---

yaml --- r: 93291 b: refs/heads/master c: 92983c2 h: refs/heads/master i: 93289: 3e99c78 93287: 368049c v: v3
git-mirror · Apr 25, 2008 · a8b59d8 · a8b59d8
1 parent cea23b7
commit a8b59d8
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Showing 2 changed files with 60 additions and 46 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6768306c3d9568bc66dc22f8b863bfbda3e7c4d2
+refs/heads/master: 92983c2121fb46f234add1c36b5e596779899d56
diff --git a/trunk/drivers/usb/serial/cypress_m8.c b/trunk/drivers/usb/serial/cypress_m8.c
@@ -291,6 +291,59 @@ static struct usb_serial_driver cypress_ca42v2_device = {
  *****************************************************************************/
 
 
+static int analyze_baud_rate(struct usb_serial_port *port, unsigned baud_mask)
+{
+	int new_rate;
+	struct cypress_private *priv;
+	priv = usb_get_serial_port_data(port);
+
+	/*
+	 * The general purpose firmware for the Cypress M8 allows for
+	 * a maximum speed of 57600bps (I have no idea whether DeLorme
+	 * chose to use the general purpose firmware or not), if you
+	 * need to modify this speed setting for your own project
+	 * please add your own chiptype and modify the code likewise.
+	 * The Cypress HID->COM device will work successfully up to
+	 * 115200bps (but the actual throughput is around 3kBps).
+	 */
+	new_rate = mask_to_rate(baud_mask);
+	if (new_rate < 0) {
+		dbg("%s - failed setting baud rate, untranslatable speed",
+		    __func__);
+		return -1;
+	}
+	if (port->serial->dev->speed == USB_SPEED_LOW) {
+		/*
+		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
+		 * Cypress app note that describes this mechanism
+		 * states the the low-speed part can't handle more
+		 * than 800 bytes/sec, in which case 4800 baud is the
+		 * safest speed for a part like that.
+		 */
+		if (new_rate > 4800) {
+			dbg("%s - failed setting baud rate, device incapable "
+			    "speed %d", __func__, new_rate);
+			return -1;
+		}
+	}
+	switch (priv->chiptype) {
+	case CT_EARTHMATE:
+		if (new_rate <= 600) {
+			/* 300 and 600 baud rates are supported under
+			 * the generic firmware, but are not used with
+			 * NMEA and SiRF protocols */
+			dbg("%s - failed setting baud rate, unsupported speed "
+			    "of %d on Earthmate GPS", __func__, new_rate);
+			return -1;
+		}
+		break;
+	default:
+		break;
+	}
+	return new_rate;
+}
+
+
 /* This function can either set or retrieve the current serial line settings */
 static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
 				   int parity_enable, int parity_type, int reset, int cypress_request_type)
@@ -309,54 +362,15 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
 
 	switch(cypress_request_type) {
 		case CYPRESS_SET_CONFIG:
-
-			/*
-			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
- 			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
-			 * firmware or not), if you need to modify this speed setting for your own
-			 * project please add your own chiptype and modify the code likewise.  The
-			 * Cypress HID->COM device will work successfully up to 115200bps (but the
-			 * actual throughput is around 3kBps).
-			 */
+			new_baudrate = priv->baud_rate;
 			if (baud_mask != priv->cbr_mask) {
 				dbg("%s - baud rate is changing", __FUNCTION__);
-				if ( priv->chiptype == CT_EARTHMATE ) {
-					/* 300 and 600 baud rates are supported under the generic firmware,
-					 * but are not used with NMEA and SiRF protocols */
-
-					if ( (baud_mask == B300) || (baud_mask == B600) ) {
-						err("%s - failed setting baud rate, unsupported speed",
-						    __FUNCTION__);
-						new_baudrate = priv->baud_rate;
-					} else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
-						err("%s - failed setting baud rate, unsupported speed",
-						    __FUNCTION__);
-						new_baudrate = priv->baud_rate;
-					}
-				} else if (priv->chiptype == CT_CYPHIDCOM) {
-					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
-						err("%s - failed setting baud rate, unsupported speed",
-						    __FUNCTION__);
-						new_baudrate = priv->baud_rate;
-					}
-				} else if (priv->chiptype == CT_CA42V2) {
-					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
-						err("%s - failed setting baud rate, unsupported speed",
-						    __FUNCTION__);
-						new_baudrate = priv->baud_rate;
-					}
-				} else if (priv->chiptype == CT_GENERIC) {
-					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
-						err("%s - failed setting baud rate, unsupported speed",
-						    __FUNCTION__);
-						new_baudrate = priv->baud_rate;
-					}
-				} else {
-					info("%s - please define your chiptype", __FUNCTION__);
-					new_baudrate = priv->baud_rate;
+				retval = analyze_baud_rate(port, baud_mask);
+				if (retval >=  0) {
+					new_baudrate = retval;
+					dbg("%s - New baud rate set to %d",
+					    __func__, new_baudrate);
 				}
-			} else {  /* baud rate not changing, keep the old */
-				new_baudrate = priv->baud_rate;
 			}
 			dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);