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 ? -- <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
