[PATCH v1 0/3] serial: Support driver-selected TTY wakeup defaults

[Stefano Radaelli <stefano.radaelli21@gmail.com>]

The initial goal was to enable TTY wakeup by default on NXP LPUART ports
marked with wakeup-source, without requiring a userspace write. Instead
of keeping this entirely within fsl_lpuart, this series introduces a
common serial core mechanism that other UART drivers can also adopt.

The new tty_wakeup_default field in struct uart_port lets a driver request
wakeup to be enabled when its TTY device is registered. Each driver
decides whether to use it. This series adds wakeup-source to the LPUART
binding and makes fsl_lpuart the first user, setting the field from that
property. Other drivers retain their existing behavior, userspace can
still change power/wakeup, and serdev wakeup policy is unchanged.

Tested on a Variscite VAR-SOM-MX93 with a Symphony carrier board using
LPUART1 (ttyLP0) as the console: with wakeup-source present, power/wakeup
was enabled after boot, and the board resumed from deep suspend when
Enter was pressed on the serial console.

Stefano Radaelli (3):
  dt-bindings: serial: fsl-lpuart: Allow wakeup-source
  serial: core: Allow drivers to enable TTY wakeup at registration
  serial: fsl_lpuart: Enable TTY wakeup for wakeup-source ports

 Documentation/devicetree/bindings/serial/fsl-lpuart.yaml | 2 ++
 drivers/tty/serial/fsl_lpuart.c                          | 1 +
 drivers/tty/serial/serial_core.c                         | 8 ++++++++
 include/linux/serial_core.h                              | 1 +
 4 files changed, 12 insertions(+)


base-commit: 2637bdec0535a2044cd830eba9a79363651d9043
-- 
2.47.3