On Tue, Aug 13, 2013 at 8:50 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, Aug 13, 2013 at 12:54:47PM +0200, Javier Martinez Canillas wrote: > > On Tue, Aug 13, 2013 at 12:22 PM, Mark Jackson <mpfj-list@xxxxxxxxxxxxx> wrote: > > > On 12/08/13 23:56, Greg KH wrote: > > >> On Sun, Aug 11, 2013 at 02:56:50PM +0100, Mark Jackson wrote: > > >>> This patch adds RS485 support to the OMAP serial driver, as > > >>> defined in:- > > >>> > > >>> Documentation/devicetree/bindings/serial/rs485.txt > > >>> > > >>> When a UART transmitter is connected to (eg) a RS485 driver, it is > > >>> necessary to turn the driver on/off as quickly as possible. This is > > >>> best achieved in the serial driver itself (rather than in userspace > > >>> where the latency can be quite large). > > >>> > > >>> This patch allows a GPIO pin to be defined (via DT) that controls > > >>> the enabling of the driver at the start of a message, and disables > > >>> the driver when the message has been completed. > > >>> > > >>> When RS485 is disabled, the RTS pin is set to on. > > >>> > > >>> Signed-off-by: Mark Jackson <mpfj@xxxxxxxxxxxxx> > > >>> --- > > >>> Changes in v2: > > >>> - Fix incorrect logic in serial_omap_config_rs485() > > >>> > > >>> drivers/tty/serial/omap-serial.c | 178 ++++++++++++++++++++++++++++++++++++++ > > >>> 1 file changed, 178 insertions(+) > > >> > > >> This doesn't apply to my tty-next branch: > > >> checking file drivers/tty/serial/omap-serial.c > > >> Hunk #1 FAILED at 40. > > >> Hunk #2 succeeded at 162 (offset 6 lines). > > >> Hunk #3 succeeded at 280 (offset 5 lines). > > >> Hunk #4 succeeded at 378 (offset 6 lines). > > >> Hunk #5 succeeded at 1312 (offset 8 lines). > > >> Hunk #6 succeeded at 1405 (offset 8 lines). > > >> Hunk #7 succeeded at 1528 (offset 10 lines). > > >> Hunk #8 FAILED at 1638. > > >> Hunk #9 succeeded at 1705 (offset 6 lines). > > >> 2 out of 9 hunks FAILED > > >> > > >> so I can't apply it, sorry. > > > > > > It was applied on top of Linus' tree, if that makes any difference. > > > > > > I'll rebase onto yours and re-post the patch. > > > -- > > > > Hi Mark, > > > > I've seen several attempts to add RS485 support to the omap serial > > driver and it is always nack-ed. There seems to be concerns about > > controlling the RTS by software when RS485 is not supported by the > > UART hardware. Please refer to [1] and [2] for more information. > > Hm, but we do support RS485 now in the kernel, look at > Documentation/serial/serial-rs485.txt. Why can't this driver support it > as well if the serial core already does? > Hi Greg, Please don't shoot the messenger :-) In fact I was one of those who needed RS485 support in the OMAP serial driver a couple of years ago and we were told that "software RS485 is not mainlinable" [1]. I just wanted to warn Mark that he could be losing time pushing this but I'm glad to learn that this seems not to be true anymore. > thanks, > > greg k-h Thanks a lot and best regards, Javier [1]: http://comments.gmane.org/gmane.linux.serial/6770 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
