The LID state provided by ACPI on the Surface 3 is not accurate.
The ACPI node doesn't get notified on LID open, which means the
LID input switch stays close most of the time.
Fortunatelly, there is a WMI method which directly queries the
GPIO underneath the LID state, so it's far more reliable than ACPI.
To get the notifications that the LID was opened/closed, we can
rely on the ACPI notification of the touchscreen: the DSDT shows
that the touchscreen will get notified on close/open as it also
controls its _STA method.
Note that we need to set the tag "power-switch" to the LID
input node through a udev rule for logind to accept it:
SUBSYSTEM=="input", KERNEL=="event*", KERNELS=="surface3-wmi", \
TAG+="power-switch"
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/platform/x86/Kconfig | 12 ++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/surface3-wmi.c | 296 ++++++++++++++++++++++++++++++++++++
3 files changed, 309 insertions(+)
create mode 100644 drivers/platform/x86/surface3-wmi.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index b8a21d7..152aac6 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -363,6 +363,18 @@ config IDEAPAD_LAPTOP
This is a driver for Lenovo IdeaPad netbooks contains drivers for
rfkill switch, hotkey, fan control and backlight control.
+config SURFACE3_WMI
+ tristate "Surface 3 WMI Driver"
+ depends on ACPI_WMI
+ depends on DMI
+ depends on INPUT
+ depends on SPI
+ ---help---
+ Say Y here if you have a Surface 3.
+
+ To compile this driver as a module, choose M here: the module will
+ be called surface3-wmi.
+
config THINKPAD_ACPI
tristate "ThinkPad ACPI Laptop Extras"
depends on ACPI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 2efa86d..38f5419 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_PANASONIC_LAPTOP) += panasonic-laptop.o
obj-$(CONFIG_INTEL_MENLOW) += intel_menlow.o
obj-$(CONFIG_ACPI_WMI) += wmi.o
obj-$(CONFIG_MSI_WMI) += msi-wmi.o
+obj-$(CONFIG_SURFACE3_WMI) += surface3-wmi.o
obj-$(CONFIG_TOPSTAR_LAPTOP) += topstar-laptop.o
# toshiba_acpi must link after wmi to ensure that wmi devices are found
diff --git a/drivers/platform/x86/surface3-wmi.c b/drivers/platform/x86/surface3-wmi.c
new file mode 100644
index 0000000..5553b2b
--- /dev/null
+++ b/drivers/platform/x86/surface3-wmi.c
@@ -0,0 +1,296 @@
+/*
+ * Driver for the LID cover switch of the Surface 3
+ *
+ * Copyright (c) 2016 Red Hat Inc.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/input.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Surface 3 platform driver");
+MODULE_LICENSE("GPL");
+
+#define ACPI_BUTTON_HID_LID "PNP0C0D"
+#define SPI_CTL_OBJ_NAME "SPI"
+#define SPI_TS_OBJ_NAME "NTRG"
+
+#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
+
+MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
+
+static const struct dmi_system_id surface3_dmi_table[] = {
+#if defined(CONFIG_X86)
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
+ },
+ },
+#endif
+ { }
+};
+
+struct surface3_wmi {
+ struct acpi_device *touchscreen_adev;
+ struct acpi_device *pnp0c0d_adev;
+ struct acpi_hotplug_context hp;
+ struct input_dev *input;
+};
+
+static struct platform_device *s3_wmi_pdev;
+
+static struct surface3_wmi s3_wmi;
+
+static DEFINE_MUTEX(s3_wmi_lock);
+
+static int s3_wmi_query_block(const char *guid, int instance, int *ret)
+{
+ acpi_status status;
+ union acpi_object *obj;
+
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+
+ mutex_lock(&s3_wmi_lock);
+ status = wmi_query_block(guid, instance, &output);
+
+ obj = output.pointer;
+
+ if (!obj || obj->type != ACPI_TYPE_INTEGER) {
+ if (obj) {
+ pr_err("query block returned object type: %d - buffer length:%d\n",
+ obj->type,
+ obj->type == ACPI_TYPE_BUFFER ?
+ obj->buffer.length : 0);
+ }
+ kfree(obj);
+ return -EINVAL;
+ }
+ *ret = obj->integer.value;
+ kfree(obj);
+ mutex_unlock(&s3_wmi_lock);
+ return 0;
+}
+
+static inline int s3_wmi_query_lid(int *ret)
+{
+ return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
+}
+
+static int s3_wmi_send_lid_state(void)
+{
+ int ret, lid_sw;
+
+ ret = s3_wmi_query_lid(&lid_sw);
+ if (ret)
+ return ret;
+
+ input_report_switch(s3_wmi.input, SW_LID, lid_sw);
+ input_sync(s3_wmi.input);
+
+ return 0;
+}
+
+static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
+{
+ return s3_wmi_send_lid_state();
+}
+
+static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
+ u32 level,
+ void *data,
+ void **return_value)
+{
+ struct acpi_device *adev, **ts_adev;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return AE_OK;
+
+ ts_adev = data;
+
+ if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
+ strlen(SPI_TS_OBJ_NAME)))
+ return AE_OK;
+
+ if (*ts_adev) {
+ pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
+ return AE_OK;
+ }
+
+ *ts_adev = adev;
+
+ return AE_OK;
+}
+
+static int s3_wmi_check_platform_device(struct device *dev, void *data)
+{
+ struct acpi_device *adev, *ts_adev;
+ acpi_handle handle;
+ acpi_status status;
+
+ /* ignore non ACPI devices */
+ handle = ACPI_HANDLE(dev);
+ if (!handle || acpi_bus_get_device(handle, &adev))
+ return 0;
+
+ /* check for LID ACPI switch */
+ if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
+ s3_wmi.pnp0c0d_adev = adev;
+ return 0;
+ }
+
+ /* ignore non SPI controllers */
+ if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
+ strlen(SPI_CTL_OBJ_NAME)))
+ return 0;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ s3_wmi_attach_spi_device, NULL,
+ &ts_adev, NULL);
+ if (ACPI_FAILURE(status))
+ dev_warn(dev, "failed to enumerate SPI slaves\n");
+
+ if (!ts_adev)
+ return 0;
+
+ s3_wmi.touchscreen_adev = ts_adev;
+
+ return 0;
+}
+
+static int s3_wmi_create_and_register_input(struct platform_device *pdev)
+{
+ struct input_dev *input;
+ int error;
+
+ input = devm_input_allocate_device(&pdev->dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = "Lid Switch";
+ input->phys = "button/input0";
+ input->id.bustype = BUS_HOST;
+ input->id.product = 0x0005;
+
+ input_set_capability(input, EV_SW, SW_LID);
+
+ error = input_register_device(input);
+ if (error)
+ goto out_err;
+
+ s3_wmi.input = input;
+
+ return 0;
+ out_err:
+ input_free_device(s3_wmi.input);
+ return error;
+}
+
+static int __init s3_wmi_probe(struct platform_device *pdev)
+{
+ int error;
+
+ if (!dmi_check_system(surface3_dmi_table))
+ return -ENODEV;
+
+ memset(&s3_wmi, 0, sizeof(s3_wmi));
+
+ bus_for_each_dev(&platform_bus_type, NULL, NULL,
+ s3_wmi_check_platform_device);
+
+ if (!s3_wmi.touchscreen_adev)
+ return -ENODEV;
+
+ acpi_bus_trim(s3_wmi.pnp0c0d_adev);
+
+ error = s3_wmi_create_and_register_input(pdev);
+ if (error)
+ goto restore_acpi_lid;
+
+ acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
+ s3_wmi_hp_notify, NULL);
+
+ s3_wmi_send_lid_state();
+
+ return 0;
+
+ restore_acpi_lid:
+ acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
+ return error;
+}
+
+static int s3_wmi_remove(struct platform_device *device)
+{
+ /* remove the hotplug context from the acpi device */
+ s3_wmi.touchscreen_adev->hp = NULL;
+
+ /* reinstall the actual PNPC0C0D LID default handle */
+ acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int s3_wmi_resume(struct device *dev)
+{
+ s3_wmi_send_lid_state();
+ return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
+
+static struct platform_driver s3_wmi_driver = {
+ .driver = {
+ .name = "surface3-wmi",
+ .pm = &s3_wmi_pm,
+ },
+ .remove = s3_wmi_remove,
+};
+
+static int __init s3_wmi_init(void)
+{
+ int error;
+
+ s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
+ if (!s3_wmi_pdev)
+ return -ENOMEM;
+
+ error = platform_device_add(s3_wmi_pdev);
+ if (error)
+ goto err_device_put;
+
+ error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
+ if (error)
+ goto err_device_del;
+
+ pr_info("Surface 3 WMI Extras loaded\n");
+ return 0;
+
+ err_device_del:
+ platform_device_del(s3_wmi_pdev);
+ err_device_put:
+ platform_device_put(s3_wmi_pdev);
+ return error;
+}
+
+static void __exit s3_wmi_exit(void)
+{
+ platform_device_unregister(s3_wmi_pdev);
+ platform_driver_unregister(&s3_wmi_driver);
+}
+
+module_init(s3_wmi_init);
+module_exit(s3_wmi_exit);
--
2.7.4
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