From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ezequiel Garcia Subject: Re: GPMC clock question Date: Thu, 18 Dec 2014 20:26:08 -0300 Message-ID: <54936290.3090500@vanguardiasur.com.ar> References: <54933CC1.9010301@vanguardiasur.com.ar> <20141218210653.GI23854@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qc0-f180.google.com ([209.85.216.180]:57473 "EHLO mail-qc0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751107AbaLRX17 (ORCPT ); Thu, 18 Dec 2014 18:27:59 -0500 Received: by mail-qc0-f180.google.com with SMTP id i8so1661596qcq.25 for ; Thu, 18 Dec 2014 15:27:58 -0800 (PST) In-Reply-To: <20141218210653.GI23854@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: Roger Quadros , linux-omap@vger.kernel.org, "linux-mtd@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" , =?windows-1252?Q?Guido_Mart=EDnez?= On 12/18/2014 06:06 PM, Tony Lindgren wrote: > * Ezequiel Garcia [141218 12:49]: >> Tony, Roger: >> >> As far as I can see, the GPMC interface clock (GPMC_FCLK) is not >> properly modeled in the devicetree. Instead, hwmod magic seems to be used. > > I guess you mean the functional clock not interface clock? > >> arch/arm/mach-omap2/omap_hwmod_33xx_43xx_interconnect_data.c: >> struct omap_hwmod_ocp_if am33xx_l3_s__gpmc = { >> .master = &am33xx_l3_s_hwmod, >> .slave = &am33xx_gpmc_hwmod, >> .clk = "l3s_gclk", >> .addr = am33xx_gpmc_addr_space, >> .user = OCP_USER_MPU, >> }; >> >> I'd like to know what would be the appropriate DT model for this clock. >> Perhaps, as child of CORE_M4_CLK, divided by 2: >> >> gpmc_fclk: gpmc_fclk { >> #clock-cells = <0>; >> compatible = "fixed-factor-clock"; >> clocks = <&dpll_core_m4_ck>; >> clock-mult = <1>; >> clock-div = <2>; >> }; >> >> How does it look? Also, I'm wondering if this works OK when used with >> the hwmod stuff. > > Hmm we do have clocks or aliases for l3s_gclk, so it's there as otherwise > the GPMC would not work at all :) Sure with device tree only systems we > should have the clock phandle directly available though. > Right. > Note that the hwmod code takes care of runtime PM clock gating for the > drivers. Not entirely sure how that works, but I'll take a look. > But the clock entry for am33xx_l3_s__gpmc should be coming > from .dts. Right. > Please also check out the hwmod dts related changes Felipe > posted last week, that might allow populating .clk from .dts already. > Ah, nice. I'll take a look. Thanks Tony! -- Ezequiel Garcia, VanguardiaSur www.vanguardiasur.com.ar