Hi Dirk, On Mon, Jul 27, 2015 at 10:12:43AM +0200, Dirk Behme wrote: > On 25.07.2015 07:19, Dirk Behme wrote: > >On 24.07.2015 23:32, Dmitry Torokhov wrote: > >>On Mon, Jul 20, 2015 at 02:56:35PM +0200, Dirk Behme wrote: > >>>From: Dirk Behme <dirk.behme@xxxxxxxxx> > >>> > >>>Swap the order of the reset and interrupt GPIO. This is the preparation > >>>to make the interrupt GPIO optional. > >>> > >>>Note that this needs the same change in the device tree. But as mainline > >>>doesn't contain any zforce device tree entries, nothing has to be done > >>>for us, here. > >>> > >>>All non-mainline device trees have to be adapted, though. > >> > >>No, we can not do that. > > > > > >The proposal to make the interrupt GPIO optional and not completely drop > >it came from you. Any other proposal how you like to get this > >implemented? With completely dropping the interrupt GPIO we would avoid > >this. > > > > > >>We will have to switch to using named gpios > >>(probably call then attn-gpio and reset-gpio respectively and > >>handle old-style DTSes with unnamed 2-entry gpios list). > > > > > >Just to understand correctly: You want the driver to support two GPIOs > >DT styles? One with unnamed 2-entry gpios list, where the interrupt GPIO > >can't be optional, and one with two named GPIOs, where the attn-gpio can > >be optional? > > > Are you talking about anything like below [1] ? Yes. > > > Best regards > > Dirk > > [1] > > Subject: [PATCH] Input: zforce - make the interrupt GPIO optional > > Add support for hardware which uses an I2C Serializer / Deserializer > (SerDes) to communicate with the zFroce touch driver. In this case the > SerDes will be configured as an interrupt controller and the zForce driver > will have no access to poll the GPIO line. > > To support this, we add two dedicated new GPIOs in the device tree: > rst-gpio and int-gpio. With the int-gpio being optional, then. > > To not break the existing device trees, the index based 'gpios' entries > are still supported, but marked as depreciated. > > With this, if the interrupt GPIO is available, either via the old or new > device tree style, the while loop will read and handle the packets as long > as the GPIO indicates that the interrupt is asserted (existing, unchanged > driver behavior). > > If the interrupt GPIO isn't available, i.e. not configured via the new > device tree stlye, we are falling back to one read per ISR invocation > (new behavior to support the SerDes). > > Note that the gpiod functions help to handle the optional GPIO: > devm_gpiod_get_index_optional() will return NULL in case the interrupt > GPIO isn't available. And gpiod_get_value_cansleep() does cover this, too, > by returning 0 in this case. > > Signed-off-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx> > --- > .../bindings/input/touchscreen/zforce_ts.txt | 15 ++++++-- > drivers/input/touchscreen/zforce_ts.c | 42 > +++++++++++++++++++++- > 2 files changed, 53 insertions(+), 4 deletions(-) > > diff --git > a/Documentation/devicetree/bindings/input/touchscreen/zforce_ts.txt > b/Documentation/devicetree/bindings/input/touchscreen/zforce_ts.txt > index 80c37df..1957877 100644 > --- a/Documentation/devicetree/bindings/input/touchscreen/zforce_ts.txt > +++ b/Documentation/devicetree/bindings/input/touchscreen/zforce_ts.txt > @@ -4,12 +4,16 @@ Required properties: > - compatible: must be "neonode,zforce" > - reg: I2C address of the chip > - interrupts: interrupt to which the chip is connected > -- gpios: gpios the chip is connected to > - first one is the interrupt gpio and second one the reset gpio > +- gpios: > + - rst-gpio: reset gpio the chip is connected to > + or > + - gpios (old style, deprecated): gpios the chip is connected to > + first one is the interrupt gpio and second one the reset gpio We do not need to keep documentation for deprecated style, so just remove reference to old "gpios" property, > - x-size: horizontal resolution of touchscreen > - y-size: vertical resolution of touchscreen > > Optional properties: > +- int-gpio : interrupt gpio the chip is connected to > - vdd-supply: Regulator controlling the controller supply > > Example: > @@ -23,9 +27,14 @@ Example: > interrupts = <2 0>; > vdd-supply = <®_zforce_vdd>; > > + rst-gpio = <&gpio5 9 0>; /* RST */ > + int-gpio = <&gpio5 6 0>; /* INT, optional */ > + > + /* or deprecated, use new style above for > + new device trees: > gpios = <&gpio5 6 0>, /* INT */ > <&gpio5 9 0>; /* RST */ Here as well. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
