From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753542Ab2H1WyG (ORCPT ); Tue, 28 Aug 2012 18:54:06 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:35178 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751939Ab2H1WyD (ORCPT ); Tue, 28 Aug 2012 18:54:03 -0400 Message-ID: <503D4C08.8040605@wwwdotorg.org> Date: Tue, 28 Aug 2012 15:54:00 -0700 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Dong Aisheng CC: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linus.walleij@stericsson.com, s.hauer@pengutronix.de, shawn.guo@linaro.org, kernel@pengutronix.de, grant.likely@secretlab.ca, rob.herring@calxeda.com, sameo@linux.intel.com, lrg@ti.com, broonie@opensource.wolfsonmicro.com, richard.zhao@freescale.com, devicetree-discuss@lists.ozlabs.org Subject: Re: [PATCH v3 1/7] mfd: add syscon driver based on regmap References: <1346145005-17961-1-git-send-email-b29396@freescale.com> <1346145005-17961-2-git-send-email-b29396@freescale.com> In-Reply-To: <1346145005-17961-2-git-send-email-b29396@freescale.com> X-Enigmail-Version: 1.5a1pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/28/2012 02:09 AM, Dong Aisheng wrote: > From: Dong Aisheng > > Add regmap based syscon driver. > This is usually used for access misc bits in registers which does not belong > to a specific module, for example, IMX IOMUXC GPR and ANATOP. > With this driver, client can use generic regmap API to access registers > which are registered into syscon. > diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt > +* System Controller Registers R/W driver I think the binding document could use some information about what a "syscon" actually is, especially since the compatible value is something generic like "syscon" rather than something with a vendor-specific prefix. How about: A system controller node represents a register region containing a set of miscellaneous registers. The registers are not cohesive enough to represent as any specific type of device. The typical use-case is for some other node's driver, or platform-specific code, to acquire a reference to the syscon node (e.g. by phandle, node path, or search using a specific compatible value), interrogate the node (or associated OS driver) to determine the location of the registers, and access the registers directly. > +Required properties: > +- compatible: Should contain "syscon". > +- reg: the register range can be access from syscon > + > +Examples: > +gpr: iomuxc-gpr@020e0000 { > + compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; > + reg = <0x020e0000 0x38>; > +}; > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > +config MFD_SYSCON > + bool "System Controller Register R/W Based on Regmap" > + select REGMAP_MMIO > + help > + Select this option to enable accessing system control registers > + via regmap. I think the indentation is off there. > +static int __devinit syscon_probe(struct platform_device *pdev) ... > + regcache_cache_only(syscon->regmap, false); Isn't that the default? Aside from that, I don't have any particular comments on this series, so please consider it, Acked-by: Stephen Warren