Merge tag 'usb-3.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here is a set of patches that revert all of the changes done to the
  pl2303 USB serial driver in the 3.12-rc timeframe, as it turns out
  they break some devices that work just fine on 3.11.  As it's not a
  good idea to break working systems, drop them all and they will be
  reworked for future kernel versions such that there is no breakage.

  I've also included a MAINTAINERS update for the USB serial subsystem
  and a new device id for the ftdi_sio driver as well"

* tag 'usb-3.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: serial: ftdi_sio: add id for Z3X Box device
  USB: Maintainers change for usb serial drivers
  Revert "USB: pl2303: restrict the divisor based baud rate encoding method to the "HX" chip type"
  Revert "usb: pl2303: fix+improve the divsor based baud rate encoding method"
  Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method"
  Revert "usb: pl2303: remove 500000 baud from the list of standard baud rates"
  Revert "usb: pl2303: move the two baud rate encoding methods to separate functions"
  Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method"
  Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips"
  Revert "usb: pl2303: add two comments concerning the supported baud rates with HX chips"
  Revert "pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()"
  Revert "pl2303: improve the chip type information output on startup"
  Revert "pl2303: improve the chip type detection/distinction"
  Revert "USB: pl2303: distinguish between original and cloned HX chips"

3 files changed, 63 insertions, 218 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index c45f9c0a1b3..b21d553c245 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -904,6 +904,7 @@ static struct usb_device_id id_table_combined [] = {
 	{ USB_DEVICE(FTDI_VID, FTDI_LUMEL_PD12_PID) },
 	/* Crucible Devices */
 	{ USB_DEVICE(FTDI_VID, FTDI_CT_COMET_PID) },
+	{ USB_DEVICE(FTDI_VID, FTDI_Z3X_PID) },
 	{ }					/* Terminating entry */
 };
 
diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h
index 1b8af461b52..a7019d1e305 100644
--- a/drivers/usb/serial/ftdi_sio_ids.h
+++ b/drivers/usb/serial/ftdi_sio_ids.h
@@ -1307,3 +1307,9 @@
  * Manufacturer: Crucible Technologies
  */
 #define FTDI_CT_COMET_PID	0x8e08
+
+/*
+ * Product: Z3X Box
+ * Manufacturer: Smart GSM Team
+ */
+#define FTDI_Z3X_PID		0x0011
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index bedf8e47713..1e6de4cd079 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -4,11 +4,6 @@
  * Copyright (C) 2001-2007 Greg Kroah-Hartman (greg@kroah.com)
  * Copyright (C) 2003 IBM Corp.
  *
- * Copyright (C) 2009, 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
- *  - fixes, improvements and documentation for the baud rate encoding methods
- * Copyright (C) 2013 Reinhard Max <max@suse.de>
- *  - fixes and improvements for the divisor based baud rate encoding method
- *
  * Original driver for 2.2.x by anonymous
  *
  *	This program is free software; you can redistribute it and/or
@@ -134,18 +129,10 @@ MODULE_DEVICE_TABLE(usb, id_table);
 
 
 enum pl2303_type {
-	type_0,		/* H version ? */
-	type_1,		/* H version ? */
-	HX_TA,		/* HX(A) / X(A) / TA version  */ /* TODO: improve */
-	HXD_EA_RA_SA,	/* HXD / EA / RA / SA version */ /* TODO: improve */
-	TB,		/* TB version */
-	HX_CLONE,	/* Cheap and less functional clone of the HX chip */
+	type_0,		/* don't know the difference between type 0 and */
+	type_1,		/* type 1, until someone from prolific tells us... */
+	HX,		/* HX version of the pl2303 chip */
 };
-/*
- * NOTE: don't know the difference between type 0 and type 1,
- * until someone from Prolific tells us...
- * TODO: distinguish between X/HX, TA and HXD, EA, RA, SA variants
- */
 
 struct pl2303_serial_private {
 	enum pl2303_type type;
@@ -185,7 +172,6 @@ static int pl2303_startup(struct usb_serial *serial)
 {
 	struct pl2303_serial_private *spriv;
 	enum pl2303_type type = type_0;
-	char *type_str = "unknown (treating as type_0)";
 	unsigned char *buf;
 
 	spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
@@ -198,53 +184,15 @@ static int pl2303_startup(struct usb_serial *serial)
 		return -ENOMEM;
 	}
 
-	if (serial->dev->descriptor.bDeviceClass == 0x02) {
+	if (serial->dev->descriptor.bDeviceClass == 0x02)
 		type = type_0;
-		type_str = "type_0";
-	} else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40) {
-		/*
-		 * NOTE: The bcdDevice version is the only difference between
-		 * the device descriptors of the X/HX, HXD, EA, RA, SA, TA, TB
-		 */
-		if (le16_to_cpu(serial->dev->descriptor.bcdDevice) == 0x300) {
-			/* Check if the device is a clone */
-			pl2303_vendor_read(0x9494, 0, serial, buf);
-			/*
-			 * NOTE: Not sure if this read is really needed.
-			 * The HX returns 0x00, the clone 0x02, but the Windows
-			 * driver seems to ignore the value and continues.
-			 */
-			pl2303_vendor_write(0x0606, 0xaa, serial);
-			pl2303_vendor_read(0x8686, 0, serial, buf);
-			if (buf[0] != 0xaa) {
-				type = HX_CLONE;
-				type_str = "X/HX clone (limited functionality)";
-			} else {
-				type = HX_TA;
-				type_str = "X/HX/TA";
-			}
-			pl2303_vendor_write(0x0606, 0x00, serial);
-		} else if (le16_to_cpu(serial->dev->descriptor.bcdDevice)
-								     == 0x400) {
-			type = HXD_EA_RA_SA;
-			type_str = "HXD/EA/RA/SA";
-		} else if (le16_to_cpu(serial->dev->descriptor.bcdDevice)
-								     == 0x500) {
-			type = TB;
-			type_str = "TB";
-		} else {
-			dev_info(&serial->interface->dev,
-					   "unknown/unsupported device type\n");
-			kfree(spriv);
-			kfree(buf);
-			return -ENODEV;
-		}
-	} else if (serial->dev->descriptor.bDeviceClass == 0x00
-		   || serial->dev->descriptor.bDeviceClass == 0xFF) {
+	else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
+		type = HX;
+	else if (serial->dev->descriptor.bDeviceClass == 0x00)
 		type = type_1;
-		type_str = "type_1";
-	}
-	dev_dbg(&serial->interface->dev, "device type: %s\n", type_str);
+	else if (serial->dev->descriptor.bDeviceClass == 0xFF)
+		type = type_1;
+	dev_dbg(&serial->interface->dev, "device type: %d\n", type);
 
 	spriv->type = type;
 	usb_set_serial_data(serial, spriv);
@@ -259,10 +207,10 @@ static int pl2303_startup(struct usb_serial *serial)
 	pl2303_vendor_read(0x8383, 0, serial, buf);
 	pl2303_vendor_write(0, 1, serial);
 	pl2303_vendor_write(1, 0, serial);
-	if (type == type_0 || type == type_1)
-		pl2303_vendor_write(2, 0x24, serial);
-	else
+	if (type == HX)
 		pl2303_vendor_write(2, 0x44, serial);
+	else
+		pl2303_vendor_write(2, 0x24, serial);
 
 	kfree(buf);
 	return 0;
@@ -316,174 +264,65 @@ static int pl2303_set_control_lines(struct usb_serial_port *port, u8 value)
 	return retval;
 }
 
-static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
-								      u8 buf[4])
+static void pl2303_encode_baudrate(struct tty_struct *tty,
+					struct usb_serial_port *port,
+					u8 buf[4])
 {
-	/*
-	 * NOTE: Only the values defined in baud_sup are supported !
-	 * => if unsupported values are set, the PL2303 uses 9600 baud instead
-	 * => HX clones just don't work at unsupported baud rates < 115200 baud,
-	 *    for baud rates > 115200 they run at 115200 baud
-	 */
 	const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600,
-				 4800, 7200, 9600, 14400, 19200, 28800, 38400,
-				 57600, 115200, 230400, 460800, 614400, 921600,
-				 1228800, 2457600, 3000000, 6000000, 12000000 };
+	                         4800, 7200, 9600, 14400, 19200, 28800, 38400,
+	                         57600, 115200, 230400, 460800, 500000, 614400,
+	                         921600, 1228800, 2457600, 3000000, 6000000 };
+
+	struct usb_serial *serial = port->serial;
+	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+	int baud;
+	int i;
+
 	/*
-	 * NOTE: With the exception of type_0/1 devices, the following
-	 * additional baud rates are supported (tested with HX rev. 3A only):
-	 * 110*, 56000*, 128000, 134400, 161280, 201600, 256000*, 268800,
-	 * 403200, 806400.	(*: not HX and HX clones)
-	 *
-	 * Maximum values: HXD, TB: 12000000; HX, TA: 6000000;
-	 *                 type_0+1: 1228800; RA: 921600; HX clones, SA: 115200
-	 *
-	 * As long as we are not using this encoding method for anything else
-	 * than the type_0+1, HX and HX clone chips, there is no point in
-	 * complicating the code to support them.
+	 * NOTE: Only the values defined in baud_sup are supported!
+	 *       => if unsupported values are set, the PL2303 seems to use
+	 *          9600 baud (at least my PL2303X always does)
 	 */
-	int i;
+	baud = tty_get_baud_rate(tty);
+	dev_dbg(&port->dev, "baud requested = %d\n", baud);
+	if (!baud)
+		return;
 
 	/* Set baudrate to nearest supported value */
 	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
 		if (baud_sup[i] > baud)
 			break;
 	}
+
 	if (i == ARRAY_SIZE(baud_sup))
 		baud = baud_sup[i - 1];
 	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
 		baud = baud_sup[i - 1];
 	else
 		baud = baud_sup[i];
-	/* Respect the chip type specific baud rate limits */
-	/*
-	 * FIXME: as long as we don't know how to distinguish between the
-	 * HXD, EA, RA, and SA chip variants, allow the max. value of 12M.
-	 */
-	if (type == HX_TA)
-		baud = min_t(int, baud, 6000000);
-	else if (type == type_0 || type == type_1)
-		baud = min_t(int, baud, 1228800);
-	else if (type == HX_CLONE)
-		baud = min_t(int, baud, 115200);
-	/* Direct (standard) baud rate encoding method */
-	put_unaligned_le32(baud, buf);
-
-	return baud;
-}
 
-static int pl2303_baudrate_encode_divisor(int baud, enum pl2303_type type,
-								      u8 buf[4])
-{
-	/*
-	 * Divisor based baud rate encoding method
-	 *
-	 * NOTE: HX clones do NOT support this method.
-	 * It's not clear if the type_0/1 chips support it.
-	 *
-	 * divisor = 12MHz * 32 / baudrate = 2^A * B
-	 *
-	 * with
-	 *
-	 * A = buf[1] & 0x0e
-	 * B = buf[0]  +  (buf[1] & 0x01) << 8
-	 *
-	 * Special cases:
-	 * => 8 < B < 16: device seems to work not properly
-	 * => B <= 8: device uses the max. value B = 512 instead
-	 */
-	unsigned int A, B;
+	/* type_0, type_1 only support up to 1228800 baud */
+	if (spriv->type != HX)
+		baud = min_t(int, baud, 1228800);
 
-	/*
-	 * NOTE: The Windows driver allows maximum baud rates of 110% of the
-	 * specified maximium value.
-	 * Quick tests with early (2004) HX (rev. A) chips suggest, that even
-	 * higher baud rates (up to the maximum of 24M baud !) are working fine,
-	 * but that should really be tested carefully in "real life" scenarios
-	 * before removing the upper limit completely.
-	 * Baud rates smaller than the specified 75 baud are definitely working
-	 * fine.
-	 */
-	if (type == type_0 || type == type_1)
-		baud = min_t(int, baud, 1228800 * 1.1);
-	else if (type == HX_TA)
-		baud = min_t(int, baud, 6000000 * 1.1);
-	else if (type == HXD_EA_RA_SA)
-		/* HXD, EA: 12Mbps; RA: 1Mbps; SA: 115200 bps */
-		/*
-		 * FIXME: as long as we don't know how to distinguish between
-		 * these chip variants, allow the max. of these values
-		 */
-		baud = min_t(int, baud, 12000000 * 1.1);
-	else if (type == TB)
-		baud = min_t(int, baud, 12000000 * 1.1);
-	/* Determine factors A and B */
-	A = 0;
-	B = 12000000 * 32 / baud;  /* 12MHz */
-	B <<= 1; /* Add one bit for rounding */
-	while (B > (512 << 1) && A <= 14) {
-		A += 2;
-		B >>= 2;
-	}
-	if (A > 14) { /* max. divisor = min. baudrate reached */
-		A = 14;
-		B = 512;
-		/* => ~45.78 baud */
+	if (baud <= 115200) {
+		put_unaligned_le32(baud, buf);
 	} else {
-		B = (B + 1) >> 1; /* Round the last bit */
-	}
-	/* Handle special cases */
-	if (B == 512)
-		B = 0; /* also: 1 to 8 */
-	else if (B < 16)
 		/*
-		 * NOTE: With the current algorithm this happens
-		 * only for A=0 and means that the min. divisor
-		 * (respectively: the max. baudrate) is reached.
+		 * Apparently the formula for higher speeds is:
+		 * baudrate = 12M * 32 / (2^buf[1]) / buf[0]
 		 */
-		B = 16;		/* => 24 MBaud */
-	/* Encode the baud rate */
-	buf[3] = 0x80;     /* Select divisor encoding method */
-	buf[2] = 0;
-	buf[1] = (A & 0x0e);		/* A */
-	buf[1] |= ((B & 0x100) >> 8);	/* MSB of B */
-	buf[0] = B & 0xff;		/* 8 LSBs of B */
-	/* Calculate the actual/resulting baud rate */
-	if (B <= 8)
-		B = 512;
-	baud = 12000000 * 32 / ((1 << A) * B);
-
-	return baud;
-}
-
-static void pl2303_encode_baudrate(struct tty_struct *tty,
-					struct usb_serial_port *port,
-					enum pl2303_type type,
-					u8 buf[4])
-{
-	int baud;
+		unsigned tmp = 12000000 * 32 / baud;
+		buf[3] = 0x80;
+		buf[2] = 0;
+		buf[1] = (tmp >= 256);
+		while (tmp >= 256) {
+			tmp >>= 2;
+			buf[1] <<= 1;
+		}
+		buf[0] = tmp;
+	}
 
-	baud = tty_get_baud_rate(tty);
-	dev_dbg(&port->dev, "baud requested = %d\n", baud);
-	if (!baud)
-		return;
-	/*
-	 * There are two methods for setting/encoding the baud rate
-	 * 1) Direct method: encodes the baud rate value directly
-	 *    => supported by all chip types
-	 * 2) Divisor based method: encodes a divisor to a base value (12MHz*32)
-	 *    => not supported by HX clones (and likely type_0/1 chips)
-	 *
-	 * NOTE: Although the divisor based baud rate encoding method is much
-	 * more flexible, some of the standard baud rate values can not be
-	 * realized exactly. But the difference is very small (max. 0.2%) and
-	 * the device likely uses the same baud rate generator for both methods
-	 * so that there is likley no difference.
-	 */
-	if (type == type_0 || type == type_1 || type == HX_CLONE)
-		baud = pl2303_baudrate_encode_direct(baud, type, buf);
-	else
-		baud = pl2303_baudrate_encode_divisor(baud, type, buf);
 	/* Save resulting baud rate */
 	tty_encode_baud_rate(tty, baud, baud);
 	dev_dbg(&port->dev, "baud set = %d\n", baud);
@@ -540,8 +379,8 @@ static void pl2303_set_termios(struct tty_struct *tty,
 		dev_dbg(&port->dev, "data bits = %d\n", buf[6]);
 	}
 
-	/* For reference:   buf[0]:buf[3] baud rate value */
-	pl2303_encode_baudrate(tty, port, spriv->type, buf);
+	/* For reference buf[0]:buf[3] baud rate value */
+	pl2303_encode_baudrate(tty, port, &buf[0]);
 
 	/* For reference buf[4]=0 is 1 stop bits */
 	/* For reference buf[4]=1 is 1.5 stop bits */
@@ -618,10 +457,10 @@ static void pl2303_set_termios(struct tty_struct *tty,
 	dev_dbg(&port->dev, "0xa1:0x21:0:0  %d - %7ph\n", i, buf);
 
 	if (C_CRTSCTS(tty)) {
-		if (spriv->type == type_0 || spriv->type == type_1)
-			pl2303_vendor_write(0x0, 0x41, serial);
-		else
+		if (spriv->type == HX)
 			pl2303_vendor_write(0x0, 0x61, serial);
+		else
+			pl2303_vendor_write(0x0, 0x41, serial);
 	} else {
 		pl2303_vendor_write(0x0, 0x0, serial);
 	}
@@ -658,7 +497,7 @@ static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
 	int result;
 
-	if (spriv->type == type_0 || spriv->type == type_1) {
+	if (spriv->type != HX) {
 		usb_clear_halt(serial->dev, port->write_urb->pipe);
 		usb_clear_halt(serial->dev, port->read_urb->pipe);
 	} else {
@@ -833,7 +672,6 @@ static void pl2303_break_ctl(struct tty_struct *tty, int break_state)
 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 				 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
 				 0, NULL, 0, 100);
-	/* NOTE: HX clones don't support sending breaks, -EPIPE is returned */
 	if (result)
 		dev_err(&port->dev, "error sending break = %d\n", result);
 }