On 17/02/2014 18:53, Alexander Shiyan wrote:

Hello.

???????????, 17 ??????? 2014, 17:57 +01:00 ?? Richard Genoud [off-list ref]:

quoted

The USART controller on sam9x5 chips (and also all AT91/SAMA5 chips
but at91rm9200) are not capable of handling DTR/DSR/DCD/RI signal.
Moreover, even if the controller can handle CTS/RTS, the dedicated
CTS/RTS pins are already muxed for other peripherals (LCDC/EMAC/MMC).

So this patchset adds the possibility to control those lines via GPIO,
as it is done for RTS in the patch "switch atmel serial to use gpiolib"

As it was suggested by Alexander Shiyan, I made that available for
every board.

Patch 1 implements the generic helpers to control modem lines via GPIO
Patches 2 and 3 are just a little tidy up of atmel_serial.c.
Patch 4 implements modem control lines in atmel_serial atmel_serial.
Patches 5 and 6 implement the get_direction() gpio call for at91, as
it is needed by gpiod_get_direction().
Patch 7 implement the interrupts of CTS/DSR/DCD/RI.

I still recommend split this series. The first patch must be a separate,
2 and 3 - independent to this series, 5 and 6 - to the appropriate mailing lists,
and finally as soon as all of the previous will be applied - you can send 7.

Well, I did this because I think:
- it's easier to review a patch when you have an implementation, like
atmel_serial, that follows.
- it's also easier to test atmel_serial patches if the patches it needs
are in the same thread. Testers/reviewers won't have to dig the MLs for
needed patches.
- having all those patches in one thread shows their order, and prevents
from breaking kernel compilation between patches (it's really annoying
when you hunt a bug with git bisect and at some point the kernel doesn't
compile anymore). If the series is split and patches goes in different
trees, nothing will prevent patch 1 to be applied after patch 7 and
break kernel compilation in between (AFAIK).
- maintainers are Cced to this thread, so they can easily speak to
each-other to say if one should take the whole series in its tree or if
it should go to several tree or...

But, I'm not a maintainer, so I may not see all the pros and cons of this...

Richard.