Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757268AbbKRVne (ORCPT ); Wed, 18 Nov 2015 16:43:34 -0500 Received: from mail-oi0-f50.google.com ([209.85.218.50]:34915 "EHLO mail-oi0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525AbbKRVnc (ORCPT ); Wed, 18 Nov 2015 16:43:32 -0500 MIME-Version: 1.0 In-Reply-To: <20151118203433.GE32672@codeaurora.org> References: <1378010420-20031-1-git-send-email-stefan.kristiansson@saunalahti.fi> <20151118203433.GE32672@codeaurora.org> Date: Wed, 18 Nov 2015 22:43:31 +0100 X-Google-Sender-Auth: CZMRsrYx5aOY-HuV-HbTBH4g5aQ Message-ID: Subject: Re: [PATCH] clk: add generic driver for fixed rate clock From: Geert Uytterhoeven To: Stephen Boyd Cc: Stefan Kristiansson , "devicetree@vger.kernel.org" , Michael Turquette , Pantelis Antoniou , linux-clk , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2311 Lines: 55 Hi Stephen, On Wed, Nov 18, 2015 at 9:34 PM, Stephen Boyd wrote: > On 11/17, Geert Uytterhoeven wrote: >> (quoting the full driver, as it predates linux-clk) >> >> On Sun, Sep 1, 2013 at 6:40 AM, Stefan Kristiansson >> wrote: >> > This adds a simple driver with the only purpose to initialise >> > the fixed rate clock. >> > This is useful for systems that do not wish to use seperate init >> > code for the fixed rate clock init, but rather only rely on a >> > device tree description of it. >> > >> > Signed-off-by: Stefan Kristiansson >> >> Thanks, this is still very useful! >> >> I stumbled across this old patch while trying to instantiate a fixed rate >> clock from a DT overlay. >> Without this, the clock is never instantiated, as drivers/clk/clk-fixed-rate.c >> uses CLK_OF_DECLARE() :-( With your driver, it works as expected >> (after fixing the modpost complaint, cfr. below). >> >> However, I think that instead of creating a new driver, you should just add >> the meat of clk-generic-fixed.c to clk-fixed-rate.c. > > Hm... what happens when of_clk_init() runs and instantiates the > clock, and then of_platform_populate() runs and creates the clock > again? The platform device probe fails because the framework > checks to make sure two clocks don't have the same name? I guess > that's going to work, but it doesn't make me feel good. My DTS does have other clocks that are compatible with "fixed-clock" and I didn't notice any ill behavior. Perhaps the driver core knows the node has already been bound to something, and thus no longer tries to bind it to a platform driver? I'll double-check that later... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/