platform/x86: ideapad-laptop: add "always on USB charging" control support

Certain models have a so-called "always on USB charging" feature,
which enables USB charging even when the computer is turned off
or suspended, and which may be controlled/queried using the
SALS/HALS ACPI methods. Expose this functionality via a new device
attribute (usb_charging). Tested on: Lenovo YOGA 520-14IKB 80X8

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210203215403.290792-28-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/Documentation/ABI/testing/sysfs-platform-ideapad-laptop b/Documentation/ABI/testing/sysfs-platform-ideapad-laptop
index fd2ac02..b17688d 100644 (file)
--- a/Documentation/ABI/testing/sysfs-platform-ideapad-laptop
+++ b/Documentation/ABI/testing/sysfs-platform-ideapad-laptop
@@ -41,3 +41,12 @@ Description:
 
                  # echo "0" >  \
                  /sys/bus/pci/devices/0000:00:1f.0/PNP0C09:00/VPC2004:00/fn_lock
+
+What:          /sys/bus/platform/devices/VPC2004:*/usb_charging
+Date:          Feb 2021
+KernelVersion: 5.12
+Contact:       platform-driver-x86@vger.kernel.org
+Description:
+               Controls whether the "always on USB charging" feature is
+               enabled or not. This feature enables charging USB devices
+               even if the computer is not turned on.

diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index 24dcb4a..6cb5ad4 100644 (file)
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -62,18 +62,22 @@ enum {
 };
 
 enum {
-       HALS_KBD_BL_SUPPORT_BIT  = 4,
-       HALS_KBD_BL_STATE_BIT    = 5,
-       HALS_FNLOCK_SUPPORT_BIT  = 9,
-       HALS_FNLOCK_STATE_BIT    = 10,
-       HALS_HOTKEYS_PRIMARY_BIT = 11,
+       HALS_KBD_BL_SUPPORT_BIT       = 4,
+       HALS_KBD_BL_STATE_BIT         = 5,
+       HALS_USB_CHARGING_SUPPORT_BIT = 6,
+       HALS_USB_CHARGING_STATE_BIT   = 7,
+       HALS_FNLOCK_SUPPORT_BIT       = 9,
+       HALS_FNLOCK_STATE_BIT         = 10,
+       HALS_HOTKEYS_PRIMARY_BIT      = 11,
 };
 
 enum {
-       SALS_KBD_BL_ON  = 0x8,
-       SALS_KBD_BL_OFF = 0x9,
-       SALS_FNLOCK_ON  = 0xe,
-       SALS_FNLOCK_OFF = 0xf,
+       SALS_KBD_BL_ON        = 0x8,
+       SALS_KBD_BL_OFF       = 0x9,
+       SALS_USB_CHARGING_ON  = 0xa,
+       SALS_USB_CHARGING_OFF = 0xb,
+       SALS_FNLOCK_ON        = 0xe,
+       SALS_FNLOCK_OFF       = 0xf,
 };
 
 enum {
@@ -134,6 +138,7 @@ struct ideapad_private {
                bool hw_rfkill_switch     : 1;
                bool kbd_bl               : 1;
                bool touchpad_ctrl_via_ec : 1;
+               bool usb_charging         : 1;
        } features;
        struct {
                bool initialized;
@@ -592,12 +597,49 @@ static ssize_t touchpad_store(struct device *dev,
 
 static DEVICE_ATTR_RW(touchpad);
 
+static ssize_t usb_charging_show(struct device *dev,
+                                struct device_attribute *attr,
+                                char *buf)
+{
+       struct ideapad_private *priv = dev_get_drvdata(dev);
+       unsigned long hals;
+       int err;
+
+       err = eval_hals(priv->adev->handle, &hals);
+       if (err)
+               return err;
+
+       return sysfs_emit(buf, "%d\n", !!test_bit(HALS_USB_CHARGING_STATE_BIT, &hals));
+}
+
+static ssize_t usb_charging_store(struct device *dev,
+                                 struct device_attribute *attr,
+                                 const char *buf, size_t count)
+{
+       struct ideapad_private *priv = dev_get_drvdata(dev);
+       bool state;
+       int err;
+
+       err = kstrtobool(buf, &state);
+       if (err)
+               return err;
+
+       err = exec_sals(priv->adev->handle, state ? SALS_USB_CHARGING_ON : SALS_USB_CHARGING_OFF);
+       if (err)
+               return err;
+
+       return count;
+}
+
+static DEVICE_ATTR_RW(usb_charging);
+
 static struct attribute *ideapad_attributes[] = {
        &dev_attr_camera_power.attr,
        &dev_attr_conservation_mode.attr,
        &dev_attr_fan_mode.attr,
        &dev_attr_fn_lock.attr,
        &dev_attr_touchpad.attr,
+       &dev_attr_usb_charging.attr,
        NULL
 };
 
@@ -620,6 +662,8 @@ static umode_t ideapad_is_visible(struct kobject *kobj,
        else if (attr == &dev_attr_touchpad.attr)
                supported = priv->features.touchpad_ctrl_via_ec &&
                            test_bit(CFG_CAP_TOUCHPAD_BIT, &priv->cfg);
+       else if (attr == &dev_attr_usb_charging.attr)
+               supported = priv->features.usb_charging;
 
        return supported ? attr->mode : 0;
 }
@@ -1459,6 +1503,9 @@ static void ideapad_check_features(struct ideapad_private *priv)
 
                        if (test_bit(HALS_KBD_BL_SUPPORT_BIT, &val))
                                priv->features.kbd_bl = true;
+
+                       if (test_bit(HALS_USB_CHARGING_SUPPORT_BIT, &val))
+                               priv->features.usb_charging = true;
                }
        }
 }