Messages in this thread | | | Date | Thu, 16 Mar 2023 10:51:26 +0100 | From | Lukas Wunner <> | Subject | Re: Wrong RS485 RTS polarity in 8250 OMAP UART Driver vs DT binding? |
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On Wed, Mar 15, 2023 at 09:41:56PM +0100, Francesco Dolcini wrote: > We have working hardware, using another UART that expect > rs485-rts-active-low, and the exact same HW, when using OMAP uart, > requires rs485-rts-active-high (the HW is modular, so we are really just > changing the uart, keeping the same RS485 transceiver / connections). > > What's going on there? Is the semantic of the 8250_omap driver just the > opposite as it should be?
Yes, sadly, for historic reasons.
See these threads:
https://lore.kernel.org/linux-serial/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/
https://lore.kernel.org/linux-serial/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de/
> Am I doing something wrong in the device tree?
No, but regrettably you need a separate device tree depending on which SoC you're using.
Thanks,
Lukas
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