From mboxrd@z Thu Jan 1 00:00:00 1970 From: ezequiel.garcia@free-electrons.com (Ezequiel Garcia) Date: Tue, 27 Aug 2013 05:36:04 -0300 Subject: [PATCH v2 7/9] watchdog: orion: Update device-tree binding documentation In-Reply-To: <20130826140843.GI13964@titan.lakedaemon.net> References: <1377295942-5955-1-git-send-email-ezequiel.garcia@free-electrons.com> <1377295942-5955-8-git-send-email-ezequiel.garcia@free-electrons.com> <20130826140843.GI13964@titan.lakedaemon.net> Message-ID: <20130827083603.GA2286@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 26, 2013 at 10:08:43AM -0400, Jason Cooper wrote: > On Fri, Aug 23, 2013 at 07:12:20PM -0300, Ezequiel Garcia wrote: > > Change the 'reg' property meaning, by defining two required cells. > > It's important to note this commit breaks DT-compatibility for this > > device. > > > > Cc: devicetree at vger.kernel.org > > Signed-off-by: Ezequiel Garcia > > --- > > Documentation/devicetree/bindings/watchdog/orion-wdt.txt | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/watchdog/orion-wdt.txt b/Documentation/devicetree/bindings/watchdog/orion-wdt.txt > > index 5dc8d30..a74c9c8 100644 > > --- a/Documentation/devicetree/bindings/watchdog/orion-wdt.txt > > +++ b/Documentation/devicetree/bindings/watchdog/orion-wdt.txt > > @@ -3,7 +3,9 @@ > > Required Properties: > > > > - Compatibility : "marvell,orion-wdt" > > -- reg : Address of the timer registers > > +- reg : Two cells are required: > > + First cell contains the global timer control register. > > + Second cell contains the watchdog counter register. > > > > Optional properties: > > > > @@ -13,7 +15,8 @@ Example: > > > > wdt at 20300 { > > compatible = "marvell,orion-wdt"; > > - reg = <0x20300 0x28>; > > + reg = <0x20300 0x4 > > > > + 0x20324 0x4>; > > Is there a reason we're going this route over adding a new compatible > string? Well, it seemed to me that this register splitting was more device-treeish: it prevents you from fixing your driver, adding a new compatible-string, and rebuilding a kernel each time a new SoC appears with a different offset between registers. Instead, and trying to follow the DT-preachers, we would just change the "reg" values and -bang!- have forward-compatibility :-) That said... > iow, why can't we keep this knowledge in the driver and have a > "marvell,armada-wdt" or similar compat string that the orion-wdt driver > also serves? > ... we still need new compatible strings for armada-xp-wdt and armada-370-wdt, for they have differences between each other and with the orion-wdt: * The clock input is obtained in a different way in each case * The watchdog enable bit inside the timer control register is at a different location. So, thinking about this again, perhaps we should simply let alone the "reg" property and add the watchdog counter offset as yet another field in the compatible-data? What do you think? -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ezequiel Garcia Subject: Re: [PATCH v2 7/9] watchdog: orion: Update device-tree binding documentation Date: Tue, 27 Aug 2013 05:36:04 -0300 Message-ID: <20130827083603.GA2286@localhost> References: <1377295942-5955-1-git-send-email-ezequiel.garcia@free-electrons.com> <1377295942-5955-8-git-send-email-ezequiel.garcia@free-electrons.com> <20130826140843.GI13964@titan.lakedaemon.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20130826140843.GI13964@titan.lakedaemon.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Jason Cooper Cc: Thomas Petazzoni , Lior Amsalem , Andrew Lunn , devicetree@vger.kernel.org, swarren@wwwdotorg.org, wim@iguana.be, Gregory Clement , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth List-Id: devicetree@vger.kernel.org T24gTW9uLCBBdWcgMjYsIDIwMTMgYXQgMTA6MDg6NDNBTSAtMDQwMCwgSmFzb24gQ29vcGVyIHdy b3RlOgo+IE9uIEZyaSwgQXVnIDIzLCAyMDEzIGF0IDA3OjEyOjIwUE0gLTAzMDAsIEV6ZXF1aWVs IEdhcmNpYSB3cm90ZToKPiA+IENoYW5nZSB0aGUgJ3JlZycgcHJvcGVydHkgbWVhbmluZywgYnkg ZGVmaW5pbmcgdHdvIHJlcXVpcmVkIGNlbGxzLgo+ID4gSXQncyBpbXBvcnRhbnQgdG8gbm90ZSB0 aGlzIGNvbW1pdCBicmVha3MgRFQtY29tcGF0aWJpbGl0eSBmb3IgdGhpcwo+ID4gZGV2aWNlLgo+ ID4gCj4gPiBDYzogZGV2aWNldHJlZUB2Z2VyLmtlcm5lbC5vcmcKPiA+IFNpZ25lZC1vZmYtYnk6 IEV6ZXF1aWVsIEdhcmNpYSA8ZXplcXVpZWwuZ2FyY2lhQGZyZWUtZWxlY3Ryb25zLmNvbT4KPiA+ IC0tLQo+ID4gIERvY3VtZW50YXRpb24vZGV2aWNldHJlZS9iaW5kaW5ncy93YXRjaGRvZy9vcmlv bi13ZHQudHh0IHwgNyArKysrKy0tCj4gPiAgMSBmaWxlIGNoYW5nZWQsIDUgaW5zZXJ0aW9ucygr KSwgMiBkZWxldGlvbnMoLSkKPiA+IAo+ID4gZGlmZiAtLWdpdCBhL0RvY3VtZW50YXRpb24vZGV2 aWNldHJlZS9iaW5kaW5ncy93YXRjaGRvZy9vcmlvbi13ZHQudHh0IGIvRG9jdW1lbnRhdGlvbi9k ZXZpY2V0cmVlL2JpbmRpbmdzL3dhdGNoZG9nL29yaW9uLXdkdC50eHQKPiA+IGluZGV4IDVkYzhk MzAuLmE3NGM5YzggMTAwNjQ0Cj4gPiAtLS0gYS9Eb2N1bWVudGF0aW9uL2RldmljZXRyZWUvYmlu ZGluZ3Mvd2F0Y2hkb2cvb3Jpb24td2R0LnR4dAo+ID4gKysrIGIvRG9jdW1lbnRhdGlvbi9kZXZp Y2V0cmVlL2JpbmRpbmdzL3dhdGNoZG9nL29yaW9uLXdkdC50eHQKPiA+IEBAIC0zLDcgKzMsOSBA QAo+ID4gIFJlcXVpcmVkIFByb3BlcnRpZXM6Cj4gPiAgCj4gPiAgLSBDb21wYXRpYmlsaXR5IDog Im1hcnZlbGwsb3Jpb24td2R0Igo+ID4gLS0gcmVnCQk6IEFkZHJlc3Mgb2YgdGhlIHRpbWVyIHJl Z2lzdGVycwo+ID4gKy0gcmVnCQk6IFR3byBjZWxscyBhcmUgcmVxdWlyZWQ6Cj4gPiArCQkgIEZp cnN0ICBjZWxsIGNvbnRhaW5zIHRoZSBnbG9iYWwgdGltZXIgY29udHJvbCByZWdpc3Rlci4KPiA+ ICsJCSAgU2Vjb25kIGNlbGwgY29udGFpbnMgdGhlIHdhdGNoZG9nIGNvdW50ZXIgcmVnaXN0ZXIu Cj4gPiAgCj4gPiAgT3B0aW9uYWwgcHJvcGVydGllczoKPiA+ICAKPiA+IEBAIC0xMyw3ICsxNSw4 IEBAIEV4YW1wbGU6Cj4gPiAgCj4gPiAgCXdkdEAyMDMwMCB7Cj4gPiAgCQljb21wYXRpYmxlID0g Im1hcnZlbGwsb3Jpb24td2R0IjsKPiA+IC0JCXJlZyA9IDwweDIwMzAwIDB4Mjg+Owo+ID4gKwkJ cmVnID0gPDB4MjAzMDAgMHg0Cj4gCj4gCj4gPiArCQkgICAgICAgMHgyMDMyNCAweDQ+Owo+IAo+ IElzIHRoZXJlIGEgcmVhc29uIHdlJ3JlIGdvaW5nIHRoaXMgcm91dGUgb3ZlciBhZGRpbmcgYSBu ZXcgY29tcGF0aWJsZQo+IHN0cmluZz8KCldlbGwsIGl0IHNlZW1lZCB0byBtZSB0aGF0IHRoaXMg cmVnaXN0ZXIgc3BsaXR0aW5nIHdhcyBtb3JlIGRldmljZS10cmVlaXNoOgppdCBwcmV2ZW50cyB5 b3UgZnJvbSBmaXhpbmcgeW91ciBkcml2ZXIsIGFkZGluZyBhIG5ldyBjb21wYXRpYmxlLXN0cmlu ZywKYW5kIHJlYnVpbGRpbmcgYSBrZXJuZWwgZWFjaCB0aW1lIGEgbmV3IFNvQyBhcHBlYXJzIHdp dGggYSBkaWZmZXJlbnQgb2Zmc2V0CmJldHdlZW4gcmVnaXN0ZXJzLgoKSW5zdGVhZCwgYW5kIHRy eWluZyB0byBmb2xsb3cgdGhlIERULXByZWFjaGVycywgd2Ugd291bGQganVzdCBjaGFuZ2UgdGhl CiJyZWciIHZhbHVlcyBhbmQgLWJhbmchLSBoYXZlIGZvcndhcmQtY29tcGF0aWJpbGl0eSA6LSkK ClRoYXQgc2FpZC4uLgoKPiBpb3csIHdoeSBjYW4ndCB3ZSBrZWVwIHRoaXMga25vd2xlZGdlIGlu IHRoZSBkcml2ZXIgYW5kIGhhdmUgYQo+ICJtYXJ2ZWxsLGFybWFkYS13ZHQiIG9yIHNpbWlsYXIg Y29tcGF0IHN0cmluZyB0aGF0IHRoZSBvcmlvbi13ZHQgZHJpdmVyCj4gYWxzbyBzZXJ2ZXM/Cj4g CgouLi4gd2Ugc3RpbGwgbmVlZCBuZXcgY29tcGF0aWJsZSBzdHJpbmdzIGZvciBhcm1hZGEteHAt d2R0IGFuZAphcm1hZGEtMzcwLXdkdCwgZm9yIHRoZXkgaGF2ZSBkaWZmZXJlbmNlcyBiZXR3ZWVu IGVhY2ggb3RoZXIKYW5kIHdpdGggdGhlIG9yaW9uLXdkdDoKCiogVGhlIGNsb2NrIGlucHV0IGlz IG9idGFpbmVkIGluIGEgZGlmZmVyZW50IHdheSBpbiBlYWNoIGNhc2UKCiogVGhlIHdhdGNoZG9n IGVuYWJsZSBiaXQgaW5zaWRlIHRoZSB0aW1lciBjb250cm9sIHJlZ2lzdGVyCiAgaXMgYXQgYSBk aWZmZXJlbnQgbG9jYXRpb24uCgpTbywgdGhpbmtpbmcgYWJvdXQgdGhpcyBhZ2FpbiwgcGVyaGFw cyB3ZSBzaG91bGQgc2ltcGx5IGxldCBhbG9uZSB0aGUKInJlZyIgcHJvcGVydHkgYW5kIGFkZCB0 aGUgd2F0Y2hkb2cgY291bnRlciBvZmZzZXQgYXMgeWV0IGFub3RoZXIgZmllbGQKaW4gdGhlIGNv bXBhdGlibGUtZGF0YT8KCldoYXQgZG8geW91IHRoaW5rPwotLSAKRXplcXVpZWwgR2FyY8OtYSwg RnJlZSBFbGVjdHJvbnMKRW1iZWRkZWQgTGludXgsIEtlcm5lbCBhbmQgQW5kcm9pZCBFbmdpbmVl cmluZwpodHRwOi8vZnJlZS1lbGVjdHJvbnMuY29tCgpfX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51 eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5v cmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==