Messages in this thread | | | Date | Thu, 12 Jan 2023 14:19:29 -0600 | Subject | Re: [PATCH 2/2] regmap: sdw: Remove 8-bit value size restriction | From | Pierre-Louis Bossart <> |
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On 1/12/23 13:50, Mark Brown wrote: > On Thu, Jan 12, 2023 at 12:43:46PM -0600, Pierre-Louis Bossart wrote: >> On 1/12/23 12:14, Mark Brown wrote: > >>> The regmap gather_write() operation allows the bus to take two buffers, >>> one for the register and one for the value, rather than requiring the >>> core combine everything into a single buffer (mainly useful for large >>> transfers like firmware downloads). > >> Right, but that's not supported in SoundWire. sdw_nwrite() will only >> work with consecutive addresses - and the auto-increment is handled in >> software, not hardware. > > No, that's exactly what this is for. It's for the *register address* > being in a separate buffer, the data is then a sequence of consecutive > register values.> >> What's suggested here is to use the first element of reg_buf, which begs >> the question how different this is from a regular write. If there was a >> discontinuity in reg_buf then this wouldn't work at all. > > reg_buf contains the address of exactly one register.
So what's the difference with a plain write() of N data?
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