linux/drivers/acpi/internal.h
Rafael J. Wysocki 8110dd281e ACPI / sleep: EC-based wakeup from suspend-to-idle on recent systems
Some recent Dell laptops, including the XPS13 model numbers 9360 and
9365, cannot be woken up from suspend-to-idle by pressing the power
button which is unexpected and makes that feature less usable on
those systems.  Moreover, on the 9365 ACPI S3 (suspend-to-RAM) is
not expected to be used at all (the OS these systems ship with never
exercises the ACPI S3 path in the firmware) and suspend-to-idle is
the only viable system suspend mechanism there.

The reason why the power button wakeup from suspend-to-idle doesn't
work on those systems is because their power button events are
signaled by the EC (Embedded Controller), whose GPE (General Purpose
Event) line is disabled during suspend-to-idle transitions in Linux.
That is done on purpose, because in general the EC tends to be noisy
for various reasons (battery and thermal updates and similar, for
example) and all events signaled by it would kick the CPUs out of
deep idle states while in suspend-to-idle, which effectively might
defeat its purpose.

Of course, on the Dell systems in question the EC GPE must be enabled
during suspend-to-idle transitions for the button press events to
be signaled while suspended at all, but fortunately there is a way
out of this puzzle.

First of all, those systems have the ACPI_FADT_LOW_POWER_S0 flag set
in their ACPI tables, which means that the OS is expected to prefer
the "low power S0 idle" system state over ACPI S3 on them.  That
causes the most recent versions of other OSes to simply ignore ACPI
S3 on those systems, so it is reasonable to expect that it should not
be necessary to block GPEs during suspend-to-idle on them.

Second, in addition to that, the systems in question provide a special
firmware interface that can be used to indicate to the platform that
the OS is transitioning into a system-wide low-power state in which
certain types of activity are not desirable or that it is leaving
such a state and that (in principle) should allow the platform to
adjust its operation mode accordingly.

That interface is a special _DSM object under a System Power
Management Controller device (PNP0D80).  The expected way to use it
is to invoke function 0 from it on system initialization, functions
3 and 5 during suspend transitions and functions 4 and 6 during
resume transitions (to reverse the actions carried out by the
former).  In particular, function 5 from the "Low-Power S0" device
_DSM is expected to cause the platform to put itself into a low-power
operation mode which should include making the EC less verbose (so to
speak).  Next, on resume, function 6 switches the platform back to
the "working-state" operation mode.

In accordance with the above, modify the ACPI suspend-to-idle code
to look for the "Low-Power S0" _DSM interface on platforms with the
ACPI_FADT_LOW_POWER_S0 flag set in the ACPI tables.  If it's there,
use it during suspend-to-idle transitions as prescribed and avoid
changing the GPE configuration in that case.  [That should reflect
what the most recent versions of other OSes do.]

Also modify the ACPI EC driver to make it handle events during
suspend-to-idle in the usual way if the "Low-Power S0" _DSM interface
is going to be used to make the power button events work while
suspended on the Dell machines mentioned above

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-23 15:24:32 +02:00

243 lines
8.6 KiB
C

/*
* acpi/internal.h
* For use by Linux/ACPI infrastructure, not drivers
*
* Copyright (c) 2009, 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.
*
*/
#ifndef _ACPI_INTERNAL_H_
#define _ACPI_INTERNAL_H_
#define PREFIX "ACPI: "
int early_acpi_osi_init(void);
int acpi_osi_init(void);
acpi_status acpi_os_initialize1(void);
void init_acpi_device_notify(void);
int acpi_scan_init(void);
void acpi_pci_root_init(void);
void acpi_pci_link_init(void);
void acpi_processor_init(void);
void acpi_platform_init(void);
void acpi_pnp_init(void);
void acpi_int340x_thermal_init(void);
#ifdef CONFIG_ARM_AMBA
void acpi_amba_init(void);
#else
static inline void acpi_amba_init(void) {}
#endif
int acpi_sysfs_init(void);
void acpi_gpe_apply_masked_gpes(void);
void acpi_container_init(void);
void acpi_memory_hotplug_init(void);
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
void pci_ioapic_remove(struct acpi_pci_root *root);
int acpi_ioapic_remove(struct acpi_pci_root *root);
#else
static inline void pci_ioapic_remove(struct acpi_pci_root *root) { return; }
static inline int acpi_ioapic_remove(struct acpi_pci_root *root) { return 0; }
#endif
#ifdef CONFIG_ACPI_DOCK
void register_dock_dependent_device(struct acpi_device *adev,
acpi_handle dshandle);
int dock_notify(struct acpi_device *adev, u32 event);
void acpi_dock_add(struct acpi_device *adev);
#else
static inline void register_dock_dependent_device(struct acpi_device *adev,
acpi_handle dshandle) {}
static inline int dock_notify(struct acpi_device *adev, u32 event) { return -ENODEV; }
static inline void acpi_dock_add(struct acpi_device *adev) {}
#endif
#ifdef CONFIG_X86
void acpi_cmos_rtc_init(void);
#else
static inline void acpi_cmos_rtc_init(void) {}
#endif
int acpi_rev_override_setup(char *str);
void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug,
const char *name);
int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
const char *hotplug_profile_name);
void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val);
#ifdef CONFIG_DEBUG_FS
extern struct dentry *acpi_debugfs_dir;
void acpi_debugfs_init(void);
#else
static inline void acpi_debugfs_init(void) { return; }
#endif
void acpi_lpss_init(void);
void acpi_apd_init(void);
acpi_status acpi_hotplug_schedule(struct acpi_device *adev, u32 src);
bool acpi_queue_hotplug_work(struct work_struct *work);
void acpi_device_hotplug(struct acpi_device *adev, u32 src);
bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent);
acpi_status acpi_sysfs_table_handler(u32 event, void *table, void *context);
void acpi_scan_table_handler(u32 event, void *table, void *context);
/* --------------------------------------------------------------------------
Device Node Initialization / Removal
-------------------------------------------------------------------------- */
#define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING)
extern struct list_head acpi_bus_id_list;
struct acpi_device_bus_id {
char bus_id[15];
unsigned int instance_no;
struct list_head node;
};
int acpi_device_add(struct acpi_device *device,
void (*release)(struct device *));
void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
int type, unsigned long long sta);
int acpi_device_setup_files(struct acpi_device *dev);
void acpi_device_remove_files(struct acpi_device *dev);
void acpi_device_add_finalize(struct acpi_device *device);
void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
bool acpi_device_is_present(struct acpi_device *adev);
bool acpi_device_is_battery(struct acpi_device *adev);
bool acpi_device_is_first_physical_node(struct acpi_device *adev,
const struct device *dev);
/* --------------------------------------------------------------------------
Device Matching and Notification
-------------------------------------------------------------------------- */
struct acpi_device *acpi_companion_match(const struct device *dev);
int __acpi_device_uevent_modalias(struct acpi_device *adev,
struct kobj_uevent_env *env);
/* --------------------------------------------------------------------------
Power Resource
-------------------------------------------------------------------------- */
int acpi_power_init(void);
void acpi_power_resources_list_free(struct list_head *list);
int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
struct list_head *list);
int acpi_add_power_resource(acpi_handle handle);
void acpi_power_add_remove_device(struct acpi_device *adev, bool add);
int acpi_power_wakeup_list_init(struct list_head *list, int *system_level);
int acpi_device_sleep_wake(struct acpi_device *dev,
int enable, int sleep_state, int dev_state);
int acpi_power_get_inferred_state(struct acpi_device *device, int *state);
int acpi_power_on_resources(struct acpi_device *device, int state);
int acpi_power_transition(struct acpi_device *device, int state);
int acpi_wakeup_device_init(void);
#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
void acpi_early_processor_set_pdc(void);
#else
static inline void acpi_early_processor_set_pdc(void) {}
#endif
#ifdef CONFIG_X86
void acpi_early_processor_osc(void);
#else
static inline void acpi_early_processor_osc(void) {}
#endif
/* --------------------------------------------------------------------------
Embedded Controller
-------------------------------------------------------------------------- */
struct acpi_ec {
acpi_handle handle;
unsigned long gpe;
unsigned long command_addr;
unsigned long data_addr;
bool global_lock;
unsigned long flags;
unsigned long reference_count;
struct mutex mutex;
wait_queue_head_t wait;
struct list_head list;
struct transaction *curr;
spinlock_t lock;
struct work_struct work;
unsigned long timestamp;
unsigned long nr_pending_queries;
bool busy_polling;
unsigned int polling_guard;
};
extern struct acpi_ec *first_ec;
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
/* External interfaces use first EC only, so remember */
typedef int (*acpi_ec_query_func) (void *data);
int acpi_ec_init(void);
int acpi_ec_ecdt_probe(void);
int acpi_ec_dsdt_probe(void);
int acpi_ec_ecdt_start(void);
void acpi_ec_block_transactions(void);
void acpi_ec_unblock_transactions(void);
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
acpi_handle handle, acpi_ec_query_func func,
void *data);
void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
/*--------------------------------------------------------------------------
Suspend/Resume
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT
extern bool acpi_s2idle_wakeup(void);
extern bool acpi_sleep_no_ec_events(void);
extern int acpi_sleep_init(void);
#else
static inline bool acpi_s2idle_wakeup(void) { return false; }
static inline bool acpi_sleep_no_ec_events(void) { return true; }
static inline int acpi_sleep_init(void) { return -ENXIO; }
#endif
#ifdef CONFIG_ACPI_SLEEP
void acpi_sleep_proc_init(void);
int suspend_nvs_alloc(void);
void suspend_nvs_free(void);
int suspend_nvs_save(void);
void suspend_nvs_restore(void);
#else
static inline void acpi_sleep_proc_init(void) {}
static inline int suspend_nvs_alloc(void) { return 0; }
static inline void suspend_nvs_free(void) {}
static inline int suspend_nvs_save(void) { return 0; }
static inline void suspend_nvs_restore(void) {}
#endif
/*--------------------------------------------------------------------------
Device properties
-------------------------------------------------------------------------- */
#define ACPI_DT_NAMESPACE_HID "PRP0001"
void acpi_init_properties(struct acpi_device *adev);
void acpi_free_properties(struct acpi_device *adev);
/*--------------------------------------------------------------------------
Watchdog
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_WATCHDOG
void acpi_watchdog_init(void);
#else
static inline void acpi_watchdog_init(void) {}
#endif
#endif /* _ACPI_INTERNAL_H_ */