On 8 August 2018 at 17:50, Mark Brown <broonie@xxxxxxxxxx> wrote: > On Wed, Aug 08, 2018 at 10:26:42AM +0800, Baolin Wang wrote: > >> Sorry for confusing. Let me try to explain it explicitly. >> We can set the word size (bits_per_word) for each transmission, for >> our SPI controller, after every word size transmission, we need one >> interval time (hardware automatically) to make sure the slave has >> enough time to receive the whole data. > > OK, so it's an inter word delay. Some other controllers definitely have > the same feature. > >> Yes, I agree we should configure it at runtime by the device, but we >> did not find one member to use in 'struct spi_transfer', we just find >> one similar 'delay_usecs' member in 'struct spi_transfer' but not >> same. We can use 'delay_usecs' to set our hardware interval value, >> but we should clean it when transfer is done, since we do not need to >> delay after the transfer in spi_transfer_one _message(). Or can we add >> one new member maybe named 'word_interval' to indicate the interval >> time between word size transmission? > > Right, I don't think we added this yet (if we did I can't see it). I'd > add a new field to spi_transfer for this, then other controllers with > the same support can implement it as well and drivers can start using > it too. OK. So I will name the new filed as 'word_delay', is it OK for you? -- Baolin Wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
