Re: [PATCH v3 4/6] pinctrl: Add pinctrl binding for Broadcom Capri SoCs

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Sat, Dec 14, 2013 at 2:16 AM, Sherman Yin <syin@xxxxxxxxxxxx> wrote:

>>> +- bias-pull-up:                        Integer. Pull up strength in Ohm:
>>> +                                       1: 1.2 kOhm
>>> +                                       2: 1.8 kOhm
>>> +                                       3: 720 Ohm
>>> +                                       4: 2.7 kOhm
>>> +                                       5: 831 Ohm
>>> +                                       6: 1.08 kOhm
>>> +                                       7: 568 Ohm
>>
>>
>> Please do not use these custom enumerators 1 thru 7.
>> Instead say that the argument is given in ohms, so for
>> example:
>>
>> bias-pull-up = <12000>;
>>
>> Then translate this into the proper enumerator in your
>> driver instead.
>
> Ok.  The 3 bits in this enumeration correspond to enabling the 3 pull up Rs
> (1.2k, 1.8k, 2.7k) in parallel, so the enum kind of make sense. But sure I
> can change it to actual ohms and will error out in the driver if specified
> value is not one of the 7.

Aha, that's how they do it :-)

Please write this in a comment in the driver because it makes
it a lot easier to understand what is going on, and e.g. how to
fuzz an apropriate resistance.

Can you tell me something about how such resistors are produced
in silicon?

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux