From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH V5 2/2] mfd: stmpe: Update DT support in stmpe driver Date: Thu, 6 Dec 2012 10:11:31 +0000 Message-ID: <20121206101131.GP2718@gmail.com> References: <2dcd7cb4c4022fa24b5328974e4226f5aaf89419.1354199865.git.viresh.kumar@linaro.org> <121653def4e985b0c1b59045637dd4518f97e73a.1354199865.git.viresh.kumar@linaro.org> <20121130105731.GN3176@sortiz-mobl> <20121130154542.GG23648@gmail.com> <20121205224203.691153E0E22@localhost> <20121206095019.GN2718@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Viresh Kumar Cc: rabin.vincent-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org, Samuel Ortiz , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, spear-devel-nkJGhpqTU55BDgjK7y7TUQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shiraz.hashim-qxv4g6HH51o@public.gmane.org List-Id: devicetree@vger.kernel.org T24gVGh1LCAwNiBEZWMgMjAxMiwgVmlyZXNoIEt1bWFyIHdyb3RlOgoKPiBPbiA2IERlY2VtYmVy IDIwMTIgMTU6MjAsIExlZSBKb25lcyA8bGVlLmpvbmVzQGxpbmFyby5vcmc+IHdyb3RlOgo+ID4+ ID4gQnV0IHJlZ2FyZGxlc3MsIGl0IGlzIHRoZSByZXNwb25zaWJsaXR5IG9mIHRoZSBwcm9iZSBm dW5jdGlvbiB0byBnbyBhbmQKPiA+PiA+IGxvb2sgaWYgb2ZfZHJpdmVyX21hdGNoX2RldmljZSgp IG1hdGNoZXMgYWdhaW5zdCBhbnl0aGluZyBpZiBpdCBjYXJlcwo+ID4+ID4gYWJvdXQgdGhlIG9m X21hdGNoX3RhYmxlIGVudHJpZXMgKGZvciBpbnN0YW5jZSwgaWYgdGhlcmUgaXMgZXh0cmEgZGF0 YQo+ID4+ID4gYXR0YWNoZWQpLgo+ID4+Cj4gPj4gT2ssIHNvIGZpbGxpbmcgLmRhdGEgZmllbGQg aW4gb2ZfZGV2aWNlX2lkW10gaXMgbm90IHJlcXVpcmVkIGZvciBvdXIgY2FzZSBhcwo+ID4+IHdl IGFyZW4ndCBkb2luZyBhbnl0aGluZyBzcGVjaWFsIGluIG91ciBkcml2ZXJzLgo+ID4KPiA+IFRo aXMgaXMgZXhhY3RseSBteSBwb2ludCwgYW5kIHRoZSByZWFzb24gSSBib3VnaHQgaXQgdXAgaW4g dGhlCj4gPiBmaXJzdCBwbGFjZS4gTm9ybWFsbHkgd2hlbiB5b3Ugc3BlY2lmeSBhbiBJRCB0YWJs ZSBhbmQgcG9wdWxhdGUKPiA+IHRoZSAuZGF0YSBhdHRyaWJ1dGUsIHlvdSBwYXJzZSBmb3IgaXQg aW4gdGhlIGNvZGUgYW5kIHRoZW4gY2FzdAo+ID4gaXQgYmFjayB0byBzb21lIGtpbmQgb2YgdXNl ZnVsIGRhdGEuIEhvd2V2ZXIsIHlvdSdyZSBub3QgZG9pbmcKPiA+IHRoYXQsIHdoaWNoIGlzIHBy ZWNpc2VseSB3aHkgSSB3b25kZXJlZCBpZiB0aGUgdGFibGUgd2FzCj4gPiBuZWNlc3NhcnkgYXQg YWxsLiBJbiBhbGwgbXkgdGVzdGluZywgdGhlIERUIHBvcnRpb24gd29ya2VkIGFuZAo+ID4gdGhl IGNvcnJlY3QgU1RNUEUgY2hpcCB3YXMgaWRlbnRpZmllZCB3aXRob3V0IGl0Lgo+IAo+IFByb2Jh Ymx5IFZpcHVsIChBdXRob3Igb2YgdGhpcyBwYXRjaCksIGNvcGllZCBpdCBmcm9tIGV4aXN0aW5n IGkyYy9zcGkKPiBjbGllbnRzLCB3aGljaCBoYXZlIGFsc28gYWRkZWQgdGhpcyBibGluZGx5IDop Cj4gCj4gPiBTbywgYXJlIHlvdSBhZGRpbmcgdGhlIHRhYmxlIGZvciBnb29kIHJlYXNvbiwgb3Ig YmVjYXVzZSB5b3UKPiA+IHRoaW5rIGl0J3MgdGhlIHJpZ2h0IHRoaW5nIHRvIGRvPwo+IAo+IEkg d291bGQgYmUga2VlcGluZyB0aGUgdGFibGUgYXMgdGhhdCdzIHRoZSByaWdodCB0aGluZyB0byBk by4gCgpTbyB0aGVuIEknbSBiYWNrIHRvIG15IG9yaWdpbmFsIHF1ZXN0aW9uLCB3aHk/CgpXaGF0 IGlzIGl0IHVzZWQgZm9yPyBXaGF0IGRpZmZlcmVuY2UgZG9lcyBpdCBtYWtlPwoKSSBjb3VsZCB1 bmRlcnN0YW5kIGlmIHRoZSAuZGF0YSBhdHRyaWJ1dGUgd2FzIHVzZWQgaW4gdGhlIGRyaXZlcgp0 byBtYWtlIHZpdGFsIGRlY2lzaW9ucyBiYXNlZCBvbiBTVE1QRSB2ZXJzaW9uLCBidXQgaXQncyBu b3QuIFNvCndoeSBhcmUgd2UgYnVyZGVuaW5nIHRoZSBkcml2ZXIgd2l0aCB1bnVzZWQgY29kZSB0 aGF0J3Mgbm90CnJlcXVpcmVkPyBPdGhlciB0aGFuIHRvIGdldCB5b3VyIG1haW5saW5lZCBwYXRj aC1jb3VudCB1cCBvZgpjb3Vyc2U/IFRoaXMgaGFzIGFuIGFpciBvZiAicGxhY2luZyBoZWFkZXIg ZmlsZXMgaW4gYWxwaGFiZXRpY2FsCm9yZGVyIiBhYm91dCBpdC4gOykKCj4gQnkgY2hhbmNlCj4g b3VyIG5vbi1EVCBhbmQgRFQgdGFibGVzIGhhZCBhIGRpZmZlcmVuY2Ugb2YgInN0LCIgb25seSBp biB0aGUgbmFtZQo+IG9mIGluc3RhbmNlcyBhbmQgc28gaXQgd29ya2VkIHdpdGhvdXQgdGFibGVz LiBPdGhlcndpc2UgaXQgY291bGRuJ3QKPiBoYXZlIHdvcmtlZC4KPiAKPiBPdmVyIHRoYXQsIGkg YW0gbG9va2luZyB0byBicmluZyB0aGUgInN0bXBlLGlkIiBiaW5kaW5nIGJhY2sgYWdhaW4gKHVu bGVzcwo+IHlvdSBoYXZlIGEgYmV0dGVyIG9wdGlvbiksIGFzIGRldmljZSBuYW1lIGlzIG5vdCBj b21pbmcgZnJvbSBEVCBjdXJyZW50bHksCj4gd2hpY2ggd2UgZGlzY3Vzc2VkIGVhcmxpZXIuCgpP ciB5b3UgY291bGQgbm90IHB1dCB1bm5lY2Vzc2FyeSBiaW5kaW5ncyBpbnRvIHRoZSBEZXZpY2Ug VHJlZQpieSBwdXR0aW5nIHR3byBhbmQgdHdvIHRvZ2V0aGVyIGFuZCByZWFsaXNlIHRoYXQgdXNp bmcgdGhlIHRhYmxlCmlzIHRoZSBjb3JyZWN0IHRoaW5nIHRvIGRvIGluc3RlYWQuIFRoaXMgYWN0 dWFsbHkgZ2l2ZXMgcmVhc29uCnRvIHlvdSBwcmV2aW91cyBwYXRjaCwgYnV0IHNob3VsZCBwcm9i YWJseSBiZSBmaXhlZC11cCBpbnRvIGl0CnNvIGl0IGhhcyBzb21lIHByb3BlciBtZWFuaW5nL3B1 cnBvc2UuIDspCgotLSAKTGVlIEpvbmVzCkxpbmFybyBTVC1Fcmljc3NvbiBMYW5kaW5nIFRlYW0g TGVhZApMaW5hcm8ub3JnIOKUgiBPcGVuIHNvdXJjZSBzb2Z0d2FyZSBmb3IgQVJNIFNvQ3MKRm9s bG93IExpbmFybzogRmFjZWJvb2sgfCBUd2l0dGVyIHwgQmxvZwpfX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkZXZpY2V0cmVlLWRpc2N1c3MgbWFpbGluZyBs aXN0CmRldmljZXRyZWUtZGlzY3Vzc0BsaXN0cy5vemxhYnMub3JnCmh0dHBzOi8vbGlzdHMub3ps YWJzLm9yZy9saXN0aW5mby9kZXZpY2V0cmVlLWRpc2N1c3MK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422996Ab2LFKLj (ORCPT ); Thu, 6 Dec 2012 05:11:39 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:50380 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422686Ab2LFKLh (ORCPT ); Thu, 6 Dec 2012 05:11:37 -0500 Date: Thu, 6 Dec 2012 10:11:31 +0000 From: Lee Jones To: Viresh Kumar Cc: Grant Likely , Samuel Ortiz , rabin.vincent@stericsson.com, shiraz.hashim@st.com, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, spear-devel@list.st.com, linus.walleij@linaro.org, Vipul Kumar Samar Subject: Re: [PATCH V5 2/2] mfd: stmpe: Update DT support in stmpe driver Message-ID: <20121206101131.GP2718@gmail.com> References: <2dcd7cb4c4022fa24b5328974e4226f5aaf89419.1354199865.git.viresh.kumar@linaro.org> <121653def4e985b0c1b59045637dd4518f97e73a.1354199865.git.viresh.kumar@linaro.org> <20121130105731.GN3176@sortiz-mobl> <20121130154542.GG23648@gmail.com> <20121205224203.691153E0E22@localhost> <20121206095019.GN2718@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 06 Dec 2012, Viresh Kumar wrote: > On 6 December 2012 15:20, Lee Jones wrote: > >> > But regardless, it is the responsiblity of the probe function to go and > >> > look if of_driver_match_device() matches against anything if it cares > >> > about the of_match_table entries (for instance, if there is extra data > >> > attached). > >> > >> Ok, so filling .data field in of_device_id[] is not required for our case as > >> we aren't doing anything special in our drivers. > > > > This is exactly my point, and the reason I bought it up in the > > first place. Normally when you specify an ID table and populate > > the .data attribute, you parse for it in the code and then cast > > it back to some kind of useful data. However, you're not doing > > that, which is precisely why I wondered if the table was > > necessary at all. In all my testing, the DT portion worked and > > the correct STMPE chip was identified without it. > > Probably Vipul (Author of this patch), copied it from existing i2c/spi > clients, which have also added this blindly :) > > > So, are you adding the table for good reason, or because you > > think it's the right thing to do? > > I would be keeping the table as that's the right thing to do. So then I'm back to my original question, why? What is it used for? What difference does it make? I could understand if the .data attribute was used in the driver to make vital decisions based on STMPE version, but it's not. So why are we burdening the driver with unused code that's not required? Other than to get your mainlined patch-count up of course? This has an air of "placing header files in alphabetical order" about it. ;) > By chance > our non-DT and DT tables had a difference of "st," only in the name > of instances and so it worked without tables. Otherwise it couldn't > have worked. > > Over that, i am looking to bring the "stmpe,id" binding back again (unless > you have a better option), as device name is not coming from DT currently, > which we discussed earlier. Or you could not put unnecessary bindings into the Device Tree by putting two and two together and realise that using the table is the correct thing to do instead. This actually gives reason to you previous patch, but should probably be fixed-up into it so it has some proper meaning/purpose. ;) -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog