From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.wrs.com (mail.windriver.com [147.11.1.11]) by ozlabs.org (Postfix) with ESMTP id A4DEDDDD0C for ; Fri, 3 Apr 2009 21:09:16 +1100 (EST) Message-ID: <49D5DF93.8020101@windriver.com> Date: Fri, 03 Apr 2009 18:06:11 +0800 From: Harry Ciao MIME-Version: 1.0 To: michael@ellerman.id.au Subject: Re: [v1 PATCH 3/3] EDAC: CPC925 MC platform device setup References: <1238739044-19926-1-git-send-email-qingtao.cao@windriver.com> <1238739044-19926-2-git-send-email-qingtao.cao@windriver.com> <1238741478.6802.44.camel@localhost> In-Reply-To: <1238741478.6802.44.camel@localhost> Content-Type: text/plain; charset=GB2312 Cc: norsk5@yahoo.com, bluesmoke-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Reply-To: qingtao.cao@windriver.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Michael Ellerman дµÀ: > On Fri, 2009-04-03 at 14:10 +0800, Harry Ciao wrote: > >> Setup a platform device for the CPC925 Memory Controller during system >> booting up, against which CPC925 MC EDAC driver would be matched. >> >> Signed-off-by: Harry Ciao >> --- >> arch/powerpc/platforms/maple/setup.c | 47 ++++++++++++++++++++++++++++++++++ >> 1 files changed, 47 insertions(+), 0 deletions(-) >> >> diff --git a/arch/powerpc/platforms/maple/setup.c b/arch/powerpc/platforms/maple/setup.c >> index bfd60e4..ca8a3ff 100644 >> --- a/arch/powerpc/platforms/maple/setup.c >> +++ b/arch/powerpc/platforms/maple/setup.c >> @@ -335,3 +335,50 @@ define_machine(maple) { >> .progress = maple_progress, >> .power_save = power4_idle, >> }; >> + >> +#ifdef CONFIG_EDAC >> +#define CPC925_MC_START 0xf8000000 >> +#define CPC925_MC_END 0xf8ffffff /* sizeof 16MB */ >> +/* Register a platform device for CPC925 memory controller */ >> +static int __init maple_cpc925_edac_setup(void) >> +{ >> + struct platform_device *pdev; >> + struct device_node *np = NULL; >> + struct resource r; >> + >> + np = of_find_node_by_name(NULL, "hostbridge"); >> > > This is way too generic IMHO. You're going to match on any node called > "hostbridge" on any 64-bit powerpc machine, there's a good chance there > are other firmwares out there with such a node, or will be in the > future. > > Is there no compatible or model property you can look for, so you're at > least somewhat confident you're actually looking at a CPC925? > > If not this should be a machine_initcall() for Maple only. > > >> + if (of_address_to_resource(np, 0, &r)) { >> + /* >> + * of_address_to_resource() would get the #address-cells >> + * and #size-cells properties for a node from its parent. >> + * On Maple 64bit target hostbridge parent node has specified >> + * both of these two properties to be 2. However, the actual >> + * "cell" value for host bridge node is 1. Since we can't >> + * fix this firmware-generated DTB, we have to setup a >> + * resource structure manually. >> + */ >> + memset(&r, 0, sizeof(r)); >> + r.start = CPC925_MC_START; >> + r.end = CPC925_MC_END; >> + r.name = "hostbridge"; >> + r.flags = IORESOURCE_MEM; >> > > We do have fixups for bogus firmware including maple, look in > prom_init.c:fixup_device_tree_maple(). Although that's for actual > firmware, not a DTB. > > cheers > > Hi Michael, Thanks a lot for your comments! I can see it would be much better than mine. Next whole week I will be on vacation, I will give some serious thoughts about your ideas and improve my patch in v2 after I come back. Best regards, Harry