From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1PGCKO-0000gs-SY for barebox@lists.infradead.org; Wed, 10 Nov 2010 15:11:13 +0000 Date: Wed, 10 Nov 2010 16:11:06 +0100 From: Sascha Hauer Message-ID: <20101110151106.GT6017@pengutronix.de> References: <4CDA5DF9.7050906@flatfrog.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4CDA5DF9.7050906@flatfrog.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: BeagleBoard sdrc init writes reserved values To: Orjan Friberg Cc: barebox@lists.infradead.org Hi Orjan, On Wed, Nov 10, 2010 at 09:55:21AM +0100, Orjan Friberg wrote: > In sdrc_init in board-beagle.c both > > writel(0x1A, SDRC_REG(SYSCONFIG)); > > and > > writel(0x18, SDRC_REG(SYSCONFIG)); > > sets bits 4:3 in the IDLEMODE field. The OMAP3 TRM (spruf98k) defines > 0x2 as the only valid value for this field, all others being marked as > "reserved - do not use". board-omap3evm.c does the same thing, > board-sdp343x.c does not. > > Anyone knows where these settings come from? Derived from an older > version of the TRM? (I'm thinking there may have been a feature that > was discovered to be unreliable or not working as intended so it was > removed from the docs.) I have no idea. I'm pretty sure though that the value has been copied from some version of U-Boot or Xloader. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox