Hi Biju, On Mon, Sep 26, 2022 at 10:00 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > Subject: Re: [PATCH v6 2/2] pwm: Add support for RZ/G2L GPT > > On Sat, Sep 24, 2022 at 6:10 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> > > wrote: > > > Note: > > > I have a plan to develop another PWM driver using MTU IP on the same > > SoC. > > > The work is not started yet. > > > > That is the MTU3, which seems to be a further evolution of the MTU2 in > > e.g. RZ/A1, which is already supported as a timer through the > > sh_mtu2 driver? > > sh_mtu2 is just supports clock events. MTU2 is much powerful and we are > not supporting more advanced features like phase counting(counter framework), > PWM(frame wok) etc... OK. > > > For this IP, I planned to use MFD framework for the MTU driver and > > > Will add counter driver, timer driver(clock source, clock event) and > > > pwm driver as child devices. > > > > > > Currently the MFD driver and 16-Bit Phase Counting using counter > > > framework is almost done. > > > > Do you really need an MFD? (MFDs trigger a red flag for me ;-) E.g. > > Similar concept is already available in mainline[1]. > See STM32 timers where there is an MFD driver supports timer, counter > And pwm as child devices. > > [1] https://elixir.bootlin.com/linux/v6.0-rc5/C/ident/TIM_ARR > > > there are two sets of bindings for renesas,tpu: when #pwm-cells is > > present, it is used for PWM, otherwise it is used as a timer. > > [2] > Yes, we could encapsulate all in PWM. But then we need to call > Other susbsytem from pwm (eg:- counter and timer). > > I am not sure, PWM subsystem people allows to call counter and > Timer subsystem calls from pwm driver?? If yes, then that will simplifies a lot. > > [3] > I almost have an RFC ready for MFD + 16-bit phase counting mode > Using counter device with MTU3 which is tested on MTU{1,2} channels. > > So basically, we need to decide whether to go with approach [2] > Or [3]?? > > Please share your views, I can post RFC patch to get a clear picture > if needed. Please let me know. I see you've done your homework ;-) OK, fine for me! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
