Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Zoltan Tamas Vajda <zoltan.tamas.vajda@gmail.com>
To:     jikos@kernel.org, benjamin.tissoires@redhat.com
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        Zoltan Tamas Vajda <zoltan.tamas.vajda@gmail.com>
Subject: [PATCH] HID: hid-input: add Surface Go battery quirk
Date:   Thu,  3 Jun 2021 20:58:14 +0200
Message-Id: <20210603185814.12659-1-zoltan.tamas.vajda@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The Elantech touchscreen/digitizer in the Surface Go mistakenly reports
having a battery. This results in a low battery message every time you
try to use the pen.

This patch adds a quirk to ignore the non-existent battery and
gets rid of the false low battery messages.

Signed-off-by: Zoltan Tamas Vajda <zoltan.tamas.vajda@gmail.com>
---
 drivers/hid/hid-ids.h   | 1 +
 drivers/hid/hid-input.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index b84a0a11e05b..63ca5959dc67 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -396,6 +396,7 @@
 #define USB_DEVICE_ID_HP_X2_10_COVER	0x0755
 #define I2C_DEVICE_ID_HP_SPECTRE_X360_15	0x2817
 #define USB_DEVICE_ID_ASUS_UX550_TOUCHSCREEN	0x2706
+#define I2C_DEVICE_ID_SURFACE_GO_TOUCHSCREEN	0x261A
 
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index abbfa91e73e4..3e39aeafca91 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -326,6 +326,8 @@ static const struct hid_device_id hid_battery_quirks[] = {
 	  HID_BATTERY_QUIRK_IGNORE },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, I2C_DEVICE_ID_HP_SPECTRE_X360_15),
 	  HID_BATTERY_QUIRK_IGNORE },
+	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, I2C_DEVICE_ID_SURFACE_GO_TOUCHSCREEN),
+	  HID_BATTERY_QUIRK_IGNORE },
 	{}
 };
 
-- 
2.30.2