From 4e9340bb551a5ad664196465ba7620009d835dbc Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 5 Jul 2021 10:20:15 +0200
Subject: [PATCH] USB: serial: cp210x: determine fw version for CP2105 and
 CP2108
Git-commit: 4e9340bb551a5ad664196465ba7620009d835dbc
References: git-fixes
Patch-mainline: v5.15-rc1

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 <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/serial/cp210x.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index a120646b0926..66a6ac50a4cd 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/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:
-- 
2.26.2