From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Subject: Re: [PATCH 2/4] Input: zforce - swap reset and interrupt GPIO Date: Tue, 28 Jul 2015 10:29:25 +0200 Message-ID: <55B73D65.4030002@de.bosch.com> References: <1437396997-3182-1-git-send-email-dirk.behme@de.bosch.com> <1437396997-3182-3-git-send-email-dirk.behme@de.bosch.com> <20150724213223.GD33241@dtor-ws> <55B31C48.6070903@gmail.com> <55B5E7FB.7050503@de.bosch.com> <20150727211723.GB5144@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp6-v.fe.bosch.de ([139.15.237.11]:59099 "EHLO smtp6-v.fe.bosch.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751447AbbG1I32 (ORCPT ); Tue, 28 Jul 2015 04:29:28 -0400 In-Reply-To: <20150727211723.GB5144@dtor-ws> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-input@vger.kernel.org Cc: Dmitry Torokhov On 27.07.2015 23:17, Dmitry Torokhov wrote: > 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 >>>>> >>>>> 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 >> --- >> .../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. Done: http://article.gmane.org/gmane.linux.kernel.input/44836 Thanks! Best regards Dirk