[PATCH v3 0/3] serial: 8250_of: support an optional bus clock

From: Alex Elder
Date: Fri Apr 11 2025 - 11:46:04 EST


The SpacemiT UART hardware requires a bus clock to be enabled in addition
to the primary function clock.

This series makes it possible to specify both clocks via DTS. If a
bus clock is required, it and the primary clock are fetched by name.

Changes between v2 and v3:
- A third patch was added to disable the bus clock on suspend and
enable it again on resume, as requested by Yixun Lan
- Rob's Reviewed-by tag has been added to patch 1
- The first two patches are otherwise identical to what was in v2

Here is version 2 of this series:
https://lore.kernel.org/lkml/20250409192213.1130181-1-elder@xxxxxxxxxxxx/

Changes between v1 and v2:
- The DT binding was fixed to properly define the number of clocks and
clock names based on the compatible string, as suggested by Rob Herring
- Logic to look up the optional bus clock was changed as requested
by Andy Shevchenko
- The bus clock pointer (which was never used after it was enabled)
was renmoved from the of_serial_info structure

Here is the first version of this series:
https://lore.kernel.org/lkml/20250408175146.979557-1-elder@xxxxxxxxxxxx/

-Alex
Alex Elder (3):
dt-bindings: serial: 8250: support an optional second clock
serial: 8250_of: add support for an optional bus clock
serial: 8250_of: manage bus clock in suspend/resume

.../devicetree/bindings/serial/8250.yaml | 30 ++++++++++++++++++-
drivers/tty/serial/8250/8250_of.c | 13 +++++++-
2 files changed, 41 insertions(+), 2 deletions(-)

base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
--
2.45.2