From: Jan Kiszka <jan.kiszka@siemens.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "Enrico Weigelt, metux IT consult" <lkml@metux.net>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH 2/2] gpio: sch: Add interrupt support
Date: Fri, 26 Apr 2019 19:37:35 +0200 [thread overview]
Message-ID: <bbc81e4d-7a3c-ef1e-e89b-739bc262f6db@siemens.com> (raw)
In-Reply-To: <CAHp75VfonL_f1GjRFFhp59R8U+bGzT9pcC7p8XDJ32-_cxT29g@mail.gmail.com>
On 26.04.19 19:20, Andy Shevchenko wrote:
> On Fri, Apr 26, 2019 at 7:05 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>
>> On 26.04.19 16:42, Enrico Weigelt, metux IT consult wrote:
>>> On 26.04.19 15:36, Jan Kiszka wrote:
>>>
>>>> At the same time, there are no real alternatives - to my> knowledge - for the value it brings (various bindings) to simply
>>> switch> the engine.
>>> Which value exactly does that collection of crude wrappers and broken
>>> attempts to buypass the kernel (driving gpios via /dev/mem *facepalm*)
>>> provide ?
>>
>> Leaving that blunt hack aside:
>>
>> import mraa
>>
>> pin = mraa.Gpio(13)
>> pin.dir(mraa.DIR_OUT)
>> pin.write(1)
>>
>> And the same goes for nodejs, java and c++.
>>
>> Moreover, this allows you to abstract away where "Pin 13" actually came from on
>> that board if the kernel changes (BSP -> upstream...) or the extension board or
>> ...
>
> The problem here is opaque number. This has to be chip + *relative* pin number/
> See this:
> https://stackoverflow.com/questions/55532410/how-do-linux-gpio-numbers-get-their-values/55579640#55579640
>
...and device path based discovery of the base:
https://github.com/siemens/mraa/commits/jan/queue
And I think that makes good use cases for application-level abstractions like in
mraa. You don't want all user having to learn those nasty details, for
devicetree, ACPI, and even worse stuff.
Jan
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2019-04-26 17:37 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-18 9:23 [PATCH 0/2] gpio: sch: Interrupt support Jan Kiszka
2019-04-18 9:23 ` [PATCH 1/2] gpio: sch: Remove write-only core_base Jan Kiszka
2019-04-23 11:09 ` Linus Walleij
2019-04-18 9:23 ` [PATCH 2/2] gpio: sch: Add interrupt support Jan Kiszka
2019-04-23 11:10 ` Linus Walleij
2019-04-24 7:58 ` Mika Westerberg
2019-04-24 8:12 ` Jan Kiszka
2019-04-24 8:18 ` Mika Westerberg
2019-04-24 8:25 ` Jan Kiszka
2019-04-24 8:42 ` Mika Westerberg
2019-04-24 9:36 ` Jan Kiszka
2019-04-24 9:45 ` Mika Westerberg
2019-04-24 9:48 ` Jan Kiszka
2019-04-24 10:01 ` Mika Westerberg
2019-04-24 10:19 ` Jan Kiszka
2019-04-24 10:33 ` Mika Westerberg
2019-04-24 10:39 ` Jan Kiszka
2019-04-24 10:46 ` Mika Westerberg
2019-04-24 12:41 ` Jan Kiszka
2019-04-24 13:13 ` Mika Westerberg
2019-04-24 14:24 ` Jan Kiszka
2019-04-24 15:33 ` Mika Westerberg
2019-04-26 13:06 ` Andy Shevchenko
2019-04-26 13:36 ` Jan Kiszka
2019-04-26 14:42 ` Enrico Weigelt, metux IT consult
2019-04-26 15:31 ` Manivannan Sadhasivam
2019-04-26 16:03 ` Jan Kiszka
2019-04-26 17:20 ` Andy Shevchenko
2019-04-26 17:33 ` Manivannan Sadhasivam
2019-04-26 17:39 ` Jan Kiszka
2019-04-26 17:46 ` Manivannan Sadhasivam
2019-04-26 17:52 ` Jan Kiszka
2019-04-26 17:56 ` Manivannan Sadhasivam
2019-04-26 17:44 ` Andy Shevchenko
2019-04-26 17:52 ` Manivannan Sadhasivam
2019-04-26 18:26 ` Andy Shevchenko
2019-04-26 17:37 ` Jan Kiszka [this message]
2019-04-29 11:09 ` Enrico Weigelt, metux IT consult
2019-05-16 12:20 ` Linus Walleij
2019-04-26 14:41 ` Linus Walleij
2019-04-26 15:44 ` Jan Kiszka
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