Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755846Ab3HWQ4S (ORCPT ); Fri, 23 Aug 2013 12:56:18 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:35183 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755824Ab3HWQ4R (ORCPT ); Fri, 23 Aug 2013 12:56:17 -0400 Date: Fri, 23 Aug 2013 17:55:39 +0100 From: Mark Rutland To: Lee Jones Cc: Sascha Hauer , Linus Walleij , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Arnd Bergmann , "devicetree@vger.kernel.org" Subject: Re: [PATCH 09/33] ARM: ux500: Supply the I2C clocks lookup to the DBX500 DT Message-ID: <20130823165539.GD7015@e106331-lin.cambridge.arm.com> References: <1370521041-32318-1-git-send-email-lee.jones@linaro.org> <1370521041-32318-10-git-send-email-lee.jones@linaro.org> <20130820093034.GL31036@pengutronix.de> <20130822133730.GB23152@e106331-lin.cambridge.arm.com> <20130822141900.GB17154@lee--X1> <20130822151723.GE23152@e106331-lin.cambridge.arm.com> <20130822154116.GC17154@lee--X1> <20130822211912.GE31036@pengutronix.de> <20130823075607.GD17154@lee--X1> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20130823075607.GD17154@lee--X1> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5087 Lines: 83 On Fri, Aug 23, 2013 at 08:56:07AM +0100, Lee Jones wrote: > I had a short chat with Rob last night about this. I'm going to loop > him in to the conversation, as he wrote the binding. > > > > When most of the other clocks that we deal with are being requested, > > > they rely on being index zero: > > > > > > drivers/i2c/busses/i2c-nomadik.c: dev->clk = clk_get(&adev->dev, NULL); > > > > Look at drivers/clk/clkdev.c, there's some fuzzy matching > > involved when you pass NULL as connection id. > > Yes, I've been looking at that. This is why it works currently. I > think I need to change all of the drivers to specify which clock they > want. At the moment that 'fuzzy matching' is what's saving us. If > anyone were to change our DTS file to match what the binding says, > then it would cease to work. I'm guessing this is the same for all > other DTS files too: I think if anything, the binding document(s) should be updated to describe that apb_pclk is referred to by name, and the names of the other clocks should be described in the specific device bindings. We can then modify the drivers which grab clock 0 to explicitly grab the first clock by name, and backwards compatibility should not be broken. I don't believe any other OS has implemented the common clock bindings, and we've never supported the binding as described. Let's correct the de-facto standard into a standard by decree. Thanks, Mark. > > arch/arm/boot/dts/imx23.dtsi: clock-names = "uart", "apb_pclk"; > arch/arm/boot/dts/imx28.dtsi: clock-names = "uart", "apb_pclk"; > arch/arm/boot/dts/nspire-cx.dts: clock-names = "uart_clk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "timclk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "timclk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "rng", "apb_pclk"; > arch/arm/boot/dts/ste-nomadik-stn8815.dtsi: clock-names = "mclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "refclk", "timclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "mclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "KMIREFCLK", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "KMIREFCLK", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "wdogclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "timclken1", "timclken2", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "timclken1", "timclken2", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m-rs1.dtsi: clock-names = "clcdclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "refclk", "timclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "mclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "KMIREFCLK", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "KMIREFCLK", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "uartclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "wdogclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "timclken1", "timclken2", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "timclken1", "timclken2", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2m.dtsi: clock-names = "clcdclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts: clock-names = "wdogclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2p-ca9.dts: clock-names = "clcdclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2p-ca9.dts: clock-names = "timclk", "apb_pclk"; > arch/arm/boot/dts/vexpress-v2p-ca9.dts: clock-names = "wdogclk", "apb_pclk"; > > -- > Lee Jones > Linaro ST-Ericsson Landing Team Lead > Linaro.org │ Open source software for ARM SoCs > Follow Linaro: Facebook | Twitter | Blog > -- 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/