linux.git/include/linux/serial_core.h, branch v6.5-rc4

serial: core: Start managing serial controllers to enable runtime PM

2023-05-31T09:46:59+00:00

We want to enable runtime PM for serial port device drivers in a generic
way. To do this, we want to have the serial core layer manage the
registered physical serial controller devices.

To manage serial controllers, let's set up a struct bus and struct device
for the serial core controller as suggested by Greg and Jiri. The serial
core controller devices are children of the physical serial port device.
The serial core controller device is needed to support multiple different
kind of ports connected to single physical serial port device.

Let's also set up a struct device for the serial core port. The serial
core port instances are children of the serial core controller device.

With the serial core port device we can now flush pending TX on the
runtime PM resume as suggested by Johan.

Suggested-by: Andy Shevchenko 
Suggested-by: Greg Kroah-Hartman 
Suggested-by: Jiri Slaby 
Suggested-by: Johan Hovold 
Signed-off-by: Tony Lindgren 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230525113034.46880-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman

serial: Make uart_remove_one_port() return void

2023-05-13T10:48:16+00:00

The return value is only ever used as a return value for remove callbacks
of platform drivers. This return value is ignored by the driver core.
(The only effect is an error message, but uart_remove_one_port() already
emitted one in this case.)

So the return value isn't used at all and uart_remove_one_port() can be
changed to return void without any loss. Also this better matches the
Linux device model as remove functions are not supposed to fail.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

serial: Make hw_stopped bool

2023-03-17T14:00:40+00:00

Convert hw_stopped in uart_port to bool because its more appropriate
type for how it is used.

Also convert the local variable in uart_change_line_settings() caching
old hw_stopped to bool.

Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230309080923.11778-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: Remove extern from func prototypes in headers

2023-03-17T14:00:40+00:00

Remove unnecessary externs from function prototypes in serial_8250.h
and serial_core.h.

Suggested-by: Jiri Slaby 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230309080923.11778-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: Make uart_handle_cts_change() status param bool active

2023-01-19T15:04:35+00:00

Convert uart_handle_cts_change() to bool which is more appropriate
than unsigned int.

Rename status to active to better describe what the parameter means.
While at it, make the comment about the active parameter easier to
parse.

Cleanup callsites from operations that are not necessary with bool.

Reviewed-by: Jiri Slaby 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230117090358.4796-10-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

tty/serial: Make ->dcd_change()+uart_handle_dcd_change() status bool active

2023-01-19T15:04:35+00:00

Convert status parameter for ->dcd_change() and
uart_handle_dcd_change() to bool which matches to how the parameter is
used.

Rename status to active to better describe what the parameter means.

Acked-by: Rodolfo Giometti 
Reviewed-by: Jiri Slaby 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230117090358.4796-9-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: core: Add option to output RS485 RX_DURING_TX state via GPIO

2023-01-19T15:01:35+00:00

This patch provides a generic GPIO variable for outputting the state
of RS485 RX_DURING_TX. The GPIO is defined by the devicetree property
"rs485-rx-during-tx-gpios". To use it in a low level serial driver,
the evaluation of this variable must be implemented there accordingly.

Signed-off-by: Christoph Niedermaier 
Link: https://lore.kernel.org/r/20221202104127.122761-2-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman

earlycon: Increase options size

2023-01-19T13:56:44+00:00

Now that the clock frequency is also part of the options, 16 bytes is
too little.

Without this patch dmesg does not show the whole options, Eg:

earlycon: uart0 at MMIO32 0x00000000fedc9000 (options '115200n8,480000')

instead of: '115200n8,48000000'

Signed-off-by: Ricardo Ribalda 
Reviewed-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20221123-serial-clk-v3-2-49c516980ae0@chromium.org
Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2022-12-16T11:31:56+00:00

Pull tty/serial driver updates from Greg KH:
 "Here is the "big" set of tty/serial driver changes for 6.2-rc1.

  As in previous kernel releases, nothing big here at all, just some
  small incremental serial/tty layer cleanups and some individual driver
  additions and fixes. Highlights are:

   - serial helper macros from Jiri Slaby to reduce the amount of
     duplicated code in serial drivers

   - api cleanups and consolidations from Ilpo Järvinen in lots of
     serial drivers

   - the usual set of n_gsm fixes from Daniel Starke as that code gets
     exercised more

   - TIOCSTI is finally able to be disabled if requested (security
     hardening feature from Kees Cook)

   - fsl_lpuart driver fixes and features added

   - other small serial driver additions and fixes

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

* tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits)
  serial: atmel: don't stop the transmitter when doing PIO
  serial: atmel: cleanup atmel_start+stop_tx()
  tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API
  serial: sunsab: Fix error handling in sunsab_init()
  serial: altera_uart: fix locking in polling mode
  serial: pch: Fix PCI device refcount leak in pch_request_dma()
  tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused
  tty: serial: fsl_lpuart: Add runtime pm support
  tty: serial: fsl_lpuart: enable wakeup source for lpuart
  serdev: Replace poll loop by readx_poll_timeout() macro
  tty: synclink_gt: unwind actions in error path of net device open
  serial: stm32: move dma_request_chan() before clk_prepare_enable()
  dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity'
  serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
  serial: amba-pl011: avoid SBSA UART accessing DMACR register
  tty: serial: altera_jtaguart: remove struct altera_jtaguart
  tty: serial: altera_jtaguart: use uart_port::read_status_mask
  tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs
  tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()
  n_tty: Rename tail to old_tail in n_tty_read()
  ...

serial_core: replace uart_console_enabled() with uart_console_registered()

2022-12-02T10:25:01+00:00

All users of uart_console_enabled() really want to know if a console
is registered. It is not reliable to check for CON_ENABLED in order
to identify if a console is registered. Use console_is_registered()
instead.

A _locked() variant is provided because uart_set_options() is always
called with the console_list_lock held and must check if a console
is registered in order to synchronize with kgdboc.

Signed-off-by: John Ogness 
Reviewed-by: Petr Mladek 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de