From: Haojian Zhuang <haojian.zhuang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> To: Robert Jarzmik <robert.jarzmik-GANU6spQydw@public.gmane.org> Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Eric Miao <eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" <linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org> Subject: Re: [PATCH 0/4] Migrate PXA27x platforms to clock framework Date: Fri, 4 Jul 2014 10:39:34 +0800 [thread overview] Message-ID: <CAN1soZwtuyWQhuLO4pK6aB51ibGjAHZN3+VDyAFMfU3gBfxdxg@mail.gmail.com> (raw) In-Reply-To: <87lhsanl7q.fsf-GANU6spQydw@public.gmane.org> On Fri, Jul 4, 2014 at 6:14 AM, Robert Jarzmik <robert.jarzmik-GANU6spQydw@public.gmane.org> wrote: > Haojian Zhuang <haojian.zhuang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes: > >>> Haojian, are you ok with that ? And BTW, does a combined kernel for PXA >>> platforms even exists (mixing pxa3xx and pxa2xx for example) ? >>> >> >> It's acceptable to me that different silicons are queued in different stages. >> I only request that it won't break the compiler building & bootup. > OK. > >> >> But I think that the pxa clock driver may be shared among all PXA silicons >> except for the clock table. What's your opinion? > I don't think so because of the core clocks. > These ones are specific to each pxa, and so their computation is : > - pxa25x plays with CCCR and specific L, M and N2 multiplication tables > - pxa27x plays with CCCR and specific L, M and N2 multiplication tables > - pxa3xx plays with ASCR, MEMCLKCFG, and AC97 div > > I don't see very well how a clock table could describe that. Do you have > something specific in mind ? > As I remember, those registers bits are encoded. So we can define a clock mux that connected to those fixed clock dividers. Then the clock gate is the child of the clock mux. In DTS file, peripheral device node could specify a clock rate. In peripheral device driver, it could also change the clock rate by clk_set_rate(). >>>> Also (for my understanding) when you say that you plan to do >>>> pxa25x and pxa3xx next, does that include pxa26x and pxa93x? >>> I don't have the Technical Reference Manuals for these ones so the answer is >>> no. And Google wasn't a great friend at providing them. >>> >> >> Converting them into new clock driver may not rely on the reference manual. > Actually I went through the code and : > - pxa26x is only a superset of pxa25x with one more clock : pxa26x-gpio > - pxa93x is the same clock set as pxa3xx, right ? > So if I convert pxa25x, pxa27x and pxa3xx I'll cover everything, right ? > >>>> I assume it does as they are apparently minor revisions of the >>>> former, but it's not completely clear from your description. >>> My description doesn't mention them, as I have no information about them, nor >>> any hardware to test on. >>> >> >> We can request others to help testing in the mailing list. > That's exactly what will enable pxa25x and pxa3xx. I have them converted in my > tree, but I don't want to mix these patches in as I can't test them, and testing > brings in bigger delays. Delay shouldn't be the block issue. Regards Haojian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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From: haojian.zhuang@gmail.com (Haojian Zhuang) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 0/4] Migrate PXA27x platforms to clock framework Date: Fri, 4 Jul 2014 10:39:34 +0800 [thread overview] Message-ID: <CAN1soZwtuyWQhuLO4pK6aB51ibGjAHZN3+VDyAFMfU3gBfxdxg@mail.gmail.com> (raw) In-Reply-To: <87lhsanl7q.fsf@free.fr> On Fri, Jul 4, 2014 at 6:14 AM, Robert Jarzmik <robert.jarzmik@free.fr> wrote: > Haojian Zhuang <haojian.zhuang@gmail.com> writes: > >>> Haojian, are you ok with that ? And BTW, does a combined kernel for PXA >>> platforms even exists (mixing pxa3xx and pxa2xx for example) ? >>> >> >> It's acceptable to me that different silicons are queued in different stages. >> I only request that it won't break the compiler building & bootup. > OK. > >> >> But I think that the pxa clock driver may be shared among all PXA silicons >> except for the clock table. What's your opinion? > I don't think so because of the core clocks. > These ones are specific to each pxa, and so their computation is : > - pxa25x plays with CCCR and specific L, M and N2 multiplication tables > - pxa27x plays with CCCR and specific L, M and N2 multiplication tables > - pxa3xx plays with ASCR, MEMCLKCFG, and AC97 div > > I don't see very well how a clock table could describe that. Do you have > something specific in mind ? > As I remember, those registers bits are encoded. So we can define a clock mux that connected to those fixed clock dividers. Then the clock gate is the child of the clock mux. In DTS file, peripheral device node could specify a clock rate. In peripheral device driver, it could also change the clock rate by clk_set_rate(). >>>> Also (for my understanding) when you say that you plan to do >>>> pxa25x and pxa3xx next, does that include pxa26x and pxa93x? >>> I don't have the Technical Reference Manuals for these ones so the answer is >>> no. And Google wasn't a great friend at providing them. >>> >> >> Converting them into new clock driver may not rely on the reference manual. > Actually I went through the code and : > - pxa26x is only a superset of pxa25x with one more clock : pxa26x-gpio > - pxa93x is the same clock set as pxa3xx, right ? > So if I convert pxa25x, pxa27x and pxa3xx I'll cover everything, right ? > >>>> I assume it does as they are apparently minor revisions of the >>>> former, but it's not completely clear from your description. >>> My description doesn't mention them, as I have no information about them, nor >>> any hardware to test on. >>> >> >> We can request others to help testing in the mailing list. > That's exactly what will enable pxa25x and pxa3xx. I have them converted in my > tree, but I don't want to mix these patches in as I can't test them, and testing > brings in bigger delays. Delay shouldn't be the block issue. Regards Haojian
next prev parent reply other threads:[~2014-07-04 2:39 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-06-29 18:32 [PATCH 0/4] Migrate PXA27x platforms to clock framework Robert Jarzmik 2014-06-29 18:32 ` Robert Jarzmik [not found] ` <1404066744-13416-1-git-send-email-robert.jarzmik-GANU6spQydw@public.gmane.org> 2014-06-29 18:32 ` [PATCH 1/4] clk: add pxa27x clock drivers Robert Jarzmik 2014-06-29 18:32 ` Robert Jarzmik [not found] ` <1404066744-13416-2-git-send-email-robert.jarzmik-GANU6spQydw@public.gmane.org> 2014-07-03 6:12 ` Haojian Zhuang 2014-07-03 6:12 ` Haojian Zhuang [not found] ` <CAN1soZzoiGAz3OicdKbg5Dv2tW3yeinsu2i=M7KX+j1HuMs3Kg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2014-07-03 22:28 ` Robert Jarzmik 2014-07-03 22:28 ` Robert Jarzmik 2014-06-29 18:32 ` [PATCH 2/4] dts: add devicetree bindings for pxa27x clocks Robert Jarzmik 2014-06-29 18:32 ` Robert Jarzmik [not found] ` <1404066744-13416-3-git-send-email-robert.jarzmik-GANU6spQydw@public.gmane.org> 2014-07-03 6:14 ` Haojian Zhuang 2014-07-03 6:14 ` Haojian Zhuang [not found] ` <CAN1soZys4k6g5RgPLbreopOxTwDJ+bfPOq8XPwsNpyt5+YURjg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2014-07-03 22:03 ` Mike Turquette 2014-07-03 22:03 ` Mike Turquette 2014-07-04 19:38 ` Robert Jarzmik 2014-07-04 19:38 ` Robert Jarzmik 2014-06-29 18:32 ` [PATCH 3/4] arm: pxa: Transition pxa27x to clk framework Robert Jarzmik 2014-06-29 18:32 ` Robert Jarzmik 2014-06-29 18:32 ` [PATCH 4/4] clk: dts: document pxa27x clock binding Robert Jarzmik 2014-06-29 18:32 ` Robert Jarzmik 2014-06-30 6:55 ` [PATCH 0/4] Migrate PXA27x platforms to clock framework Arnd Bergmann 2014-06-30 6:55 ` Arnd Bergmann 2014-06-30 18:38 ` Robert Jarzmik 2014-06-30 18:38 ` Robert Jarzmik [not found] ` <877g3yp7ie.fsf-GANU6spQydw@public.gmane.org> 2014-06-30 20:14 ` Arnd Bergmann 2014-06-30 20:14 ` Arnd Bergmann 2014-07-03 6:21 ` Haojian Zhuang 2014-07-03 6:21 ` Haojian Zhuang [not found] ` <CAN1soZyu192Y7z-HJHo+3_bddFcf=H0udgJSWez1=Lmrb5wVfg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2014-07-03 22:14 ` Robert Jarzmik 2014-07-03 22:14 ` Robert Jarzmik [not found] ` <87lhsanl7q.fsf-GANU6spQydw@public.gmane.org> 2014-07-04 2:39 ` Haojian Zhuang [this message] 2014-07-04 2:39 ` Haojian Zhuang
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