From 97c4cb71c18fe045a763ff6681a8ebbbbbec0b2b Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Sat, 25 Jun 2011 17:34:11 +0100 Subject: 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: Daniel Drake Link: http://lkml.kernel.org/r/1309019658-1712-5-git-send-email-dsd@laptop.org Acked-by: Andres Salomon Signed-off-by: H. Peter Anvin --- arch/x86/Kconfig | 4 +- arch/x86/include/asm/olpc.h | 15 ++++- arch/x86/platform/olpc/Makefile | 2 +- arch/x86/platform/olpc/olpc-xo1-pm.c | 92 ++++++++++++++++++++++++++ arch/x86/platform/olpc/xo1-wakeup.S | 124 +++++++++++++++++++++++++++++++++++ 5 files changed, 231 insertions(+), 6 deletions(-) create mode 100644 arch/x86/platform/olpc/xo1-wakeup.S (limited to 'arch/x86') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 29615ee..f473151 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -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 diff --git a/arch/x86/include/asm/olpc.h b/arch/x86/include/asm/olpc.h index 5ca6801..10ea595 100644 --- a/arch/x86/include/asm/olpc.h +++ b/arch/x86/include/asm/olpc.h @@ -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 */ @@ -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_SET_SCI_INHIBIT_RELEASE 0x34 +#define EC_WLAN_ENTER_RESET 0x35 /* SCI source values */ diff --git a/arch/x86/platform/olpc/Makefile b/arch/x86/platform/olpc/Makefile index cd25038..1ae7bed 100644 --- a/arch/x86/platform/olpc/Makefile +++ b/arch/x86/platform/olpc/Makefile @@ -1,2 +1,2 @@ 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 diff --git a/arch/x86/platform/olpc/olpc-xo1-pm.c b/arch/x86/platform/olpc/olpc-xo1-pm.c index a2a59d3..6f3855a 100644 --- a/arch/x86/platform/olpc/olpc-xo1-pm.c +++ b/arch/x86/platform/olpc/olpc-xo1-pm.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -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"); } diff --git a/arch/x86/platform/olpc/xo1-wakeup.S b/arch/x86/platform/olpc/xo1-wakeup.S new file mode 100644 index 0000000..948deb2 --- /dev/null +++ b/arch/x86/platform/olpc/xo1-wakeup.S @@ -0,0 +1,124 @@ +.text +#include +#include +#include +#include + + .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 -- cgit v1.1