On 08/12/2013 05:13 PM, Mark Brown wrote:
On Mon, Aug 12, 2013 at 04:57:53PM -0600, Stephen Warren wrote:
On 08/12/2013 03:49 AM, Padmavathi Venna wrote:
+- compatible : should be one of the following. + - samsung,s3c6410-i2s: for 8/16/24bit stereo I2S. + - samsung,s5pv210-i2s: for 8/16/24bit multichannel(5.1) I2S with
secondary fifo, s/w reset control and internal mux forroot clk src.
Those descriptions seem a little odd. If I have an SoC that isn't s5pv210, yet supports "8/16/24bit multichannel(5.1) I2S with secondary fifo, s/w reset control and internal mux for root clk src", will compatible="samsung,s5pv210-i2s" work for my HW?
I wonder if you should instead include the IP block version in the compatible value?
We've been round this loop several times, I'd prefer the IP block versions too but they're at best patchily documented and so as a general policy the Samsung bindings use the name of the SoC an IP first appeared in as the version.
In other words, I don't think we have an answer to the question: Should differences between similar HW blocks be encoded into DT properties, or should the driver encode them into some table, and look them up from compatible value?
For usability it seems better to just be able to say which IP you've got, this also makes it easier to implement support for new IP features later on without having to go back and add new properties which would be sad.
That seems quite reasonable, but I don't think everyone involved in DT has come out and agreed on that. I'm quite happy with the approach of looking up everything based on compatible.
(although I dare say that at least samsung,supports-rstclr should be modified to use the new reset controller bindings)
Really? That doesn't seem terribly sane - I had thought that was for bodging resets on the side of things that don't normally have them or need board specific logic. Also note that this is actually a magic register write done to reset the IP on some specific IPs.
I believe that's exactly what the reset subsystem and associated DT bindings were designed for.