Messages in this thread | | | Date | Wed, 10 Sep 2014 17:07:02 +0200 | From | Johan Hovold <> | Subject | Re: [PATCH 5/5] rtc: at91sam9: add DT bindings documentation |
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On Wed, Sep 10, 2014 at 03:20:19PM +0200, Boris BREZILLON wrote: > On Wed, 10 Sep 2014 14:14:24 +0200 > Johan Hovold <johan@kernel.org> wrote:
> > This does not describe the hardware, but rather a specific software > > configuration. > > > > The RTT is first of all not an RTC (although it can be used as one in a > > specific software configuration). And the second register resource above > > is not an RTT register, but a general-purpose backup register could be > > used for other purposes (which register to use is currently configurable > > for legacy booting using CONFIG_RTC_DRV_AT91SAM9_GPBR). > > We could use a syscon device (which exposes a regmap) for the GPBR > block. > > rtc@ffffff20 {
rtt
> compatible = "atmel,at91sam9260-rtt"; > reg = <0xfffffd20 0x10>; > interrupts = <1 4 7>; > clocks = <&clk32k>; > atmel,time-reg = <&gpbr 0x0>; > }; > > gpbr: syscon@fffffd50 { > compatible = "atmel,at91sam9260-gpbr", "syscon"; > reg = <0xfffffd50 0x10>; > > };
Yes, this essentially what I suggested in the thread (and my last reply) and relying on syscon rather than a custom driver seems like a good idea. It would allow early access to the registers too with the recently proposed changes. It would not guarantee any kind of exclusivity, though, but I guess that's tolerable?
Johan
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