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=-6.8 required=3.0 tests=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 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 B428BC433DF for ; Tue, 16 Jun 2020 18:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E76B2080D for ; Tue, 16 Jun 2020 18:06:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="eT5JoBPm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731350AbgFPSGh (ORCPT ); Tue, 16 Jun 2020 14:06:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727083AbgFPSGg (ORCPT ); Tue, 16 Jun 2020 14:06:36 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2BC0C061573 for ; Tue, 16 Jun 2020 11:06:35 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id r15so4042702wmh.5 for ; Tue, 16 Jun 2020 11:06:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=DD5dv8f3kbS4Lt6FjLNiFQNU5uypKmgKX/iJRJKhHaM=; b=eT5JoBPmlEEug8g/fyjqCQbvQKEJ4ldNTIZpxKXGyAebvYJGP+81qbkB4D1UlEmjgr 8hsH37MxYG7dKz1ObKDQqwiYk/Pfb1CpjH4jwvZ8fvbw3FsodkpnvFW9UcqjKvonV0tB 58r0xFFBYSGUt7qwHBJ+TLFFD/bY4kagEQjAjaHmqp5exN14llZiXeXQC9Nq2NriSphm 7ZH/4Sk2mnfmYWsQ+/9xrB5z4Rd/7PWTmKOXl/DLMOigO0XQEUjRQr5bWRdP4NvnghQw 7iD6DXgy2S6Z6d/qdMss+ESAlnhmxoAiDEY4qZFonRK29JGWf2KYS1izxkfkuwOEj3kJ 0jOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=DD5dv8f3kbS4Lt6FjLNiFQNU5uypKmgKX/iJRJKhHaM=; b=DC7f4bcryic2IgQqM7A8d97IqMi0uAc1Kth1LGSykgP7roMvuk17cwd/IaQTpUxlpB qoFLIoVwHZNX86KAs0nSKL+Taj1rlCxwa/RsSb0UtqcwA41DiJWmd16l+0dqvYYw1ucJ X9rGh+AkYWBRasYW9qYBK0nZTrWa5td5D3F/032pO9vvkwGLPfki3hvpsavSckwmQmPV T3YON6lLo1yv9HLwsz4WW1MjbIJtCSj29EbitJ6+qLU1x6yeBQuSmj4YJ4R3snuXMFLt +jWu3bxKUJ2SUfoDVX9zLJAZ49voKBMILWQkpdjz646OwNnNnt/V5eXwW9oDwPDx/W7v MVxw== X-Gm-Message-State: AOAM533avqIjfB6FROh57DUltswyxvy2fkBt7dmjndVAqtF1vw8dESxR GBewf6n4GI+2CBHj1UmXcmIXCVVEFLc= X-Google-Smtp-Source: ABdhPJw93jYh2fDrrn5QAqAe0usYGtqFaCWsXtyifWngNyIbvPjUJK1dkZLsoWLC0nptVjlSQ7PPSQ== X-Received: by 2002:a7b:c0cc:: with SMTP id s12mr4605287wmh.111.1592330794362; Tue, 16 Jun 2020 11:06:34 -0700 (PDT) Received: from dell ([2.27.167.65]) by smtp.gmail.com with ESMTPSA id v66sm5288274wme.13.2020.06.16.11.06.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2020 11:06:33 -0700 (PDT) Date: Tue, 16 Jun 2020 19:06:32 +0100 From: Lee Jones To: michael@walle.cc, robh+dt@kernel.org, broonie@kernel.org, gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com, devicetree@vger.kernel.org, linus.walleij@linaro.org, bgolaszewski@baylibre.com, arnd@arndb.de Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] mfd: Add I2C based System Configuaration (SYSCON) access Message-ID: <20200616180632.GT2608702@dell> References: <20200616172904.373045-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200616172904.373045-1-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 16 Jun 2020, Lee Jones wrote: > The existing SYSCON implementation only supports MMIO (memory mapped) > accesses, facilitated by Regmap. This extends support for registers > held behind I2C busses. > > Signed-off-by: Lee Jones > --- > drivers/mfd/Kconfig | 7 +++ > drivers/mfd/Makefile | 1 + > drivers/mfd/syscon-i2c.c | 89 ++++++++++++++++++++++++++++++++++ > include/linux/mfd/syscon-i2c.h | 26 ++++++++++ > 4 files changed, 123 insertions(+) > create mode 100644 drivers/mfd/syscon-i2c.c > create mode 100644 include/linux/mfd/syscon-i2c.h > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 0a59249198d34..63ae78b92b086 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -1300,6 +1300,13 @@ config MFD_SYSCON > Select this option to enable accessing system control registers > via regmap. > > +config MFD_SYSCON_I2C > + bool "System Controller Register R/W Based on I2C Regmap" > + select REGMAP_I2C > + help > + Select this option to enable accessing system control registers > + via I2C using regmap. > + > config MFD_DAVINCI_VOICECODEC > tristate > select MFD_CORE > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index f935d10cbf0fc..0aec1f42ac979 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -219,6 +219,7 @@ obj-$(CONFIG_MFD_RK808) += rk808.o > obj-$(CONFIG_MFD_RN5T618) += rn5t618.o > obj-$(CONFIG_MFD_SEC_CORE) += sec-core.o sec-irq.o > obj-$(CONFIG_MFD_SYSCON) += syscon.o > +obj-$(CONFIG_MFD_SYSCON_I2C) += syscon-i2c.o > obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o > obj-$(CONFIG_MFD_VEXPRESS_SYSREG) += vexpress-sysreg.o > obj-$(CONFIG_MFD_RETU) += retu-mfd.o > diff --git a/drivers/mfd/syscon-i2c.c b/drivers/mfd/syscon-i2c.c > new file mode 100644 > index 0000000000000..404e595d7646c > --- /dev/null > +++ b/drivers/mfd/syscon-i2c.c > @@ -0,0 +1,89 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * System Control Driver accessed over I2C > + * > + * Copyright (C) 2020 Linaro Ltd. > + * > + * Author: Lee Jones > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +static DEFINE_SPINLOCK(syscon_i2c_list_slock); > +static LIST_HEAD(syscon_i2c_list); > + > +struct syscon { > + struct device_node *np; Note to self: struct i2c_client *client; > + struct regmap *regmap; > + struct list_head list; > +}; > + > +static const struct regmap_config syscon_i2c_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > +}; > + > +static struct syscon *of_syscon_i2c_register(struct i2c_client *client) > +{ > + struct regmap_config syscon_config = syscon_i2c_regmap_config; > + struct device_node *np = client->dev.of_node; > + struct syscon *syscon; > + struct regmap *regmap; > + int ret; > + > + syscon = devm_kzalloc(&client->dev, sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return ERR_PTR(-ENOMEM); > + > + syscon_config.name = of_node_full_name(np); Note to self: Use dev_name(); > + regmap = devm_regmap_init_i2c(client, &syscon_config); > + if (IS_ERR(regmap)) { > + dev_err(&client->dev, "Failed to initialise Regmap I2C\n"); > + ret = PTR_ERR(regmap); > + return ERR_PTR(ret); > + } > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + spin_lock(&syscon_i2c_list_slock); > + list_add_tail(&syscon->list, &syscon_i2c_list); > + spin_unlock(&syscon_i2c_list_slock); > + > + return syscon; > +} > + > +static struct regmap *i2c_device_node_get_regmap(struct i2c_client *client) Note to self: i2c_client_get_regmap() > +{ > + struct device_node *np = client->dev.of_node; > + struct syscon *entry, *syscon = NULL; > + > + spin_lock(&syscon_i2c_list_slock); > + > + list_for_each_entry(entry, &syscon_i2c_list, list) > + if (entry->np == np) { > + syscon = entry; > + break; > + } > + > + spin_unlock(&syscon_i2c_list_slock); > + > + if (!syscon) > + syscon = of_syscon_i2c_register(client); > + > + if (IS_ERR(syscon)) > + return ERR_CAST(syscon); > + > + return syscon->regmap; > +} > + > +struct regmap *i2c_device_node_to_regmap(struct i2c_client *client) Note to self: i2c_client_to_regmap() > +{ > + return i2c_device_node_get_regmap(client); > +} > +EXPORT_SYMBOL_GPL(i2c_device_node_to_regmap); > diff --git a/include/linux/mfd/syscon-i2c.h b/include/linux/mfd/syscon-i2c.h > new file mode 100644 > index 0000000000000..854e316fec93e > --- /dev/null > +++ b/include/linux/mfd/syscon-i2c.h > @@ -0,0 +1,26 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * System Control Driver accessed via I2C > + * > + * Copyright (C) 2020 Linaro Ltd. > + * > + * Author: Lee Jones > + */ > + > +#ifndef __LINUX_MFD_SYSCON_I2C_H__ > +#define __LINUX_MFD_SYSCON_I2C_H__ > + > +#include > +#include > +#include > + > +#ifdef CONFIG_MFD_SYSCON_I2C > +extern struct regmap *i2c_device_node_to_regmap(struct i2c_client *client); > +#else > +static inline struct regmap *i2c_device_node_to_regmap(struct i2c_client *client) > +{ > + return ERR_PTR(-ENOTSUPP); > +} > +#endif > + > +#endif /* __LINUX_MFD_SYSCON_I2C_H__ */ -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog