fix ps2m not work on boot

If the touchpad is touched during early boot, sometimes
the ec i2c controller can get stuck and needs to be kicked
to restart communication with the touchpad.

This fixes the issue that touchpad does not work in
windows installer if the user touches it during
the boot process

Signed-off-by: Kieran Levin <[email protected]>

Author: kiram9

board/hx20/ps2mouse.c

@@ -329,6 +329,9 @@ void read_touchpad_in_report(void)
 	int xfer_len = 0;
 	int16_t x, y;
 	uint8_t response_byte = 0x08;
+
+	/* Make sure report id is set to an invalid value */
+	data[2] = 0;
 	/*dont trigger disable state during our own transactions*/
 	gpio_disable_interrupt(GPIO_EC_I2C_3_SDA);
 	i2c_lock(I2C_PORT_TOUCHPAD, 1);
@@ -338,6 +341,11 @@ void read_touchpad_in_report(void)
 	if (rv != EC_SUCCESS)
 		goto read_failed;
 	xfer_len = (data[1]<<8) + data[0];
+	if (xfer_len == 0) {
+		/* touchpad has reset per i2c-hid-protocol 7.3 */
+		CPRINTS("PS2M Touchpad Reset");
+		goto read_failed;
+	}
 	xfer_len = MIN(126, xfer_len-2);
 	rv = i2c_xfer_unlocked(I2C_PORT_TOUCHPAD,
 							TOUCHPAD_I2C_HID_EP | I2C_FLAG_ADDR16_LITTLE_ENDIAN,
@@ -354,6 +362,10 @@ void read_touchpad_in_report(void)
 			/* try again some other time later if the TP keeps interrupting us */
 			detected_host_packet = true;
 			inreport_retries = 0;
+			MCHP_I2C_CTRL(MCHP_I2C_CTRL4) = BIT(7) |
+				BIT(6) |
+				BIT(3) |
+				BIT(0);
 			CPRINTS("PS2M Too many retries");
 		} else {
 			hook_call_deferred(&retry_tp_read_evt_deferred_data, 25*MSEC);