Re: [alsa-devel] [PATCH v6 07/14] regmap: Add SoundWire bus support

From: Vinod Koul
Date: Sat Jan 06 2018 - 01:08:25 EST


On Fri, Jan 05, 2018 at 11:22:15AM -0600, Pierre-Louis Bossart wrote:
> On 1/5/18 11:04 AM, Mark Brown wrote:
> >On Thu, Dec 14, 2017 at 11:19:38AM +0530, Vinod Koul wrote:
> >
> >>+ /* SoundWire register address are contiguous */
> >>+ if (config->reg_stride != 0)
> >>+ return -ENOTSUPP;
> >
> >That doesn't mean the chip hasn't decided not to use half the addresses
> >for some reason - this isn't something the bus should be enforcing.
>
> Good point. The contiguous requirement is valid only for normative
> registers, where the device has no choice but to follow the standard. For
> the imp-def part where regmap would typically be used, then indeed there is
> no restriction, chip implementers can do whatever they want.
> I have a vague memory that regmap was only intended to be used for this
> latter case, but Vinod and team should clarify this.

Right now it is used by codec for imp-def area. We do plan to add for all
registers eventually

Thanks
--
~Vinod