From: Lee Jones <lee.jones@linaro.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: sameo@linux.intel.com, devicetree-discuss@lists.ozlabs.org,
linux-kernel@vger.kernel.org, spear-devel@list.st.com,
Vipul Kumar Samar <vipulkumar.samar@st.com>
Subject: Re: [PATCH V2 2/2] mfd: stmpe: Extend DT support in stmpe driver
Date: Fri, 23 Nov 2012 15:43:11 +0000 [thread overview]
Message-ID: <20121123154311.GA28552@gmail.com> (raw)
In-Reply-To: <CAKohpo=4orAgwVRRvukj+tu67CyVvoUegsJ7eXaCMA9exruqEA@mail.gmail.com>
On Fri, 23 Nov 2012, Viresh Kumar wrote:
> On 23 November 2012 15:06, Lee Jones <lee.jones@linaro.org> wrote:
> > On Fri, 23 Nov 2012, Viresh Kumar wrote:
> >> pdev = platform_device_alloc(cell->name, id + cell->id);
> >>
> >> This is required when we have multiple instances of MFD device present
> >> on board. How do you want me to handle this ?
> >
> > There are lots of examples of this already. I have to leave something
> > to the imagination, or I'll be requesting a cut of your salary. :D
>
> My manager already reduced my salary by 20% after reading this mail :(
Ah, Good.
Tell your manager I'll send my offshore bank details over soon. :)
> Ok, this is what my understanding of whole this is. Platform devices are
> named like:
> - pdev-name: if id passed in pdev.id is -1
> - pdev-name.0[1|2|...]: if id passed is 0[1|2|...]
> - pdev-name.<dynamically allocated by kernel>: if id passed is -2
>
> Now, we don't declare cell->id fields and they are currently zero and so
> value is passed from pdata->id field. So, for example with multiple instances
> of stmpe on a board, we have:
>
> - stmpe-0: //Name just for reference...
> - stmpe-gpio.0
> - stmpe-ts.0
> - stmpe-1:
> - stmpe-gpio.1
> - stmpe-ts.1
> - stmpe-2:
> - stmpe-gpio.2
> - stmpe-ts.2
>
> I main idea is to distinguish various instances of sub modules, like stmpe-gpio.
> And this works well with non-DT support we have currently.
Yes, when !DT, then passing ID is no problem.
> With DT, i am not sure how should we pass id field to mfd_add_devices(). If
> we pass it -1, then multiple instances will have same name: "stmpe-gpio"
No, in DT devices named as part of the hiearchy, so you'd have:
soc-u9500/i2c@80004000/stmpe1601@40/stmpe_keypad
soc-u9500/i2c@80004000/stmpe1601@41/stmpe_keypad
... etc
The only time we need to be concerned is if one stmpe device can
handle more than one keypad, gpio controller, etc. Which I don't
think is the case.
> Sorry, for my lack of knowledge. Don't send another mail with salary cut
> suggestion as that will make it -40% in total ;)
Ah, I promise I'll spend it wisely. :)
--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
next prev parent reply other threads:[~2012-11-23 15:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-22 5:10 [PATCH V2 1/2] mfd: stmpe: Use devm_*() routines Viresh Kumar
2012-11-22 5:10 ` [PATCH V2 2/2] mfd: stmpe: Extend DT support in stmpe driver Viresh Kumar
2012-11-22 11:24 ` Lee Jones
2012-11-22 13:54 ` Viresh Kumar
2012-11-22 15:46 ` Lee Jones
2012-11-22 17:01 ` Viresh Kumar
2012-11-23 3:45 ` Shiraz Hashim
2012-11-23 9:33 ` Lee Jones
2012-11-23 9:23 ` Lee Jones
2012-11-22 18:31 ` Viresh Kumar
2012-11-23 9:39 ` Lee Jones
2012-11-23 4:29 ` Viresh Kumar
2012-11-23 9:36 ` Lee Jones
2012-11-23 12:39 ` Viresh Kumar
2012-11-23 15:43 ` Lee Jones [this message]
2012-11-23 15:45 ` Viresh Kumar
2012-11-22 10:27 ` [PATCH V2 1/2] mfd: stmpe: Use devm_*() routines Lee Jones
2012-11-22 10:30 ` Viresh Kumar
2012-11-22 17:10 ` Viresh Kumar
2012-11-23 9:40 ` Lee Jones
2012-11-23 9:42 ` Lee Jones
2012-11-23 9:44 ` Viresh Kumar
2012-11-23 11:03 ` Samuel Ortiz
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