diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index e7a84f0f5179..bedf8e47713b 100644
--- 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);
}