On Thu, Dec 14, 2023 at 03:35:18PM +0100, Michael Walle wrote: > > > >> >> This driver enables configuration of GPIO direction, GPIO values, > > > >> >> GPIO debounce settings and handles GPIO interrupts. > > > >> > > > > >> >Why gpio-regmap can't be used? > > > >> > > > >> I will try to use gpio-remap in the next version. > > > > > > > >If it appears that it makes code uglier / complicated, please add the note > > > >somewhere to answer the above question. > > > > > > I've traced the gpio-regmap.c file. It appears that for the driver > > > to register > > > gpio_irq_chip, it must create the irq_domain and add it into > > > gpio_regmap_config. > > > Additionally, the driver needs to register the irq handler by itself. > > > However, this process can be managed by the gpiolib if the driver > > > fills in the struct > > > gpio_irq_chip inside struct gpio_chip before invoking > > > gpiochip_add_data. > > > > Hmm... I thought this is solvable issue. > > Michael, is there a limitation in GPIO regmap that this driver can't be > > converted? > > gpio-regmap is designed that regmap-irq (drivers/base/regmap/irq.c) can be > used. So, if regmap-irq fit this driver, then it can be used together with > gpio-regmap. > > From a quick glance at the patch, it looks like the gpio portion might fit > gpio-regmap. > > > > Moreover, apart from managing the registers for gpio direction and > > > value, there > > > are several other registers that require access(interrupt enable, > > > debounce...). > > > The GPIO IRQ status registers are located at different base > > > addresses and are > > > not contiguous. It may need to create an additional regmap and > > > assign the access > > > table to this regmap. > > > > AFAIK this is not a problem as you can provide your own xlate function > > that > > will take care about register mapping. > > Just for the gpio part. IIRC regmap has it own translation (regmap fields). > > > > With the above consideration, I tend to keep using the existing > > > method. > > > > I would like to hear from Michael if it's indeed a big obstacle. > > So, regarding the irq portion, again, it must fit the regmap-irq. For the > additional requirement to set the debounce, you can add a .set_config to > gpio_regmap_config and supply your own set_config callback. See also [1]. Thank you, Michael, for the prompt answer. It's insightful to me, I will try to remember these aspects for the future reviews. > [1] > https://lore.kernel.org/linux-gpio/d4a6a640c373b6d939e147691efa596c@xxxxxxxx/ -- With Best Regards, Andy Shevchenko
