This patch adds a bus driver to handle the graceful shutdown
requests as described in the section 6.3.5.1, section 5.6.6
and table 5-143 of ACPI spec 6.1
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 described in section 6.2.5.1 -
"Processing Sequence for Graceful Shutdown Request"
Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx>
---
drivers/acpi/Kconfig | 6 +++
drivers/acpi/Makefile | 1 +
drivers/acpi/sybus.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 123 insertions(+)
create mode 100644 drivers/acpi/sybus.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 82b96ee..78cf770 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -209,6 +209,12 @@ config ACPI_DOCK
This driver supports ACPI-controlled docking stations and removable
drive bays such as the IBM Ultrabay and the Dell Module Bay.
+config ACPI_SYBUS
+ bool "System Bus"
+ help
+ This driver handles the events on system bus which includes
+ support for a graceful shutdown request from the platform.
+
config ACPI_CPU_FREQ_PSS
bool
select THERMAL
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index cb648a4..fe56427 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
obj-$(CONFIG_ACPI_BGRT) += bgrt.o
obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o
obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
+obj-$(CONFIG_ACPI_SYBUS) += sybus.o
# processor has its own "processor." module_param namespace
processor-y := processor_driver.o
diff --git a/drivers/acpi/sybus.c b/drivers/acpi/sybus.c
new file mode 100644
index 0000000..f9fa821
--- /dev/null
+++ b/drivers/acpi/sybus.c
@@ -0,0 +1,116 @@
+/*
+ * ACPI System Bus Device (\_SB, LNXSYBUS) Driver
+ * ACPI System Bus Device Driver is used to handle events reported to
+ * the device.
+ *
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/workqueue.h>
+#include <linux/reboot.h>
+
+#include <acpi/acpi_drivers.h>
+
+#define _COMPONENT ACPI_BUS_COMPONENT
+#define SYBUS_PFX "ACPI SYBUS: "
+
+/*
+ * According to section 6.3.5 of ACPI 6.0 spec, the kernel
+ * should evaluate _OST (an ACPI control method) every 10 seconds
+ * to indicate "OS shutdown in progress" to the platform.
+ */
+#define SYBUS_INDICATE_INTERVAL 10000
+
+#define SYBUS_NOTIFY_RESERVED (0x80)
+#define SYBUS_NOTIFY_SHUTDOWN_REQUEST (0x81)
+
+ACPI_MODULE_NAME("sybus");
+
+static void sybus_evaluate_ost(struct work_struct *);
+
+static struct acpi_device_id acpi_sybus_ids[] = {
+ {ACPI_BUS_HID, 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, acpi_sybus_ids);
+
+static acpi_handle sybus_handle;
+static DECLARE_DELAYED_WORK(acpi_sybus_work, sybus_evaluate_ost);
+
+static void sybus_evaluate_ost(struct work_struct *dummy)
+{
+ pr_info(SYBUS_PFX "OS shutdown in progress.\n");
+ acpi_evaluate_ost(sybus_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
+ ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
+ schedule_delayed_work(&acpi_sybus_work,
+ msecs_to_jiffies(SYBUS_INDICATE_INTERVAL));
+}
+
+static void acpi_sybus_notify(struct acpi_device *device, u32 event)
+{
+ /*
+ * The only event that ACPI System Bus Device should handle is
+ * SYBUS_NOTIFY_SHUTDOWN_REQUEST.
+ */
+ if (event != SYBUS_NOTIFY_SHUTDOWN_REQUEST) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "event %x is not supported by ACPI system bus device.\n",
+ event));
+ return;
+ }
+
+ pr_warn(SYBUS_PFX "Shutdown request notification received.\n");
+
+ if (!delayed_work_pending(&acpi_sybus_work)) {
+ sybus_evaluate_ost(NULL);
+ schedule_delayed_work(&acpi_sybus_work,
+ msecs_to_jiffies(SYBUS_INDICATE_INTERVAL));
+
+ orderly_poweroff(true);
+ } else
+ pr_info(SYBUS_PFX "Shutdown in already progress!\n");
+}
+
+static int acpi_sybus_add(struct acpi_device *device)
+{
+ /* Only one ACPI system bus device */
+ if (sybus_handle)
+ return -EINVAL;
+ sybus_handle = device->handle;
+ return 0;
+}
+
+static int acpi_sybus_remove(struct acpi_device *device)
+{
+ cancel_delayed_work_sync(&acpi_sybus_work);
+ sybus_handle = NULL;
+ return 0;
+}
+
+static struct acpi_driver acpi_sybus_driver = {
+ .name = "system_bus_device",
+ .class = "system_bus",
+ .ids = acpi_sybus_ids,
+ .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
+ .ops = {
+ .notify = acpi_sybus_notify,
+ .add = acpi_sybus_add,
+ .remove = acpi_sybus_remove,
+ },
+};
+module_acpi_driver(acpi_sybus_driver);
+
+MODULE_DESCRIPTION("ACPI System Bus Device Driver");
+MODULE_LICENSE("GPL");
--
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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