Messages in this thread | | | Date | Sun, 19 Jun 2016 15:09:02 +0900 | From | Andi Shyti <> | Subject | Re: [PATCH 1/5] spi: do not fail if the CS line is not connected |
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Hi Mark,
> > > > In this case do not fail and defer to the SPI device drivers the > > > > responsibility to check whether the num-cs is '0'. > > > > A SPI controller always has one chip seelct, it may not be controllable > > > but it's at least logically present. > > > This is true, but there are cases where the CS is not connected > > and this case needs to be treated separately to allow the device > > to work. > > In what way? It is just as easy for a device with no physical chip > select to have a logical chip select of 0 that it does nothing with as > it is for that device to handle any other number.
That is indeed my case: the s3c64xx doesn't send anything, unless I manually enable CS (from the next patches I need to write '0' in the CS register). But I need smoething to tell to the device that the CS line is not connected, for example a flag in the DTS.
It comes natural to me to set "num-cs = <0>" instead of defining a new property. In this case I will consider that there is no CS line, even though there is a CS controller.
Thanks, Andi
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