On 22 August 2012 03:08, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > 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? > Hi Stephen, Yes, Samsung SoC support the "awake" and "sleep" configuration in that way you described. Thanks, Thomas. -- 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
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