From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lugano.hostireland.com (lugano.hostireland.com [67.192.77.34]) by ozlabs.org (Postfix) with ESMTP id 84191DDE9A for ; Tue, 29 Jan 2008 10:55:36 +1100 (EST) Subject: Re: PATCH[1/1] 8xx: Add clock-frequency to .dts brg entries From: Bryan O'Donoghue To: Scott Wood In-Reply-To: <20080128155012.GA27054@ld0162-tx32.am.freescale.net> References: <1201485191.5537.55.camel@neuromancer.mindspace> <20080128155012.GA27054@ld0162-tx32.am.freescale.net> Content-Type: text/plain Date: Mon, 28 Jan 2008 23:55:20 +0000 Message-Id: <1201564520.3912.29.camel@neuromancer.mindspace> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2008-01-28 at 09:50 -0600, Scott Wood wrote: > On Mon, Jan 28, 2008 at 01:53:11AM +0000, Bryan O'Donoghue wrote: > > cpm_uart_core has a dependency on fsl,cpm-brg/clock-frequency, this > > means that a .dts that uses the cpm uart driver needs to supply a > > clock-frequency entry for get_brgfreq to return a meaningful number. > > > > Included is a patchset which adds the correct brgclk to the adder port - > > @ 50Mhz and also adds an entry for mpc885ads - which I've noticed is > > missing a clock-frequency entry. > > It's not missing -- it's added by the bootwrapper. > > -Scott Hmm.. You mean that arch/powerpc/boot/mpc8xx.c mpc8xx_set_clocks is supposed to be adding this field ? I see arch/powerpc/boot/wrapper.a has a reference to the function but - and this time I've checked all documentation - there's no mention of how to use this library at all... it _looks_ to me like this isn't being linked in any way. It for sure is nowhere in the uImage - and I've taken the preferred route of making a uImage with .dtb - genreated from adder875-uboot.dts dtc -O -o adder875-uboot.dtb arch/powerpc/boot/dts/adder875-uboot.dtb cpm_uart depends on "fsl,cpm-brg" and a field called "clock-frequency" as I understand it that's fsl,cpm-brg |_clock-frequency whereas mpc8xx_set_clocks seems to add /soc/cpm/brg |_clock-frequency So unless I'm not understanding the structure of the tree - possible - I don't see how /soc/cpm/brg => clock-frequency could /possibly/ satisfy get_brgfreq in fsl_soc.c If there's something other then making a uImage and dtb and booting these from u-boot that I'm supposed to be doing here ... it'd help if you could say.. Otherwise in order to get the UART working using a uImage + dbt I've found it necessary to add this field to the .dts.... mpc866ads.dts - also has a "fsl,cpm-brg" => clock-frequency entry in linux/arch/powerpc/boot/dts/mpc866ads.dts - and to me this looks like the correct approach for get_brgfreq to function properly... What do you think ?