Revert "pl2303: improve the chip type detection/distinction"

This reverts commit 034d1527adebd302115c87ef343497a889638275.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.

Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 72 deletions

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index e7a84f0f5179..409000a836dd 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -134,17 +134,10 @@ 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 */
+        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;
@@ -201,28 +194,8 @@ static int pl2303_startup(struct usb_serial *serial)
                 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) {
-                        type = HX_TA;
-                        type_str = "X/HX/TA";
-                } 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;
-                }
+                type = HX;
+                type_str = "X/HX";
         } else if (serial->dev->descriptor.bDeviceClass == 0x00
                    || serial->dev->descriptor.bDeviceClass == 0xFF) {
                 type = type_1;
@@ -243,10 +216,10 @@ 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;
@@ -311,19 +284,12 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
         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 };
+                                 1228800, 2457600, 3000000, 6000000 };
         /*
-         * 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)
-         *
-         * Maximum values: HXD, TB: 12000000; HX, TA: 6000000;
-         *                 type_0+1: 1228800; RA: 921600; SA: 115200
-         *
-         * As long as we are not using this encoding method for anything else
-         * than the type_0+1 and HX chips, there is no point in complicating
-         * the code to support them.
+         * NOTE: The PL2303HX (tested with rev. 3A) also supports the following
+         * baud rates: 128000, 134400, 161280, 201600, 268800, 403200, 806400.
+         * As long as we are not using this encoding method for them, there is
+         * no point in complicating the code to support them.
          */
         int i;
 
@@ -338,14 +304,8 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
                 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)
+        /* type_0, type_1 only support up to 1228800 baud */
+        if (type != HX)
                 baud = min_t(int, baud, 1228800);
         /* Direct (standard) baud rate encoding method */
         put_unaligned_le32(baud, buf);
@@ -384,19 +344,10 @@ static int pl2303_baudrate_encode_divisor(int baud, enum pl2303_type type,
          * 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)
+        if (type == HX)
                 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);
+        else
+                baud = min_t(int, baud, 1228800 * 1.1);
         /* Determine factors A and B */
         A = 0;
         B = 12000000 * 32 / baud;  /* 12MHz */
@@ -460,7 +411,7 @@ static void pl2303_encode_baudrate(struct tty_struct *tty,
          * 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)
+        if (type != HX)
                 baud = pl2303_baudrate_encode_direct(baud, type, buf);
         else
                 baud = pl2303_baudrate_encode_divisor(baud, type, buf);
@@ -598,10 +549,10 @@ 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);
         }
@@ -638,7 +589,7 @@ 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 {