USB: Serial: cypress_M8: Enable FRWD Dongle hidcom device

The patch adds a new HIDCOM device and does not affect other devices
driven by the cypress_M8 module. Changes are:
- add VendorID ProductID to device tables
- skip unstable speed check because FRWD uses 115200bps
- skip reset at probe which is an issue workaround for this
particular device.

Signed-off-by: Robert Butora <robert.butora.fi@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/cypress_m8.c

@@ -65,6 +65,7 @@ static const struct usb_device_id id_table_earthmate[] = {
 static const struct usb_device_id id_table_cyphidcomrs232[] = {
 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
+	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
 	{ }						/* Terminating entry */
 };
 
@@ -78,6 +79,7 @@ static const struct usb_device_id id_table_combined[] = {
 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
+	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
 	{ }						/* Terminating entry */
 };
@@ -229,6 +231,12 @@ static struct usb_serial_driver * const serial_drivers[] = {
  * Cypress serial helper functions
  *****************************************************************************/
 
+/* FRWD Dongle hidcom needs to skip reset and speed checks */
+static inline bool is_frwd(struct usb_device *dev)
+{
+	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
+		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
+}
 
 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
 {
@@ -238,6 +246,10 @@ static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
 	if (unstable_bauds)
 		return new_rate;
 
+	/* FRWD Dongle uses 115200 bps */
+	if (is_frwd(port->serial->dev))
+		return new_rate;
+
 	/*
 	 * The general purpose firmware for the Cypress M8 allows for
 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
@@ -448,7 +460,11 @@ static int cypress_generic_port_probe(struct usb_serial_port *port)
 		return -ENOMEM;
 	}
 
-	usb_reset_configuration(serial->dev);
+	/* Skip reset for FRWD device. It is a workaound:
+	   device hangs if it receives SET_CONFIGURE in Configured
+	   state. */
+	if (!is_frwd(serial->dev))
+		usb_reset_configuration(serial->dev);
 
 	priv->cmd_ctrl = 0;
 	priv->line_control = 0;

drivers/usb/serial/cypress_m8.h

@@ -24,6 +24,10 @@
 #define VENDOR_ID_CYPRESS		0x04b4
 #define PRODUCT_ID_CYPHIDCOM		0x5500
 
+/* FRWD Dongle - a GPS sports watch */
+#define VENDOR_ID_FRWD			0x6737
+#define PRODUCT_ID_CYPHIDCOM_FRWD	0x0001
+
 /* Powercom UPS, chip CY7C63723 */
 #define VENDOR_ID_POWERCOM		0x0d9f
 #define PRODUCT_ID_UPS			0x0002