From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Enrico Weigelt, metux IT consult" Date: Mon, 08 Jun 2015 12:11:19 +0000 Subject: Re: [lm-sensors] Dealing with optional i2c devices in a devicetree Message-Id: <55758667.70501@melag.de> List-Id: References: <55713BB1.80004@alliedtelesis.co.nz> <55714FFB.3000608@roeck-us.net> <55752FD4.6050700@alliedtelesis.co.nz> In-Reply-To: <55752FD4.6050700-6g8wRflRTwXFdCa3tKVlE6U/zSkkHjvu@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Chris Packham , Guenter Roeck , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: "jdelvare-l3A5Bk7waGM@public.gmane.org" , "lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org" , "shardy-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , "guillaume.roguez-4ysUXcep3aM1wj+D4I0NRVaTQe2KTcn/@public.gmane.org" QW0gMDguMDYuMjAxNSB1bSAwODowMSBzY2hyaWViIENocmlzIFBhY2toYW06CgpIaSBmb2xrcywK CiA+IFNvdW5kcyBsaWtlIG15IGJlc3QgYmV0IGlzIHRvIG1hcmsgdGhlIG5vZGVzIGFzIGRpc2Fi bGVkIGluIHRoZQogPiBkdHMgYW5kIGhhdmUgbXkgYm9vdGxvYWRlciB1cGRhdGUgdGhlbSBvbiB0 aGUgd2F5IHRocm91Z2guCgpJbiBjYXNlIHlvdXIgYm9vdGxvYWRlciBjYW4gdGFrZSB0aGF0IGRl Y2lzaW9uIChlZy4gaWYgdGhlIGRldmljZQppcyBwcmVzZW50IGF0IGJvb3QgdGltZSwgYW5kIHRo ZSBib290bG9hZGVyIGhhcyB0aGUgcHJvcGVyIHByb2JpbmcKbG9naWMgb3Igc2ltcGx5IGtub3dz IHRoZSBkZXZpY2UgaGFzIHRvIGJlIHRoZXJlKSwgdGhhdCB3b3VsZCBiZQphbiBwcmV0dHkgZWFz eSB3YXkuCgoKQnV0IGxldCBtZSBhZGQgYW5vdGhlciB1c2VjYXNlLCB3aGljaCBtaWdodCBiZSBh IGJpdCBtb3JlIHRyaWNreToKCkxldCdzIGFzc3VtZSB3ZSBjYW4gcGx1ZyBpbiBzb21lIG1vcmUg Y29tcGxleCBkZXZpY2UsIHdoaWNoIGNvbnNpc3RzCm9mIHNldmVyYWwgKHByZXR0eSBzdGFuZGFy ZCkgc3ViZGV2aWNlcywgYmVoaW5kIGNlcnRhaW4gYnVzJ2VzIChtYXliZQppdCdzIGF0dGFjaGVk IHZpYSBVU0IsIGFuZCBzb21ld2hlcmUgYmVoaW5kIGFyZSBzb21lIEkyQyBidXMnZXMgd2l0aApy ZWd1bGF0b3JzLCBwd20tZ2VuZXJhdG9ycywgZXRjKS4KCkxldCdzIGZ1cnRoZXIgYXNzdW1lLCB3 ZSBhbHJlYWR5IGdvdCBzb21lIERUUyBvciBzb21lIHBpZWNlIG9mIG1lbW9yeQp3aXRoIGFuIERU QiBzdWJ0cmVlIGZvciB0aGF0IGRldmljZSAoZWcuIHNvbWUgc2ltcGxlIGJ1bGsgZW5kcG9pbnQg dGhhdApqdXN0IGdpdmVzIGJhY2sgYSBidW5jaCBvZiBieXRlcyB3aXRoIHRoZSBEVEIpLgoKTm93 LCB3aGVuIHRoZSBkZXZpY2UgaXMgcGx1Z2dlZCBpbiwgSSdkIGxpa2UgdG8gZ2V0IHRoYXQgcGll Y2Ugb2YgRFRCCmxvYWRlZCBhbmQgdGhlIGNvcnJlc3BvbmRpbmcgZHJpdmVycyBpbml0aWFsaXpl ZC4gQW5kLCBvZiBjb3Vyc2UsIHdoZW4KaXQncyBwbHVnZ2VkLW91dCwgZXZlcnl0aGluZyBzaG91 bGQgYmUgc2h1dCBkb3duIGNsZWFubHkuCgpIb3cgY291bGQgd2UgYWNoaWV2ZSB0aGF0ID8KCgot LW10eAotLQpFbnJpY28gV2VpZ2VsdCwgbWV0dXggSVQgY29uc3VsdAorNDktMTUxLTI3NTY1Mjg3 Ck1FTEFHIE1lZGl6aW50ZWNobmlrIG9IRyBTaXR6IEJlcmxpbiBSZWdpc3RlcmdlcmljaHQgQUcg Q2hhcmxvdHRlbmJ1cmcgSFJBIDIxMzMzIEIKCldpY2h0aWdlciBIaW53ZWlzOiBEaWVzZSBOYWNo cmljaHQga2FubiB2ZXJ0cmF1bGljaGUgb2RlciBudXIgZsO8ciBlaW5lbiBiZWdyZW56dGVuIFBl cnNvbmVua3JlaXMgYmVzdGltbXRlIEluZm9ybWF0aW9uZW4gZW50aGFsdGVuLiBTaWUgaXN0IGF1 c3NjaGxpZcOfbGljaCBmw7xyIGRlbmplbmlnZW4gYmVzdGltbXQsIGFuIGRlbiBzaWUgZ2VyaWNo dGV0IHdvcmRlbiBpc3QuIFdlbm4gU2llIG5pY2h0IGRlciBBZHJlc3NhdCBkaWVzZXIgRS1NYWls IHNpbmQsIGTDvHJmZW4gU2llIGRpZXNlIG5pY2h0IGtvcGllcmVuLCB3ZWl0ZXJsZWl0ZW4sIHdl aXRlcmdlYmVuIG9kZXIgc2llIGdhbnogb2RlciB0ZWlsd2Vpc2UgaW4gaXJnZW5kZWluZXIgV2Vp c2UgbnV0emVuLiBTb2xsdGVuIFNpZSBkaWVzZSBFLU1haWwgaXJydMO8bWxpY2ggZXJoYWx0ZW4g aGFiZW4sIHNvIGJlbmFjaHJpY2h0aWdlbiBTaWUgYml0dGUgZGVuIEFic2VuZGVyLCBpbmRlbSBT aWUgYXVmIGRpZXNlIE5hY2hyaWNodCBhbnR3b3J0ZW4uIEJpdHRlIGzDtnNjaGVuIFNpZSBpbiBk aWVzZW0gRmFsbCBkaWVzZSBOYWNocmljaHQgdW5kIGFsbGUgQW5ow6RuZ2UsIG9obmUgZWluZSBL b3BpZSB6dSBiZWhhbHRlbi4KSW1wb3J0YW50IE5vdGljZTogVGhpcyBtZXNzYWdlIG1heSBjb250 YWluIGNvbmZpZGVudGlhbCBvciBwcml2aWxlZ2VkIGluZm9ybWF0aW9uLiBJdCBpcyBpbnRlbmRl ZCBvbmx5IGZvciB0aGUgcGVyc29uIGl0IHdhcyBhZGRyZXNzZWQgdG8uIElmIHlvdSBhcmUgbm90 IHRoZSBpbnRlbmRlZCByZWNpcGllbnQgb2YgdGhpcyBlbWFpbCB5b3UgbWF5IG5vdCBjb3B5LCBm b3J3YXJkLCBkaXNjbG9zZSBvciBvdGhlcndpc2UgdXNlIGl0IG9yIGFueSBwYXJ0IG9mIGl0IGlu IGFueSBmb3JtIHdoYXRzb2V2ZXIuIElmIHlvdSByZWNlaXZlZCB0aGlzIGVtYWlsIGluIGVycm9y IHBsZWFzZSBub3RpZnkgdGhlIHNlbmRlciBieSByZXBseWluZyBhbmQgZGVsZXRlIHRoaXMgbWVz c2FnZSBhbmQgYW55IGF0dGFjaG1lbnRzIHdpdGhvdXQgcmV0YWluaW5nIGEgY29weS4KCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxtLXNlbnNvcnMgbWFp bGluZyBsaXN0CmxtLXNlbnNvcnNAbG0tc2Vuc29ycy5vcmcKaHR0cDovL2xpc3RzLmxtLXNlbnNv cnMub3JnL21haWxtYW4vbGlzdGluZm8vbG0tc2Vuc29ycw= From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Enrico Weigelt, metux IT consult" Subject: Re: Dealing with optional i2c devices in a devicetree Date: Mon, 8 Jun 2015 14:11:19 +0200 Message-ID: <55758667.70501@melag.de> References: <55713BB1.80004@alliedtelesis.co.nz> <55714FFB.3000608@roeck-us.net> <55752FD4.6050700@alliedtelesis.co.nz> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <55752FD4.6050700-6g8wRflRTwXFdCa3tKVlE6U/zSkkHjvu@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Chris Packham , Guenter Roeck , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: "jdelvare-l3A5Bk7waGM@public.gmane.org" , "lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org" , "shardy-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , "guillaume.roguez-4ysUXcep3aM1wj+D4I0NRVaTQe2KTcn/@public.gmane.org" List-Id: devicetree@vger.kernel.org Am 08.06.2015 um 08:01 schrieb Chris Packham: Hi folks, > Sounds like my best bet is to mark the nodes as disabled in the > dts and have my bootloader update them on the way through. In case your bootloader can take that decision (eg. if the device is present at boot time, and the bootloader has the proper probing logic or simply knows the device has to be there), that would be an pretty easy way. But let me add another usecase, which might be a bit more tricky: Let's assume we can plug in some more complex device, which consists of several (pretty standard) subdevices, behind certain bus'es (maybe it's attached via USB, and somewhere behind are some I2C bus'es with regulators, pwm-generators, etc). Let's further assume, we already got some DTS or some piece of memory with an DTB subtree for that device (eg. some simple bulk endpoint that just gives back a bunch of bytes with the DTB). Now, when the device is plugged in, I'd like to get that piece of DTB loaded and the corresponding drivers initialized. And, of course, when it's plugged-out, everything should be shut down cleanly. How could we achieve that ? --mtx -- Enrico Weigelt, metux IT consult +49-151-27565287 MELAG Medizintechnik oHG Sitz Berlin Registergericht AG Charlottenburg = HRA 21333 B Wichtiger Hinweis: Diese Nachricht kann vertrauliche oder nur f=C3=BCr = einen begrenzten Personenkreis bestimmte Informationen enthalten. Sie i= st ausschlie=C3=9Flich f=C3=BCr denjenigen bestimmt, an den sie gericht= et worden ist. Wenn Sie nicht der Adressat dieser E-Mail sind, d=C3=BCr= fen Sie diese nicht kopieren, weiterleiten, weitergeben oder sie ganz o= der teilweise in irgendeiner Weise nutzen. Sollten Sie diese E-Mail irr= t=C3=BCmlich erhalten haben, so benachrichtigen Sie bitte den Absender,= indem Sie auf diese Nachricht antworten. Bitte l=C3=B6schen Sie in die= sem Fall diese Nachricht und alle Anh=C3=A4nge, ohne eine Kopie zu beha= lten. Important Notice: This message may contain confidential or privileged i= nformation. It is intended only for the person it was addressed to. 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