USB: serial: cp210x: determine fw version for CP2105 and CP2108

CP2105, CP2108 and CP2102N have vendor requests that can be used to
retrieve the firmware version. Having this information available is
essential when trying to work around buggy firmware as a recent CP2102N
regression showed.

Determine and log the firmware version also for CP2105 and CP2108
during type detection at probe.

Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>

Author: jhovold

drivers/usb/serial/cp210x.c

@@ -400,6 +400,7 @@ struct cp210x_special_chars {
 };
 
 /* CP210X_VENDOR_SPECIFIC values */
+#define CP210X_GET_FW_VER	0x000E
 #define CP210X_READ_2NCONFIG	0x000E
 #define CP210X_GET_FW_VER_2N	0x0010
 #define CP210X_READ_LATCH	0x00C2
@@ -2108,6 +2109,10 @@ static void cp210x_determine_type(struct usb_serial *serial)
 	}
 
 	switch (priv->partnum) {
+	case CP210X_PARTNUM_CP2105:
+	case CP210X_PARTNUM_CP2108:
+		cp210x_get_fw_version(serial, CP210X_GET_FW_VER);
+		break;
 	case CP210X_PARTNUM_CP2102N_QFN28:
 	case CP210X_PARTNUM_CP2102N_QFN24:
 	case CP210X_PARTNUM_CP2102N_QFN20: