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From:   Johan Hovold <johan@kernel.org>
To:     Johan Hovold <johan@kernel.org>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 6/6] USB: serial: cp210x: determine fw version for CP2105 and CP2108
Date:   Fri,  2 Jul 2021 15:42:27 +0200
Message-Id: <20210702134227.24621-7-johan@kernel.org>
In-Reply-To: <20210702134227.24621-1-johan@kernel.org>
References: <20210702134227.24621-1-johan@kernel.org>
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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.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 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 0f4cdba160d9..7908e336f962 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -399,6 +399,7 @@ 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
@@ -2103,6 +2104,10 @@ 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:
-- 
2.31.1