+Cc: Lukas, who did recently some work WRT RS485 support in 8250. On Wed, Mar 18, 2020 at 03:26:33PM +0100, Heiko Stuebner wrote: > This series tries to revive the work of Giulio Benetti from 2018 [0] > which seemed to have stalled at that time. > > The board I needed that on also had the additional caveat that it > uses non-standard pins for DE/RE so needed gpio mctrl layer as well > and even more special needed to control the RE pin manually not as > part of it being connected to the DE signal as seems to be the standard. > > So I've marked the patch doing this as DTR pin as RFC but that patch > isn't needed for the other core functionality, so could also be left out. Thank you, I'll look at them later on. > Changes from the 2018 submission include: > - add timeout when waiting for fifos to clear using a new helper > - move on-boot enablement of the rs485 mode to after registering > the port. This saves having to copy the em485 struct as done > originally, which also ran into spinlock-debug warnings when testing > and also makes it actually possible to use the mctrl gpio layer > for non-standard gpios. > > [0] Link: https://lore.kernel.org/linux-serial/20180601124021.102970-1-giulio.benetti@xxxxxxxxxxxxxxxx/ > > Giulio Benetti (4): > serial: 8250: Make em485_rts_after_send() set mctrl according to rts > state. > serial: 8250: Handle case port doesn't have TEMT interrupt using > em485. > serial: 8250_dw: add em485 support > serial: 8250_dw: allow enable rs485 at boot time > > Heiko Stuebner (3): > serial: 8250: add serial_in_poll_timeout helper > serial: 8250: Start rs485 after registering port if rs485 is enabled > in probe > serial: 8250: handle DTR in rs485 emulation > > drivers/tty/serial/8250/8250.h | 36 ++++++++++++++++++++- > drivers/tty/serial/8250/8250_core.c | 9 ++++++ > drivers/tty/serial/8250/8250_dw.c | 35 +++++++++++++++++++- > drivers/tty/serial/8250/8250_of.c | 2 +- > drivers/tty/serial/8250/8250_omap.c | 2 +- > drivers/tty/serial/8250/8250_port.c | 50 +++++++++++++++++++++++------ > include/linux/serial_8250.h | 1 + > 7 files changed, 121 insertions(+), 14 deletions(-) > > -- > 2.24.1 > -- With Best Regards, Andy Shevchenko
