Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config().
Since this function is called with the port lock held, this can be a
problem in case that setting the GPIO line can sleep (e.g. if a GPIO
expander is used which is connected via SPI or I2C).

Avoid this issue by moving the GPIO setting outside of the port lock into
the serial core and thus making it a generic feature.

Also with commit c54d4854 ("serial: stm32: Add support for rs485
RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a
rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too.

Furthermore reset old GPIO settings in case that changing the RS485
configuration failed.

Fixes: c54d4854 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO")
Fixes: ca530cfa ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO")
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc:  <stable@vger.kernel.org>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Debug Communication Channel (DCC) provides the way how to pass data between
target CPU and host via JTAG interface. Every CPU has own interface for
communication via dbgdtrtx_el0 and dbgdtrrx_el0 registers.
Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/9d7e85914eb1cdb313b28cb019093a84dd9b4773.1703167505.git.michal.simek@amd.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit fcc446c8 ("serial: 8250_bcm2835aux: Add ACPI support")
dropped the error handling for clock acquiring. But even an optional
clock needs this.

Fixes: fcc446c8 ("serial: 8250_bcm2835aux: Add ACPI support")
Cc: stable <stable@kernel.org>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231220114334.4712-1-wahrenst@gmx.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In PCI1XXXX C0 endpoint, support for Burst mode is added.
pci1xxxx_handle_irq checks the burst status and based on that
incoming characters are received in DWORDs, RX handling is done
in pci1xxxx_rx_burst. While reading the burst status the RX error
is checked and the corresponding error statistics are updated.
Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20231215151123.41812-4-rengarajan.s@microchip.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Different Host drivers can attempt to access system registers
simultaneously from different memory spaces at the same time. The
syslock mechanism provides a safe option for reading UART system
registers and prevents conflicts by serializing access. Added
three padding bytes in the structure for memory alignment.
Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20231215151123.41812-3-rengarajan.s@microchip.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Structure declarations in 8250_pci1xxxx.c have been moved above
the functions for code readability.
Signed-off-by: Rengarajan S <rengarajan.s@microchip.com>
Link: https://lore.kernel.org/r/20231215151123.41812-2-rengarajan.s@microchip.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use devm_kmemdup() helper to copy dma_param instead of doing it manually.
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20240102055006.27256-1-raag.jadav@intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

After switching the serial interface of the Moxa RS232 PCIe boards, it
fails to reset to RS232 when attempting to reload 8250_pci driver.

This patch set RS232 as the default setting during the initialization of
Moxa PCIe board.
Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Link: https://lore.kernel.org/r/20240102053133.9795-1-crescentcy.hsieh@moxa.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Designware UART has optional feature FIFO_MODE to implement FIFO.
Encoding FIFO capabilities through Component Parameter Register CPR is
optional and it can be enabled using parameter UART_ADD_ENCODED_PARAMS.

Driver can exercise fifo capabilities by decoding CPR if implemented
or from cpr_val provided from the dw8250_platform_data otherwise.

dw8250_setup_port() checks for CPR or cpr_val to determine FIFO size
only when Component Version (UCV) is non-zero. Bailing out early on UCV
read returning zero will leave fifosize as zero and !UART_CAP_FIFO,
hence prevent early return and continue to process CPR or cpr_val for
the driver to utilize FIFO.

Non-zero UCV implies ADDITIONAL_FEATURES=1, preventing early return
will not be an overhead here.
Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20231231182951.877805-1-vamshigajjela@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There are register accesses in the function imx_uart_rs485_config(). The
clock must be enabled for these accesses. This was ensured by calling it
via the function uart_rs485_config() in the probe() function within the
range where the clock is enabled. With the commit 7c7f9bc9 ("serial:
Deassert Transmit Enable on probe in driver-specific way") it was removed
from the probe() function and is now only called through the function
uart_add_one_port() which is located at the end of the probe() function.
But the clock is already switched off in this area. To ensure that the
clock is enabled during register access, move the disabling of the clock
to the very end of the probe() function. To avoid leaking enabled clocks
on error also add an error path for exiting with disabling the clock.

Fixes: 7c7f9bc9 ("serial: Deassert Transmit Enable on probe in driver-specific way")
Cc: stable <stable@kernel.org>
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20231226113647.39376-1-cniedermaier@dh-electronics.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When using a leon kernel with qemu there where no console prompt.
The root cause is the handling of the fifo size in the tx part of the
apbuart driver.

The qemu uart driver only have a very rudimentary status handling and do
not report the number of chars queued in the tx fifo in the status register.
So the driver ends up with a fifo size of 1.

In the tx path the fifo size is divided by 2 - resulting in a fifo
size of zero.

The original implementation would always try to send one char, but
after the introduction of uart_port_tx_limited() the fifo size is
respected even for the first char.

There seems to be no good reason to divide the fifo size with two - so
remove this. It looks like something copied from the original amba driver.

With qemu we now have a minimum fifo size of one char, so we show
the prompt.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Fixes: d11cc8c3 ("tty: serial: use uart_port_tx_limited()")
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc:  <linux-serial@vger.kernel.org>
Cc:  <sparclinux@vger.kernel.org>
Link: https://lore.kernel.org/r/20231226121607.GA2622970@ravnborg.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Check if port type is not PORT_UNKNOWN during poll_init.
The kgdboc calls the tty_find_polling_driver that check
if the serial is able to use poll_init. The poll_init calls
the uart uart_poll_init that try to configure the uart with the
selected boot parameters. The uart must be ready before setting
parameters. Seems that PORT_UNKNOWN is already used by other
functions in serial_core to detect uart status, so use the same
to avoid to use it in invalid state.

The crash happen for instance in am62x architecture where the 8250
register the platform driver after the 8250 core is initialized.

Follow the report crash coming from KGDB

Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584		__raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt

This section of the code is too early because in this case
the omap serial is not probed

Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584		__raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt

Thread 2 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
_outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
584		__raw_writeb(value, PCI_IOBASE + addr);
(gdb) bt
0  _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584
1  logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299
2  0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416
3  0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>)
    at ./include/linux/serial_core.h:677
4  serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0)
    at drivers/tty/serial/8250/8250_port.c:2860
5  0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0)
    at drivers/tty/serial/8250/8250_port.c:2912
6  0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110)
    at drivers/tty/serial/serial_core.c:2285
7  0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8")
    at drivers/tty/serial/serial_core.c:2656
8  0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90)
    at drivers/tty/tty_io.c:410
9  0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194
10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249
11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404
12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579
13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658
14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810)
    at drivers/base/dd.c:800
15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830
16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48)
    at drivers/base/dd.c:958
17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48,
    fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457
18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030
19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079
20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532
21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625
22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716
23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292
24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236
25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298
26 do_initcalls () at init/main.c:1314
27 do_basic_setup () at init/main.c:1333
28 kernel_init_freeable () at init/main.c:1551
29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441
30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Correct the clock error message by changing the clock name.

Fixes: 1e512d45 ("serial: imx: add error messages when .probe fails")
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231224093209.2612-1-cniedermaier@dh-electronics.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Prior to this patch:

~# cat /proc/interrupts
...
 40:        123          0     GIC-0  72 Level     altera_uart
 41:          9          0     GIC-0  73 Level     altera_uart

After this patch:

~# cat /proc/interrupts
...
 40:          6          0     GIC-0  72 Level     ff200100.fpga-uart0
 41:         28          0     GIC-0  73 Level     ff200200.fpga-uart1
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/r/20231217195601.236002-1-antonynpavlov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add "SER_RS485_MODE_RS422" flag to struct serial_rs485, so that serial
port can switch interface into RS422 if supported by using ioctl command
"TIOCSRS485".

By treating RS422 as a mode of RS485, which means while enabling RS422
there are two flags need to be set (SER_RS485_ENABLED and
SER_RS485_MODE_RS422), it would make things much easier. For example
some places that checks for "SER_RS485_ENABLED" won't need to be rewritten.
Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Link: https://lore.kernel.org/r/20231201071554.258607-3-crescentcy.hsieh@moxa.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch replaces the bit shift code with "_BITUL()" macro inside
"serial_rs485" struct.
Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Link: https://lore.kernel.org/r/20231201071554.258607-2-crescentcy.hsieh@moxa.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename the variable size to temp and change its data type from
unsigned int to u64 to avoid type casting in multiplication. Remove the
intermediate variable frame_time and use temp instead to accommodate
the nanoseconds(ns). port->frame_time is an unsigned int, therefore an
explicit cast is used to improve readability. Having said this unsigned
int is sufficinet to hold frame time duration in nanoseconds for all
the standard baudrates.

Consider 9600 baud, it takes 1/9600 seconds for one bit, for a total of
10 bits (start, 8-bit data, stop) 10/9600=1.04 ms for 1 byte transfer,
frame_time here is 1041667ns. As baudrate increases frame_time
decreases, say for 115200 baud it is 86806ns.

To avoid costly 64-bit arithmetic we do not upconvert the type for
variable frame_time as overflow happens for extremely low baudrates
which are impractical and are not used in real-world applications.
Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20231109063417.3971005-3-vamshigajjela@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The function uart_fifo_timeout() returns an unsigned long value, which
is the number of jiffies. Therefore, change the variable timeout in the
function uart_poll_timeout() from int to unsigned long.
Change the return type of the function uart_poll_timeout() from int to
unsigned long to be consistent with the type of timeout values.
Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20231109063417.3971005-2-vamshigajjela@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MOXA PCIe RS422/RS485 boards will not function by default because of the
initial default serial interface of all MOXA PCIe boards is set to
RS232.

This patch fixes the problem above by setting the initial default serial
interface to RS422 for those MOXA RS422/RS485 PCIe boards.
Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231214060234.6147-1-crescentcy.hsieh@moxa.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

On this platform, different vendor data is used. That requires a
compile-time check as we access (1) a global boolean & (2) our local
vendor data. Both symbols are accessible only when
CONFIG_ACPI_SPCR_TABLE is enabled.

Factor the vendor data overriding to a separate function that is empty
when CONFIG_ACPI_SPCR_TABLE is not defined.
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-8-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The whole function body is encapsulated inside an if-condition. Reverse
the if logic and early return to remove one indentation level.

Also turn two nested ifs into a single one at the end of the function.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-7-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the following messages from checkpatch:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

    ERROR: do not initialise statics to false
    WARNING: Possible unnecessary 'out of memory' message
    WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
    WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then
             dev_info(dev, ... then pr_info(...  to
    CHECK: Prefer using the BIT macro
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-6-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the following checkpatch warnings & checks:

	$ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

    CHECK: Unbalanced braces around else statement
    CHECK: Unnecessary parentheses around '[...]'
    CHECK: braces {} should be used on all arms of this statement
    CHECK: Comparison to NULL could be written "[...]"
    WARNING: Comparisons should place the constant on the right side of the test
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-5-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove all instances of quoted strings split across lines. Fix four
checkpatch warnings:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c
    WARNING: quoted string split across lines
    [...]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-4-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
simplify the logic. Those look scary to checkpatch because they contain
ifs without do-while loops.

Avoid the macros by creating small equivalent static functions; that
lets the compiler do its type checking & avoids checkpatch errors.

For the second instance __assign_bit is not usable because it deals with
unsigned long pointers whereas we have an unsigned int in
pl011_set_mctrl.

This addresses the following checkpatch warnings:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

    ERROR: Macros starting with if should be enclosed by a do -
           while loop to avoid possible if/else logic defects

    CHECK: Macro argument 'uartbit' may be better as '(uartbit)' to
           avoid precedence issues

    ERROR: Macros starting with if should be enclosed by a do - while
           loop to avoid possible if/else logic defects

    CHECK: Macro argument 'tiocmbit' may be better as '(tiocmbit)' to
           avoid precedence issues
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-3-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Follow recommandations from:

    $ ./scripts/checkpatch.pl --strict --file \
        drivers/tty/serial/amba-pl011.c

We fix 5 warnings and 48 checks, all related to whitespace.
Culprits are:

CHECK: Alignment should match open parenthesis
CHECK: Blank lines aren't necessary after an open brace '{'
CHECK: Lines should not end with a '('
CHECK: Please don't use multiple blank lines
CHECK: Please use a blank line after function/struct/union/enum
       declarations
CHECK: spaces preferred around that '/' (ctx:VxV)
CHECK: spaces preferred around that '|' (ctx:VxV)
WARNING: Missing a blank line after declarations
WARNING: please, no spaces at the start of a line
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-2-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver uses bit shifts and hexadecimal expressions to declare
constants. Replace that with the BIT(), GENMASK() & FIELD_PREP_CONST()
macros to clarify intent.

include/linux/amba/serial.h gets included from arch/arm/include/debug/pl01x.S.
Avoid includes and macro tricks for the four defines that are involved:
UART01x_DR, UART01x_FR, UART01x_FR_TXFF and UART01x_FR_BUSY.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-1-e384afa5e78c@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It can happen that while a break is received the transmitter gets empty
and IIR signals a Transmitter holding register empty (THRI) event. In
this case it's too early for the break workaround. Still doing it then
results in the THRI event not being rereported which makes the driver
miss that and e.g. for RS485 half-duplex communication it fails to
switch back to RX mode.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231213174312.2341013-1-u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a spelling mistake in a pr_warn message. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20231208102331.3267192-1-colin.i.king@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The UMS9620 also uses the same serial device with SC9836.
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20231215085630.984892-4-chunyan.zhang@unisoc.comAcked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit cc4c1d05 ("sc16is7xx: Properly resume TX after stop") changed
behavior to unconditionnaly set the THRI interrupt in sc16is7xx_tx_proc().

For example when sending a 65 bytes message, and assuming the Tx FIFO is
initially empty, sc16is7xx_handle_tx() will write the first 64 bytes of the
message to the FIFO and sc16is7xx_tx_proc() will then activate THRI. When
the THRI IRQ is fired, the driver will write the remaining byte of the
message to the FIFO, and disable THRI by calling sc16is7xx_stop_tx().

When sending a 2 bytes message, sc16is7xx_handle_tx() will write the 2
bytes of the message to the FIFO and call sc16is7xx_stop_tx(), disabling
THRI. After sc16is7xx_handle_tx() exits, control returns to
sc16is7xx_tx_proc() which will unconditionally set THRI. When the THRI IRQ
is fired, the driver simply acknowledges the interrupt and does nothing
more, since all the data has already been written to the FIFO. This results
in 2 register writes and 4 register reads all for nothing and taking
precious cycles from the I2C/SPI bus.

Fix this by enabling the THRI interrupt only when we fill the Tx FIFO to
its maximum capacity and there are remaining bytes to send in the message.

Fixes: cc4c1d05 ("sc16is7xx: Properly resume TX after stop")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-7-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The SC16IS7XX IC supports a burst mode to access the FIFOs where the
initial register address is sent ($00), followed by all the FIFO data
without having to resend the register address each time. In this mode, the
IC doesn't increment the register address for each R/W byte.

The regmap_raw_read() and regmap_raw_write() are functions which can
perform IO over multiple registers. They are currently used to read/write
from/to the FIFO, and although they operate correctly in this burst mode on
the SPI bus, they would corrupt the regmap cache if it was not disabled
manually. The reason is that when the R/W size is more than 1 byte, these
functions assume that the register address is incremented and handle the
cache accordingly.

Convert FIFO R/W functions to use the regmap _noinc_ versions in order to
remove the manual cache control which was a workaround when using the
_raw_ versions. FIFO registers are properly declared as volatile so
cache will not be used/updated for FIFO accesses.

Fixes: dfeae619 ("serial: sc16is7xx")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-6-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the driver has been converted to use one regmap per port, change
efr locking to operate on a channel basis instead of on the whole IC.

Fixes: 3837a037 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org> # 6.1.x: 3837a037 serial: sc16is7xx: improve regmap debugfs by using one regmap per port
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-5-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the driver has been converted to use one regmap per port, the line
structure member is no longer used, so remove it.

Fixes: 3837a037 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-4-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove global struct regmap so that it is more obvious that this
regmap is to be used only in the probe function.

Also add a comment to that effect in probe function.

Fixes: 3837a037 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-3-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using a static buffer inside sc16is7xx_regmap_name() was a convenient and
simple way to set the regmap name without having to allocate and free a
buffer each time it is called. The drawback is that the static buffer
wastes memory for nothing once regmap is fully initialized.

Remove static buffer and use constant strings instead.

This also avoids a truncation warning when using "%d" or "%u" in snprintf
which was flagged by kernel test robot.

Fixes: 3837a037 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org> # 6.1.x: 3837a037 serial: sc16is7xx: improve regmap debugfs by using one regmap per port
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-2-hugo@hugovil.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/d20d3ac106bac6b7cabe39f22ad00ac86910e0a5.1702230342.git.christophe.jaillet@wanadoo.frSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root
users to checkpoint and restore processes as non-root with CRIU.

This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option
'--shell-job' as non-root. CRIU's man-page describes the '--shell-job'
option like this:

  Allow one to dump shell jobs. This implies the restored task will
  inherit session and process group ID from the criu itself. This option
  also allows to migrate a single external tty connection, to migrate
  applications like top.

TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and
this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE.

With this change it is possible to checkpoint and restore processes
which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is
set.
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Adrian Reber <areber@redhat.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.

Error checking for matching was not necessary as matching is always
successful if we're already in probe and the match tables always have data
pointers.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231207162632.2650356-2-robh@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it was merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. Soon the implicit includes are going to be removed.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231207162632.2650356-1-robh@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>