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authorFrank Schäfer <fschaefer.oss@googlemail.com>2013-09-14 09:36:48 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-17 12:36:10 -0400
commit7d26a78f62ff4fb08bc5ba740a8af4aa7ac67da4 (patch)
tree43b958cc7e60bc1b37c8f9a8ff562bcf0a733db9
parentdfe2902032ac9f8899214767dc5bc172254838ad (diff)
USB: pl2303: distinguish between original and cloned HX chips
According to Prolific, several (unauthorized) cheap and less functional clones of the PL2303HX chip are in circulation. [1] I've had the chance to test such a cloned device and it turned out that it doesn't support any baud rates above 115200 baud (original: 6 Mbaud) It also doesn't support the divisior based baud rate encoding method, so no continuous baud rate adjustment is possible. Nevertheless, these devices have been working (unintentionally) with the driver up to commit 61fa8d694b ("pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips"), and this commit broke support for them. Fortunately, it is pretty simple to distinguish between the original and the cloned HX chips, so I've added a check and an extra chip type to keep the clones working. The same check is used by the latest Prolific Windows driver, so it should be solid. [1] http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=225&pcid=41 Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/serial/pl2303.c43
1 files changed, 32 insertions, 11 deletions
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 {
139 HX_TA, /* HX(A) / X(A) / TA version */ /* TODO: improve */ 139 HX_TA, /* HX(A) / X(A) / TA version */ /* TODO: improve */
140 HXD_EA_RA_SA, /* HXD / EA / RA / SA version */ /* TODO: improve */ 140 HXD_EA_RA_SA, /* HXD / EA / RA / SA version */ /* TODO: improve */
141 TB, /* TB version */ 141 TB, /* TB version */
142 HX_CLONE, /* Cheap and less functional clone of the HX chip */
142}; 143};
143/* 144/*
144 * NOTE: don't know the difference between type 0 and type 1, 145 * NOTE: don't know the difference between type 0 and type 1,
@@ -206,8 +207,23 @@ static int pl2303_startup(struct usb_serial *serial)
206 * the device descriptors of the X/HX, HXD, EA, RA, SA, TA, TB 207 * the device descriptors of the X/HX, HXD, EA, RA, SA, TA, TB
207 */ 208 */
208 if (le16_to_cpu(serial->dev->descriptor.bcdDevice) == 0x300) { 209 if (le16_to_cpu(serial->dev->descriptor.bcdDevice) == 0x300) {
209 type = HX_TA; 210 /* Check if the device is a clone */
210 type_str = "X/HX/TA"; 211 pl2303_vendor_read(0x9494, 0, serial, buf);
212 /*
213 * NOTE: Not sure if this read is really needed.
214 * The HX returns 0x00, the clone 0x02, but the Windows
215 * driver seems to ignore the value and continues.
216 */
217 pl2303_vendor_write(0x0606, 0xaa, serial);
218 pl2303_vendor_read(0x8686, 0, serial, buf);
219 if (buf[0] != 0xaa) {
220 type = HX_CLONE;
221 type_str = "X/HX clone (limited functionality)";
222 } else {
223 type = HX_TA;
224 type_str = "X/HX/TA";
225 }
226 pl2303_vendor_write(0x0606, 0x00, serial);
211 } else if (le16_to_cpu(serial->dev->descriptor.bcdDevice) 227 } else if (le16_to_cpu(serial->dev->descriptor.bcdDevice)
212 == 0x400) { 228 == 0x400) {
213 type = HXD_EA_RA_SA; 229 type = HXD_EA_RA_SA;
@@ -305,8 +321,9 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
305{ 321{
306 /* 322 /*
307 * NOTE: Only the values defined in baud_sup are supported ! 323 * NOTE: Only the values defined in baud_sup are supported !
308 * => if unsupported values are set, the PL2303 seems to 324 * => if unsupported values are set, the PL2303 uses 9600 baud instead
309 * use 9600 baud (at least my PL2303X always does) 325 * => HX clones just don't work at unsupported baud rates < 115200 baud,
326 * for baud rates > 115200 they run at 115200 baud
310 */ 327 */
311 const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600, 328 const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600,
312 4800, 7200, 9600, 14400, 19200, 28800, 38400, 329 4800, 7200, 9600, 14400, 19200, 28800, 38400,
@@ -316,14 +333,14 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
316 * NOTE: With the exception of type_0/1 devices, the following 333 * NOTE: With the exception of type_0/1 devices, the following
317 * additional baud rates are supported (tested with HX rev. 3A only): 334 * additional baud rates are supported (tested with HX rev. 3A only):
318 * 110*, 56000*, 128000, 134400, 161280, 201600, 256000*, 268800, 335 * 110*, 56000*, 128000, 134400, 161280, 201600, 256000*, 268800,
319 * 403200, 806400. (*: not HX) 336 * 403200, 806400. (*: not HX and HX clones)
320 * 337 *
321 * Maximum values: HXD, TB: 12000000; HX, TA: 6000000; 338 * Maximum values: HXD, TB: 12000000; HX, TA: 6000000;
322 * type_0+1: 1228800; RA: 921600; SA: 115200 339 * type_0+1: 1228800; RA: 921600; HX clones, SA: 115200
323 * 340 *
324 * As long as we are not using this encoding method for anything else 341 * As long as we are not using this encoding method for anything else
325 * than the type_0+1 and HX chips, there is no point in complicating 342 * than the type_0+1, HX and HX clone chips, there is no point in
326 * the code to support them. 343 * complicating the code to support them.
327 */ 344 */
328 int i; 345 int i;
329 346
@@ -347,6 +364,8 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type,
347 baud = min_t(int, baud, 6000000); 364 baud = min_t(int, baud, 6000000);
348 else if (type == type_0 || type == type_1) 365 else if (type == type_0 || type == type_1)
349 baud = min_t(int, baud, 1228800); 366 baud = min_t(int, baud, 1228800);
367 else if (type == HX_CLONE)
368 baud = min_t(int, baud, 115200);
350 /* Direct (standard) baud rate encoding method */ 369 /* Direct (standard) baud rate encoding method */
351 put_unaligned_le32(baud, buf); 370 put_unaligned_le32(baud, buf);
352 371
@@ -359,7 +378,8 @@ static int pl2303_baudrate_encode_divisor(int baud, enum pl2303_type type,
359 /* 378 /*
360 * Divisor based baud rate encoding method 379 * Divisor based baud rate encoding method
361 * 380 *
362 * NOTE: it's not clear if the type_0/1 chips support this method 381 * NOTE: HX clones do NOT support this method.
382 * It's not clear if the type_0/1 chips support it.
363 * 383 *
364 * divisor = 12MHz * 32 / baudrate = 2^A * B 384 * divisor = 12MHz * 32 / baudrate = 2^A * B
365 * 385 *
@@ -452,7 +472,7 @@ static void pl2303_encode_baudrate(struct tty_struct *tty,
452 * 1) Direct method: encodes the baud rate value directly 472 * 1) Direct method: encodes the baud rate value directly
453 * => supported by all chip types 473 * => supported by all chip types
454 * 2) Divisor based method: encodes a divisor to a base value (12MHz*32) 474 * 2) Divisor based method: encodes a divisor to a base value (12MHz*32)
455 * => supported by HX chips (and likely not by type_0/1 chips) 475 * => not supported by HX clones (and likely type_0/1 chips)
456 * 476 *
457 * NOTE: Although the divisor based baud rate encoding method is much 477 * NOTE: Although the divisor based baud rate encoding method is much
458 * more flexible, some of the standard baud rate values can not be 478 * 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,
460 * the device likely uses the same baud rate generator for both methods 480 * the device likely uses the same baud rate generator for both methods
461 * so that there is likley no difference. 481 * so that there is likley no difference.
462 */ 482 */
463 if (type == type_0 || type == type_1) 483 if (type == type_0 || type == type_1 || type == HX_CLONE)
464 baud = pl2303_baudrate_encode_direct(baud, type, buf); 484 baud = pl2303_baudrate_encode_direct(baud, type, buf);
465 else 485 else
466 baud = pl2303_baudrate_encode_divisor(baud, type, buf); 486 baud = pl2303_baudrate_encode_divisor(baud, type, buf);
@@ -813,6 +833,7 @@ static void pl2303_break_ctl(struct tty_struct *tty, int break_state)
813 result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 833 result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
814 BREAK_REQUEST, BREAK_REQUEST_TYPE, state, 834 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
815 0, NULL, 0, 100); 835 0, NULL, 0, 100);
836 /* NOTE: HX clones don't support sending breaks, -EPIPE is returned */
816 if (result) 837 if (result)
817 dev_err(&port->dev, "error sending break = %d\n", result); 838 dev_err(&port->dev, "error sending break = %d\n", result);
818} 839}