On 08/21/2012 05:25 AM, Linus Walleij wrote: > On Wed, Aug 15, 2012 at 9:57 PM, Thomas Abraham > <thomas.abraham@xxxxxxxxxx> wrote: > >> Add a new device tree enabled pinctrl and gpiolib driver for Samsung >> SoC's. ... >> + The child node can also optionally specify one or more of the pin >> + configuration that should be applied on all the pins listed in the >> + "samsung,pins" property of the child node. The following pin configuration >> + properties are supported. >> + >> + - samsung,pin-pud: Pull up/down configuration. >> + - samsung,pin-drv: Drive strength configuration. >> + - samsung,pin-pud-pdn: Pull up/down configuration in power down mode. >> + - samsung,pin-drv-pdn: Drive strength configuration in power down mode. > > This looks a bit scary, as it seems to be orthogonal to the pin config > interface. I.e. this will be programmed "behind the back" of the > pin config system. However as long as the pin config implementation > reads back these things from the registers it will work, too. > > In the U300 and Ux500 I explicitly use pin config hogs to set up > the pin configuration, and when we enter a state such as > "default" the mux setting and config settings are set from the > framework separately. I know that some HW has a separate set of registers (or fields) for the "awake" and "sleep" configuration, and the HW switches between the two automatically when sleeping. I have no idea if the Samsung SoCs do this, but I think if this were the case, it'd be quite legitimate to define both these HW states as separate sets of properties within a single pinctrl SW state. So, that might be the explanation here? -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |