Hi Tony,
On 09/06/2012 10:10 PM, Tony Lindgren wrote:
> Hi Peter,
>
> * Peter Ujfalusi <peter.ujfalusi@xxxxxx> [120905 02:02]:
>> With pinctrl-single,bits it is possible to update just part of the register
>> within the pinctrl-single,function-mask area.
>> This is useful when one register configures mmore than one pin's mux.
>
> You have a typo here: ^^^^^
Oh, I'll fix this up.
>> --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
>> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
>> @@ -31,6 +31,15 @@ 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.
>>
>> +In case when one register changes more than one pin's mux the
>> +pinctrl-single,bits can be used which takes three parameters:
>> +
>> + pinctrl-single,bits = <0xdc 0x18, 0xff>;
>> +
>> +Where 0xdc is the offset from the pinctrl register base address for the
>> +device pinctrl register, 0x18 is the desired value, and 0xff is the sub mask to
>> +be used when applying this change to the register.
>> +
>
> Is it now safe to assume that we always have width of three if
> pinctrl-single,bits is specified? The reason I'm asking is..
>
>> @@ -657,18 +664,29 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
>> {
>> struct pcs_func_vals *vals;
>> const __be32 *mux;
>> - int size, rows, *pins, index = 0, found = 0, res = -ENOMEM;
>> + int size, params, rows, *pins, index = 0, found = 0, res = -ENOMEM;
>> struct pcs_function *function;
>>
>> - mux = of_get_property(np, PCS_MUX_NAME, &size);
>> - if ((!mux) || (size < sizeof(*mux) * 2)) {
>> - dev_err(pcs->dev, "bad data for mux %s\n",
>> - np->name);
>> + mux = of_get_property(np, PCS_MUX_PINS_NAME, &size);
>> + if (mux) {
>> + params = 2;
>> + } else {
>> + mux = of_get_property(np, PCS_MUX_BITS_NAME, &size);
>> + if (!mux) {
>> + dev_err(pcs->dev, "no valid property for %s\n",
>> + np->name);
>> + return -EINVAL;
>> + }
>> + params = 3;
>> + }
>
> ..because here we could assume the default value for params is 2
> if pinctrl-single,pins is specified, and otherwise params is 3
> if pinctrl-single,bits is specified for the controller. That would
> avoid querying a potentially non-exiting property for each entry.
>
>> @@ -686,6 +704,10 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
>> val = be32_to_cpup(mux + index++);
>> vals[found].reg = pcs->base + offset;
>> vals[found].val = val;
>> + if (params == 3) {
>> + val = be32_to_cpup(mux + index++);
>> + vals[found].mask = val;
>> + }
>>
>> pin = pcs_get_pin_by_offset(pcs, offset);
>> if (pin < 0) {
>
> Here params too would be then set during probe already.
I'm afraid you lost me here...
We only know if the user specified the mux configuration with
pinctrl-single,pins or pinctrl-single,bits in this function.
One thing I could do to make the code a bit better to look at is:
int params = 2;
mux = of_get_property(np, PCS_MUX_PINS_NAME, &size);
if (!mux) {
mux = of_get_property(np, PCS_MUX_BITS_NAME, &size);
if (!mux) {
dev_err(pcs->dev, "no valid property for %s\n",
np->name);
return -EINVAL;
}
params = 3;
}
This might make the code a bit more compact but at the same time one might
need to spend few more seconds to understand it.
Regards,
Péter
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