From mboxrd@z Thu Jan 1 00:00:00 1970 From: t-kristo@ti.com (Tero Kristo) Date: Wed, 17 Dec 2014 17:45:05 +0200 Subject: [PATCH 2/2] ARM: omap5/dra7xx: Fix counter frequency drift for AM572x errata i856. In-Reply-To: <20141217152710.GT24110@csclub.uwaterloo.ca> References: <358281a880ccd89873efeea75edaa6c953eac2bd.1418421100.git.lsorense@csclub.uwaterloo.ca> <20141214044517.GD24110@csclub.uwaterloo.ca> <549018EC.8020207@ti.com> <20141216145856.GA23358@kahuna> <54918357.8060801@ti.com> <20141217145533.GS24110@csclub.uwaterloo.ca> <20141217152225.GA737@kahuna> <20141217152710.GT24110@csclub.uwaterloo.ca> Message-ID: <5491A501.100@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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