[PATCH] HID: i2c-hid: Delayed i2c resume wakeup for Goodix touchpads

[Bartłomiej Maryńczak]

Patch for Goodix 27c6:0d42 touchpads found in Inspiron 5515 laptops.

After resume from suspend, one can communicate with this device just fine.
We can read data from it or request a reset,
but for some reason the interrupt line will not go up
when new events are available.
(it can correctly respond to a reset with an interrupt tho)

The only way I found to wake this device up
is to send anything to it after ~1.5s mark,
for example a simple read request, or power mode change.

In this patch, I simply delay the resume steps with msleep,
this will cause the set_power request to happen after
the ~1.5s barrier causing the device to resume its event interrupts.

Sleep was used rather than delayed_work
to make this workaround as non-invasive as possible.

Signed-off-by: Bartłomiej Maryńczak <marynczakbartlomiej@xxxxxxxxx>
---
 drivers/hid/hid-ids.h              |  1 +
 drivers/hid/i2c-hid/i2c-hid-core.c | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 86820a3d9766..8d21d250a258 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -509,6 +509,7 @@
 #define I2C_DEVICE_ID_GOODIX_01E8	0x01e8
 #define I2C_DEVICE_ID_GOODIX_01E9	0x01e9
 #define I2C_DEVICE_ID_GOODIX_01F0	0x01f0
+#define I2C_DEVICE_ID_GOODIX_0D42	0x0d42
 
 #define USB_VENDOR_ID_GOODTOUCH		0x1aad
 #define USB_DEVICE_ID_GOODTOUCH_000f	0x000f
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index be5d342d5d13..43664a24176f 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -50,6 +50,7 @@
 #define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(3)
 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET	BIT(4)
 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND	BIT(5)
+#define I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME BIT(6)
 
 /* Command opcodes */
 #define I2C_HID_OPCODE_RESET			0x01
@@ -140,6 +141,8 @@ static const struct i2c_hid_quirks {
 	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
 		 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
 		 I2C_HID_QUIRK_BOGUS_IRQ },
+	{ I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42,
+		 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME },
 	{ 0, 0 }
 };
 
@@ -981,6 +984,13 @@ static int i2c_hid_core_resume(struct i2c_hid *ihid)
 		return -ENXIO;
 	}
 
+	/* On Goodix 27c6:0d42 wait extra time before device wakeup.
+	 * It's not clear why but if we send wakeup too early, the device will
+	 * never trigger input interrupts.
+	 */
+	if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
+		msleep(1500);
+
 	/* Instead of resetting device, simply powers the device on. This
 	 * solves "incomplete reports" on Raydium devices 2386:3118 and
 	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
-- 
2.46.2