On 26/09/2018 08:01, Paul Cercueil wrote: > > Le 25 sept. 2018 10:12 PM, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> a écrit : >> >> On 25/09/2018 15:38, Paul Cercueil wrote: >>> >>> Le 24 sept. 2018 9:14 AM, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> a écrit : >>>> >>>> On 24/09/2018 08:53, Paul Cercueil wrote: >>>>> >>>>> Le 24 sept. 2018 07:58, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> a écrit : >>>>>> >>>>>> On 24/09/2018 07:49, Paul Cercueil wrote: >>>>>>> >>>>>>> Le 24 sept. 2018 07:35, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> a >>>>>>> écrit : >>>>>>>> >>>>>>>> On 24/09/2018 07:24, Paul Cercueil wrote: >>>>>>>>> Hi Daniel, >>>>>>>>> >>>>>>>>> Le 24 sept. 2018 05:12, Daniel Lezcano >>>>>>>>> <daniel.lezcano@xxxxxxxxxx> a écrit : >>>>>>>>>> >>>>>>>>>> On 21/08/2018 19:16, Paul Cercueil wrote: >>>>>>>>>>> This driver handles the TCU (Timer Counter Unit) present on >>>>>>>>>>> the Ingenic JZ47xx SoCs, and provides the kernel with a >>>>>>>>>>> system timer, and optionally with a clocksource and a >>>>>>>>>>> sched_clock. >>>>>>>>>>> >>>>>>>>>>> It also provides clocks and interrupt handling to client >>>>>>>>>>> drivers. >>>>>>>>>> >>>>>>>>>> Can you provide a much more complete description of the timer >>>>>>>>>> in order to make my life easier for the review of this patch? >>>>>>>>> >>>>>>>>> See patch [03/24], it adds a doc file that describes the >>>>>>>>> hardware. >>>>>>>> >>>>>>>> Thanks, I went through but it is incomplete to understand what the >>>>>>>> timer do. I will reverse-engineer the code but it would help if you >>>>>>>> can give the gross approach. Why multiple channels ? mutexes and >>>>>>>> completion ? >>>>>>> >>>>>>> Much of the complexity is because of the multi-purpose nature of the >>>>>>> TCU channels. Each one can be used as timer/clocksource, or PWM. >>>>>>> >>>>>>> The driver starts by using channels 0 and 1 as system timer and >>>>>>> clocksource, respectively, the other ones being unused for now. Then, >>>>>>> *if* the PWM driver requests one of the channels in use by the >>>>>>> timer/clocksource driver, say channel 0, the timer/clocksource driver >>>>>>> will dynamically reassign the system timer to a free channel, from >>>>>>> channel 0 to e.g. channel 2. Only in that case the completion/mutex >>>>>>> are actually used. >>>>>> >>>>>> Why do you need to do this? Can't be the channels dedicated and reserved >>>>>> for clocksource and clockevent? >>>>> >>>>> That's what I had in place (ingenic,timer-channel and ingenic,clocksource-channel DT properties), but Rob didn't want any linux-specific properties in the devicetree binding :( >>>> >>>> Isn't possible to specify the channel to use in the DT? like renesas16 ? >>> >>> That's what I did in V6 (and before), but Rob did not want me to add properties for Linux-specific concepts such as clocksource. >> >> Hmm, I remember something like that, yes but I did a delete of the >> previous version when you posted the v7. Can you give a pointer to its >> answer ? > > Yes, this was his answer: > https://lkml.org/lkml/2018/7/25/508 > > Then mine: > https://lkml.org/lkml/2018/7/30/883 Thanks ! -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
