Messages in this thread | | | Date | Sat, 28 Sep 2013 17:08:20 +0530 | From | Laxman Dewangan <> | Subject | Re: [PATCH 1/2] pinctrl: palmas: do not abort pin configuration for BIAS_DEFAULT |
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On Friday 27 September 2013 09:36 PM, Stephen Warren wrote: > On 09/27/2013 07:30 AM, Laxman Dewangan wrote: >> On Thursday 26 September 2013 09:08 PM, Stephen Warren wrote: >>> On 09/26/2013 06:48 AM, Laxman Dewangan wrote: >>>> Recent movement of all configurations of pin in the single call of >>>> pin_config_set(), it is aborting configuration if BIAS_PULL_PIN_DEFAULT >>>> is selected as return of configuration. >>>> >>>> The original idea was to just avoid any update on register for pull >>>> up/down >>>> configuration if this option is selected. >>> That doesn't sound correct. If a config option is specified in DT or the >>> mapping table, it should be applied to HW. If someone doesn't want a >>> particular config option applied, then it simply shouldn't be mentioned >>> in DT or the mapping table. >>> >>> IIUC, BIAS_DEFAULT should be used only on HW where there is a concept of >>> a true default bias, and in that case, that is what should be applied. >>> >> Hmm.. When I added the PIN_DEFAULT, I just though that do not update >> anything in the register and implemented like that. >> There is nothing "default" option in HW. > The description of that pinconfig option is: > >> 7970cb77 (Heiko Stübner 2013-06-06 16:44:25 +0200 43) * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based >> 70637a6d (Heiko Stübner 2013-06-25 14:55:42 +0200 44) * on embedded knowledge of the controller hardware, like current mux >> 70637a6d (Heiko Stübner 2013-06-25 14:55:42 +0200 45) * function. The pull direction and possibly strength too will normally >> 70637a6d (Heiko Stübner 2013-06-25 14:55:42 +0200 46) * be decided completely inside the hardware block and not be readable >> 70637a6d (Heiko Stübner 2013-06-25 14:55:42 +0200 47) * from the kernel side. >> 5ca3353b (Linus Walleij 2013-06-16 12:43:06 +0200 48) * If the argument is != 0 pull up/down is enabled, if it is 0, the >> 5ca3353b (Linus Walleij 2013-06-16 12:43:06 +0200 49) * configuration is ignored. The proper way to disable it is to use >> 5ca3353b (Linus Walleij 2013-06-16 12:43:06 +0200 50) * @PIN_CONFIG_BIAS_DISABLE. > If the HW doesn't support any concept of a default pull, I think the > driver shouldn't support that option; it should return an error if asked > to program it.
Yes, I will remove this option as I have not seen default option for pins.
> > > But what made you come across this issue? Is some pin mapping table or > DT pinctrl node actually using that value? If so, then presumably that > needs to be fixed, as well as removing driver support for that option.
When referring the code for the AMSAS3722 pincontrol driver, I just found that it is breaking the earlier code.
Removing this option makes more reasonable here and will post the next patch.
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