X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=Documentation%2Fgpio.txt;h=b1b9887012478f9b654edaa90bcdd13e72a9f20e;hb=db0fb1848a645b0b1b033765f3a5244e7afd2e3c;hp=8a7c45956d2412d69a26f8de991db19ed25a838f;hpb=0f6d504e73b49374c6093efe6aa60ab55058248a;p=karo-tx-linux.git diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 8a7c45956d24..b1b988701247 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -240,6 +240,10 @@ signal, or (b) something wrongly believes it's safe to remove drivers needed to manage a signal that's in active use. That is, requesting a GPIO can serve as a kind of lock. +Some platforms may also use knowledge about what GPIOs are active for +power management, such as by powering down unused chip sectors and, more +easily, gating off unused clocks. + These two calls are optional because not not all current Linux platforms offer such functionality in their GPIO support; a valid implementation could return success for all gpio_request() calls. Unlike the other calls,