From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-13.arcor-online.net (mail-in-13.arcor-online.net [151.189.21.53]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.arcor.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 072EDDDDF3 for ; Mon, 4 Jun 2007 00:42:49 +1000 (EST) In-Reply-To: <20070603124357.GA6419@iram.es> References: <20070602085359.GA10333@iram.es> <3ebd6ca6877ea74925f066ff96ac81db@kernel.crashing.org> <20070602195308.GA21618@iram.es> <12ad593bd17f769e44f05bc24eac4d0a@kernel.crashing.org> <1180828907.14025.37.camel@localhost.localdomain> <28e0600256815f93db45b2f4eb2d9df5@kernel.crashing.org> <20070603083339.GB2157@iram.es> <34eddd7ce58e7983017077454d592332@kernel.crashing.org> <20070603101052.GA3313@iram.es> <20070603124357.GA6419@iram.es> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <3ffee021f3b721bde0253b1310d4958a@kernel.crashing.org> From: Segher Boessenkool Subject: Re: [PATCH 2/8] Add uli1575 pci-bridge sector to MPC8641HPCN dts file. Date: Sun, 3 Jun 2007 16:42:38 +0200 To: Gabriel Paubert Cc: "linuxppc-dev@ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> This is an IBM NVRAM thing -- write address to ISA I/O >> 0x74/0x75, read/write a byte from 0x76. > > Data is 0x77 actually. Port 0x76 systematically returns 0xff > on this board (I have one at hand right now and am doing > accesses with the firmware). Oh okay, I don't know exactly what chip this is so obviously my information isn't 100% ;-) >>> ISA Device, Slot 0, LogicalDev 0: PNP0B00, SystemPeripheral, >>> RealTimeClock, #-1, interface 129 >>> Device flags 2800: Integrated, Static >>> Packets describing allocated resources: >>> Variable (16 decoded bits) I/O port >>> from 0x0074 to 0x0074, alignment 1, 2 ports >>> Variable (16 decoded bits) I/O port >>> from 0x0077 to 0x0077, alignment 1, 1 ports >>> Chip identification: MOT3040 >>> Small vendor item type 0x00, data (hex): 01 f8 1f 00 00 >> >> The I/O port numbers here are wrong. > > No they aren't. It uses exactly the same port as for the NVRAM. Then its claim to be PNP 0b00 is incorrect. > Otherwise the "feature" of this RTC is that its interrupt > is not connected. Dunno what you mean here? >> rtc@i70 { >> device_type = "rtc"; >> reg = <1 70 2>; >> compatible = "pnpPNP,b00"; >> } >> > > Nope, there is nothing at 0x70-0x71 (read returns 0xff). The chip > is a 48T59. [Not so easy to find a datasheet for that -- STM M48T59Y is what I found in the end] This chip doesn't sit on any I/O port range, it is 8kB of direct-mapped standard SRAM stuff. There must be some latches or such on your board, or perhaps this is driven via some superio chip or something like that. > Actually I wonder > whether using PNP0B00 is correct in the residual data here. It's not correct at all, no. Not sure how best to describe this thing -- one master node with a kid for both nvram and rtc; one node; or perhaps one node for rtc, with a child node for nvram. Segher