Messages in this thread | | | Date | Sat, 30 Apr 2016 13:07:33 +0200 | Subject | Re: [PATCH V5 0/4] gpio: tegra: Cleanups and support for debounce | From | Linus Walleij <> |
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On Fri, Apr 29, 2016 at 11:20 AM, Laxman Dewangan <ldewangan@nvidia.com> wrote: > On Friday 29 April 2016 02:37 PM, Linus Walleij wrote: >> On Mon, Apr 25, 2016 at 12:38 PM, Laxman Dewangan <ldewangan@nvidia.com> >> wrote: >> >>> Add support for the debounce as Tegra210 support debounce in HW. >>> Also do the clenaups to remove all global variables. >> >> OK this v5 is applied. >> >> Laxman does this GPIO also have open drain and/or open source >> handling? > > > Some of the pins support the open drain and these are part of pinmux > register set. > For that we have property for setting open drain. > > Is it possible to link the gpio APIs to pincontrol for setting that pin?
I have the same issue with Nomadik pin control that I use as a testbed: there is a backend in pin control to the GPIO side.
I was thinking about adding a new cross call. We now have this:
/* External interface to pin control */ extern int pinctrl_request_gpio(unsigned gpio); extern void pinctrl_free_gpio(unsigned gpio); extern int pinctrl_gpio_direction_input(unsigned gpio); extern int pinctrl_gpio_direction_output(unsigned gpio);
I was going to add:
extern int pinctrl_gpio_set_config(unsigned gpio, unsigned long config);
That can be used by GPIO drivers to call back into pincontrol and set up any config flags using the conventions of the corresponding pin control back-end.
This could be used for as well open drain as other things (like pull-up) as the userspace ABI matures (it currently only has in/out and open drain/source).
What do you think about this idea?
>> Then you might want to look into supporting that too as I just added >> support for native single-endedness to gpiolib, c.f.: >> http://marc.info/?l=linux-gpio&m=146011780301280&w=2 > > Yaah, Some of PMIC's (which I am handling) gpios support open drain and I > think I can have changes for the PMIC gpio driver.
Nice! :)
>> It would be nice if you also implement .get_direction() which >> makes debugfs and initial reading of the state of the lines >> more accurate. > > Sure, this can be implemented. > Will post the patch on top of the series soon.
Thanks.
Yours, Linus Walleij
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