Re: [PATCH V4 1/5] dt-bindings: rtc: Remove the LS2X from the trivial RTCs

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 30/05/2023 17:13:12+0800, Keguang Zhang wrote:
> On Tue, May 30, 2023 at 4:40 PM Alexandre Belloni
> <alexandre.belloni@bootlin.com> wrote:
> >
> > On 30/05/2023 10:17:43+0200, Krzysztof Kozlowski wrote:
> > > On 29/05/2023 10:31, Binbin Zhou wrote:
> > > > Hi Krzysztof:
> > > >
> > > > Excuse me.
> > > > We have different opinions on how to better describe rtc-loongson compatible.
> > > >
> > > > Based on my previous communication with you, I think we should list
> > > > all the Socs in the driver and drop the wildcards.
> > >
> > > Suggestion was about the bindings. Not in the driver. I never said to
> > > list all compatibles in the driver...
> > >
> > > > This should be clearer and more straightforward:
> > > >
> > > >         { .compatible = "loongson,ls1b-rtc", .data = &ls1x_rtc_config
> > > > }, //ls1b soc
> > > >         { .compatible = "loongson,ls1c-rtc", .data = &ls1x_rtc_config
> > > > }, //ls1c soc
> > > >         { .compatible = "loongson,ls7a-rtc", .data =
> > > > &generic_rtc_config }, //ls7a bridge chip
> > > >         { .compatible = "loongson,ls2k0500-rtc", .data =
> > > > &generic_rtc_config }, // ls2k0500 soc
> > > >         { .compatible = "loongson,ls2k2000-rtc", .data =
> > > > &generic_rtc_config }, // ls2k2000 soc
> > > >         { .compatible = "loongson,ls2k1000-rtc", .data =
> > > > &ls2k1000_rtc_config }, // ls2k1000 soc
> > >
> > > I would suggest to use fallbacks as suggested by Conor at least for some
> > > of them. You referred to my previous comments about wildcards.
> > > Wildcard != fallback.
> > >
> > > >
> > > > And Conor thought it should be rendered using a fallback compatible
> > > > form based on ".data".
> > >
> > > Based on common (compatible) programming model unless you already have
> > > clear hardware differences making them incompatible.
> > >
> > > >
> > > >         "loongson,ls1b-rtc"
> > > >         "loongson,ls1c-rtc", "loongson,ls1b-rtc"
> > > >         "loongson,ls7a-rtc"
> > > >         "loongson,ls2k0500-rtc", "loongson,ls7a-rtc"
> > > >         "longson,ls2k2000-rtc", "longson,ls7a-rtc"
> > > >         "loonson,ls2k1000-rtc"
> > > >
> > > >         { .compatible = "loongson,ls1b-rtc", .data = &ls1x_rtc_config }
> > > >         { .compatible = "loongson,ls7a-rtc", .data = &generic_rtc_config }
> > > >         { .compatible = "loongson,ls2k1000-rtc", .data = &ls2k1000_rtc_config }
> > > >
> > > > In this form,  I think it might not be possible to show very
> > > > graphically which chips are using the driver.
> > >
> > > ??? How is it impossible? For all other SoCs and architectures it is
> > > possible, so what is special for Loongson?
> > >
> > > > Also, for example, "ls7a" is a bridge chip, while
> > > > "ls2k2000"/"ls2k0500" are soc chips, and it seems inappropriate to
> > > > integrate them into one item.
> > >
> > > Why it is inappropriate? I don't see the issue here... what is a
> > > "bridge" chip? Isn't this also an SoC?
> > >
> > >
> > > >
> > > > Which one do you think is more suitable for us?
> > >
> > > Use fallbacks for some. You pointed difference in alarm for ls1x, right?
> > > If so, then they can stay separate.
> >
> > From what I seen the IP and register set is the same, it is just the
> > integration on the SoC that differs.
> >
> Actually, ls1c RTC registers are not the same as ls1b.
> ls1c doesn't have the following resgisters.
> +#define TOY_MATCH0_REG         0x34 /* TOY timing interrupt 0 */
> +#define TOY_MATCH1_REG         0x38 /* TOY timing interrupt 1 */
> +#define TOY_MATCH2_REG         0x3c /* TOY timing interrupt 2 */
> 
> +#define RTC_CTRL_REG           0x40 /* TOY and RTC control register */
> +#define RTC_TRIM_REG           0x60 /* Must be initialized to 0 */
> +#define RTC_WRITE0_REG         0x64 /* RTC counters value (write-only) */
> +#define RTC_READ0_REG          0x68 /* RTC counters value (read-only) */
> +#define RTC_MATCH0_REG         0x6c /* RTC timing interrupt 0 */
> +#define RTC_MATCH1_REG         0x70 /* RTC timing interrupt 1 */
> +#define RTC_MATCH2_REG         0x74 /* RTC timing interrupt 2 */
> 
> As you can see, it doesn't support match function, which is why ls1c
> doesn't support RTC interrupt.

They are in the Loongson1C Processor User Manual I have which states:

21.2.6 SYS_TOYMATCH0/1/2 (no register in 1C2)

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com