Huawei Matebook laptops come with a WMI management interface that can
control various aspects of the device. This interface is also found on
the old Matebook X released in 2017.
Implement basic functionality of this interface along with supported
command IDs that are implemented in this series.
Signed-off-by: Ayman Bagabas <ayman.bagabas@xxxxxxxxx>
---
drivers/platform/x86/huawei-wmi.c | 130 ++++++++++++++++++++++++++++++
1 file changed, 130 insertions(+)
diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
index 12cae450fc1f..27520b0f8956 100644
--- a/drivers/platform/x86/huawei-wmi.c
+++ b/drivers/platform/x86/huawei-wmi.c
@@ -10,24 +10,36 @@
#include <linux/input/sparse-keymap.h>
#include <linux/leds.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/wmi.h>
/*
* Huawei WMI GUIDs
*/
+#define HWMI_METHOD_GUID "ABBC0F5B-8EA1-11D1-A000-C90629100000"
#define HWMI_EVENT_GUID "ABBC0F5C-8EA1-11D1-A000-C90629100000"
/* Legacy GUIDs */
#define WMI0_EXPENSIVE_GUID "39142400-C6A3-40fa-BADB-8A2652834100"
#define WMI0_EVENT_GUID "59142400-C6A3-40fa-BADB-8A2652834100"
+/* HWMI commands */
+
+enum {
+ BATTERY_THRESH_GET = 0x00001103, /* \GBTT */
+ BATTERY_THRESH_SET = 0x00001003, /* \SBTT */
+ FN_LOCK_GET = 0x00000604, /* \GFRS */
+ FN_LOCK_SET = 0x00000704, /* \SFRS */
+ MICMUTE_LED_SET = 0x00000b04, /* \SMLS */
+};
struct huawei_wmi_priv {
struct input_dev *idev[2];
struct led_classdev cdev;
acpi_handle handle;
char *acpi_method;
+ struct mutex wmi_lock;
struct platform_device *pdev;
};
@@ -50,6 +62,116 @@ static const struct key_entry huawei_wmi_keymap[] = {
{ KE_END, 0 }
};
+/* Utils */
+
+static int huawei_wmi_call(struct device *dev, struct acpi_buffer *in,
+ struct acpi_buffer *out)
+{
+ struct huawei_wmi_priv *priv = dev_get_drvdata(dev);
+ acpi_status status;
+
+ mutex_lock(&priv->wmi_lock);
+ status = wmi_evaluate_method(HWMI_METHOD_GUID, 0, 1, in, out);
+ mutex_unlock(&priv->wmi_lock);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "Failed to evaluate wmi method\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/* HWMI takes a 64 bit input and returns either a package with 2 buffers, one of
+ * 4 bytes and the other of 256 bytes, or one buffer of size 0x104 (260) bytes.
+ * The first 4 bytes are ignored, we ignore the first 4 bytes buffer if we got a
+ * package, or skip the first 4 if a buffer of 0x104 is used. The first byte of
+ * the remaining 0x100 sized buffer has the return status of every call. In case
+ * the return status is non-zero, we return -ENODEV but still copy the returned
+ * buffer to the given buffer parameter (buf).
+ */
+static int huawei_wmi_cmd(struct device *dev, u64 arg, u8 *buf, size_t buflen)
+{
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer in;
+ union acpi_object *obj;
+ size_t len;
+ int err, i;
+
+ in.length = sizeof(arg);
+ in.pointer = &arg;
+
+ /* Some models require calling HWMI twice to execute a command. We evaluate
+ * HWMI and if we get a non-zero return status we evaluate it again.
+ */
+ for (i = 0; i < 2; i++) {
+ err = huawei_wmi_call(dev, &in, &out);
+ if (err)
+ goto fail_cmd;
+
+ obj = out.pointer;
+ if (!obj) {
+ err = -EIO;
+ goto fail_cmd;
+ }
+
+ switch (obj->type) {
+ /* Models that implement both "legacy" and HWMI tend to return a 0x104
+ * sized buffer instead of a package of 0x4 and 0x100 buffers.
+ */
+ case ACPI_TYPE_BUFFER:
+ if (obj->buffer.length == 0x104) {
+ // Skip the first 4 bytes.
+ obj->buffer.pointer += 4;
+ len = 0x100;
+ } else {
+ dev_err(dev, "Bad buffer length, got %d\n", obj->buffer.length);
+ err = -EIO;
+ goto fail_cmd;
+ }
+
+ break;
+ /* HWMI returns a package with 2 buffer elements, one of 4 bytes and the
+ * other is 256 bytes.
+ */
+ case ACPI_TYPE_PACKAGE:
+ if (obj->package.count != 2) {
+ dev_err(dev, "Bad package count, got %d\n", obj->package.count);
+ err = -EIO;
+ goto fail_cmd;
+ }
+
+ obj = &obj->package.elements[1];
+ if (obj->type != ACPI_TYPE_BUFFER) {
+ dev_err(dev, "Bad package element type, got %d\n", obj->type);
+ err = -EIO;
+ goto fail_cmd;
+ }
+ len = obj->buffer.length;
+
+ break;
+ /* Shouldn't get here! */
+ default:
+ dev_err(dev, "Unexpected obj type, got: %d\n", obj->type);
+ err = -EIO;
+ goto fail_cmd;
+ }
+
+ if (!*obj->buffer.pointer)
+ break;
+ }
+
+ err = (*obj->buffer.pointer) ? -ENODEV : 0;
+
+ if (buf) {
+ len = min(buflen, len);
+ memcpy(buf, obj->buffer.pointer, len);
+ }
+
+fail_cmd:
+ kfree(out.pointer);
+ return err;
+}
+
/* LEDs */
static int huawei_wmi_micmute_led_set(struct led_classdev *led_cdev,
@@ -222,6 +344,10 @@ static int huawei_wmi_probe(struct platform_device *pdev)
}
}
+ if (wmi_has_guid(HWMI_METHOD_GUID)) {
+ mutex_init(&priv->wmi_lock);
+ }
+
return huawei_wmi_leds_setup(&pdev->dev);
}
@@ -233,6 +359,9 @@ static int huawei_wmi_remove(struct platform_device *pdev)
if (wmi_has_guid(HWMI_EVENT_GUID))
wmi_remove_notify_handler(HWMI_EVENT_GUID);
+ if (wmi_has_guid(HWMI_METHOD_GUID)) {
+ }
+
return 0;
}
@@ -272,6 +401,7 @@ module_exit(huawei_wmi_exit);
MODULE_ALIAS("wmi:"WMI0_EVENT_GUID);
MODULE_ALIAS("wmi:"HWMI_EVENT_GUID);
+MODULE_ALIAS("wmi:"HWMI_METHOD_GUID);
MODULE_AUTHOR("Ayman Bagabas <ayman.bagabas@xxxxxxxxx>");
MODULE_DESCRIPTION("Huawei WMI laptop extras driver");
MODULE_LICENSE("GPL v2");
--
2.20.1
