platform/x86: hp-wmi: Add HP WMI camera switch

Previously, when the camera toggle switch was hit, the hp-wmi driver
would report an invalid event code. By adding a case for that in the
event handling switch statement we can eliminate that error code and
enable a framework for potential further kernel handling of that key.
This change was tested on my HP Envy x360 15-ey0023dx laptop, but it
would likely work for any HP laptop with a camera toggle button. Now
we emit an SW_CAMERA_LENS_COVER event, on a device that gets created
on the first such event so as to not report incorrectly the state of
the camera shutter before we can know its state.

Signed-off-by: Jonathan Singer <jes965@nyu.edu>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20230426184852.2100-1-jes965@nyu.edu
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
index 6364ae2627058384a71da53504693e067687f204..c1b122944df5a57e94aeb7303ce1df22a195bc24 100644 (file)
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -90,6 +90,7 @@ enum hp_wmi_event_ids {
        HPWMI_PEAKSHIFT_PERIOD          = 0x0F,
        HPWMI_BATTERY_CHARGE_PERIOD     = 0x10,
        HPWMI_SANITIZATION_MODE         = 0x17,
+       HPWMI_CAMERA_TOGGLE             = 0x1A,
        HPWMI_OMEN_KEY                  = 0x1D,
        HPWMI_SMART_EXPERIENCE_APP      = 0x21,
 };
@@ -229,6 +230,7 @@ static const struct key_entry hp_wmi_keymap[] = {
 };
 
 static struct input_dev *hp_wmi_input_dev;
+static struct input_dev *camera_shutter_input_dev;
 static struct platform_device *hp_wmi_platform_dev;
 static struct platform_profile_handler platform_profile_handler;
 static bool platform_profile_support;
@@ -740,6 +742,33 @@ static ssize_t postcode_store(struct device *dev, struct device_attribute *attr,
        return count;
 }
 
+static int camera_shutter_input_setup(void)
+{
+       int err;
+
+       camera_shutter_input_dev = input_allocate_device();
+       if (!camera_shutter_input_dev)
+               return -ENOMEM;
+
+       camera_shutter_input_dev->name = "HP WMI camera shutter";
+       camera_shutter_input_dev->phys = "wmi/input1";
+       camera_shutter_input_dev->id.bustype = BUS_HOST;
+
+       __set_bit(EV_SW, camera_shutter_input_dev->evbit);
+       __set_bit(SW_CAMERA_LENS_COVER, camera_shutter_input_dev->swbit);
+
+       err = input_register_device(camera_shutter_input_dev);
+       if (err)
+               goto err_free_dev;
+
+       return 0;
+
+ err_free_dev:
+       input_free_device(camera_shutter_input_dev);
+       camera_shutter_input_dev = NULL;
+       return err;
+}
+
 static DEVICE_ATTR_RO(display);
 static DEVICE_ATTR_RO(hddtemp);
 static DEVICE_ATTR_RW(als);
@@ -867,6 +896,20 @@ static void hp_wmi_notify(u32 value, void *context)
                break;
        case HPWMI_SANITIZATION_MODE:
                break;
+       case HPWMI_CAMERA_TOGGLE:
+               if (!camera_shutter_input_dev)
+                       if (camera_shutter_input_setup()) {
+                               pr_err("Failed to setup camera shutter input device\n");
+                               break;
+                       }
+               if (event_data == 0xff)
+                       input_report_switch(camera_shutter_input_dev, SW_CAMERA_LENS_COVER, 1);
+               else if (event_data == 0xfe)
+                       input_report_switch(camera_shutter_input_dev, SW_CAMERA_LENS_COVER, 0);
+               else
+                       pr_warn("Unknown camera shutter state - 0x%x\n", event_data);
+               input_sync(camera_shutter_input_dev);
+               break;
        case HPWMI_SMART_EXPERIENCE_APP:
                break;
        default:
@@ -1565,6 +1608,9 @@ static void __exit hp_wmi_exit(void)
        if (wmi_has_guid(HPWMI_EVENT_GUID))
                hp_wmi_input_destroy();
 
+       if (camera_shutter_input_dev)
+               input_unregister_device(camera_shutter_input_dev);
+
        if (hp_wmi_platform_dev) {
                platform_device_unregister(hp_wmi_platform_dev);
                platform_driver_unregister(&hp_wmi_driver);