On Fri, Jun 14, 2013 at 5:42 PM, Heiko Stübner <he...@sntech.de> wrote:
> The BIAS_DISABLE and BIAS_HIGH_IMPEDANCE generic pinconfig options were > missing information about their argument - which should be ignored. > > Also the BIAS_PULL_* options may have the pull strength as argument > when they are activated, while simpler hardware can use any > non-0 value for it. > > Update the kerneldoc to reflect this. > > Signed-off-by: Heiko Stuebner <he...@sntech.de> I'm holding this patch off. > * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high > - * impedance to VDD). If the argument is != 0 pull-up is enabled, > - * if it is 0, pull-up is disabled. > + * impedance to VDD). If the argument is != 0 pull-up is enabled. On > + * hardware supporting this, the argument should contain the strength of > + * the pull in Ohm. If it is 0, pull-up is disabled. As noted by Laurent, a pull-up of 0 Ohm is a short-circuit (bascially the TOTAL pull-up) and it is pretty counter-intuitive to have that mean "disable pull-up". Can we avoid this? > * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high > - * impedance to GROUND). If the argument is != 0 pull-down is enabled, > - * if it is 0, pull-down is disabled. > + * impedance to GROUND). If the argument is != 0 pull-down is enabled. On > + * hardware supporting this, the argument should contain the strength of > + * the pull in Ohm. If it is 0, pull-down is disabled. Dito. > * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based > * on embedded knowledge of the controller, like current mux function. > - * If the argument is != 0 pull up/down is enabled, if it is 0, > - * the pull is disabled. > + * If the argument is != 0 pull up/down is enabled. On hardware > supporting > + * this, the argument should contain the strength of the pull in Ohm. > + * If it is 0, pull is disabled. Dito. Can't we rely on PIN_CONFIG_BIAS_DISABLE for all this? Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
