From patchwork Mon Sep 14 21:43:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Walle X-Patchwork-Id: 254385 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=-12.8 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, URIBL_BLOCKED, USER_AGENT_GIT 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 51685C31E51 for ; Mon, 14 Sep 2020 21:45:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10C6720936 for ; Mon, 14 Sep 2020 21:45:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="Vq5JMhrW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726117AbgINVoN (ORCPT ); Mon, 14 Sep 2020 17:44:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726035AbgINVoD (ORCPT ); Mon, 14 Sep 2020 17:44:03 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72F67C061788; Mon, 14 Sep 2020 14:43:59 -0700 (PDT) Received: from apollo.fritz.box (unknown [IPv6:2a02:810c:c200:2e91:6257:18ff:fec4:ca34]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 2825522E0A; Mon, 14 Sep 2020 23:43:56 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1600119836; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=do3NDFjUJuferfg8grh3X8/2Pc3n8xO+4DbgzJyyx9Y=; b=Vq5JMhrWvMwC2CH5nSfR77S6Oo5iwtqgFM8IPS4qq3bRbt9NDVnNtnEHy5qmJQOtzf9Nha ziWqo5rPqjIewrSA9Ol5qUXUjpr0d7cWv0Q1GKLNd+fsGo6uJnoLhe2HwxKvJym+jywA2O Hz1mQg8py9mlXy9fLun6KP1m8hDLcWQ= From: Michael Walle To: 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 Cc: Linus Walleij , Bartosz Golaszewski , Rob Herring , Jean Delvare , Guenter Roeck , Lee Jones , Thierry Reding , =?utf-8?q?Uwe_Kleine-K?= =?utf-8?b?w7ZuaWc=?= , 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 , Michael Walle Subject: [PATCH v10 01/13] mfd: add simple regmap based I2C driver Date: Mon, 14 Sep 2020 23:43:29 +0200 Message-Id: <20200914214341.14268-2-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200914214341.14268-1-michael@walle.cc> References: <20200914214341.14268-1-michael@walle.cc> MIME-Version: 1.0 X-Spam: Yes Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org 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 Acked-for-MFD-by: Lee Jones --- Changes since v9: - none Changes since v8: - fixed typo Changes since v7: - none Changes since v6: - added SIMPLE_MFD_I2C help text - revised description in module header Changes since v5: - removed "select MFD_CORE" in Kconfig - removed help text in Kconfig, we assume that the users of this 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 | 12 ++++++++ drivers/mfd/Makefile | 1 + drivers/mfd/simple-mfd-i2c.c | 56 ++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+) create mode 100644 drivers/mfd/simple-mfd-i2c.c diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 2bc3073d4891..b66b60eed003 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1173,6 +1173,18 @@ 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 + help + This driver creates a single register map with the intention for it + to be shared by all sub-devices. + + Once the register map has been successfully initialised, any + sub-devices represented by child nodes in Device Tree will be + subsequently registered. + config MFD_SM501 tristate "Silicon Motion SM501" depends on HAS_DMA diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index d660be7fef1b..e6c7520ed129 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -265,3 +265,4 @@ 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..28e96a246be1 --- /dev/null +++ b/drivers/mfd/simple-mfd-i2c.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Simple MFD - I2C + * + * 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 to reference it. + * + * Once the register map has been successfully initialised, any sub-devices + * represented by child nodes in Device Tree will be subsequently registered. + */ + +#include +#include +#include +#include +#include + +static const struct regmap_config simple_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int simple_mfd_i2c_probe(struct i2c_client *i2c) +{ + const struct regmap_config *config; + struct regmap *regmap; + + config = device_get_match_data(&i2c->dev); + if (!config) + config = &simple_regmap_config; + + regmap = devm_regmap_init_i2c(i2c, config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + return devm_of_platform_populate(&i2c->dev); +} + +static const struct of_device_id simple_mfd_i2c_of_match[] = { + {} +}; +MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match); + +static struct i2c_driver simple_mfd_i2c_driver = { + .probe_new = simple_mfd_i2c_probe, + .driver = { + .name = "simple-mfd-i2c", + .of_match_table = simple_mfd_i2c_of_match, + }, +}; +module_i2c_driver(simple_mfd_i2c_driver); + +MODULE_AUTHOR("Michael Walle "); +MODULE_DESCRIPTION("Simple MFD - I2C driver"); +MODULE_LICENSE("GPL v2");