[v2,0/7] tty: serial: meson: support ttyS devname

Message

Dmitry Rokosov July 5, 2023, 6:18 p.m. UTC

During a IRC discussion with Neil, as reported in reference [1], an idea
emerged to provide support for a standard devname 'ttyS' in new SoCs
such as A1, S4, T7, C3 and others. The current devname 'ttyAML' is not
widely known and has caused several issues with both low and high-level
software, without any apparent justification for its implementation.
Consequently, it has been deemed necessary to introduce the 'ttyS'
devname for all new 'compatible' entries, while still retaining backward
compatibility with the old 'ttyAML' devname by supporting it in parallel
with the new approach. This patch series therefore aims to implement
these changes.

Changes v2 since v1 at [2]:
    - as suggested by Conor, relocate modifications with the new
      uart_data structures of S4 and A1 SoC from the main meson_uart
      patchset to a separate patchsets
    - ensure that the uart_driver is not unregistered if there is at
      least one active port
    - per Neil's suggestion declare separate uart_driver and console
      objects for both tty devnames (ttyAML and ttyS) to enable the use
      of multiple uart objects with different compatibility strings

Links:
    [1]: https://libera.irclog.whitequark.org/linux-amlogic/2023-07-03
    [2]: https://lore.kernel.org/linux-amlogic/[e-mail]/

Dmitry Rokosov (7):
  tty: serial: meson: use dev_err_probe
  tty: serial: meson: redesign the module to platform_driver
  tty: serial: meson: apply ttyS devname instead of ttyAML for new SoCs
  tty: serial: meson: introduce separate uart_data for S4 SoC family
  tty: serial: meson: add independent uart_data for A1 SoC family
  dt-bindings: serial: amlogic,meson-uart: support Amlogic A1
  arm64: dts: meson: a1: change uart compatible string

 .../bindings/serial/amlogic,meson-uart.yaml   |   2 +
 arch/arm64/boot/dts/amlogic/meson-a1.dtsi     |   4 +-
 drivers/tty/serial/meson_uart.c               | 145 ++++++++++--------
 3 files changed, 88 insertions(+), 63 deletions(-)