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-rw-r--r--drivers/acpi/sleep.c152
1 files changed, 147 insertions, 5 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 097d630ab886..be17664736b2 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -650,38 +650,165 @@ static const struct platform_suspend_ops acpi_suspend_ops_old = {
.recover = acpi_pm_finish,
};
+static bool s2idle_in_progress;
+static bool s2idle_wakeup;
+
+/*
+ * On platforms supporting the Low Power S0 Idle interface there is an ACPI
+ * device object with the PNP0D80 compatible device ID (System Power Management
+ * Controller) and a specific _DSM method under it. That method, if present,
+ * can be used to indicate to the platform that the OS is transitioning into a
+ * low-power state in which certain types of activity are not desirable or that
+ * it is leaving such a state, which allows the platform to adjust its operation
+ * mode accordingly.
+ */
+static const struct acpi_device_id lps0_device_ids[] = {
+ {"PNP0D80", },
+ {"", },
+};
+
+#define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
+
+#define ACPI_LPS0_SCREEN_OFF 3
+#define ACPI_LPS0_SCREEN_ON 4
+#define ACPI_LPS0_ENTRY 5
+#define ACPI_LPS0_EXIT 6
+
+#define ACPI_S2IDLE_FUNC_MASK ((1 << ACPI_LPS0_ENTRY) | (1 << ACPI_LPS0_EXIT))
+
+static acpi_handle lps0_device_handle;
+static guid_t lps0_dsm_guid;
+static char lps0_dsm_func_mask;
+
+static void acpi_sleep_run_lps0_dsm(unsigned int func)
+{
+ union acpi_object *out_obj;
+
+ if (!(lps0_dsm_func_mask & (1 << func)))
+ return;
+
+ out_obj = acpi_evaluate_dsm(lps0_device_handle, &lps0_dsm_guid, 1, func, NULL);
+ ACPI_FREE(out_obj);
+
+ acpi_handle_debug(lps0_device_handle, "_DSM function %u evaluation %s\n",
+ func, out_obj ? "successful" : "failed");
+}
+
+static int lps0_device_attach(struct acpi_device *adev,
+ const struct acpi_device_id *not_used)
+{
+ union acpi_object *out_obj;
+
+ if (lps0_device_handle)
+ return 0;
+
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
+ return 0;
+
+ guid_parse(ACPI_LPS0_DSM_UUID, &lps0_dsm_guid);
+ /* Check if the _DSM is present and as expected. */
+ out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 1, 0, NULL);
+ if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) {
+ char bitmask = *(char *)out_obj->buffer.pointer;
+
+ if ((bitmask & ACPI_S2IDLE_FUNC_MASK) == ACPI_S2IDLE_FUNC_MASK) {
+ lps0_dsm_func_mask = bitmask;
+ lps0_device_handle = adev->handle;
+ }
+
+ acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
+ bitmask);
+ } else {
+ acpi_handle_debug(adev->handle,
+ "_DSM function 0 evaluation failed\n");
+ }
+ ACPI_FREE(out_obj);
+ return 0;
+}
+
+static struct acpi_scan_handler lps0_handler = {
+ .ids = lps0_device_ids,
+ .attach = lps0_device_attach,
+};
+
static int acpi_freeze_begin(void)
{
acpi_scan_lock_acquire();
+ s2idle_in_progress = true;
return 0;
}
static int acpi_freeze_prepare(void)
{
- acpi_enable_wakeup_devices(ACPI_STATE_S0);
- acpi_enable_all_wakeup_gpes();
- acpi_os_wait_events_complete();
+ if (lps0_device_handle) {
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
+ } else {
+ /*
+ * The configuration of GPEs is changed here to avoid spurious
+ * wakeups, but that should not be necessary if this is a
+ * "low-power S0" platform and the low-power S0 _DSM is present.
+ */
+ acpi_enable_all_wakeup_gpes();
+ acpi_os_wait_events_complete();
+ }
if (acpi_sci_irq_valid())
enable_irq_wake(acpi_sci_irq);
+
return 0;
}
+static void acpi_freeze_wake(void)
+{
+ /*
+ * If IRQD_WAKEUP_ARMED is not set for the SCI at this point, it means
+ * that the SCI has triggered while suspended, so cancel the wakeup in
+ * case it has not been a wakeup event (the GPEs will be checked later).
+ */
+ if (acpi_sci_irq_valid() &&
+ !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) {
+ pm_system_cancel_wakeup();
+ s2idle_wakeup = true;
+ }
+}
+
+static void acpi_freeze_sync(void)
+{
+ /*
+ * Process all pending events in case there are any wakeup ones.
+ *
+ * The EC driver uses the system workqueue, so that one needs to be
+ * flushed too.
+ */
+ acpi_os_wait_events_complete();
+ flush_scheduled_work();
+ s2idle_wakeup = false;
+}
+
static void acpi_freeze_restore(void)
{
- acpi_disable_wakeup_devices(ACPI_STATE_S0);
if (acpi_sci_irq_valid())
disable_irq_wake(acpi_sci_irq);
- acpi_enable_all_runtime_gpes();
+
+ if (lps0_device_handle) {
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
+ acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
+ } else {
+ acpi_enable_all_runtime_gpes();
+ }
}
static void acpi_freeze_end(void)
{
+ s2idle_in_progress = false;
acpi_scan_lock_release();
}
static const struct platform_freeze_ops acpi_freeze_ops = {
.begin = acpi_freeze_begin,
.prepare = acpi_freeze_prepare,
+ .wake = acpi_freeze_wake,
+ .sync = acpi_freeze_sync,
.restore = acpi_freeze_restore,
.end = acpi_freeze_end,
};
@@ -696,13 +823,28 @@ static void acpi_sleep_suspend_setup(void)
suspend_set_ops(old_suspend_ordering ?
&acpi_suspend_ops_old : &acpi_suspend_ops);
+
+ acpi_scan_add_handler(&lps0_handler);
freeze_set_ops(&acpi_freeze_ops);
}
#else /* !CONFIG_SUSPEND */
+#define s2idle_in_progress (false)
+#define s2idle_wakeup (false)
+#define lps0_device_handle (NULL)
static inline void acpi_sleep_suspend_setup(void) {}
#endif /* !CONFIG_SUSPEND */
+bool acpi_s2idle_wakeup(void)
+{
+ return s2idle_wakeup;
+}
+
+bool acpi_sleep_no_ec_events(void)
+{
+ return !s2idle_in_progress || !lps0_device_handle;
+}
+
#ifdef CONFIG_PM_SLEEP
static u32 saved_bm_rld;