Hi,
* Stephen Warren <swarren@xxxxxxxxxxxxx> [120621 15:17]:
> On 06/19/2012 07:56 AM, Tony Lindgren wrote:
> > +
> > +- pinctrl-single,pinconf-mask : mask of allowed pinconf bits in the
> > + pinmux register; this gets combined with pinconf mask but is a separate
> > + mask to allow the option of setting pinconf separatately from the
> > + function
>
> Given that this binding doesn't allow describing pin configuration at
> present, I would simply remove all mention of that property in the
> binding documentation. It can be added back if/when that feature is
> added. Any future driver using this binding can refuse to allow pin
> configuration if that property is missing.
It might be better to just add support for pin_config_get/set to avoid
changing the binding later:
static int pcs_pinconf_get(struct pinctrl_dev *pctldev,
unsigned pin, unsigned long *config)
{
- return -ENOTSUPP;
+ struct pcs_device *pcs;
+ void __iomem *reg;
+ int res;
+
+ pcs = pinctrl_dev_get_drvdata(pctldev);
+ res = pcs_pin_to_reg(pcs, pin, ®);
+ if (res)
+ return res;
+
+ return pcs->read(reg) & pcs->cmask;
}
A have not done that yet as currently the pcs_pin_to_reg() would need to be
sorted out in somewhat clean manner.
> > +- pinctrl-single,function-off : function off mode for disabled state if
> > + available and same for all registers; if not, use a value larger than
> > + function-mask to ignore disabling of registers
>
> Rather than requiring an invalid value in this property, shouldn't the
> lack of a valid function-off value be represented by the property not
> being present in the DT?
Heh good point :) Will change.
> > +This driver assumes that there is only one register for each pin,
> > +and uses the common pinctrl bindings as specified in the pinctrl-bindings.txt
> > +document in this directory.
>
> At this point in the file, I think you need to mention that you're
> switching from describing the top-level device node to describing pin
> configuration nodes.
Will add.
> > +The pinctrl register offsets and default values are specified as pairs
>
> I thought we were going to remove "default" here?
Oops, looks like one was left, will remove.
> > +using pinctrl-single,pins. For example, setting a pin for a device
> > +could be done with:
> > +
> > + pinctrl-single,pins = <0xdc 0x118>;
> > +
> > +Where 0xdc is the offset from the pinctrl register base address for the
> > +device pinctrl register, and 0x118 contains the desired value of the
> > +pinctrl register. See the device example and static board pins example
> > +below for more information.
>
> There should be some explanation only the portion of this value covered
> by the pinctrl-single,function-mask value is updated in the register.
OK
> > +This driver tries to avoid understanding pin and function names because of
> > +the extra bloat they would cause especially in the case of a large number
> > +of pins. This driver just sets what is specified for the board in the .dts file.
> > +Further user space debugging tools can be developed to decipher the pin and
> > +function names using debugfs.
>
> There shouldn't be any discussion of a driver here; the binding is a HW
> description.
Will move that to the driver comments.
> > +Example:
>
> I only reviewed the binding document, not the code.
Thanks,
Tony
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