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110 commits

Author SHA1 Message Date
Hugo Villeneuve
1a0a2a1e57 serial: sc16is7xx: use device_property APIs when configuring irda mode
Convert driver to be property provider agnostic and allow it to be
used on non-OF platforms.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20230927160153.2717788-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-03 14:59:08 +02:00
Thomas Gleixner
b465848be8 serial: sc16is7xx: Use port lock wrappers
When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.

Converted with coccinelle. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-56-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-18 11:18:14 +02:00
Hugo Villeneuve
064f3bb3bc serial: sc16is7xx: improve comments about variants
Replace 740/750/760 with generic terms like 74x/75x/76x to account for
variants like 741, 752 and 762.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Link: https://lore.kernel.org/r/20230905151300.15365-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-18 11:14:43 +02:00
Hugo Villeneuve
22a048b074 serial: sc16is7xx: remove unused to_sc16is7xx_port macro
This macro is not used anywhere.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230905181649.134720-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-18 11:14:42 +02:00
Hugo Villeneuve
b4a778303e serial: sc16is7xx: add missing support for rs485 devicetree properties
Retrieve rs485 devicetree properties on registration of sc16is7xx ports in
case they are attached to an rs485 transceiver.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
Link: https://lore.kernel.org/r/20230807214556.540627-7-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22 15:30:00 +02:00
Hugo Villeneuve
9baeea723c serial: sc16is7xx: fix bug when first setting GPIO direction
When configuring a pin as an output pin with a value of logic 0, we
end up as having a value of logic 1 on the output pin. Setting a
logic 0 a second time (or more) after that will correctly output a
logic 0 on the output pin.

By default, all GPIO pins are configured as inputs. When we enter
sc16is7xx_gpio_direction_output() for the first time, we first set the
desired value in IOSTATE, and then we configure the pin as an output.
The datasheet states that writing to IOSTATE register will trigger a
transfer of the value to the I/O pin configured as output, so if the
pin is configured as an input, nothing will be transferred.

Therefore, set the direction first in IODIR, and then set the desired
value in IOSTATE.

This is what is done in NXP application note AN10587.

Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
Link: https://lore.kernel.org/r/20230807214556.540627-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22 15:30:00 +02:00
Hugo Villeneuve
0499942928 serial: sc16is7xx: fix regression with GPIO configuration
Commit 679875d1d8 ("sc16is7xx: Separate GPIOs from modem control lines")
and commit 21144bab4f ("sc16is7xx: Handle modem status lines")
changed the function of the GPIOs pins to act as modem control
lines without any possibility of selecting GPIO function.

As a consequence, applications that depends on GPIO lines configured
by default as GPIO pins no longer work as expected.

Also, the change to select modem control lines function was done only
for channel A of dual UART variants (752/762). This was not documented
in the log message.

Allow to specify GPIO or modem control line function in the device
tree, and for each of the ports (A or B).

Do so by using the new device-tree property named
"nxp,modem-control-line-ports" (property added in separate patch).

When registering GPIO chip controller, mask-out GPIO pins declared as
modem control lines according to this new DT property.

Fixes: 679875d1d8 ("sc16is7xx: Separate GPIOs from modem control lines")
Fixes: 21144bab4f ("sc16is7xx: Handle modem status lines")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230807214556.540627-5-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22 15:30:00 +02:00
Hugo Villeneuve
dabc54a457 serial: sc16is7xx: remove obsolete out_thread label
Commit c8f71b49ee ("serial: sc16is7xx: setup GPIO controller later
in probe") moved GPIO setup code later in probe function. Doing so
also required to move ports cleanup code (out_ports label) after the
GPIO cleanup code.

After these moves, the out_thread label becomes misplaced and makes
part of the cleanup code illogical.

This patch remove the now obsolete out_thread label and make GPIO
setup code jump to out_ports label if it fails.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230807214556.540627-3-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22 15:30:00 +02:00
Hugo Villeneuve
2861ed4d6e serial: sc16is7xx: fix broken port 0 uart init
The sc16is7xx_config_rs485() function is called only for the second
port (index 1, channel B), causing initialization problems for the
first port.

For the sc16is7xx driver, port->membase and port->mapbase are not set,
and their default values are 0. And we set port->iobase to the device
index. This means that when the first device is registered using the
uart_add_one_port() function, the following values will be in the port
structure:
    port->membase = 0
    port->mapbase = 0
    port->iobase  = 0

Therefore, the function uart_configure_port() in serial_core.c will
exit early because of the following check:
	/*
	 * If there isn't a port here, don't do anything further.
	 */
	if (!port->iobase && !port->mapbase && !port->membase)
		return;

Typically, I2C and SPI drivers do not set port->membase and
port->mapbase.

The max310x driver sets port->membase to ~0 (all ones). By
implementing the same change in this driver, uart_configure_port() is
now correctly executed for all ports.

Fixes: dfeae619d7 ("serial: sc16is7xx")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
Link: https://lore.kernel.org/r/20230807214556.540627-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-22 15:30:00 +02:00
Hui Wang
77a82cebf0 serial: sc16is7xx: Put IOControl register into regmap_volatile
According to the IOControl register bits description in the page 31 of
the product datasheet, we know the bit 3 of IOControl register is
softreset, this bit will self-clearing once the reset finish.

In the probe, the softreset bit is set, and when we read this register
from debugfs/regmap interface, we found the softreset bit is still
setting, this confused us for a while. Finally we found this register
is cached, to read the real value from register, we could put it
into the regmap_volatile().

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20230724034727.17335-1-hui.wang@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-30 13:53:35 +02:00
Jiri Slaby
fd2b55f86b serial: drivers: switch ch and flag to u8
Now that the serial layer explicitly expects 'u8' for flags and
characters, propagate this type to drivers' (RX) routines.

Note that amba-pl011's, clps711x's and st-asc's 'ch' are left unchanged
because 'ch' contains not only a character, but whole status.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Cc: Taichi Sugaya <sugaya.taichi@socionext.com>
Cc: Takao Orito <orito.takao@socionext.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Hammer Hsieh <hammerh0314@gmail.com>
Acked-by: Richard GENOUD <richard.genoud@gmail.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/20230712081811.29004-11-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-25 19:21:04 +02:00
Uwe Kleine-König
0d07703be7 serial: Switch i2c drivers back to use .probe()
After commit b8a1a4cd5a ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498 ("i2c: Switch .probe() to not take an id parameter")
convert back to (the new) .probe() to be able to eventually drop
.probe_new() from struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230525210147.734737-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30 11:46:05 +01:00
Uwe Kleine-König
01d93875da serial: sc16is7xx: Convert to i2c's .probe_new()
.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in the probe function.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/lkml/20221118224540.619276-572-uwe@kleine-koenig.org
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-03-09 21:58:53 +01:00
Isaac True
c8f71b49ee serial: sc16is7xx: setup GPIO controller later in probe
The GPIO controller component of the sc16is7xx driver is setup too
early, which can result in a race condition where another device tries
to utilise the GPIO lines before the sc16is7xx device has finished
initialising.

This issue manifests itself as an Oops when the GPIO lines are configured:

    Unable to handle kernel read from unreadable memory at virtual address
    ...
    pc : sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
    lr : sc16is7xx_gpio_direction_output+0x4c/0x108 [sc16is7xx]
    ...
    Call trace:
    sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
    gpiod_direction_output_raw_commit+0x64/0x318
    gpiod_direction_output+0xb0/0x170
    create_gpio_led+0xec/0x198
    gpio_led_probe+0x16c/0x4f0
    platform_drv_probe+0x5c/0xb0
    really_probe+0xe8/0x448
    driver_probe_device+0xe8/0x138
    __device_attach_driver+0x94/0x118
    bus_for_each_drv+0x8c/0xe0
    __device_attach+0x100/0x1b8
    device_initial_probe+0x28/0x38
    bus_probe_device+0xa4/0xb0
    deferred_probe_work_func+0x90/0xe0
    process_one_work+0x1c4/0x480
    worker_thread+0x54/0x430
    kthread+0x138/0x150
    ret_from_fork+0x10/0x1c

This patch moves the setup of the GPIO controller functions to later in the
probe function, ensuring the sc16is7xx device has already finished
initialising by the time other devices try to make use of the GPIO lines.
The error handling has also been reordered to reflect the new
initialisation order.

Co-developed-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Isaac True <isaac.true@canonical.com>
Link: https://lore.kernel.org/r/20221130105529.698385-1-isaac.true@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:53:41 +01:00
Ilpo Järvinen
a2a74303b3 serial: sc16is7xx: Use uart_xmit_advance()
Take advantage of the new uart_xmit_advance() helper.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221019091151.6692-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03 03:35:41 +01:00
Linus Torvalds
6181073dd6 TTY/Serial driver update for 6.1-rc1
Here is the big set of TTY and Serial driver updates for 6.1-rc1.
 
 Lots of cleanups in here, no real new functionality this time around,
 with the diffstat being that we removed more lines than we added!
 
 Included in here are:
 	- termios unification cleanups from Al Viro, it's nice to
 	  finally get this work done
 	- tty serial transmit cleanups in various drivers in preparation
 	  for more cleanup and unification in future releases (that work
 	  was not ready for this release.)
 	- n_gsm fixes and updates
 	- ktermios cleanups and code reductions
 	- dt bindings json conversions and updates for new devices
 	- some serial driver updates for new devices
 	- lots of other tiny cleanups and janitorial stuff.  Full
 	  details in the shortlog.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of TTY and Serial driver updates for 6.1-rc1.

  Lots of cleanups in here, no real new functionality this time around,
  with the diffstat being that we removed more lines than we added!

  Included in here are:

   - termios unification cleanups from Al Viro, it's nice to finally get
     this work done

   - tty serial transmit cleanups in various drivers in preparation for
     more cleanup and unification in future releases (that work was not
     ready for this release)

   - n_gsm fixes and updates

   - ktermios cleanups and code reductions

   - dt bindings json conversions and updates for new devices

   - some serial driver updates for new devices

   - lots of other tiny cleanups and janitorial stuff. Full details in
     the shortlog.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (102 commits)
  serial: cpm_uart: Don't request IRQ too early for console port
  tty: serial: do unlock on a common path in altera_jtaguart_console_putc()
  tty: serial: unify TX space reads under altera_jtaguart_tx_space()
  tty: serial: use FIELD_GET() in lqasc_tx_ready()
  tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar()
  tty: serial: allow pxa.c to be COMPILE_TESTed
  serial: stm32: Fix unused-variable warning
  tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMEL
  serial: 8250: Fix restoring termios speed after suspend
  serial: Deassert Transmit Enable on probe in driver-specific way
  serial: 8250_dma: Convert to use uart_xmit_advance()
  serial: 8250_omap: Convert to use uart_xmit_advance()
  MAINTAINERS: Solve warning regarding inexistent atmel-usart binding
  serial: stm32: Deassert Transmit Enable on ->rs485_config()
  serial: ar933x: Deassert Transmit Enable on ->rs485_config()
  tty: serial: atmel: Use FIELD_PREP/FIELD_GET
  tty: serial: atmel: Make the driver aware of the existence of GCLK
  tty: serial: atmel: Only divide Clock Divisor if the IP is USART
  tty: serial: atmel: Separate mode clearing between UART and USART
  dt-bindings: serial: atmel,at91-usart: Add gclk as a possible USART clock
  ...
2022-10-07 16:36:24 -07:00
Ilpo Järvinen
bec5b814d4 serial: Make ->set_termios() old ktermios const
There should be no reason to adjust old ktermios which is going to get
discarded anyway.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30 14:22:35 +02:00
Uwe Kleine-König
ed5c2f5fd1 i2c: Make remove callback return void
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00
Ilpo Järvinen
0139da50dc serial: Embed rs485_supported to uart_port
Embed rs485_supported to uart_port to allow serial core to tweak it as
needed.

Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-08 15:14:09 +02:00
Ilpo Järvinen
ae50bb2752 serial: take termios_rwsem for ->rs485_config() & pass termios as param
To be able to alter ADDRB within ->rs485_config(), take termios_rwsem
before calling ->rs485_config() and pass termios.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220624204210.11112-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27 14:44:20 +02:00
Ilpo Järvinen
bbdcbc1301 serial: sc16is7xx: Remove serial_rs485 assignment
Serial core handles serial_rs485 assignment. It is safe to remove this
assignment because sc16is7xx_reg_proc() takes port.lock at start (and
sc16is7xx_reconf_rs485() would too).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-36-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10 13:49:58 +02:00
Ilpo Järvinen
267913ecf7 serial: sc16is7xx: Fill in rs485_supported
Add information on supported serial_rs485 features.

This driver does not support delay_rts_after_send but the pre-existing
behavior is to return -EINVAL if delay_rts_after_send is non-zero. In
contrast, other drivers that do not support delay_rts_after_send either
zero delay_rts_after_send or do not care (leave the inaccurate value).
As changing this would cause userspace visible impact, the change is
not attempted here. But perhaps it should be still tried (maybe nobody
finds that kind of API oddity significant)?

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220606100433.13793-21-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10 13:49:56 +02:00
Greg Kroah-Hartman
9e6a907903 Merge 5.18-rc5 into tty-next
We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-02 14:56:14 +02:00
Hui Wang
41c606879f Revert "serial: sc16is7xx: Clear RS485 bits in the shutdown"
This reverts commit 927728a34f.

Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port
should always work in RS485 mode. If users want the port to leave
RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED.

So here we shouldn't clear the RS485 bits in the shutdown().

Fixes: 927728a34f ("serial: sc16is7xx: Clear RS485 bits in the shutdown")
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22 16:37:00 +02:00
Lino Sanfilippo
afea2a93c2 serial: sc16is7xx: remove redundant check in rs485_config
In uart_set_rs485_config() the serial core already ensures that only one of
both options RTS on send or RTS after send is set.

So remove this check from the drivers rs485_config() function to avoid
redundancy.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Link: https://lore.kernel.org/r/20220410104642.32195-5-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-15 11:30:22 +02:00
Linus Torvalds
7203062171 TTY/Serial driver changes for 5.18-rc1
Here are the big set of tty and serial driver changes for 5.18-rc1.
 
 Nothing major, some more good cleanups from Jiri and 2 new serial
 drivers.  Highlights include:
 	- termbits cleanups
 	- export symbol cleanups and other core cleanups from Jiri Slaby
 	- new sunplus and mvebu uart drivers (amazing that people are
 	  still creating new uarts...)
 	- samsung serial driver cleanups
 	- ldisc 29 is now "reserved" for experimental/development line
 	  disciplines
 	- lots of other tiny fixes and cleanups to serial drivers and
 	  bindings
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here are the big set of tty and serial driver changes for 5.18-rc1.

  Nothing major, some more good cleanups from Jiri and 2 new serial
  drivers. Highlights include:

   - termbits cleanups

   - export symbol cleanups and other core cleanups from Jiri Slaby

   - new sunplus and mvebu uart drivers (amazing that people are still
     creating new uarts...)

   - samsung serial driver cleanups

   - ldisc 29 is now "reserved" for experimental/development line
     disciplines

   - lots of other tiny fixes and cleanups to serial drivers and
     bindings

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (104 commits)
  vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE
  serial: 8250: fix XOFF/XON sending when DMA is used
  tty: serial: samsung: Add ARTPEC-8 support
  dt-bindings: serial: samsung: Add ARTPEC-8 UART
  serial: sc16is7xx: Clear RS485 bits in the shutdown
  tty: serial: samsung: simplify getting OF match data
  tty: serial: samsung: constify variables and pointers
  tty: serial: samsung: constify s3c24xx_serial_drv_data members
  tty: serial: samsung: constify UART name
  tty: serial: samsung: constify s3c24xx_serial_drv_data
  tty: serial: samsung: reduce number of casts
  tty: serial: samsung: embed s3c2410_uartcfg in parent structure
  tty: serial: samsung: embed s3c24xx_uart_info in parent structure
  serial: 8250_tegra: mark acpi_device_id as unused with !ACPI
  tty: serial: bcm63xx: use more precise Kconfig symbol
  serial: SERIAL_SUNPLUS should depend on ARCH_SUNPLUS
  tty: serial: jsm: fix two assignments in if conditions
  tty: serial: jsm: remove redundant assignments to variable linestatus
  serial: 8250_mtk: make two read-only arrays static const
  serial: samsung_tty: do not unlock port->lock for uart_write_wakeup()
  ...
2022-03-28 13:00:51 -07:00
Linus Torvalds
ad9c6ee642 spi: Updates for v5.18
The overwhelming bulk of this pull request is a change from Uwe
 Kleine-König which changes the return type of the remove() function to
 void as part of some wider work he's doing to do this for all bus types,
 causing updates to most SPI device drivers.  The branch with that on has
 been cross merged with a couple of other trees which added new SPI
 drivers this cycle, I'm not expecting any build issues resulting from
 the change.
 
 Otherwise it's been a relatively quiet release with some new device
 support, a few minor features and the welcome completion of the
 conversion of the subsystem to use GPIO descriptors rather than numbers:
 
  - Change return type of remove() to void.
  - Completion of the conversion of SPI controller drivers to use GPIO
    descriptors rather than numbers.
  - Quite a few DT schema conversions.
  - Support for multiple SPI devices on a bus in ACPI systems.
  - Big overhaul of the PXA2xx SPI driver.
  - Support for AMD AMDI0062, Intel Raptor Lake, Mediatek MT7986 and
    MT8186, nVidia Tegra210 and Tegra234, Renesas RZ/V2L, Tesla FSD and
    Sunplus SP7021.
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Merge tag 'spi-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The overwhelming bulk of this pull request is a change from Uwe
  Kleine-König which changes the return type of the remove() function to
  void as part of some wider work he's doing to do this for all bus
  types, causing updates to most SPI device drivers. The branch with
  that on has been cross merged with a couple of other trees which added
  new SPI drivers this cycle, I'm not expecting any build issues
  resulting from the change.

  Otherwise it's been a relatively quiet release with some new device
  support, a few minor features and the welcome completion of the
  conversion of the subsystem to use GPIO descriptors rather than
  numbers:

   - Change return type of remove() to void.

   - Completion of the conversion of SPI controller drivers to use GPIO
     descriptors rather than numbers.

   - Quite a few DT schema conversions.

   - Support for multiple SPI devices on a bus in ACPI systems.

   - Big overhaul of the PXA2xx SPI driver.

   - Support for AMD AMDI0062, Intel Raptor Lake, Mediatek MT7986 and
     MT8186, nVidia Tegra210 and Tegra234, Renesas RZ/V2L, Tesla FSD and
     Sunplus SP7021"

[ And this is obviously where that spi change that snuck into the
  regulator tree _should_ have been :^]

* tag 'spi-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (124 commits)
  spi: fsi: Implement a timeout for polling status
  spi: Fix erroneous sgs value with min_t()
  spi: tegra20: Use of_device_get_match_data()
  spi: mediatek: add ipm design support for MT7986
  spi: Add compatible for MT7986
  spi: sun4i: fix typos in comments
  spi: mediatek: support tick_delay without enhance_timing
  spi: Update clock-names property for arm pl022
  spi: rockchip-sfc: fix platform_get_irq.cocci warning
  spi: s3c64xx: Add spi port configuration for Tesla FSD SoC
  spi: dt-bindings: samsung: Add fsd spi compatible
  spi: topcliff-pch: Prevent usage of potentially stale DMA device
  spi: tegra210-quad: combined sequence mode
  spi: tegra210-quad: add acpi support
  spi: npcm-fiu: Fix typo ("npxm")
  spi: Fix Tegra QSPI example
  spi: qup: replace spin_lock_irqsave by spin_lock in hard IRQ
  spi: cadence: fix platform_get_irq.cocci warning
  spi: Update NXP Flexspi maintainer details
  dt-bindings: mfd: maxim,max77802: Convert to dtschema
  ...
2022-03-21 18:33:57 -07:00
Hui Wang
927728a34f serial: sc16is7xx: Clear RS485 bits in the shutdown
We tested RS485 function on an EVB which has SC16IS752, after
finishing the test, we started the RS232 function test, but found the
RTS is still working in the RS485 mode.

That is because both startup and shutdown call port_update() to set
the EFCR_REG, this will not clear the RS485 bits once the bits are set
in the reconf_rs485(). To fix it, clear the RS485 bits in shutdown.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20220308110042.108451-1-hui.wang@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-18 13:25:09 +01:00
Tomasz Moń
6e124e58ae sc16is7xx: Set AUTOCTS and AUTORTS bits
Let serial core know that the chip automatically handles RTS/CTS signal.
This elimines completely unnecessary I2C/SPI bus traffic.

Cease reading from RX FIFO (by disabling RDI interrupt) when throttled.
Eventually the FIFO will fill up and the device will drive RTS output
inactive. Unthrottle by enabling back RDI interrupt.

Indirectly controlling RTS via RX FIFO state seems to be the only option
because RTS bit is ignored when hardware flow control is enabled.

Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220301060332.2561851-4-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-01 22:16:59 +01:00
Tomasz Moń
21144bab4f sc16is7xx: Handle modem status lines
The uart_handle_cts_change() and uart_handle_dcd_change() must be called
with port lock being held. Acquire the lock after reading MSR register.
Do not acquire spin lock when reading MSR register because I2C/SPI port
functions cannot be called with spinlocks held.

Update rng and dsr counters. Wake up delta_msr_wait to allow tty notice
modem status change.

Co-developed-by: Lech Perczak <l.perczak@camlintechnologies.com>
Co-developed-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Signed-off-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220301060332.2561851-3-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-01 22:16:59 +01:00
Tomasz Moń
cc4c1d05eb sc16is7xx: Properly resume TX after stop
sc16is7xx_stop_tx() clears THRI bit and thus disables THRI interrupt.
This makes it possible for transmission to cease indefinitely when more
than 64 characters are being sent.

The sc16is7xx_handle_tx() call executed by sc16is7xx_tx_proc() can send
up to FIFO length (64) characters. If more characters are written to the
output buffer, then the THRI interrupt is needed.

Solve the issue by enabling THRI interrupt in sc16is7xx_tx_proc().

Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220301060332.2561851-2-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-01 22:16:58 +01:00
Greg Kroah-Hartman
d4ab5487cc Merge 5.17-rc6 into tty-next
We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-28 21:48:16 +01:00
Lech Perczak
679875d1d8 sc16is7xx: Separate GPIOs from modem control lines
Export only the GPIOs that are not shared with hardware modem control
lines. Introduce new device parameter indicating whether modem control
lines are available.

Signed-off-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220221105618.3503470-4-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-25 10:24:27 +01:00
Lech Perczak
6cca8f154a sc16is7xx: Update status lines in single call
RTS, DTR and LOOP bits can be updated in a single MCR register update.
This reduces the number of (slow) SPI/I2C bus transactions.

Signed-off-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220221105618.3503470-3-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-25 10:24:27 +01:00
Lech Perczak
c112653b89 sc16is7xx: Preserve EFR bits on update
Preserve unaffected bits state when accessing EFR register. This
prevents hardware flow control bits from being cleared on enhanced
functions access.

Signed-off-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220221105618.3503470-2-tomasz.mon@camlingroup.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-25 10:24:27 +01:00
Phil Elwell
eebb0f4e89 sc16is7xx: Fix for incorrect data being transmitted
UART drivers are meant to use the port spinlock within certain
methods, to protect against reentrancy. The sc16is7xx driver does
very little locking, presumably because when added it triggers
"scheduling while atomic" errors. This is due to the use of mutexes
within the regmap abstraction layer, and the mutex implementation's
habit of sleeping the current thread while waiting for access.
Unfortunately this lack of interlocking can lead to corruption of
outbound data, which occurs when the buffer used for I2C transmission
is used simultaneously by two threads - a work queue thread running
sc16is7xx_tx_proc, and an IRQ thread in sc16is7xx_port_irq, both
of which can call sc16is7xx_handle_tx.

An earlier patch added efr_lock, a mutex that controls access to the
EFR register. This mutex is already claimed in the IRQ handler, and
all that is required is to claim the same mutex in sc16is7xx_tx_proc.

See: https://github.com/raspberrypi/linux/issues/4885

Fixes: 6393ff1c44 ("sc16is7xx: Use threaded IRQ")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Link: https://lore.kernel.org/r/20220216160802.1026013-1-phil@raspberrypi.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-21 19:51:39 +01:00
Uwe Kleine-König
a0386bba70
spi: make remove callback a void function
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00
Uwe Kleine-König
9b29075c1a serial: sc16is7xx: Make sc16is7xx_remove() return void
Up to now sc16is7xx_remove() returns zero unconditionally. Make it
return void instead which makes it easier to see in the callers that
there is no error to handle.

Also the return value of spi remove callbacks is ignored anyway.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211012153945.2651412-19-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13 14:34:07 +02:00
Andy Shevchenko
cb1b206cff serial: sc16is7xx: Use devm_clk_get_optional()
Replace open coded variants of devm_clk_get_optional().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517173415.7483-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 16:30:40 +02:00
Annaliese McDermond
158e800e0f sc16is7xx: Defer probe if device read fails
A test was added to the probe function to ensure the device was
actually connected and working before successfully completing a
probe.  If the device was actually there, but the I2C bus was not
ready yet for whatever reason, the probe fails permanently.

Change the probe so that we defer the probe on a regmap read
failure so that we try the probe again when the dependent drivers
are potentially loaded.  This should not affect the case where the
device truly isn't present because the probe will never successfully
complete.

Fixes: 2aa916e67d ("sc16is7xx: Read the LSR register for basic device presence check")
Cc: stable@vger.kernel.org
Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
Link: https://lore.kernel.org/r/010101787f9c3fd8-c1815c00-2d6b-4c85-a96a-a13e68597fda-000000@us-west-2.amazonses.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-05 12:07:32 +02:00
Daniel Mack
5da6b1c079 sc16is7xx: Set iobase to device index
Some derivates of sc16is7xx devices expose more than one tty device to
userspace. If multiple such devices exist in a system, userspace
currently has no clean way to infer which tty maps to which physical
line.

Set the .iobase value to the relative index within the device to allow
infering the order through sysfs.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200901120329.4176302-1-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-04 17:14:47 +02:00
Peter Zijlstra
28d2f209cd sched,serial: Convert to sched_set_fifo()
Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

Effectively no change.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2020-06-15 14:10:23 +02:00
Pascal Huerst
9eb90d57b5 sc16is7xx: Add flag to activate IrDA mode
This series of uart controllers is able to work in IrDA mode.
Add per-port flag to the device-tree to enable that feature if needed.

Signed-off-by: Pascal Huerst <pascal.huerst@gmail.com>
Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200529055058.1606910-3-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-29 12:42:56 +02:00
Daniel Mack
2aa916e67d sc16is7xx: Read the LSR register for basic device presence check
Currently, the driver probes just fine and binds all its resources even
if the physical device is not present.

As the device lacks an identification register, let's at least read the
LSR register to check whether a device at the configured address responds
to the request at all.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-7-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-22 11:06:15 +02:00
Daniel Mack
2d12fc792c sc16is7xx: Allow sharing the IRQ line
When the interrupt line is shared with other devices, the IRQ must be
level-triggered, as only one device can trigger a falling edge. To support
this, try to acquire the IRQ with IRQF_TRIGGER_LOW|IRQF_SHARED first.

Interrupt controllers that lack support for level-triggers will return an
error, in which case the driver will now retry the acqusition with
IRQF_TRIGGER_FALLING, which was also the default before.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-6-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-22 11:06:14 +02:00
Daniel Mack
6393ff1c44 sc16is7xx: Use threaded IRQ
Use a threaded IRQ handler to get rid of the irq_work kthread.
This also allows for the driver to use interrupts generated by
a threaded controller.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-5-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-22 11:05:46 +02:00
Daniel Mack
37f3965d74 sc16is7xx: Always use falling edge IRQ
The driver currently only uses IRQF_TRIGGER_FALLING if the probing
happened without a device-tree setup. The device however will always
generate falling edges on its IRQ line, so let's use that flag in
all cases.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-4-daniel@zonque.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-22 11:04:23 +02:00
Gustavo A. R. Silva
4a37c0fcf5 serial: sc16is7xx: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200213004611.GA8748@embeddedor.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-13 12:00:23 -08:00
Greg Kroah-Hartman
3b8a1f45e1 Merge 5.1-rc6 into tty-next
We want the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-21 23:20:08 +02:00
Guoqing Jiang
c53051128b sc16is7xx: put err_spi and err_i2c into correct #ifdef
err_spi is only called within SERIAL_SC16IS7XX_SPI
while err_i2c is called inside SERIAL_SC16IS7XX_I2C.
So we need to put err_spi and err_i2c into each #ifdef
accordingly.

This change fixes ("sc16is7xx: move label 'err_spi'
to correct section").

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-19 14:09:23 +02:00