This patch adds support for platform initited graceful shutdown as
described in sections 5.6.6(Table-143) and 6.3.5.1 of ACPI 6.1 spec
The OSPM will get a graceful shutdown request via a Notify operator
on \_SB device with a value of 0x81 per section 5.6.6. Following the
shutdown request from platform the OSPM needs to follow the
processing sequence as described in section 6.2.5.1.
v3
* Switched to regular work with delays from delayed work
* Dropped changes to actypes.h
* Small style changes
v2
* Switched from standalone driver to a simple notify handler
v1
* Initial
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
---
drivers/acpi/bus.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 262ca31..51adbae 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -30,6 +30,9 @@
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/regulator/machine.h>
+#include <linux/workqueue.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
@@ -475,6 +478,56 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device)
acpi_device_notify);
}
+/* Handle events targeting \_SB device (at present only graceful shutdown) */
+
+#define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
+#define ACPI_SB_INDICATE_INTERVAL 10000
+
+static void sb_notify_work(struct work_struct *dummy)
+{
+ acpi_handle sb_handle;
+
+ orderly_poweroff(true);
+
+ /*
+ * After initiating graceful shutdown, the ACPI spec requires OSPM
+ * to evaluate _OST method once every 10seconds to indicate that
+ * the shutdown is in progress
+ */
+ acpi_get_handle(NULL, "\\_SB", &sb_handle);
+ while (1) {
+ pr_info("Graceful shutdown in progress.\n");
+ acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
+ ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
+ msleep(ACPI_SB_INDICATE_INTERVAL);
+ }
+}
+
+static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
+{
+ static DECLARE_WORK(acpi_sb_work, sb_notify_work);
+
+ if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
+ if (!work_busy(&acpi_sb_work))
+ schedule_work(&acpi_sb_work);
+ } else
+ pr_warn("event %x is not supported by \\_SB device\n", event);
+}
+
+static int __init acpi_setup_sb_notify_handler(void)
+{
+ acpi_handle sb_handle;
+
+ if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
+ return -ENXIO;
+
+ if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
+ acpi_sb_notify, NULL)))
+ return -EINVAL;
+
+ return 0;
+}
+
/* --------------------------------------------------------------------------
Device Matching
-------------------------------------------------------------------------- */
@@ -1124,6 +1177,7 @@ static int __init acpi_init(void)
acpi_sleep_proc_init();
acpi_wakeup_device_init();
acpi_debugger_init();
+ acpi_setup_sb_notify_handler();
return 0;
}
--
Qualcomm Technologies, Inc. on behalf
of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc.
is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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