From mboxrd@z Thu Jan 1 00:00:00 1970 From: shc_work@mail.ru (Alexander Shiyan) Date: Thu, 30 Aug 2012 21:57:48 +0400 Subject: [PATCH] ARM: clps711x: convert to clocksource/clockevents In-Reply-To: References: <1346344678-18248-1-git-send-email-linus.walleij@linaro.org> <20120830210210.55e0899d.shc_work@mail.ru> Message-ID: <20120830215748.492ce5e3.shc_work@mail.ru> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 30 Aug 2012 10:21:44 -0700 Linus Walleij wrote: > >> This converts the ageing clps711x timer driver to the modern > >> clocksource/clockevent API. > > The patch does not account for the changes that I sent to the mailing list > > recently, where I did support different clock frequencies for the processor. > No problem, I can rebase on top of your patches as soon as you > submit them to ARM SoC so I can see them in linux-next. Patches have already been sent to the mailing list, and as far I understand, these patches are awaiting approval from Arnd. ... > > The patch uses a second timer, which does not allow its use for other purposes, > What does this mean? Reading the datasheet it didn't say anything about > this timer being dedicated to something else. > I am using TC1D as clocksource and TC2D as clockevent, repurposing > it from the previous use as singe time source. > Doing "git grep TC1D" I cannot see any code in the kernel making use > of this timer? These timers are only two in the processor and I just want to say that the second timer CAN be used for other purposes, such as I use. In the kernel of the second timer is really not used. > I could think of things like the boot loader or firmware setting it up > to run in free-running mode ... in that case we use > it as clocksource without initialization as long as we know what > frequency it's running on. Not understand this... > As far as I could understand from the datasheet there is really > no way to actually disable these timers, so they always run > anyway? Yes. We can only enable/disable IRQ for the timers, switch clock source and mode. > > I have also tried to do something like this without using additional processor > > resources, but not yet brought to the finish line yet. > OK do you think you can switch the clps71x over to generic time and > clockevents inspired by this patch or so? Unfortunately, I'm leaving tomorrow for a little while so I can not check anything or try to do better, but the idea of ??switching to a new API I like. Upon arrival back, I'll try to make a similar using only one timer or use the CLOCKSOURCE/CLOCKEVENTS resources to generate intervals necessary for me. -- Alexander Shiyan