2024-04-20 18:29:07

by Konstantin Pugin

[permalink] [raw]
Subject: [PATCH v5 0/3] add support for EXAR XR20M1172 UAR

From: Konstantin Pugin <[email protected]>

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

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.h | 1 +
drivers/tty/serial/sc16is7xx_i2c.c | 1 +
drivers/tty/serial/sc16is7xx_spi.c | 1 +
6 files changed, 71 insertions(+), 13 deletions(-)


base-commit: f70f95b485d78838ad28dbec804b986d11ad7bb0
--
2.44.0



2024-04-20 18:30:23

by Konstantin Pugin

[permalink] [raw]
Subject: [PATCH v5 1/3] serial: sc16is7xx: announce support of SER_RS485_RTS_ON_SEND

From: Konstantin Pugin <[email protected]>

The hardware supports both RTS_ON_SEND and RTS_AFTER_SEND modes, but
after the commit 4afeced55baa ("serial: core: fix sanitizing check for
RTS settings") we always end up with SER_RS485_RTS_AFTER_SEND set and
always write to the register field SC16IS7XX_EFCR_RTS_INVERT_BIT, which
breaks some hardware using these chips.

Fixes: 267913ecf737 ("serial: sc16is7xx: Fill in rs485_supported")
Signed-off-by: Konstantin Pugin <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 03cf30e20b75..dfcc804f558f 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1449,7 +1449,7 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
}

static const struct serial_rs485 sc16is7xx_rs485_supported = {
- .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
+ .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
.delay_rts_before_send = 1,
.delay_rts_after_send = 1, /* Not supported but keep returning -EINVAL */
};
--
2.44.0