From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vw0-f230.google.com (mail-vw0-f230.google.com [209.85.212.230]) by ozlabs.org (Postfix) with ESMTP id DBA82B7BBA for ; Wed, 9 Dec 2009 00:53:43 +1100 (EST) Received: by vws19 with SMTP id 19so164913vws.2 for ; Tue, 08 Dec 2009 05:53:41 -0800 (PST) MIME-Version: 1.0 Message-ID: <0016363b7ec8d1ffb8047a37e663@google.com> Date: Tue, 08 Dec 2009 13:53:41 +0000 Subject: DTS parsing and kernel bus support query From: vinayak.kale@gmail.com To: linuxppc-dev@lists.ozlabs.org Content-Type: multipart/alternative; boundary=0016363b7ec8d1ff9c047a37e660 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --0016363b7ec8d1ff9c047a37e660 Content-Type: text/plain; charset=windows-1252; format=flowed; delsp=yes Content-Transfer-Encoding: base64 SGkNCg0KSSBoYXZlIGZvbGxvd2luZyBxdWVyaWVzIGFib3V0IERUUyBwYXJzaW5nIGFuZCBrZXJu ZWwgYnVzIHN1cHBvcnQuIEkgd291bGQgIA0KcmVhbGx5IGFwcHJlY2lhdGUgYW55IGhlbHAuDQoN CkkgaGF2ZSBhIFBvd2VyUEMgNDQwIGNvcmUgYmFzZWQgYm9hcmQuIFdlIGFyZSBwb3J0aW5nIExp bnV4IGtlcm5lbCCWIDIuNi4zMS4NCg0KMSkgRm9yIG90aGVyIFBvd2VyUEMgNHh4IGJhc2VkIGJv YXJkcywgd2hhdCB3ZSBmb3VuZCBpcyBkZXZpY2VzIGxpa2UgIA0KVUFSVC9JMkMvR1BJTyBhcmUg Y29ubmVjdGVkIHRocm91Z2ggUExCLT5PUEIgYnVzZXMuIEFjY29yZGluZ2x5IHdlIHNwZWNpZnkg IA0KdGhlIG5vZGUgc3RydWN0dXJlIGluc2lkZSBhIGR0cyBmaWxlLiBEb2VzIGtlcm5lbCB1c2Vz IHRoZSBhY3R1YWwgcGF0aCB0byAgDQpsb2NhdGUgYSBub2RlIGVnIC9wbGIvb3BiL2kyYz8gb3Ig aXQgdXNlcyB0aGUgY29tcGF0aWJsZSBwcm9wZXJ0eSB0byBsb2NhdGUgIA0KYSBub2RlPw0KDQoy KUluIGNhc2Ugb2Ygb3VyIGJvYXJkLCBpbnN0ZWFkIG9mIE9QQiBhbmQgRUJDIHdlIGhhdmUgYnVz ZXMgbGlrZSBBSSBhbmQgIA0KQVBCLiBTbyBvdXIgRFRTIG5vZGUgc3RydWN0IGZvciBVQVJUIGxv b2tzIGxpa2UgL3BsYi9haS9hcGIvc2VyaWFsLiBGb3IgIA0KdGhpcyBkbyB3ZSBuZWVkIHRvIGFk ZCBhbnkgZXh0cmEgc3VwcG9ydCBpbiBrZXJuZWwgaW4gb3JkZXIgdG8gcmVjb2duaXplICANCnRo ZSBkZXZpY2VzIG9uIEFJIGFuZCBBUEIgYnVzZXM/IFNpbWlsYXIgcXVlc3Rpb24gZm9yIEZsYXNo IGRldmljZS4gSXQncyBvbiAgDQp0aGUgcGF0aCAvcGxiL2FpL2ZsYXNoLg0KSSBuZWVkIHRvIGFj Y2VzcyBVQVJUL0kyQy9HUElPL0ZsYXNoIGRldmljZXMgb3ZlciBBSSBhbmQgQVBCIGJ1cy4gUExC IGlzICANCmNvbm5lY3RlZCB0byBBSSBidXMuIEFJIGlzIGZ1cnRoZXIgY29ubmVjdGVkIHRvIEFQ Qi4NCg0KMykgRG8gd2UgbmVlZCB0byBhZGQgZXh0cmEgc3VwcG9ydCBmb3IgQUkvQVBCIGJ1cyBp biBrZXJuZWw/DQoNClRoYW5rcywNClZpbmF5YWsNCg== --0016363b7ec8d1ff9c047a37e660 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hi=20

I have following queries about DTS parsing and kernel bus support. I = would really appreciate any help.

I have a PowerPC 440 core based board. We are porting Linux kernel = =96 2.6.31.

1) For other PowerPC 4xx based boards, what we found is devices like = UART/I2C/GPIO are connected through PLB->OPB buses. Accordingly we speci= fy the node structure inside a dts file. Does kernel uses the actual path t= o locate a node e.g. /plb/opb/i2c? or it uses the compatible property to lo= cate a node?

2)In case of our board, instead of OPB and EBC we have buses like AI = and APB. So our DTS node struct for UART looks like /plb/ai/apb/serial. For= this do we need to add any extra support in kernel in order to recognize t= he devices on AI and APB buses? Similar question for Flash device. It=92s o= n the path /plb/ai/flash.=20
I need to access UART/I2C/GPIO/Flash devices over AI and APB bus. PLB= is connected to AI bus. AI is further connected to APB.

3) Do we need to add extra support for AI/APB bus in kernel?

Thanks,
Vinayak --0016363b7ec8d1ff9c047a37e660--