From: Henning Schild <henning.schild@siemens.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux LED Subsystem <linux-leds@vger.kernel.org>,
Platform Driver <platform-driver-x86@vger.kernel.org>,
linux-watchdog@vger.kernel.org,
Srikanth Krishnakar <skrishnakar@gmail.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
Gerd Haeussler <gerd.haeussler.ext@siemens.com>,
Guenter Roeck <linux@roeck-us.net>,
Wim Van Sebroeck <wim@linux-watchdog.org>,
Mark Gross <mgross@linux.intel.com>,
Hans de Goede <hdegoede@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Enrico Weigelt <lkml@metux.net>
Subject: Re: [PATCH v3 2/4] leds: simatic-ipc-leds: add new driver for Siemens Industial PCs
Date: Thu, 1 Apr 2021 12:44:15 +0200 [thread overview]
Message-ID: <20210401124415.3c9321c0@md1za8fc.ad001.siemens.net> (raw)
In-Reply-To: <CAHp75VcSwW42_oQDpxn34gN7+aJNmB=HdJUbaWsYkBokYAHkSA@mail.gmail.com>
Am Wed, 31 Mar 2021 18:40:23 +0300
schrieb Andy Shevchenko <andy.shevchenko@gmail.com>:
> On Tue, Mar 30, 2021 at 6:33 PM Henning Schild
> <henning.schild@siemens.com> wrote:
> > Am Tue, 30 Mar 2021 15:41:53 +0300
> > schrieb Andy Shevchenko <andy.shevchenko@gmail.com>:
> > > On Tue, Mar 30, 2021 at 3:35 PM Henning Schild
> > > <henning.schild@siemens.com> wrote:
> > > > Am Tue, 30 Mar 2021 15:15:16 +0300
> > > > schrieb Andy Shevchenko <andy.shevchenko@gmail.com>:
> > > > > On Tue, Mar 30, 2021 at 2:58 PM Henning Schild
> > > > > <henning.schild@siemens.com> wrote:
> > > > > > Am Tue, 30 Mar 2021 14:04:35 +0300
> > > > > > schrieb Andy Shevchenko <andy.shevchenko@gmail.com>:
> > > > > > > On Mon, Mar 29, 2021 at 8:59 PM Henning Schild
> > > > > > > <henning.schild@siemens.com> wrote:
> > >
> > > > > > > > +static struct simatic_ipc_led simatic_ipc_leds_mem[] =
> > > > > > > > {
> > > > > > > > + {0x500 + 0x1A0, "red:" LED_FUNCTION_STATUS
> > > > > > > > "-1"},
> > > > > > > > + {0x500 + 0x1A8, "green:" LED_FUNCTION_STATUS
> > > > > > > > "-1"},
> > > > > > > > + {0x500 + 0x1C8, "red:" LED_FUNCTION_STATUS
> > > > > > > > "-2"},
> > > > > > > > + {0x500 + 0x1D0, "green:" LED_FUNCTION_STATUS
> > > > > > > > "-2"},
> > > > > > > > + {0x500 + 0x1E0, "red:" LED_FUNCTION_STATUS
> > > > > > > > "-3"},
> > > > > > > > + {0x500 + 0x198, "green:" LED_FUNCTION_STATUS
> > > > > > > > "-3"},
> > > > > > > > + { }
> > > > > > > > +};
> > > > > > >
> > > > > > > It seems to me like poking GPIO controller registers
> > > > > > > directly. This is not good. The question still remains:
> > > > > > > Can we simply register a GPIO (pin control) driver and
> > > > > > > use an LED GPIO driver with an additional board file that
> > > > > > > instantiates it?
> > > > > >
> > > > > > I wrote about that in reply to the cover letter. My view is
> > > > > > still that it would be an abstraction with only one user,
> > > > > > just causing work and likely not ending up as generic as it
> > > > > > might eventually have to be.
> > > > > >
> > > > > > The region is reserved, not sure what the problem with the
> > > > > > "poking" is.
> > > > >
> > > > >
> > > > > > Maybe i do not understand all the benefits of such a split
> > > > > > at this point in time. At the moment i only see work with
> > > > > > hardly any benefit, not just work for me but also for
> > > > > > maintainers. I sure do not mean to be ignorant. Maybe you
> > > > > > go into details and convince me or we wait for other
> > > > > > peoples opinions on how to proceed, maybe there is a second
> > > > > > user that i am not aware of? Until i am convinced otherwise
> > > > > > i will try to argue that a single-user-abstraction is
> > > > > > needless work/code, and should be done only when actually
> > > > > > needed.
> > > > >
> > > > > I have just read your messages (there is a cover letter and
> > > > > additional email which was sent lately).
> > > > >
> > > > > I would like to know what the CPU model number on that board
> > > > > is. Than we can continue to see what possibilities we have
> > > > > here.
> > > >
> > > > I guess we are talking about the one that uses memory mapped,
> > > > that is called an "IPC127E" and seems to have either Intel Atom
> > > > E3940 or E3930 which seems to be Apollo Lake.
> > >
> > > Yep. And now the question, in my patch series you should have got
> > > the apollolake-pinctrl driver loaded (if not, we have to
> > > investigate why it's not being instantiated). This will give you
> > > a read GPIO driver.
> >
> > Ok, so there is the existing driver i asked about several times.
> > Thanks for pointing it out.
>
> If you remember, I asked you about the chip twice :-)
> I assumed that we were talking about Apollo Lake and that's why I
> insisted that the driver is in the kernel source tree.
Sorry, maybe i did not get the context of your question and which of
the machines you asked about. Now it is clear i guess.
>
> > > So, you may use regular LED GPIO on top of it
> > > (https://elixir.bootlin.com/linux/latest/source/drivers/leds/leds-gpio.c).
> > > I would like to understand why it can't be achieved.
> >
> > Will have a look. Unfortunately this one box is missing in my
> > personal collection, but let us assume that one can be converted to
> > that existing driver.
>
> OK!
>
> > I guess that will still mean the PIO-based part of the LED driver
> > will have to stay as is.
>
> Probably yes. I haven't looked into that part and I have no idea
> what's going on on that platform(s).
>
Which i guess means the series can be reviewed as if the mmio bits for
that apollo lake would not be in it, maybe i will even send a version
without that one box. We have others in the "backlog" might as well
delay that one if it helps sorting out a base-line.
regards,
Henning
next prev parent reply other threads:[~2021-04-01 10:45 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-29 17:49 [PATCH v3 0/4] add device drivers for Siemens Industrial PCs Henning Schild
2021-03-29 17:49 ` [PATCH v3 1/4] platform/x86: simatic-ipc: add main driver for Siemens devices Henning Schild
2021-11-26 12:39 ` Henning Schild
2021-03-29 17:49 ` [PATCH v3 2/4] leds: simatic-ipc-leds: add new driver for Siemens Industial PCs Henning Schild
2021-03-30 11:04 ` Andy Shevchenko
2021-03-30 11:58 ` Henning Schild
2021-03-30 12:15 ` Andy Shevchenko
2021-03-30 12:30 ` Henning Schild
2021-03-30 12:41 ` Andy Shevchenko
2021-03-30 15:23 ` Henning Schild
2021-03-31 15:40 ` Andy Shevchenko
2021-04-01 10:44 ` Henning Schild [this message]
2021-04-01 11:04 ` Andy Shevchenko
2021-04-12 11:56 ` Henning Schild
2021-05-05 14:58 ` Enrico Weigelt, metux IT consult
2021-04-12 15:15 ` Henning Schild
2021-11-26 13:28 ` Henning Schild
2021-11-26 14:02 ` Andy Shevchenko
2021-11-26 14:44 ` Henning Schild
2021-11-26 14:59 ` Andy Shevchenko
2021-11-26 19:54 ` Henning Schild
2021-11-25 17:11 ` Henning Schild
2021-03-29 17:49 ` [PATCH v3 3/4] watchdog: simatic-ipc-wdt: add new driver for Siemens Industrial PCs Henning Schild
2021-04-01 16:15 ` Enrico Weigelt, metux IT consult
2021-04-06 14:52 ` Henning Schild
2021-04-07 8:53 ` Andy Shevchenko
2021-04-07 12:17 ` Guenter Roeck
2021-11-26 13:18 ` Henning Schild
2021-04-12 15:35 ` Henning Schild
2021-04-12 16:06 ` Guenter Roeck
2021-04-12 16:17 ` Henning Schild
2021-11-25 17:08 ` Henning Schild
2021-11-25 17:10 ` Henning Schild
2021-03-29 17:49 ` [PATCH v3 4/4] platform/x86: pmc_atom: improve critclk_systems matching for Siemens PCs Henning Schild
2021-03-29 18:00 ` [PATCH v3 0/4] add device drivers for Siemens Industrial PCs Henning Schild
2021-04-07 11:36 ` Hans de Goede
2021-04-12 11:27 ` Henning Schild
2021-07-12 11:35 ` Henning Schild
2021-07-12 12:09 ` Andy Shevchenko
2021-07-12 16:11 ` Henning Schild
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210401124415.3c9321c0@md1za8fc.ad001.siemens.net \
--to=henning.schild@siemens.com \
--cc=andy.shevchenko@gmail.com \
--cc=gerd.haeussler.ext@siemens.com \
--cc=hdegoede@redhat.com \
--cc=jan.kiszka@siemens.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-leds@vger.kernel.org \
--cc=linux-watchdog@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=lkml@metux.net \
--cc=mgross@linux.intel.com \
--cc=pavel@ucw.cz \
--cc=platform-driver-x86@vger.kernel.org \
--cc=skrishnakar@gmail.com \
--cc=wim@linux-watchdog.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).