Merge remote-tracking branch 'wireless-next/master'

[karo-tx-linux.git] / drivers / usb / serial / pl2303.c

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index e7a84f0f517969fec4bbb59ac270eeb97fbf22d3..bedf8e47713be02dfc80b8a2e3512cb24a455a15 100644 (file)
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -139,6 +139,7 @@ enum pl2303_type {
        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 */
 };
 /*
  * NOTE: don't know the difference between type 0 and type 1,
@@ -206,8 +207,23 @@ static int pl2303_startup(struct usb_serial *serial)
                 * 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";
+                       /* 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;
@@ -305,8 +321,9 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
 {
        /*
         * 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)
+        * => 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,
@@ -316,14 +333,14 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
         * 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)
+        * 403200, 806400.      (*: not HX and HX clones)
         *
         * Maximum values: HXD, TB: 12000000; HX, TA: 6000000;
-        *                 type_0+1: 1228800; RA: 921600; SA: 115200
+        *                 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 and HX chips, there is no point in complicating
-        * the code to support them.
+        * than the type_0+1, HX and HX clone chips, there is no point in
+        * complicating the code to support them.
         */
        int i;
 
@@ -347,6 +364,8 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
                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);
 
@@ -359,7 +378,8 @@ static int pl2303_baudrate_encode_divisor(int baud, enum pl2303_type type,
        /*
         * Divisor based baud rate encoding method
         *
-        * NOTE: it's not clear if the type_0/1 chips support this 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
         *
@@ -452,7 +472,7 @@ static void pl2303_encode_baudrate(struct tty_struct *tty,
         * 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)
-        *    => supported by HX chips (and likely not by type_0/1 chips)
+        *    => 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
@@ -460,7 +480,7 @@ 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 == 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);
@@ -813,6 +833,7 @@ 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);
 }