Re: [PATCH 2/2] regmap: sdw: Remove 8-bit value size restriction

From: Pierre-Louis Bossart
Date: Fri Jan 13 2023 - 13:12:31 EST




On 1/13/23 11:11, Mark Brown wrote:
> On Fri, Jan 13, 2023 at 10:57:39AM -0600, Pierre-Louis Bossart wrote:
>
>> The change from reg_write/read_reg to write/read seems ok, what I was
>> asking about was the gather_write.
>
>> + .write = regmap_sdw_write,
>> + .gather_write = regmap_sdw_gather_write,
>> + .read = regmap_sdw_read,
>
>> what happens if you only have .write and .read? What does the
>> .gather_write help with if you only use only address?
>
> Like I said before it means that the core doesn't have to put the
> register in a linear buffer with the values, meaning it can avoid
> copying already formatted data around or allocating memory.

Ah ok, I read sideways and missed the pointer arithmetic in the write
implementation

return sdw_nwrite_no_pm(slave, addr, val_size - sizeof(addr), val +
sizeof(addr));

Thanks for the clarification.