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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 552DFC282C2 for ; Thu, 7 Feb 2019 20:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10C9721721 for ; Thu, 7 Feb 2019 20:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727203AbfBGUA3 (ORCPT ); Thu, 7 Feb 2019 15:00:29 -0500 Received: from mslow2.mail.gandi.net ([217.70.178.242]:52152 "EHLO mslow2.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726821AbfBGUA2 (ORCPT ); Thu, 7 Feb 2019 15:00:28 -0500 Received: from relay12.mail.gandi.net (unknown [217.70.178.232]) by mslow2.mail.gandi.net (Postfix) with ESMTP id 66F243A4687; Thu, 7 Feb 2019 20:51:03 +0100 (CET) Received: from localhost (lfbn-lyo-1-149-219.w86-202.abo.wanadoo.fr [86.202.231.219]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 3566A200004; Thu, 7 Feb 2019 19:50:57 +0000 (UTC) Date: Thu, 7 Feb 2019 20:50:57 +0100 From: Alexandre Belloni To: Nick Crews Cc: linux-kernel@vger.kernel.org, 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 , linux-rtc@vger.kernel.org, Alessandro Zummo , Benson Leung Subject: Re: [PATCH v4 4/9] platform/chrome: rtc: Add RTC driver Message-ID: <20190207195057.GA5015@piout.net> References: <20190123183325.92946-1-ncrews@chromium.org> <20190123183325.92946-5-ncrews@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190123183325.92946-5-ncrews@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/01/2019 11:33:20-0700, Nick Crews wrote: > 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 Acked-by: Alexandre Belloni > --- > > 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 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com