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From: Konstantin Pugin <rilian.la.te@ya.ru>
To: 
Cc: Konstantin Pugin <ria.freelander@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>,
	Hugo Villeneuve <hvilleneuve@dimonoff.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Lech Perczak <lech.perczak@camlingroup.com>,
	=?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org
Subject: [PATCH v4 0/3] add support for EXAR XR20M1172 UART
Date: Fri, 19 Apr 2024 15:45:00 +0300
Message-Id: <20240419124506.1531035-1-rilian.la.te@ya.ru>
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From: Konstantin Pugin <ria.freelander@gmail.com>

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

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                    | 18 +++---
 drivers/tty/serial/sc16is7xx.c                | 62 +++++++++++++++++--
 drivers/tty/serial/sc16is7xx_i2c.c            |  1 +
 drivers/tty/serial/sc16is7xx_spi.c            |  1 +
 5 files changed, 70 insertions(+), 13 deletions(-)


base-commit: c6795fbffc4547b40933ec368200bd4926a41b44
-- 
2.34.1