm/olpc.h

+12 −3
Original line number Diff line number Diff line
@@ -76,6 +76,12 @@ static inline int olpc_has_dcon(void) 


#endif



#ifdef CONFIG_OLPC_XO1_PM

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);

#endif



extern int pci_olpc_init(void);



/* EC related functions */
@@ -89,8 +95,11 @@ extern int olpc_ec_mask_unset(uint8_t bits); 
/* EC commands */



#define EC_FIRMWARE_REV			0x08

#define EC_WLAN_ENTER_RESET	0x35

#define EC_WAKE_UP_WLAN			0x24

#define EC_WLAN_LEAVE_RESET		0x25

#define EC_SET_SCI_INHIBIT		0x32

#define EC_SET_SCI_INHIBIT_RELEASE	0x34

#define EC_WLAN_ENTER_RESET		0x35



/* SCI source values */

arch/x86/platform/olpc/Makefile

+1 −1
Original line number Diff line number Diff line 
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

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

+92 −0
Original line number Diff line number Diff line
@@ -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;

}

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;

	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 */

	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);



	/* Tell the EC to stop inhibiting SCIs */

	olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0);



	/*

	 * 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) {

		suspend_set_ops(&xo1_suspend_ops);

		pm_power_off = xo1_power_off;

		printk(KERN_INFO "OLPC XO-1 support registered\n");

	}

arch/x86/platform/olpc/xo1-wakeup.S

0 → 100644
+124 −0
Original line number Diff line number Diff line 
.text

#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

	.endm



wakeup_start:

	# OFW lands us here, running in protected mode, with a

	# kernel-compatible GDT already setup.



	# Clear any dangerous flags

	pushl $0

	popfl



	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

1:



	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

1:

	movl    %cr3, %eax

	movl    %eax, %cr3

	wbinvd



	# Go back to the return point

	jmp ret_point



save_registers:

	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



	pushfl

	popl saved_context_eflags



	ret



restore_registers:

	movl saved_context_ebp, %ebp

	movl saved_context_ebx, %ebx

	movl saved_context_esi, %esi

	movl saved_context_edi, %edi



	pushl saved_context_eflags

	popfl



	ret



ENTRY(do_olpc_suspend_lowlevel)

	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

ret_point:

	movl    saved_context_esp, %esp



	writepost 0x32



	call	restore_registers

	call	restore_processor_state

	ret



.data

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