From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: Re: spi_mpc8xxx.c: chip select polarity problem Date: Thu, 26 Nov 2009 22:01:01 +0300 Message-ID: <20091126190101.GA19404@oksana.dev.rtsoft.ru> References: <200911161742.46663.to-fleischer@t-online.de> <200911211708.47253.to-fleischer@t-online.de> <200911252141.59549.to-fleischer@t-online.de> <20091126121204.GA3558@oksana.dev.rtsoft.ru> <20091126184157.GA16607@oksana.dev.rtsoft.ru> Reply-To: avorontsov@ru.mvista.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: Torsten Fleischer , spi-devel-general@lists.sourceforge.net, linuxppc-dev@lists.ozlabs.org To: Grant Likely Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org List-Id: linux-spi.vger.kernel.org T24gVGh1LCBOb3YgMjYsIDIwMDkgYXQgMTE6NTA6MDVBTSAtMDcwMCwgR3JhbnQgTGlrZWx5IHdy b3RlOgo+IE9uIFRodSwgTm92IDI2LCAyMDA5IGF0IDExOjQxIEFNLCBBbnRvbiBWb3JvbnRzb3YK PiA8YXZvcm9udHNvdkBydS5tdmlzdGEuY29tPiB3cm90ZToKPiA+IE9uIFRodSwgTm92IDI2LCAy MDA5IGF0IDExOjE2OjM0QU0gLTA3MDAsIEdyYW50IExpa2VseSB3cm90ZToKPiA+IFsuLi5dCj4g Pj4gVGhlIHNwaS1jcy1oaWdoIHByb3BlcnR5IGlzIGRlZmluZWQgaW4KPiA+PiBEb2N1bWVudGF0 aW9uL3Bvd2VycGMvZHRzLWJpbmRpbmdzL3NwaS1idXMudHh0LCBidXQgaXQgZGVmaW5pdGVseSB3 YXMKPiA+PiBhIG1pc3Rha2UKPiA+Cj4gPiBZdXAuCj4gPgo+ID4+IEN1cnJlbnRseSB0aGUgc3Bp LWNzLWhpZ2ggcHJvcGVydHkgaXMgcGFyc2VkIGluIHRoZQo+ID4+IG9mX3JlZ2lzdGVyX3NwaV9k ZXZpY2VzKCkgZnVuY3Rpb24sIGJ1dCB0aGUgQ1MgcG9sYXJpdHkgbmVlZHMgdG8gYmUKPiA+PiBr bm93biBiZWZvcmUgcmVnaXN0ZXJpbmcgZGV2aWNlcy4gwqBJdCBuZWVkcyB0byBiZSBmYWN0b3Jl ZCBvdXQgaW50bwo+ID4+IGFub3RoZXIgdXRpbGl0eSBmdW5jdGlvbiBjYWxsYWJsZSBieSBzcGkg YnVzIGRyaXZlcnMgc28gdGhhdCBpdCBjYW4KPiA+PiBnZXQgcG9sYXJpdHkgZGF0YSBhdCBwcm9i ZSB0aW1lLgo+ID4KPiA+IFVudGlsbCB3ZSBoYXZlIHRoaXMsIFRvcnN0ZW4ncyBwYXRjaCBpcyBh IHJlYWwgaW1wcm92ZW1lbnQsIGFuZAo+ID4gd29ya3MgZm9yIG5vbi1icm9rZW4gaHcvZncuCj4g Pgo+ID4gU28gSSB0aGluayBpdCBzaG91bGQgYmUgYXBwbGllZC4KPiAKPiBJIGRpc2FncmVlIHNp bmNlIGl0IG9ubHkgYmFuZC1haWRzIHRoZSBwcm9ibGVtIGFuZCB1Z2xpZmllcyB0aGUgZHJpdmVy Cj4gaW4gdGhlIHByb2Nlc3MuICBJbiB0aGUgaW1tZWRpYXRlIHRlcm0gdGhlIGRyaXZlciBuZWVk cyB0byBiZSBjaGFuZ2VkCj4gdG8gcmVhZCB0aGUgc3BpLWNzLWhpZ2ggcHJvcGVydHkgb3V0IG9m IHRoZSBjaGlsZCBub2RlcyBiZWZvcmUKPiByZWdpc3RlcmluZyB0aGUgZGV2aWNlcy4KCkhtLiBJ IHRob3VnaHQgd2UgYWdyZWVkIHRoYXQgc3BpLWNzLWhpZ2ggaXMgbm90IGdvb2Q/IFdoeSBkbyB5 b3UKZW5jb3VyYWdlIHVzaW5nIGl0IHRoZW4/IFdlJ2xsIGhhdmUgdG8gdWdsaWZ5IHRoZSBkcml2 ZXIgd2l0aApsZWdhY3kgZGV2aWNlLXRyZWUgaGFuZGxpbmcgY29kZS4KCi0tIApBbnRvbiBWb3Jv bnRzb3YKZW1haWw6IGNib3VhdG1haWxydUBnbWFpbC5jb20KaXJjOi8vaXJjLmZyZWVub2RlLm5l dC9iZDIKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KTGlu dXhwcGMtZGV2IG1haWxpbmcgbGlzdApMaW51eHBwYy1kZXZAbGlzdHMub3psYWJzLm9yZwpodHRw czovL2xpc3RzLm96bGFicy5vcmcvbGlzdGluZm8vbGludXhwcGMtZGV2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from buildserver.ru.mvista.com (unknown [213.79.90.228]) by ozlabs.org (Postfix) with ESMTP id D6E6E1007D1 for ; Fri, 27 Nov 2009 06:01:03 +1100 (EST) Date: Thu, 26 Nov 2009 22:01:01 +0300 From: Anton Vorontsov To: Grant Likely Subject: Re: spi_mpc8xxx.c: chip select polarity problem Message-ID: <20091126190101.GA19404@oksana.dev.rtsoft.ru> References: <200911161742.46663.to-fleischer@t-online.de> <200911211708.47253.to-fleischer@t-online.de> <200911252141.59549.to-fleischer@t-online.de> <20091126121204.GA3558@oksana.dev.rtsoft.ru> <20091126184157.GA16607@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: Cc: Torsten Fleischer , spi-devel-general@lists.sourceforge.net, linuxppc-dev@lists.ozlabs.org Reply-To: avorontsov@ru.mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Nov 26, 2009 at 11:50:05AM -0700, Grant Likely wrote: > On Thu, Nov 26, 2009 at 11:41 AM, Anton Vorontsov > wrote: > > On Thu, Nov 26, 2009 at 11:16:34AM -0700, Grant Likely wrote: > > [...] > >> The spi-cs-high property is defined in > >> Documentation/powerpc/dts-bindings/spi-bus.txt, but it definitely was > >> a mistake > > > > Yup. > > > >> Currently the spi-cs-high property is parsed in the > >> of_register_spi_devices() function, but the CS polarity needs to be > >> known before registering devices.  It needs to be factored out into > >> another utility function callable by spi bus drivers so that it can > >> get polarity data at probe time. > > > > Untill we have this, Torsten's patch is a real improvement, and > > works for non-broken hw/fw. > > > > So I think it should be applied. > > I disagree since it only band-aids the problem and uglifies the driver > in the process. In the immediate term the driver needs to be changed > to read the spi-cs-high property out of the child nodes before > registering the devices. Hm. I thought we agreed that spi-cs-high is not good? Why do you encourage using it then? We'll have to uglify the driver with legacy device-tree handling code. -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2