From patchwork Tue Dec 8 01:09:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?J=2E_Neusch=C3=A4fer?= X-Patchwork-Id: 339916 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 20ADBC4361B for ; Tue, 8 Dec 2020 02:13:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D26CE23A57 for ; Tue, 8 Dec 2020 02:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727809AbgLHCNK (ORCPT ); Mon, 7 Dec 2020 21:13:10 -0500 Received: from mout.gmx.net ([212.227.15.18]:34417 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726830AbgLHCNK (ORCPT ); Mon, 7 Dec 2020 21:13:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1607393457; bh=F3QtjZZG93hHA6vRPJKE8IwnWeenHV4ItwEp0aN02oM=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=A8pr6+cN7UcqKm8MIbbVL/YVBiqwVGeSWa6NFTB80MWN0i6kwDsAKCnrTL+zb/qhL hjiy6KXg2jhbxk38iyIC7Ugnn+0+LWFSEsHcR5SS/tJoiYFUR3Ftz7SkRa/SJGLO/f z/DtsZpb4AF5398cMlsLHInROT21twXqofLbxoh8= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from longitude ([37.201.214.162]) by mail.gmx.com (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MjjCL-1kJQMs0Psp-00lDBu; Tue, 08 Dec 2020 03:10:57 +0100 From: =?utf-8?q?Jonathan_Neusch=C3=A4fer?= To: linux-kernel@vger.kernel.org Cc: Lee Jones , Rob Herring , =?utf-8?q?Jonathan_Neusch=C3=A4fer?= , Thierry Reding , =?utf-8?q?Uwe_Kleine-K?= =?utf-8?b?w7ZuaWc=?= , Alessandro Zummo , Alexandre Belloni , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Sam Ravnborg , Linus Walleij , Heiko Stuebner , Stephan Gerhold , Lubomir Rintel , Mark Brown , allen , Mauro Carvalho Chehab , "David S. Miller" , devicetree@vger.kernel.org, linux-pwm@vger.kernel.org, linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Heiko Stuebner , Josua Mayer , Andreas Kemnade , Arnd Bergmann , Daniel Palmer , Andy Shevchenko Subject: [PATCH v6 5/7] rtc: New driver for RTC in Netronix embedded controller Date: Tue, 8 Dec 2020 02:09:58 +0100 Message-Id: <20201208011000.3060239-6-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201208011000.3060239-1-j.neuschaefer@gmx.net> References: <20201208011000.3060239-1-j.neuschaefer@gmx.net> MIME-Version: 1.0 X-Provags-ID: V03:K1:sht59cd5i0srtO/cpZxBHhJuGkEEFFbVQJvUZwFZz3n/KIHtPvt yvetNFklqpjWwZS5aN7V0p+EFevvEjq2r3+buaaHnB0PRmm4PWj3eFRPSTB0FiIqe7fYq8r yagYGoU+542qE9GqAjNbpvU6bjTPW/VaK+eH2rnzUnEVlf38WqZ//Zp18Av1xmNUOodVoYQ XOnhfDcZiZVjZGRsWxQig== X-UI-Out-Filterresults: notjunk:1; V03:K0:bjPLcYvEBSU=:llMiPVdh3HdX1gZn2OzTPV LUJlYJKYnyJTRk8UyUNsaan4DanqNXX2vvDCtlf5yGLuyirGzCpiuQXAQanasMpF+dsw1m3J/ N5xyX4bZoUNuovqn0Bxt/rQrtPMAp9U6QBqdSPOayIj20mjeEK1pCfcEfk14hnm/5seqdiHfs nyPwrJWYkp2clq8VL9yk2nG3Kez46lBZdLiPQuUXE93d9le/HZ5rRpViX4U+fUhQEQwGToGIU FUetirHt3G6Ln9rs6YMEu6Obw9Tnhso7yOkF1MGrvVJm6TaezI2ikM7YlBRxzbhOy5DDVAW2G RtgWDBo87Na9YdtJBGlvIHvsaHKUtHhc4EXQxm/u8674iAolT3p4m5e+eGxuM1VcWiqrDDZKo +Y+BJnFdKaSVtKV4+cFd72zkEOYJ7LzrFFXAzDIxvjcVFqHnsoEvNus0Zo4owXhHQwPAsYQ8y XOEHIF2QiPWrjnT4l687nhGI/wIKtXkPiu0bjej63LF72GD4bgAFDB5nFf84EDvGuI+dfjrPK olRTZEq8eXvOK0ODSFpQeUrWkxBZSjdmoQCKlgleg8bjgUaEsY84Iv0GbcHiI/xTGK45VCq9M ueaWovJa3ZmusAiZMO2PgfZrzkPjDzGVkP6lREn2lmhjdjjYu+I9ZGa+qAjTx6ajJVreDOBH9 UREqEZHRxoWkbnviUD0x4gO68+AiWgkZ60gCRsdvfaC8ODgyzTSdEaMHXTZLwsiGtrjC/67WE tkWORYu8Ldb+qHqbRQif9NJ37RKhGu2aOfQO1q3TywGkkygeyQ56OPa1d/c7YCTOIJp5v/oTa iXmFzCOCkoNHFX39xMf8XWN/r0FsGiuTNw7LuRWllOdnlC2d7Dbgji08REs11IVb5Qjjs5Q3B xa1WZ8toatv1qnHigEfg== Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org With this driver, mainline Linux can keep its time and date in sync with the vendor kernel. Advanced functionality like alarm and automatic power-on is not yet supported. Signed-off-by: Jonathan Neuschäfer Acked-by: Alexandre Belloni --- v6: - no changes v5: - Add Alexandre Belloni's A-b - Use regmap_multi_reg_write v4: - https://lore.kernel.org/lkml/20201122222739.1455132-6-j.neuschaefer@gmx.net/ - Remove "driver" from Kconfig entry for consistency with most other entries - Add missing MODULE_ALIAS line - Give NTXEC_REG_READ_ macros longer names - Solve the read tearing issue using Alexandre Belloni's algorithm - Solve the write tearing issue using Uwe Kleine-König's algorithm - Spell out ODM v3: - https://lore.kernel.org/lkml/20200924192455.2484005-6-j.neuschaefer@gmx.net/ - Add email address to copyright line - Remove OF compatible string and don't include linux/of_device.h - Don't use a comma after sentinels - Avoid ret |= ... pattern - Move 8-bit register conversion to ntxec.h - Relicense as GPLv2 or later v2: - https://lore.kernel.org/lkml/20200905133230.1014581-7-j.neuschaefer@gmx.net/ - Rework top-of-file comment [Lee Jones] - Sort the #include lines [Alexandre Belloni] - don't align = signs in struct initializers [Uwe Kleine-König] - Switch to regmap - Fix register number used to read minutes and seconds - Prefix registers with NTXEC_REG_ - Add help text to the Kconfig option - Use devm_rtc_allocate_device and rtc_register_device, set ->range_min and ->range_max --- drivers/rtc/Kconfig | 8 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-ntxec.c | 143 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 152 insertions(+) create mode 100644 drivers/rtc/rtc-ntxec.c -- 2.29.2 diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 65ad9d0b47ab1..fe009949728b3 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1311,6 +1311,14 @@ config RTC_DRV_CROS_EC This driver can also be built as a module. If so, the module will be called rtc-cros-ec. +config RTC_DRV_NTXEC + tristate "Netronix embedded controller RTC" + depends on MFD_NTXEC + help + Say yes here if you want to support the RTC functionality of the + embedded controller found in certain e-book readers designed by the + original design manufacturer Netronix. + comment "on-CPU RTC drivers" config RTC_DRV_ASM9260 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index bfb57464118d0..5f2a7582b2780 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -111,6 +111,7 @@ obj-$(CONFIG_RTC_DRV_MT7622) += rtc-mt7622.o obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o obj-$(CONFIG_RTC_DRV_MXC) += rtc-mxc.o obj-$(CONFIG_RTC_DRV_MXC_V2) += rtc-mxc_v2.o +obj-$(CONFIG_RTC_DRV_NTXEC) += rtc-ntxec.o obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o obj-$(CONFIG_RTC_DRV_OPAL) += rtc-opal.o obj-$(CONFIG_RTC_DRV_PALMAS) += rtc-palmas.o diff --git a/drivers/rtc/rtc-ntxec.c b/drivers/rtc/rtc-ntxec.c new file mode 100644 index 0000000000000..c7cff7802895b --- /dev/null +++ b/drivers/rtc/rtc-ntxec.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * The Netronix embedded controller is a microcontroller found in some + * e-book readers designed by the original design manufacturer Netronix, Inc. + * It contains RTC, battery monitoring, system power management, and PWM + * functionality. + * + * This driver implements access to the RTC time and date. + * + * Copyright 2020 Jonathan Neuschäfer + */ + +#include +#include +#include +#include +#include +#include + +struct ntxec_rtc { + struct device *dev; + struct ntxec *ec; +}; + +#define NTXEC_REG_WRITE_YEAR 0x10 +#define NTXEC_REG_WRITE_MONTH 0x11 +#define NTXEC_REG_WRITE_DAY 0x12 +#define NTXEC_REG_WRITE_HOUR 0x13 +#define NTXEC_REG_WRITE_MINUTE 0x14 +#define NTXEC_REG_WRITE_SECOND 0x15 + +#define NTXEC_REG_READ_YEAR_MONTH 0x20 +#define NTXEC_REG_READ_MDAY_HOUR 0x21 +#define NTXEC_REG_READ_MINUTE_SECOND 0x23 + +static int ntxec_read_time(struct device *dev, struct rtc_time *tm) +{ + struct ntxec_rtc *rtc = dev_get_drvdata(dev); + unsigned int value; + int res; + +retry: + res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MINUTE_SECOND, &value); + if (res < 0) + return res; + + tm->tm_min = value >> 8; + tm->tm_sec = value & 0xff; + + res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MDAY_HOUR, &value); + if (res < 0) + return res; + + tm->tm_mday = value >> 8; + tm->tm_hour = value & 0xff; + + res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_YEAR_MONTH, &value); + if (res < 0) + return res; + + tm->tm_year = (value >> 8) + 100; + tm->tm_mon = (value & 0xff) - 1; + + /* + * Read the minutes/seconds field again. If it changed since the first + * read, we can't assume that the values read so far are consistent, + * and should start from the beginning. + */ + res = regmap_read(rtc->ec->regmap, NTXEC_REG_READ_MINUTE_SECOND, &value); + if (res < 0) + return res; + + if (tm->tm_min != value >> 8 || tm->tm_sec != (value & 0xff)) + goto retry; + + return 0; +} + +static int ntxec_set_time(struct device *dev, struct rtc_time *tm) +{ + struct ntxec_rtc *rtc = dev_get_drvdata(dev); + + /* + * To avoid time overflows while we're writing the full date/time, + * set the seconds field to zero before doing anything else. For the + * next 59 seconds (plus however long it takes until the RTC's next + * update of the second field), the seconds field will not overflow + * into the other fields. + */ + struct reg_sequence regs[] = { + { NTXEC_REG_WRITE_SECOND, ntxec_reg8(0) }, + { NTXEC_REG_WRITE_YEAR, ntxec_reg8(tm->tm_year - 100) }, + { NTXEC_REG_WRITE_MONTH, ntxec_reg8(tm->tm_mon + 1) }, + { NTXEC_REG_WRITE_DAY, ntxec_reg8(tm->tm_mday) }, + { NTXEC_REG_WRITE_HOUR, ntxec_reg8(tm->tm_hour) }, + { NTXEC_REG_WRITE_MINUTE, ntxec_reg8(tm->tm_min) }, + { NTXEC_REG_WRITE_SECOND, ntxec_reg8(tm->tm_sec) }, + }; + + return regmap_multi_reg_write(rtc->ec->regmap, regs, ARRAY_SIZE(regs)); +} + +static const struct rtc_class_ops ntxec_rtc_ops = { + .read_time = ntxec_read_time, + .set_time = ntxec_set_time, +}; + +static int ntxec_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *dev; + struct ntxec_rtc *rtc; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc->dev = &pdev->dev; + rtc->ec = dev_get_drvdata(pdev->dev.parent); + platform_set_drvdata(pdev, rtc); + + dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(dev)) + return PTR_ERR(dev); + + dev->ops = &ntxec_rtc_ops; + dev->range_min = RTC_TIMESTAMP_BEGIN_2000; + dev->range_max = 9025257599LL; /* 2255-12-31 23:59:59 */ + + return rtc_register_device(dev); +} + +static struct platform_driver ntxec_rtc_driver = { + .driver = { + .name = "ntxec-rtc", + }, + .probe = ntxec_rtc_probe, +}; +module_platform_driver(ntxec_rtc_driver); + +MODULE_AUTHOR("Jonathan Neuschäfer "); +MODULE_DESCRIPTION("RTC driver for Netronix EC"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ntxec-rtc");