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=-10.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 C33E1C282C0 for ; Wed, 23 Jan 2019 18:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A46221872 for ; Wed, 23 Jan 2019 18:37:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Lu3Hv9Ef" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726661AbfAWSgP (ORCPT ); Wed, 23 Jan 2019 13:36:15 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:38807 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726887AbfAWSgN (ORCPT ); Wed, 23 Jan 2019 13:36:13 -0500 Received: by mail-it1-f196.google.com with SMTP id z20so590672itc.3 for ; Wed, 23 Jan 2019 10:36:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Otv22ARhWch1v2LLN/dGqVfhIIfGRtdqkSL65FemqNQ=; b=Lu3Hv9Ef8yeu/m0+gjbOjyMrj0eLkBoFBhdnXuMeG9HtTn/VldLjr6m6QgwEp5pZX+ 7P3ZD9lXs87mga2uWhasm/oeFv9AkRHeTfk7DwCP06NJXc5DMxAxtOE8Txyn4NFSrWWj rnIgutTOBaxzdA5qtBebv8/kHua0P8ud+tOhs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Otv22ARhWch1v2LLN/dGqVfhIIfGRtdqkSL65FemqNQ=; b=OueB6ab7Y5R5Pq3FtoWesYtq0RTy55TfHf2aS/jZII0lML5Q+U0yd/M2RDuYd0jl6J 9Df8K445T434IGHBV824bK6B5RNFGTKJ7KaKI2g9xS1Y7v9c0wDRxrJjxdBAxW6qx4E8 XPK+KghoOCr4RMehSCC3yhoaovPRvC7XPhSnHs5SjG4tYiny0UTf72D6MaD+URVvAA2T VqcnMV5cxFBtpCm7kU6ZJwgG1g8Vb9fG10t+rhUT/aVn9XlW0MfhQal6HAIG6Vc96u6u 8L40iiD+k/UQyDp1E/vMD3dBbammBuCfWdD5/sbupn0ZrpLRYUANR4l8DIbtoFpa7zM6 jIfQ== X-Gm-Message-State: AJcUukePW7F5fpBAEV8z5Md+qcaTCLbdbjNsVM2vaO8CoWNSHG1RfV/m MFZKp8uwLNtgCU49ja8y5w2DhA== X-Google-Smtp-Source: ALg8bN7M7t6AanRmjU8RWajSbghD3vLWpGwNMXDsHBA793+R+GISN8Xlq2kRtioOdcdopgoBV9Uzcg== X-Received: by 2002:a02:a484:: with SMTP id d4mr2163835jam.77.1548268572146; Wed, 23 Jan 2019 10:36:12 -0800 (PST) Received: from ncrews2.bld.corp.google.com ([2620:15c:183:200:8140:8e3f:aea5:bcdf]) by smtp.gmail.com with ESMTPSA id 189sm9537577itw.33.2019.01.23.10.36.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 Jan 2019 10:36:11 -0800 (PST) From: Nick Crews To: linux-kernel@vger.kernel.org Cc: sjg@chromium.org, dmitry.torokhov@gmail.com, sre@kernel.org, linux-input@vger.kernel.org, groeck@chromium.org, dlaurie@chromium.org, Duncan Laurie , Enric Balletbo i Serra , Nick Crews , linux-rtc@vger.kernel.org, Alessandro Zummo , Benson Leung , Alexandre Belloni Subject: [PATCH v4 4/9] platform/chrome: rtc: Add RTC driver Date: Wed, 23 Jan 2019 11:33:20 -0700 Message-Id: <20190123183325.92946-5-ncrews@chromium.org> X-Mailer: git-send-email 2.20.1.321.g9e740568ce-goog In-Reply-To: <20190123183325.92946-1-ncrews@chromium.org> References: <20190123183325.92946-1-ncrews@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org From: Duncan Laurie This Embedded Controller has an internal RTC that is exposed as a standard RTC class driver with read/write functionality. The driver is added to the drivers/rtc/ so that the maintainer of that directory will be able to comment on this change, as that maintainer is the expert on this system. In addition, the driver code is called indirectly after a corresponding device is registered from core.c, as opposed to core.c registering the driver callbacks directly. > hwclock --show --rtc /dev/rtc1 2007-12-31 16:01:20.460959-08:00 > hwclock --systohc --rtc /dev/rtc1 > hwclock --show --rtc /dev/rtc1 2018-11-29 17:08:00.780793-08:00 Signed-off-by: Duncan Laurie Acked-by: Enric Balletbo i Serra Signed-off-by: Nick Crews --- Changes in v4: - Change me email to @chromium.org from @google.com - Move "Add RTC driver" before "Add sysfs attributes" so that it could get accepted earlier, since it is less contentious Changes in v3: - rm #define for driver name - Don't compute weekday when reading from RTC. Still set weekday when writing, as RTC needs this to control advanced power scheduling - rm check for invalid month data - Set range_min and range_max on rtc_device Changes in v2: - rm license boiler plate - rm "wilco_ec_rtc -" prefix in docstring - Make rtc driver its own module within the drivers/rtc/ directory - Register a rtc device from core.c that is picked up by this driver drivers/platform/chrome/wilco_ec/core.c | 14 ++ drivers/rtc/Kconfig | 11 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-wilco-ec.c | 177 ++++++++++++++++++++++++ 4 files changed, 203 insertions(+) create mode 100644 drivers/rtc/rtc-wilco-ec.c diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c index e036d88b6dd8..7cfb047e2c89 100644 --- a/drivers/platform/chrome/wilco_ec/core.c +++ b/drivers/platform/chrome/wilco_ec/core.c @@ -87,6 +87,20 @@ static int wilco_ec_probe(struct platform_device *pdev) goto destroy_mec; } + /* + * Register a RTC platform device that will get picked up by the RTC + * subsystem. This platform device will get freed when its parent device + * dev is unregistered. + */ + child_pdev = platform_device_register_data(dev, "rtc-wilco-ec", + PLATFORM_DEVID_AUTO, + NULL, 0); + if (IS_ERR(child_pdev)) { + dev_err(dev, "Failed to create RTC platform device\n"); + ret = PTR_ERR(child_pdev); + goto destroy_mec; + } + return 0; destroy_mec: diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 225b0b8516f3..d5063c791515 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1814,4 +1814,15 @@ config RTC_DRV_GOLDFISH Goldfish is a code name for the virtual platform developed by Google for Android emulation. +config RTC_DRV_WILCO_EC + tristate "Wilco EC RTC" + depends on WILCO_EC + default m + help + If you say yes here, you get read/write support for the Real Time + Clock on the Wilco Embedded Controller (Wilco is a kind of Chromebook) + + This can also be built as a module. If so, the module will + be named "rtc_wilco_ec". + endif # RTC_CLASS diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index df022d820bee..6255ea78da25 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -172,6 +172,7 @@ obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o obj-$(CONFIG_RTC_DRV_VRTC) += rtc-mrst.o obj-$(CONFIG_RTC_DRV_VT8500) += rtc-vt8500.o +obj-$(CONFIG_RTC_DRV_WILCO_EC) += rtc-wilco-ec.o obj-$(CONFIG_RTC_DRV_WM831X) += rtc-wm831x.o obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c new file mode 100644 index 000000000000..35cc56114c1c --- /dev/null +++ b/drivers/rtc/rtc-wilco-ec.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC interface for Wilco Embedded Controller with R/W abilities + * + * Copyright 2018 Google LLC + * + * The corresponding platform device is typically registered in + * drivers/platform/chrome/wilco_ec/core.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define EC_COMMAND_CMOS 0x7c +#define EC_CMOS_TOD_WRITE 0x02 +#define EC_CMOS_TOD_READ 0x08 + +/** + * struct ec_rtc_read - Format of RTC returned by EC. + * @second: Second value (0..59) + * @minute: Minute value (0..59) + * @hour: Hour value (0..23) + * @day: Day value (1..31) + * @month: Month value (1..12) + * @year: Year value (full year % 100) + * @century: Century value (full year / 100) + * + * All values are presented in binary (not BCD). + */ +struct ec_rtc_read { + u8 second; + u8 minute; + u8 hour; + u8 day; + u8 month; + u8 year; + u8 century; +} __packed; + +/** + * struct ec_rtc_write - Format of RTC sent to the EC. + * @param: EC_CMOS_TOD_WRITE + * @century: Century value (full year / 100) + * @year: Year value (full year % 100) + * @month: Month value (1..12) + * @day: Day value (1..31) + * @hour: Hour value (0..23) + * @minute: Minute value (0..59) + * @second: Second value (0..59) + * @weekday: Day of the week (0=Saturday) + * + * All values are presented in BCD. + */ +struct ec_rtc_write { + u8 param; + u8 century; + u8 year; + u8 month; + u8 day; + u8 hour; + u8 minute; + u8 second; + u8 weekday; +} __packed; + +int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) +{ + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); + u8 param = EC_CMOS_TOD_READ; + struct ec_rtc_read rtc; + struct wilco_ec_message msg = { + .type = WILCO_EC_MSG_LEGACY, + .flags = WILCO_EC_FLAG_RAW_RESPONSE, + .command = EC_COMMAND_CMOS, + .request_data = ¶m, + .request_size = sizeof(param), + .response_data = &rtc, + .response_size = sizeof(rtc), + }; + int ret; + + ret = wilco_ec_mailbox(ec, &msg); + if (ret < 0) + return ret; + + tm->tm_sec = rtc.second; + tm->tm_min = rtc.minute; + tm->tm_hour = rtc.hour; + tm->tm_mday = rtc.day; + tm->tm_mon = rtc.month - 1; + tm->tm_year = rtc.year + (rtc.century * 100) - 1900; + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); + + /* Don't compute day of week, we don't need it. */ + tm->tm_wday = -1; + + return 0; +} + +int wilco_ec_rtc_write(struct device *dev, struct rtc_time *tm) +{ + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); + struct ec_rtc_write rtc; + struct wilco_ec_message msg = { + .type = WILCO_EC_MSG_LEGACY, + .flags = WILCO_EC_FLAG_RAW_RESPONSE, + .command = EC_COMMAND_CMOS, + .request_data = &rtc, + .request_size = sizeof(rtc), + }; + int year = tm->tm_year + 1900; + /* + * Convert from 0=Sunday to 0=Saturday for the EC + * We DO need to set weekday because the EC controls battery charging + * schedules that depend on the day of the week. + */ + int wday = tm->tm_wday == 6 ? 0 : tm->tm_wday + 1; + int ret; + + rtc.param = EC_CMOS_TOD_WRITE; + rtc.century = bin2bcd(year / 100); + rtc.year = bin2bcd(year % 100); + rtc.month = bin2bcd(tm->tm_mon + 1); + rtc.day = bin2bcd(tm->tm_mday); + rtc.hour = bin2bcd(tm->tm_hour); + rtc.minute = bin2bcd(tm->tm_min); + rtc.second = bin2bcd(tm->tm_sec); + rtc.weekday = bin2bcd(wday); + + ret = wilco_ec_mailbox(ec, &msg); + if (ret < 0) + return ret; + + return 0; +} + +static const struct rtc_class_ops wilco_ec_rtc_ops = { + .read_time = wilco_ec_rtc_read, + .set_time = wilco_ec_rtc_write, +}; + +static int wilco_ec_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &wilco_ec_rtc_ops; + /* EC only supports this century */ + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + rtc->owner = THIS_MODULE; + + return rtc_register_device(rtc); +} + +static struct platform_driver wilco_ec_rtc_driver = { + .driver = { + .name = "rtc-wilco-ec", + }, + .probe = wilco_ec_rtc_probe, +}; + +module_platform_driver(wilco_ec_rtc_driver); + +MODULE_ALIAS("platform:rtc-wilco-ec"); +MODULE_AUTHOR("Nick Crews "); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Wilco EC RTC driver"); -- 2.20.1.321.g9e740568ce-goog