From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Fritz Subject: Re: [PATCH v4 4/4] ARM: OMAP2+: Add pdata quirk for sys_clkout2 for omap3 DBB056 Date: Wed, 05 Mar 2014 14:25:32 +0100 Message-ID: <1394025932.16566.44.camel@mars> References: <1392387656-15186-1-git-send-email-chf.fritz@googlemail.com> <1392387656-15186-5-git-send-email-chf.fritz@googlemail.com> <20140228223741.GM13624@atomide.com> <53172175.5060603@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53172175.5060603@ti.com> Sender: linux-omap-owner@vger.kernel.org To: Tero Kristo Cc: Tony Lindgren , bcousson@baylibre.com, Tomi Valkeinen , Nishanth Menon , Javier Martinez Canillas , Daniel Mack , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org List-Id: devicetree@vger.kernel.org On Wed, 2014-03-05 at 15:07 +0200, Tero Kristo wrote: > On 03/01/2014 12:37 AM, Tony Lindgren wrote: > > * Christoph Fritz [140214 06:24]: > >> Full device tree support for clock control, especially to set frequencies, > >> is not yet accomplished. Until then, configure the 24Mhz of sys_clkout2 to > >> feed an USB-Hub here. > > > > Hmm would like to see Tero's comments on this, I wonder if we should > > wait on this to avoid extra churn? > > Well, the set I posted that adds default clock parenting / default rate > support to DT hasn't actually moved forward, so you might want to take > this in as is now if it should be rushed. The clk-enable part isn't done > currently by anything anyway. Just wondering though, should you create > some sort of driver for your usb-hub which would control these clocks? The USB-Hub, a USB2512 is wired as non-configurable. Its pin 'XTAL1/CLKIN' can be connected to either a crystal or an external clock input. To economise the crystal, the clock-out of the omap is wired here. So in my view, a driver is unnecessary. Thanks -- Christoph