2024-04-24 19:26:36

by Konstantin Pugin

[permalink] [raw]
Subject: [PATCH v8 0/3] add support for EXAR XR20M1172 UART

EXAR XR20M1172 UART is mostly SC16IS762-compatible, but
it has additional register which can change UART multiplier
to 4x and 8x, similar to UPF_MAGIC_MULTIPLIER does. So, I used this
flag to guard access to its specific DLD register. It seems than
other EXAR SPI UART modules also have this register, but I tested
only XR20M1172.
Yes, in datasheet this register is called "DLD - Divisor Fractional"
or "DLD - Divisor Fractional Register", calling depends on datasheet
version.

I am sorry about too many submissions and top post reply. About second -
I do not know how to reply properly to this ML from GMail phone app. About first - I just
get very good feedback from Andy Shevchenko, and want to fix his review picks ASAP.

Changes in v2:
- use full name in git authorship

Changes in v3:
- change formatting of commit messages to unify width
- rework commit messages according to code review
- add XR20M117X namespace for EXAR-specific register
- do not use UPF_MAGIC_MULTIPLIER for checking EXAR chip,
use s->devtype directly
- replace while loop to fls function and expanded check
- sort compatibles
- reformat multiline comment.

Changes in v4:
- rebase onto tty-next branch
- added Kconfig mention of the chip
- used rounddown_power_of_two instead of fls and manual shift
- used FIELD_PREP instead of custom macro
- removed has_dld bit from common struct, replaced by check function,
which checks directly by s->devtype
- fixed tab count
- properly apply Vladimir Zapolskiy's tag to patch 2 only

Changes in v5:
- fixes for tty-next branch
- address a new code review picks
- send properly to all participants
- added Ack tag

Changes in v6:
- KConfig fixes
- New code review fixes

Changes in v7:
- Added missed tag
- Added missed v5 fixes

Changes in v8:
- Fixed semicolon
- Added missed tags
- Fixed commit messages

Konstantin Pugin (3):
serial: sc16is7xx: announce support of SER_RS485_RTS_ON_SEND
dt-bindings: sc16is7xx: Add compatible line for XR20M1172 UART
serial: sc16is7xx: add support for EXAR XR20M1172 UART

.../bindings/serial/nxp,sc16is7xx.yaml | 1 +
drivers/tty/serial/Kconfig | 3 +-
drivers/tty/serial/sc16is7xx.c | 63 +++++++++++++++++--
drivers/tty/serial/sc16is7xx.h | 1 +
drivers/tty/serial/sc16is7xx_i2c.c | 1 +
drivers/tty/serial/sc16is7xx_spi.c | 1 +
6 files changed, 64 insertions(+), 6 deletions(-)


base-commit: 660a708098569a66a47d0abdad998e29e1259de6
--
2.44.0



2024-04-25 10:01:30

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v8 0/3] add support for EXAR XR20M1172 UART

On Wed, Apr 24, 2024 at 10:18:51PM +0300, Konstantin Pugin wrote:
> EXAR XR20M1172 UART is mostly SC16IS762-compatible, but
> it has additional register which can change UART multiplier
> to 4x and 8x, similar to UPF_MAGIC_MULTIPLIER does. So, I used this
> flag to guard access to its specific DLD register. It seems than
> other EXAR SPI UART modules also have this register, but I tested
> only XR20M1172.
> Yes, in datasheet this register is called "DLD - Divisor Fractional"
> or "DLD - Divisor Fractional Register", calling depends on datasheet
> version.

A side note about email. It seems you have To: email header empty which may
increase chances to get these messages into spam. Again, I recommend to look
at the implementation of my script [1] which I use on daily-basis and re-use
it or taking an ideas how to send patches to the Linux kernel mailing lists.
Alternatively you may study `b4` tool, it also has something like that in
recent versions.

[1]: https://github.com/andy-shev/home-bin-tools/blob/master/ge2maintainer.sh

--
With Best Regards,
Andy Shevchenko