From: Elia Devito <eliadev...@gmail.com>
Some convertible use the intel-hid ACPI interface to report SW_TABLET_MODE,
implement this with DMI based allow-list to be sure to activate support
only on models that effectively have it.
Signed-off-by: Elia Devito <eliadev...@gmail.com>
---
v2:
patch reworked according to received feedbacks
v3:
improved code according to received feedbacks
drivers/platform/x86/intel-hid.c | 95 ++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-hid.c
index 86261970bd8f..d2f892665ec6 100644
--- a/drivers/platform/x86/intel-hid.c
+++ b/drivers/platform/x86/intel-hid.c
@@ -15,6 +15,9 @@
#include <linux/platform_device.h>
#include <linux/suspend.h>
+/* When NOT in tablet mode, VGBS returns with the flag 0x40 */
+#define TABLET_MODE_FLAG BIT(6)
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alex Hung");
@@ -89,9 +92,26 @@ static const struct dmi_system_id button_array_table[] = {
{ }
};
+/*
+ * Some convertible use the intel-hid ACPI interface to report SW_TABLET_MODE,
+ * these need to be compared via a DMI based authorization list because some
+ * models have unreliable VGBS return which could cause incorrect
+ * SW_TABLET_MODE report.
+ */
+static const struct dmi_system_id dmi_vgbs_allow_list[] = {
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "HP Spectre x360
Convertible 15-df0xxx"),
+ },
+ },
+ { }
+};
+
struct intel_hid_priv {
struct input_dev *input_dev;
struct input_dev *array;
+ struct input_dev *switches;
bool wakeup_mode;
};
@@ -347,6 +367,57 @@ static int intel_button_array_input_setup(struct
platform_device *device)
return input_register_device(priv->array);
}
+static int intel_hid_switches_setup(struct platform_device *device)
+{
+ struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
+
+ /* Setup input device for switches */
+ priv->switches = devm_input_allocate_device(&device->dev);
+ if (!priv->switches)
+ return -ENOMEM;
+
+ __set_bit(EV_SW, priv->switches->evbit);
+ __set_bit(SW_TABLET_MODE, priv->switches->swbit);
+
+ priv->switches->name = "Intel HID switches";
+ priv->switches->id.bustype = BUS_HOST;
+ return input_register_device(priv->switches);
+}
+
+static void report_tablet_mode_state(struct platform_device *device)
+{
+ struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
+ acpi_handle handle = ACPI_HANDLE(&device->dev);
+ unsigned long long vgbs;
+ int m;
+
+ if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_VGBS_FN, &vgbs))
+ return;
+
+ m = !(vgbs & TABLET_MODE_FLAG);
+ input_report_switch(priv->switches, SW_TABLET_MODE, m);
+ input_sync(priv->switches);
+}
+
+static bool report_tablet_mode_event(struct input_dev *input_dev, u32 event)
+{
+ if (!input_dev)
+ return false;
+
+ switch (event) {
+ case 0xcc:
+ input_report_switch(input_dev, SW_TABLET_MODE, 1);
+ input_sync(input_dev);
+ return true;
+ case 0xcd:
+ input_report_switch(input_dev, SW_TABLET_MODE, 0);
+ input_sync(input_dev);
+ return true;
+ default:
+ return false;
+ }
+}
+
static void notify_handler(acpi_handle handle, u32 event, void *context)
{
struct platform_device *device = context;
@@ -363,6 +434,13 @@ static void notify_handler(acpi_handle handle, u32 event,
void *context)
if (event == 0xce)
goto wakeup;
+ /*
+ * Switch events will wake the device and report the new switch
+ * position to the input subsystem.
+ */
+ if (priv->switches && (event == 0xcc || event == 0xcd))
+ goto wakeup;
+
/* Wake up on 5-button array events only. */
if (event == 0xc0 || !priv->array)
return;
@@ -374,6 +452,10 @@ static void notify_handler(acpi_handle handle, u32 event,
void *context)
wakeup:
pm_wakeup_hard_event(&device->dev);
+
+ if (report_tablet_mode_event(priv->switches, event))
+ return;
+
return;
}
@@ -398,6 +480,9 @@ static void notify_handler(acpi_handle handle, u32 event,
void *context)
}
}
+ if (report_tablet_mode_event(priv->switches, event))
+ return;
+
/* 0xC0 is for HID events, other values are for 5 button array */
if (event != 0xc0) {
if (!priv->array ||
@@ -485,6 +570,16 @@ static int intel_hid_probe(struct platform_device *device)
pr_err("Failed to setup Intel 5 button array
hotkeys\n");
}
+ /* Setup switches for devices that we know VGBS return correctly */
+ if (dmi_check_system(dmi_vgbs_allow_list)) {
+ dev_info(&device->dev, "platform supports switches\n");
+ err = intel_hid_switches_setup(device);
+ if (err)
+ pr_err("Failed to setup Intel HID switches\n");
+ else
+ report_tablet_mode_state(device);
+ }
+
status = acpi_install_notify_handler(handle,
ACPI_DEVICE_NOTIFY,
notify_handler,
--
2.28.0
