GitLab

commit 2d9a0070 upstream.

In the unlikely event that setting the software flow-control characters
fails the other flow-control settings should still be updated (just like
all other terminal settings).

Move out the error message printed by the set_chars() helper to make it
more obvious that this is intentional.

Fixes: 7748feff

 ("USB: serial: cp210x: add support for software flow control")
Cc: stable@vger.kernel.org	# 5.11
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the USB serial device ID for the CEL ZigBee EM3588 radio stick.
Signed-off-by: John Keeping <john@metanate.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

Fix comments for GE CS1000 CP210x USB ID assignments.

Fixes: 42213a01

 ("USB: serial: cp210x: add some more GE USB IDs")
Signed-off-by: Ian Ray <ian.ray@ge.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

Similar to some other CP210x device types, CP2108 has a number of GPIO
pins that can be exposed through gpiolib.

CP2108 has four serial interfaces but only one set of GPIO pins, which
is modelled as a single gpio chip and registered as a child of the first
interface.

CP2108 has 16 GPIOs so the width of the state variables needs to be
extended to 16 bits and this is also reflected in the control requests.

Like CP2104, CP2108 have GPIO pins with configurable alternate
functions and pins unavailable for GPIO use are determined and reported
to gpiolib at probe.
Signed-off-by: Pho Tran <pho.tran@silabs.com>
Co-developed-by: Tung Pham <tung.pham@silabs.com>
Signed-off-by: Tung Pham <tung.pham@silabs.com>
[ johan: rewrite gpio get() and set(); misc cleanups; amend commit
         message ]
Link: https://lore.kernel.org/r/20210610132844.25495-1-johan@kernel.org

Signed-off-by: Johan Hovold <johan@kernel.org>

CP2102N revision A01 (firmware version <= 1.0.4) has a buggy
flow-control implementation that uses the ulXonLimit instead of
ulFlowReplace field of the flow-control settings structure (erratum
CP2102N_E104).

A recent change that set the input software flow-control limits
incidentally broke RTS control for these devices when CRTSCTS is not set
as the new limits would always enable hardware flow control.

Fix this by explicitly disabling flow control for the buggy firmware
versions and only updating the input software flow-control limits when
IXOFF is requested. This makes sure that the terminal settings matches
the default zero ulXonLimit (ulFlowReplace) for these devices.

Link: https://lore.kernel.org/r/20210609161509.9459-1-johan@kernel.org

Reported-by: David Frey <dpfrey@gmail.com>
Reported-by: Alex Villacís Lasso <a_villacis@palosanto.com>
Tested-by: Alex Villacís Lasso <a_villacis@palosanto.com>
Fixes: f61309d9

 ("USB: serial: cp210x: set IXOFF thresholds")
Cc: stable@vger.kernel.org      # 5.12
Signed-off-by: Johan Hovold <johan@kernel.org>

The QFN20 part has a different GPIO/port function assignment. The
configuration struct bit field ordered as TX/RX/RS485/WAKEUP/CLK
which exactly matches GPIO0-3 for QFN24/28. However, QFN20 has a
different GPIO to primary function assignment.

Special case QFN20 to follow to properly detect which GPIOs are
available.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Link: https://lore.kernel.org/r/51830b2b24118eb0f77c5c9ac64ffb2f519dbb1d.1622218300.git.stefan@agner.ch
Fixes: c8acfe0a

 ("USB: serial: cp210x: implement GPIO support for CP2102N")
Cc: stable@vger.kernel.org	# 4.19
Signed-off-by: Johan Hovold <johan@kernel.org>

Add a debug printk to dump the GPIO configuration stored in EEPROM
during probe.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the new GPIO valid-mask feature to inform gpiolib which pins are
available for use instead of handling that in a request callback.

This also allows user space to figure out which pins are available
through the chardev interface without having to request each pin in
turn.

Note that the return value when requesting an unavailable pin will now
be -EINVAL instead of -ENODEV.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

GE CS1000 has some more custom USB IDs for CP2102N; add them
to the driver to have working auto-probing.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

IDs of nLight Air Adapter, Acuity Brands, Inc.:
vid: 10c4
pid: 88d8
Signed-off-by: Karan Singhal <karan.singhal@acuitybrands.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

All usb_serial drivers return 0 in their remove callbacks and driver
core ignores the value returned by usb_serial_device_remove(). So change
the remove callback to return void and return 0 unconditionally in
usb_serial_device_remove().
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210208143149.963644-2-uwe@kleine-koenig.org

Signed-off-by: Johan Hovold <johan@kernel.org>

Clear the RTS bits of the flow-control request before determining the
new value when updating the settings.
Signed-off-by: Johan Hovold <johan@kernel.org>

Clearing TIOCM_RTS should always deassert RTS and setting the same bit
should enable auto-RTS if hardware flow control is enabled.

This allows user space to throttle input directly at the source also
when hardware-assisted flow control is enabled and makes dtr_rts()
always deassert both lines during close (when HUPCL is set).
Signed-off-by: Johan Hovold <johan@kernel.org>

Use the 0-flag and a field width to specify zero-padding consistently in
printk messages.
Signed-off-by: Johan Hovold <johan@kernel.org>

Shorten the flow-control debug message by abbreviating the field names
and reducing the value width to two characters. The latter improves
readability since all but the least significant byte will almost always
be zero anyway.
Signed-off-by: Johan Hovold <johan@kernel.org>

Drop the macros used to shift the flow-control settings to make the code
more readable for consistency with the other requests.
Signed-off-by: Johan Hovold <johan@kernel.org>

The vendor request used to set the flow-control settings also sets the
state of the modem-control lines.

Add state variables to keep track of the modem-control lines to avoid
always asserting the lines whenever the flow-control settings are
updated.

This specifically also avoids asserting DTR/RTS when opening a port with
the line speed set to B0.
Signed-off-by: Johan Hovold <johan@kernel.org>

The CP210X_SET_MHS request cannot be used to control RTS when hardware
flow control (auto-RTS) is enabled and instead returns an error which is
currently logged as:

	cp210x ttyUSB0: failed set request 0x7 status: -32

when opening and closing a port (and on TIOCMSET requests).

Add a crtscts flag to keep track of the hardware flow-control setting
and use it to suppress any request to change RTS when auto-RTS is
enabled.

Note that RTS is still deasserted when disabling the UART as part of
close.
Reported-by: Pho Tran <pho.tran@silabs.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

Information pid/vid of WSDA-200-USB, Lord corporation company:
vid: 199b
pid: ba30
Signed-off-by: Pho Tran <pho.tran@silabs.com>
[ johan: amend comment with product name ]
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

Add a copyright notice for myself.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Drop include directives that are no longer used.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

There's no need to check for short control transfers when sending data
so remove the redundant sanity checks.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Update the XON/XOFF control characters also when no other flow-control
flag has changed and software flow control is enabled.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

At least CP2102 requires the XON/XOFF limits to be initialised in order
for software input flow control (IXOFF) to work. Specifically, XOFF is
never sent if the XOFF limit is left at its default value of zero.

Set the limits so that input is throttled when the FIFO free level drops
below 128 bytes and restarted when the FIFO fill level drops below 128
bytes.

Note that the threshold values have been chosen so that they can be used
also with CP2105 which has the smallest FIFO of the currently supported
device types (288 byte for the SCI port). If needed the limits can be
made device specific later.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

When data is transmitted between two serial ports, the phenomenon of
data loss often occurs. The two kinds of flow control commonly used in
serial communication are hardware flow control and software flow
control.

In serial communication, If you only use RX/TX/GND Pins, you can't do
hardware flow. So we often used software flow control and prevent data
loss. The user sets the software flow control through the application
program, and the application program sets the software flow control mode
for the serial port chip through the driver.

For the cp210 serial port chip, its driver lacks the software flow
control setting code, so the user cannot set the software flow control
function through the application program. This adds the missing software
flow control.
Signed-off-by: Wang Sheng Long <shenglong.wang.ext@siemens.com>
Link: https://lore.kernel.org/r/20210104094502.3942-1-china_shenglong@163.com


[ johan: rework properly on top of recent termios changes ]
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Teraoka AD2000 uses the CP210x driver, but the chip VID/PID is
customized with 0988/0578. We need the driver to support the new
VID/PID.
Signed-off-by: Chenxin Jin <bg4akv@hotmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>

Clean up dtr_rts() by renaming the port parameter and adding missing
whitespace.
Signed-off-by: Johan Hovold <johan@kernel.org>

Add a helper function to be used to configure flow control.

The flow-control code was the last caller that relied on the
memset-on-failure behaviour of cp210x_read_reg_block(), which we can now
drop in favour of bailing out on errors when retrieving the flow-control
settings.

This should also simplify adding support for software flow control.
Signed-off-by: Johan Hovold <johan@kernel.org>

Drop some unnecessary flow-control debugging.
Signed-off-by: Johan Hovold <johan@kernel.org>

Unlike other drivers cp210x have been retrieving the current terminal
settings from the device on open and reflecting those in termios.

Due to how set_termios() used to be implemented, this saved a few
control requests on open but has instead caused problems like broken
flow control and has required adding workarounds for swapped
line-control in cp2108 and line-speed initialisation on cp2104.

This unusual implementation also complicates adding new features for no
good reason.

Rip out the corresponding code and the above mentioned workarounds and
instead initialise the terminal settings unconditionally on open.
Signed-off-by: Johan Hovold <johan@kernel.org>

Update the line-control settings in one request unconditionally instead
of setting the word-length, parity and stop-bit settings separately.

This avoids multiple requests when several settings are changed even if
this scheme could potentially also be used to detect unsupported device
settings. Since all device types but CP2101 appears to support all
settings, let's handle that one specifically and also report back the
unsupported settings properly through termios by clearing the
corresponding bits.

Also drop the related unnecessary debug printks.
Signed-off-by: Johan Hovold <johan@kernel.org>

Return early from set_termios() in case no relevant terminal settings
have changed.

This avoids testing each parameter in turn and specifically allows the
line-control handling to be cleaned up further.
Signed-off-by: Johan Hovold <johan@kernel.org>

The port data is not exported to user space so use the in-kernel u8
type.

Link: https://lore.kernel.org/r/20200713105517.27796-6-johan@kernel.org

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Drop unnecessary packed attributes from structs without padding.

Link: https://lore.kernel.org/r/20200713105517.27796-5-johan@kernel.org

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Enable TIOCGICOUNT to allow reading out the (unused) interrupt counters
and error statistics.

Note that modem-status events are currently left unimplemented as they
appear to be buffered on at least CP2102 and therefore cannot be used to
implement TIOCMIWAIT.

Link: https://lore.kernel.org/r/20200713105517.27796-4-johan@kernel.org

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Add support for line-status events that specifically can be used to
detect and report parity errors.

Enable the device's event-insertion mode whenever input-parity checking
is requested. This will insert line and modem status events into the
data stream.

Note that modem-status changes appear to be buffered until a character
is received (at least on CP2102) and support is therefore left
unimplemented.

On at least one type of these chips (CP2102), line breaks are not
reported as expected either (regardless of whether SERIAL_BREAK_CHAR is
set) so do not enable event-mode when !IGNBRK is requested for now.

Link: https://lore.kernel.org/r/20200713105517.27796-3-johan@kernel.org

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

Try to disable the serial interface in the unlikely event that generic
open() fails.

Link: https://lore.kernel.org/r/20200713105517.27796-2-johan@kernel.org

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

CP210x hardware disables auto-RTS but leaves auto-CTS when in hardware
flow control mode and UART on cp210x hardware is disabled. When
re-opening the port, if auto-CTS is enabled on the cp210x, then auto-RTS
must be re-enabled in the driver.
Signed-off-by: Brant Merryman <brant.merryman@silabs.com>
Co-developed-by: Phu Luu <phu.luu@silabs.com>
Signed-off-by: Phu Luu <phu.luu@silabs.com>
Link: https://lore.kernel.org/r/ECCF8E73-91F3-4080-BE17-1714BC8818FB@silabs.com
[ johan: fix up tags and problem description ]
Fixes: 39a66b8d

 ("[PATCH] USB: CP2101 Add support for flow control")
Cc: stable <stable@vger.kernel.org>     # 2.6.12
Signed-off-by: Johan Hovold <johan@kernel.org>

Assign the .throttle and .unthrottle functions to be generic function
in the driver structure to prevent data loss that can otherwise occur
if the host does not enable USB throttling.
Signed-off-by: Brant Merryman <brant.merryman@silabs.com>
Co-developed-by: Phu Luu <phu.luu@silabs.com>
Signed-off-by: Phu Luu <phu.luu@silabs.com>
Link: https://lore.kernel.org/r/57401AF3-9961-461F-95E1-F8AFC2105F5E@silabs.com
[ johan: fix up tags ]
Fixes: 39a66b8d

 ("[PATCH] USB: CP2101 Add support for flow control")
Cc: stable <stable@vger.kernel.org>     # 2.6.12
Signed-off-by: Johan Hovold <johan@kernel.org>

Add support for the Mark-10 digital force gauge device to the cp201x
driver.

Based on a report and a larger patch from Joel Jennings
Reported-by: Joel Jennings <joel.jennings@makeitlabs.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191118092119.GA153852@kroah.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>