Re: [PATCH v3] platform/x86: add lenovo generic wmi driver
From: Armin Wolf
Date: Fri Mar 01 2024 - 05:10:08 EST
Am 01.03.24 um 09:16 schrieb Ai Chao:
Add lenovo generic wmi driver to support camera button.
Signed-off-by: Ai Chao <aichao@xxxxxxxxxx>
---
v2: Adjust GPL v2 to GPL, adjust sprintf to sysfs_emit.
v3: Remove lenovo_wmi_remove function.
drivers/platform/x86/Kconfig | 10 +++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/lenovo-wmi.c | 113 ++++++++++++++++++++++++++++++
3 files changed, 124 insertions(+)
create mode 100644 drivers/platform/x86/lenovo-wmi.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index bdd302274b9a..fbbb8fb843d7 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1001,6 +1001,16 @@ config INSPUR_PLATFORM_PROFILE
To compile this driver as a module, choose M here: the module
will be called inspur-platform-profile.
+config LENOVO_WMI
+ tristate "Lenovo Geneirc WMI driver"
+ depends on ACPI_WMI
+ depends on INPUT
+ help
+ This driver provides support for Lenovo WMI driver.
+
+ To compile this driver as a module, choose M here: the module
+ will be called lenovo-wmi.
+
Hi,
does the WMI driver only handle the camera button? If yes, then please change the
driver name to something more specific like "lenovo-wmi-camera".
And please add a more descriptive help text.
source "drivers/platform/x86/x86-android-tablets/Kconfig"
config FW_ATTR_CLASS
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 1de432e8861e..d51086552192 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_SENSORS_HDAPS) += hdaps.o
obj-$(CONFIG_THINKPAD_ACPI) += thinkpad_acpi.o
obj-$(CONFIG_THINKPAD_LMI) += think-lmi.o
obj-$(CONFIG_YOGABOOK) += lenovo-yogabook.o
+obj-$(CONFIG_LENOVO_WMI) += lenovo-wmi.o
# Intel
obj-y += intel/
diff --git a/drivers/platform/x86/lenovo-wmi.c b/drivers/platform/x86/lenovo-wmi.c
new file mode 100644
index 000000000000..96c2ec9e6441
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lenovo Generic WMI Driver
+ *
See note above.
+ * Copyright (C) 2024 Ai Chao <aichao@xxxxxxxxxx>
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/wmi.h>
+
+#define WMI_LENOVO_CAMERABUTTON_EVENT_GUID "50C76F1F-D8E4-D895-0A3D-62F4EA400013"
+
+static u8 camera_mode;
Please avoid unnecessary global state, the WMI driver should be able to be instantiated
multiple times by the WMI driver core.
Instead move camera_mode into struct lenovo_wmi_priv.
+
+struct lenovo_wmi_priv {
+ struct input_dev *idev;
+};
+
+static ssize_t camerabutton_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%u\n", camera_mode);
+}
+
+DEVICE_ATTR_RO(camerabutton);
+
+static struct attribute *lenovo_wmi_attrs[] = {
+ &dev_attr_camerabutton.attr,
+ NULL,
+};
+
+static const struct attribute_group lenovo_wmi_group = {
+ .attrs = lenovo_wmi_attrs,
+};
+
+const struct attribute_group *lenovo_wmi_groups[] = {
+ &lenovo_wmi_group,
+ NULL,
+};
+
+static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
+{
+ struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+
+ if (obj->type == ACPI_TYPE_BUFFER) {
+ camera_mode = obj->buffer.pointer[0];
+ input_report_key(priv->idev, KEY_CAMERA, 1);
+ input_sync(priv->idev);
+ input_report_key(priv->idev, KEY_CAMERA, 0);
+ input_sync(priv->idev);
Two things:
- you should validate the size of the received ACPI buffer
- what data does camera_mode contain? Maybe it would make sense to
export camera_mode over the input subsystem _if_ it contains the current
state of the camera button (or something similar).
I think of a construct like this (assuming camera_mode contains the current state of the button):
input_report_key(priv->idev, KEY_CAMERA, camera_mode == CAMERA_BUTTON_PRESSED);
input_sync(priv->idev);
+ } else {
+ dev_dbg(&wdev->dev, "Bad response type %d\n", obj->type);
+ }
+}
+
+static int lenovo_wmi_input_setup(struct wmi_device *wdev)
+{
+ struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+
+ priv->idev = devm_input_allocate_device(&wdev->dev);
+ if (!priv->idev)
+ return -ENOMEM;
+
+ priv->idev->name = "Lenovo WMI Camera Button";
+ priv->idev->phys = "wmi/input0";
+ priv->idev->id.bustype = BUS_HOST;
+ priv->idev->dev.parent = &wdev->dev;
+ priv->idev->evbit[0] = BIT_MASK(EV_KEY);
+ priv->idev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);
+
I thing set_bit() could be used here, like the xiaomi-wmi driver does it.
+ return input_register_device(priv->idev);
+}
+
+static int lenovo_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+ struct lenovo_wmi_priv *priv;
+ int err;
+
+ priv = devm_kzalloc(&wdev->dev, sizeof(struct lenovo_wmi_priv),
+ GFP_KERNEL);
Please use sizeof(*priv) instead of sizeof(struct lenovo_wmi_priv).
+ if (!priv)
+ return -ENOMEM;
+
+ dev_set_drvdata(&wdev->dev, priv);
+
+ err = lenovo_wmi_input_setup(wdev);
+ return err;
I think lenovo_wmi_input_setup() is small enough to merge it with lenovo_wmi_probe().
+}
+
+static const struct wmi_device_id lenovo_wmi_id_table[] = {
+ { .guid_string = WMI_LENOVO_CAMERABUTTON_EVENT_GUID },
+ { }
+};
+
+static struct wmi_driver lenovo_wmi_driver = {
+ .driver = {
+ .name = "lenovo-wmi",
+ .dev_groups = lenovo_wmi_groups,
+ },
+ .id_table = lenovo_wmi_id_table,
+ .probe = lenovo_wmi_probe,
+ .notify = lenovo_wmi_notify,
+};
Please set probe_type = PROBE_PREFER_ASYNCHRONOUS like the inspur_platform_profile driver.
Also please set the no_singleton flag inside the WMI driver struct after you moved
camera_mode into struct lenovo_wmi_priv, as i wont accept new WMI drivers without
this flag.
Please note that the no_singleton flag was added very recently and you will need to rebase
your driver onto for-next.
Thanks,
Armin Wolf
+
+module_wmi_driver(lenovo_wmi_driver);
+
+MODULE_DEVICE_TABLE(wmi, lenovo_wmi_id_table);
+MODULE_AUTHOR("Ai Chao <aichao@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Lenovo Generic WMI Driver");
+MODULE_LICENSE("GPL");