From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FE08C433E5 for ; Tue, 28 Jul 2020 07:42:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4E252250E for ; Tue, 28 Jul 2020 07:42:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="I6rNi06z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727782AbgG1Hmb (ORCPT ); Tue, 28 Jul 2020 03:42:31 -0400 Received: from ssl.serverraum.org ([176.9.125.105]:33621 "EHLO ssl.serverraum.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726850AbgG1Hmb (ORCPT ); Tue, 28 Jul 2020 03:42:31 -0400 Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 69A5C22F00; Tue, 28 Jul 2020 09:42:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1595922147; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DC6gum5wOvUP2X+C5yQP2AHFRnsyKf6fYNW2wyHxMVM=; b=I6rNi06zPnazYFalcbs0vLthy4gWBQJg8/qm5BUVtwruTFD/KLG2Dt4JaIQJiucRvBMC+E pXWjrsc7NzX6sKxMPMsXnBWPzdU/gvRm0JPSE0ewoTBJdzD0PzPeEymnqHDi8Y/CTfpyvK 0iBV1hk6gqZvMxj+xCiKPeFG+hPp2oM= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 28 Jul 2020 09:42:26 +0200 From: Michael Walle To: Lee Jones Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linus Walleij , Bartosz Golaszewski , Rob Herring , Jean Delvare , Guenter Roeck , Thierry Reding , =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Wim Van Sebroeck , Shawn Guo , Li Yang , Thomas Gleixner , Jason Cooper , Marc Zyngier , Mark Brown , Greg Kroah-Hartman , Andy Shevchenko , Catalin Marinas , Will Deacon , Pavel Machek Subject: Re: [PATCH v6 01/13] mfd: add simple regmap based I2C driver In-Reply-To: <20200728071949.GE1850026@dell> References: <20200725231834.25642-1-michael@walle.cc> <20200725231834.25642-2-michael@walle.cc> <20200728071949.GE1850026@dell> User-Agent: Roundcube Webmail/1.4.7 Message-ID: <23a9ecf5fe4f15b9b20a91cc292aca80@walle.cc> X-Sender: michael@walle.cc Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Am 2020-07-28 09:19, schrieb Lee Jones: > On Sun, 26 Jul 2020, Michael Walle wrote: > >> There are I2C devices which contain several different functions but >> doesn't require any special access functions. For these kind of >> drivers >> an I2C regmap should be enough. >> >> Create an I2C driver which creates an I2C regmap and enumerates its >> children. If a device wants to use this as its MFD core driver, it has >> to add an individual compatible string. It may provide its own regmap >> configuration. >> >> Subdevices can use dev_get_regmap() on the parent to get their regmap >> instance. >> >> Signed-off-by: Michael Walle >> --- >> Changes since v5: >> - removed "select MFD_CORE" in Kconfig >> - removed help text in Kconfig, we assume that the users of this > > That's the opposite of what I asked for. What is the use to describe the symbol, if it is not user selectable? I'm not aware this is done anywhere in the kernel, am I missing something? >> driver will have a "select MFD_SIMPLE_MFD_I2C". Instead added >> a small description to the driver itself. >> - removed "struct simple_mfd_i2c_config" and use regmap_config >> directly >> - changed builtin_i2c_driver() to module_i2c_driver(), added >> MODULE_ boilerplate >> - cleaned up the included files >> >> Changes since v4: >> - new patch. Lee, please bear with me. I didn't want to delay the >> new version (where a lot of remarks on the other patches were >> addressed) even more, just because we haven't figured out how >> to deal with the MFD part. So for now, I've included this one. >> >> drivers/mfd/Kconfig | 5 ++++ >> drivers/mfd/Makefile | 1 + >> drivers/mfd/simple-mfd-i2c.c | 55 >> ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 61 insertions(+) >> create mode 100644 drivers/mfd/simple-mfd-i2c.c >> >> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig >> index 33df0837ab41..c08539c7a166 100644 >> --- a/drivers/mfd/Kconfig >> +++ b/drivers/mfd/Kconfig >> @@ -1162,6 +1162,11 @@ config MFD_SI476X_CORE >> To compile this driver as a module, choose M here: the >> module will be called si476x-core. >> >> +config MFD_SIMPLE_MFD_I2C >> + tristate >> + depends on I2C >> + select REGMAP_I2C > > Please provide a full help. See above. > >> config MFD_SM501 >> tristate "Silicon Motion SM501" >> depends on HAS_DMA >> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile >> index a60e5f835283..78d24a3e7c9e 100644 >> --- a/drivers/mfd/Makefile >> +++ b/drivers/mfd/Makefile >> @@ -264,3 +264,4 @@ obj-$(CONFIG_MFD_STMFX) += stmfx.o >> obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o >> >> obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o >> +obj-$(CONFIG_MFD_SIMPLE_MFD_I2C) += simple-mfd-i2c.o >> diff --git a/drivers/mfd/simple-mfd-i2c.c >> b/drivers/mfd/simple-mfd-i2c.c >> new file mode 100644 >> index 000000000000..45090ddad104 >> --- /dev/null >> +++ b/drivers/mfd/simple-mfd-i2c.c >> @@ -0,0 +1,55 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * A very simple I2C MFD driver > > Simple MFD - I2C ok. >> + * The driver enumerates its children and registers a common regmap. >> Use >> + * dev_get_regmap(pdev->dev.parent, NULL) in the child nodes to fetch >> that >> + * regmap instance. > > This driver creates a single register map with the intention for it to > be shared by all sub-devices. Children can use their parent's device > structure (dev.parent) in order reference it. Should this be appended or should it replace my paragraph? If its the latter, the "enumeration of the children" is missing. >> + * In the future this driver might be extended to support also other >> interfaces >> + * like SPI etc. > > Remove this please. Why would you remove information about the intention of this driver? If someone looks for a place to implement its SPI/I3C/Slimbus MFD driver this might come in handy. -michael