On Mon, Nov 11, 2013 at 06:24:47PM +0000, Stephen Warren wrote: > On 11/11/2013 11:01 AM, Mark Rutland wrote: > > On Mon, Nov 11, 2013 at 05:41:58PM +0000, Ashwini Ghuge wrote: > >> The driver uses the common Tegra pinctrl driver utility functions to > >> implement the majority of the driver. It is based on the similar Tegra114 > >> pinctrl > > >> diff --git a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-pinctrl.txt > > >> @@ -0,0 +1,120 @@ > >> +NVIDIA Tegra124 pinmux controller > >> + > >> +The Tegra124 pinctrl binding is very similar to the Tegra114 > >> +pinctrl binding, as described in nvidia,tegra114-pinmux.txt. In fact, this > >> +document assumes that binding as a baseline, and only documents the > >> +differences between the two bindings. > >> + > >> +Required properties: > >> +- compatible: "nvidia,tegra124-pinmux" > >> +- reg: Should contain the register physical address and length for each of > >> + the pad control and mux registers. The first bank of address must be the > >> + driver strength pad control register address and second bank address must > >> + be pinmux register address. > > > > It might be worth using reg-names here, in case a future hardware > > variant builds atop of this. > > This binding is essentially identical to the existing Tegra20/30/114 > bindings, it'd just that the HW has different sets of valid values for > pin/group/function names. I'd rather keep it consistent with the other > bindings. > > It's quite unlikely some future binding will build on top of this; if > the HW changes at all, we'll almost certainly have a completely new > binding definition to cater for the differing pin/group/function names. Ok. > > >> +Tegra124 has the following optional properties for pin configuration subnodes: > >> +- nvidia,enable-input: Integer. Enable the pin's input path. 0: no, 1: yes. > > > > Why are the properties representing boolean values not empty / boolean > > properties (as can be handled in the kernel with of_property_read_bool)? > > They aren't Boolean, they're tri-state: Set off, set on, don't change > the setting. The "pinctrl state" nodes each list a set of changes to > make to the HW to enter/set-up that state, and those sets of changes may > not need to alter all values, hence it's important to be able to > differentiate between not changing a value, and the value to change it to. Sorry, I had missed that. > > >> +- nvidia,open-drain: Integer. Enable open drain mode. 0: no, 1: yes. > >> +- nvidia,lock: Integer. Lock the pin configuration against further changes > >> + until reset. 0: no, 1: yes. > >> +- nvidia,io-reset: Integer. Reset the IO path. 0: no, 1: yes. > >> +- nvidia,rcv-sel: Integer. Select VIL/VIH receivers. 0: normal, 1: high. > > > > Why not just have nvidia,rcv-high as a boolean property, and default to > > normal? > > Same argument. > > >> +- nvidia,drive-type: Integer. Valid range 0...3. > > > > What do these values mean? > > They're the raw HW values. We probably should add something like, "See > the TRM's definition of field XXX for further details". That would be helpful :) > > >> +As with Tegra114, see the Tegra TRM for complete details regarding which > >> +groups support which functionality. > > > > Where can I find this TRM? > > The TRM for earlier Tegras is available at e.g.: > https://developer.nvidia.com/tegra-3-technical-reference-manual > > We probably haven't published the Tegra124 TRM yet:-( However, the > overall structure of the Tegra124 pinmux is the same as for the Tegra30 > pinmux documented at that link. The difference is the set of > pins/groups/functions. Ok. > > > [...] > > > >> +Example: > >> + > >> + pinmux: pinmux { > >> + compatible = "nvidia,tegra124-pinmux"; > >> + reg = <0x70000868 0x148 /* Pad control registers */ > >> + 0x70003000 0x40c>; /* PinMux registers */ > > > > For consistency, please bracket entries in lists individually: > > > > reg = <0x70000868 0x148>, /* Pad control registers */ > > <0x70003000 0x40c>; /* PinMux registers */ > > I had pointed this out to Ashwini in internal review, along with a few > other minor formatting/wording issues elsewhere. Hopefully that'll all > be rolled into v2... > Sounds good. Cheers, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
