Commit Graph

221 Commits

Author SHA1 Message Date
Michał Pecio
49bda21266 USB: pl2303: fix baud-rate divisor calculations
This commit fixes the following issues:

1. The 9th bit of buf was believed to be the LSB of divisor's
exponent, but the hardware interprets it as MSB (9th bit) of the
mantissa. The exponent is actually one bit shorter and applies
to base 4, not 2 as previously believed.

2. Loop iterations doubled the exponent instead of incrementing.

3. The exponent wasn't checked for overflow.

4. The function returned requested rate instead of actual rate.

Due to issue #2, the old code deviated from the wrong formula
described in #1 and actually yielded correct rates when divisor
was lower than 4096 by using exponents of 0, 2 or 4 base-2,
interpreted as 0, 1, 2 base-4 with the 9th mantissa bit clear.
However, at 93.75 kbaud or less the rate turned out too slow
due to #2 or too fast due to #2 and #3.

I tested this patch by sending and validating 0x00,0x01,..,0xff
to an FTDI dongle at 234, 987, 2401, 9601, 31415, 115199, 250k,
500k, 750k, 1M, 1.5M, 3M+1 baud. All rates passed.

I also used pv to check speed at some rates unsupported by FTDI:
45 (the lowest possible), 2M, 4M, 5M and 6M-1. Looked sane.

Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
Fixes: 399aa9a75a ("USB: pl2303: use divisors for unsupported baud
rates")
Cc: stable <stable@vger.kernel.org> # v3.18
[johan: update summary ]
Signed-off-by: Johan Hovold <johan@kernel.org>
2015-07-30 18:11:07 +02:00
Jason A. Donenfeld
48ef23a4f6 USB: pl2303: Remove support for Samsung I330
This phone is already supported by the visor driver.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
2015-04-29 12:34:24 +02:00
Johan Hovold
52772a7fd3 USB: pl2303: disable break on shutdown
Currently an enabled break state is not disabled on final close nor on
re-open and has to be disabled manually.

Fix this by disabling break on port shutdown.

Reported-by: Jari Ruusu <jariruusu@users.sourceforge.net>
Tested-by: Jari Ruusu <jariruusu@users.sourceforge.net>
Signed-off-by: Johan Hovold <johan@kernel.org>
2015-02-26 17:35:25 +01:00
Lauri Hintsala
399aa9a75a USB: pl2303: use divisors for unsupported baud rates
Use direct method for supported baud rates, otherwise use divisors.
Limit baud rate to 12 Mbaud with HX type.

This change has been tested to work with PL-2303HX at 115200, 500000,
1000000, 2000000, 2500000, 3000000 and 4000000 baud rates.

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
2014-09-01 12:04:17 +02:00
Greg KH
91fcb1ce42 USB: serial: pl2303: add device id for ztek device
This adds a new device id to the pl2303 driver for the ZTEK device.

Reported-by: Mike Chu <Mike-Chu@prolific.com.tw>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
2014-08-18 13:09:27 +02:00
Aaron Sanders
b16c02fbfb USB: pl2303: add ids for Hewlett-Packard HP POS pole displays
Add device ids to pl2303 for the Hewlett-Packard HP POS pole displays:

LD960: 03f0:0B39
LCM220: 03f0:3139
LCM960: 03f0:3239

[ Johan: fix indentation and sort PIDs numerically ]

Signed-off-by: Aaron Sanders <aaron.sanders@hp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 13:56:07 -07:00
Paul Gortmaker
803a536243 usb: delete non-required instances of include <linux/init.h>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-08 15:01:39 -08:00
Johan Hovold
a4bcb29459 USB: pl2303: switch to generic TIOCMIWAIT implementation
Switch to the generic TIOCMIWAIT implementation which does not suffer
from the races involved when using the deprecated sleep_on functions.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:42:23 -08:00
Johan Hovold
dbfd2866ac USB: pl2303: only wake up MSR queue on changes
Only wake up MSR wait queue on actual modem-status changes.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:42:23 -08:00
Johan Hovold
6020c3bec3 USB: pl2303: clean up line-status handling
Clean up line-status handling somewhat.
Get tty-reference only when actually needed.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:42:23 -08:00
Johan Hovold
b693468155 USB: pl2303: make type data const
Declare constant device-type data as const.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:42:23 -08:00
Johan Hovold
619c43543a USB: pl2303: use C_CMSPAR macro
Use the new C_CMSPAR macro for consistency.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:34:33 -08:00
Johan Hovold
5d85045f4b USB: pl2303: use direct baud-rate encoding when possible
Use direct baud-rate encoding rather than divisors for supported baud
rates.

This restores the way baud rates were set prior to commit 8d48fdf689
("USB: PL2303: correctly handle baudrates above 115200") which added
divisor encoding, but also switched to the new encoding method for all
baudrates above 115200.

As noted by Frank Schäfer <fschaefer.oss@googlemail.com>, baud rate 500k
was later errounously added to the supported baud-rate table although
it can only be set using divisors.

Note that the current implementation could easily be extended to support
arbitrary non-standard baud rates using divisors (e.g. by falling back
to divisors when the table lookup fails).

Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:48 -08:00
Johan Hovold
20b4c78719 USB: pl2303: add helper function for direct baud-rate encoding
Add helper function for direct baud-rate encoding.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:48 -08:00
Johan Hovold
c82c6d45a2 USB: pl2303: refactor baud-rate divisor handling
Refactor baud-rate divisor handling.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:48 -08:00
Johan Hovold
871996ede1 USB: pl2303: enforce baud-rate limits before lookup
Enforce any baud-rate limits before doing table lookup.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:48 -08:00
Johan Hovold
59afe10e8d USB: pl2303: refactor baud-rate table lookup
Refactor supported baud-rate table lookup.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:48 -08:00
Johan Hovold
79816824c1 USB: pl2303: rename pl2303_encode_baud_rate
Rename baud-rate encoding function to match tty naming.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
359defdaa4 USB: pl2303: add device-type abstraction
Encode all device-type specifics in a struct rather than testing for
device type and spreading such information throughout the driver.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
23c6acb968 USB: pl2303: add quirk for legacy devices
Add quirk for legacy devices (type 0 and 1) rather than testing on
device type throughout the driver.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
7f966ac7a9 USB: pl2303: clean up type handling
Merge types 0 and 1, whose differences are unknown and have always been
treated the same.
Add TYPE_-prefix to both types.
Test for TYPE_01 (rather than !TYPE_HX) for legacy device quirks.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
f84ee3b2f5 USB: pl2303: use speed_t for baud rates
Use speed_t for baud rates throughout.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
228e410537 USB: pl2303: add line-status quirk for Siemens phones
Implement line-status handling for Siemens phones as a quirk rather than
spreading such information all over the driver by matching on vendor and
and product ids.

Note that the SIEMENS_PRODUCT_ID_EF81, which was added after the
line-status handling for the other Siemens phones was fixed, might also
need this quirk.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
294bb2c617 USB: pl2303: remove redundant line-request call
Remove redundant get_line_request (the read back settings are never
used).

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
383d19c587 USB: pl2303: add error handling to line requests
Refactor and add error handling to line requests.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
a6ec8245bf USB: pl2303: add error handling to set_control_lines
Add error handling to set_control_lines.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
362eb02603 USB: pl2303: add error handling to vendor read and write functions
Add error handling and clean up vendor read and write functions.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
ccfe8188a3 USB: pl2303: clean up driver somewhat
Use u16 rather than __u16.
Fix multi-line comment style.
Remove some comments.
Remove unnecessary whitespace and add some where appropriate.
Drop DRIVER_DESC define.
Merge and simplify multi-line error message.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
71c671bf4c USB: pl2303: remove bogus delta_msr_wait wake up
Remove bogus MSR wait-queue wake up from process_read_urb which never
updates the MSR flags.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:47 -08:00
Johan Hovold
10c642d077 USB: serial: remove redundant OOM messages
Remove redundant error messages on allocation failures, which have
already been logged.

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:46 -08:00
Johan Hovold
4d5147ec90 USB: serial: clean up ioctl debugging
Remove redundant ioctl debugging from subdrivers. The ioctl request code
has already been logged by usb-serial core.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:46 -08:00
Johan Hovold
623c826337 USB: pl2303: fix data corruption on termios updates
Some PL2303 devices are known to lose bytes if you change serial
settings even to the same values as before. Avoid this by comparing the
encoded settings with the previsouly used ones before configuring the
device.

The common case was fixed by commit bf5e5834bf ("pl2303: Fix mode
switching regression"), but this problem was still possible to trigger,
for instance, by using the TCSETS2-interface to repeatedly request
115201 baud, which gets mapped to 115200 and thus always triggers a
settings update.

Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-03 12:31:46 -08:00
Colin Leitner
a313249937 USB: pl2303: fixed handling of CS5 setting
This patch fixes the CS5 setting on the PL2303 USB-to-serial devices. CS5 has a
value of 0 and the CSIZE setting has been skipped altogether by the enclosing
if. Tested on 3.11.6 and the scope shows the correct output after the fix has
been applied.

Tagged to be added to stable, because it fixes a user visible driver bug and is
simple enough to backport easily.

Signed-off-by: Colin Leitner <colin.leitner@gmail.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-02 21:52:57 -08:00
Greg Kroah-Hartman
54dc5792ea Revert "USB: pl2303: restrict the divisor based baud rate encoding method to the "HX" chip type"
This reverts commit b8bdad6082.

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>
2013-11-01 09:19:56 -07:00
Greg Kroah-Hartman
1796a22876 Revert "usb: pl2303: fix+improve the divsor based baud rate encoding method"
This reverts commit 57ce61aad7.

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>
2013-11-01 09:19:45 -07:00
Greg Kroah-Hartman
7e12a6fcbf Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method"
This reverts commit 75417d9f99.

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>
2013-11-01 09:19:34 -07:00
Greg Kroah-Hartman
336b9daf90 Revert "usb: pl2303: remove 500000 baud from the list of standard baud rates"
This reverts commit b9208c721c.

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>
2013-11-01 09:19:24 -07:00
Greg Kroah-Hartman
692ed4ddf0 Revert "usb: pl2303: move the two baud rate encoding methods to separate functions"
This reverts commit e917ba01d6.

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>
2013-11-01 09:19:03 -07:00
Greg Kroah-Hartman
92dfe41088 Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method"
This reverts commit b5c16c6a03.

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>
2013-11-01 09:18:47 -07:00
Greg Kroah-Hartman
e2afb1d666 Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips"
This reverts commit 61fa8d694b.

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>
2013-11-01 09:18:38 -07:00
Greg Kroah-Hartman
233c3dda5c Revert "usb: pl2303: add two comments concerning the supported baud rates with HX chips"
This reverts commit c23bda365d.

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>
2013-11-01 09:18:25 -07:00
Greg Kroah-Hartman
281393ad0b Revert "pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()"
This reverts commit 73b583af59.

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>
2013-11-01 09:18:10 -07:00
Greg Kroah-Hartman
b52e111363 Revert "pl2303: improve the chip type information output on startup"
This reverts commit a77a8c23e4.

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>
2013-11-01 09:17:50 -07:00
Greg Kroah-Hartman
e8bbd5c42b Revert "pl2303: improve the chip type detection/distinction"
This reverts commit 034d1527ad.

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>
2013-11-01 09:16:09 -07:00
Greg Kroah-Hartman
09169197c9 Revert "USB: pl2303: distinguish between original and cloned HX chips"
This reverts commit 7d26a78f62.

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>
2013-11-01 09:12:52 -07:00
Frank Schäfer
7d26a78f62 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>
2013-09-17 09:36:10 -07:00
Frank Schäfer
034d1527ad pl2303: improve the chip type detection/distinction
The driver currently knows about 3 different PL2303 chip types:
The two legacy chip types type_0 and type_1 (PL2303H ?) and the HX
type.
The device distinction is currently completely based on the examination
of the USB descriptors.
During the last years, Prolific has introduced further PL2303 chips,
such as the HXD (HX rev. D), TA (which replaced the X/HX chips), SA,
RA, EA and TB variants.
Unfortunately, all these new chips are currently detected as HX chips,
because they are all using the same bMaxPacketSize0 = 0x40 value in the
USB device descriptor.

At this point it is not clear if these chips are really working with
the driver, there are just some positive indicators (like device
manufacturers claiming Linux support for these devices or commit
8d48fdf689 "correctly handle baudrates above 115200" which should only
be necessary for newer devices, ...)

For a complete support of all devices, we need to distinguish between
them, because they differ in several functional aspects, such  as the
maximum supported baud rate (HXD, TB, EA: 12Mbps, HX, TA: 6Mbps,
RA: 1Mbps, SA: 115.2kbps), handshaking line support, RS422/485 and
GPIO ports support (currently not supported by the driver).
And there might be further differences that we don't know yet.

This patch improves the chip type detection by evaluating the bcdDevice
value of the device descriptor. The values are taken from the
datasheets and are safe to use because manufacturers can't change them:

3.00: X/HX, TA
4.00: HXD, EA, RA, SA
5.00: TB

The rest of the device descriptors is completely identical, so no
further distinction is possible this way.
Anyway, Prolifics "checkChipVersion.exe"-tool is definitely able to
distinguish for example between the X/HX and the TA chips, so there
must be a possibility to improve the distinction further...

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-14 12:12:43 -07:00
Frank Schäfer
a77a8c23e4 pl2303: improve the chip type information output on startup
The chip type distinction is getting more and more relevant and
complicating, so always print the chip type.
Printing a name string is also much better than just printing an
internal index number.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-14 12:12:42 -07:00
Frank Schäfer
73b583af59 pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()
There is no need for two else-if constructs for the type_1 chip
detection in pl2303_startup(), so merge them.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-14 12:12:42 -07:00
Frank Schäfer
c23bda365d usb: pl2303: add two comments concerning the supported baud rates with HX chips
I've found some new datasheets which describe some additionally
supported standard baud rates and I've verified them with my HX
(rev. 3A) device. But adding support for individual (chip type
specific) baud rates would add a good amount of extra code (especially
when support for further chips will be added to the driver one day),
which makes no sense as long as we are not using the direct baud rate
encoding method for newer chips.
So for now, just drop a comment about these additionally supported baud
rates.

The second comment is about the baud rate differences between the two
encoding methods. In theory, we could optimize the code a bit by
comparing the resulting baud rates of both methods and selecting the
one which is closer to the requested baud rate. But that seems to be a
bit overkill, because the differences are very small and the device
likely uses the same baud rate generator for both methods so that the
resulting baud rate would be the same.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 15:43:41 -07:00