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From: t-kristo@ti.com (Tero Kristo)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: omap5/dra7xx: Fix counter frequency drift for AM572x errata i856.
Date: Wed, 17 Dec 2014 17:45:05 +0200	[thread overview]
Message-ID: <5491A501.100@ti.com> (raw)
In-Reply-To: <20141217152710.GT24110@csclub.uwaterloo.ca>

On 12/17/2014 05:27 PM, Lennart Sorensen wrote:
> On Wed, Dec 17, 2014 at 09:22:25AM -0600, Nishanth Menon wrote:
>> A clock mux might do the job?
>>
>> value 1, 2 , 3 will imply sysclk1 / 610
>> value of 0 implies fixed 32768
>>
>> soemthing like
>> sys_clk32_crystal {
>>                 compatible = "fixed-clock";
>>                 clock-frequency = <32768>;
>> }
>>
>> sys_clk32_pseudo {
>>                 compatible = "fixed-clock";
>>                 compatible = "fixed-factor-clock";
>>                 clocks = <&sys_clkin1>;
>>                 clock-mult = <1>;
>>                 clock-div = <610>;
>> }
>>
>> sys_32k_ck: sys_32k_ck {
>> 	compatible = "ti,mux-clock";
>> 	clocks = <&sys_clk32_crystal>, <&sys_clk32_pseudo>, <&sys_clk32_pseudo>, <&sys_clk32_pseudo>;
>> };
>>
>> I think... The only issue is that the BOOTSTRAP register is not around
>> the usual CM1,2 address region...
>
> OK, I like where that idea is headed.  That looks promising.
>

Yea clock mux can be used. However, we don't have support for DRA7 
control module clocks in the DT yet. I have posted patches with support 
towards this a couple of weeks back, but they need some revising.

Thus, we maybe need to apply the timer patches as is for now, and fix 
the clock tree a bit later.

-Tero

  reply	other threads:[~2014-12-17 15:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-12 22:08 [PATCH 0/2] ARM: omap5/dra7xx counter frequency fixes Lennart Sorensen
2014-12-12 22:08 ` [PATCH 1/2] ARM: omap5/dra7xx: Fix frequency typos Lennart Sorensen
2014-12-16 11:38   ` Lokesh Vutla
2014-12-16 14:06   ` Nishanth Menon
2014-12-16 16:39     ` Lennart Sorensen
2014-12-12 22:08 ` [PATCH 2/2] ARM: omap5/dra7xx: Fix counter frequency drift for AM572x errata i856 Lennart Sorensen
2014-12-14  4:45   ` Lennart Sorensen
2014-12-16 11:35     ` Lokesh Vutla
2014-12-16 14:58       ` Nishanth Menon
2014-12-16 16:36         ` Lennart Sorensen
2014-12-16 18:59           ` Nishanth Menon
2014-12-16 19:27             ` Lennart Sorensen
2014-12-16 19:33               ` Nishanth Menon
2014-12-17 13:21         ` Tero Kristo
2014-12-17 14:55           ` Lennart Sorensen
2014-12-17 15:22             ` Nishanth Menon
2014-12-17 15:27               ` Lennart Sorensen
2014-12-17 15:45                 ` Tero Kristo [this message]
2014-12-17 15:49                   ` Lennart Sorensen
2014-12-17 15:53                   ` Nishanth Menon
2014-12-17 15:56                     ` Tero Kristo
2014-12-16 16:16       ` Lennart Sorensen
2014-12-16 19:56         ` Nishanth Menon
2014-12-16 19:58           ` Lennart Sorensen

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