[PATCH v2 8/9] platform/x86: asus-wmi: Add support for MCU powersave

From: Luke D. Jones
Date: Mon Apr 01 2024 - 22:28:48 EST


Add support for an MCU powersave WMI call. This is intended to set the
MCU in to a low-power mode when sleeping. This mode can cut sleep power
use by around half.

Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx>
---
.../ABI/testing/sysfs-platform-asus-wmi | 11 +++-
drivers/platform/x86/asus-wmi.c | 50 +++++++++++++++++++
2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-platform-asus-wmi b/Documentation/ABI/testing/sysfs-platform-asus-wmi
index 41b92e53e88a..28144371a0f1 100644
--- a/Documentation/ABI/testing/sysfs-platform-asus-wmi
+++ b/Documentation/ABI/testing/sysfs-platform-asus-wmi
@@ -202,4 +202,13 @@ Contact: "Luke Jones" <luke@xxxxxxxxxx>
Description:
Set if the BIOS POST sound is played on boot.
* 0 - False,
- * 1 - True
\ No newline at end of file
+ * 1 - True
+
+What: /sys/devices/platform/<platform>/mcu_powersave
+Date: Apr 2024
+KernelVersion: 6.10
+Contact: "Luke Jones" <luke@xxxxxxxxxx>
+Description:
+ Set if the MCU can go in to low-power mode on system sleep
+ * 0 - False,
+ * 1 - True
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index ddf568ef8c5e..cf872eed0986 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1292,6 +1292,53 @@ static ssize_t nv_temp_target_show(struct device *dev,
}
static DEVICE_ATTR_RW(nv_temp_target);

+/* Ally MCU Powersave ********************************************************/
+static ssize_t mcu_powersave_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+ int result;
+
+ result = asus_wmi_get_devstate_simple(asus, ASUS_WMI_DEVID_MCU_POWERSAVE);
+ if (result < 0)
+ return result;
+
+ return sysfs_emit(buf, "%d\n", result);
+}
+
+static ssize_t mcu_powersave_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int result, err;
+ u32 enable;
+
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ result = kstrtou32(buf, 10, &enable);
+ if (result)
+ return result;
+
+ if (enable > 1)
+ return -EINVAL;
+
+ err = asus_wmi_set_devstate(ASUS_WMI_DEVID_MCU_POWERSAVE, enable, &result);
+ if (err) {
+ pr_warn("Failed to set MCU powersave: %d\n", err);
+ return err;
+ }
+
+ if (result > 1) {
+ pr_warn("Failed to set MCU powersave (result): 0x%x\n", result);
+ return -EIO;
+ }
+
+ sysfs_notify(&asus->platform_device->dev.kobj, NULL, "mcu_powersave");
+
+ return count;
+}
+static DEVICE_ATTR_RW(mcu_powersave);
+
/* Battery ********************************************************************/

/* The battery maximum charging percentage */
@@ -4299,6 +4346,7 @@ static struct attribute *platform_attributes[] = {
&dev_attr_ppt_platform_sppt.attr,
&dev_attr_nv_dynamic_boost.attr,
&dev_attr_nv_temp_target.attr,
+ &dev_attr_mcu_powersave.attr,
&dev_attr_boot_sound.attr,
&dev_attr_panel_od.attr,
&dev_attr_mini_led_mode.attr,
@@ -4352,6 +4400,8 @@ static umode_t asus_sysfs_is_visible(struct kobject *kobj,
devid = ASUS_WMI_DEVID_NV_DYN_BOOST;
else if (attr == &dev_attr_nv_temp_target.attr)
devid = ASUS_WMI_DEVID_NV_THERM_TARGET;
+ else if (attr == &dev_attr_mcu_powersave.attr)
+ devid = ASUS_WMI_DEVID_MCU_POWERSAVE;
else if (attr == &dev_attr_boot_sound.attr)
devid = ASUS_WMI_DEVID_BOOT_SOUND;
else if (attr == &dev_attr_panel_od.attr)
--
2.44.0