From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B0EE225DB0D; Sun, 22 Feb 2026 14:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771770072; cv=none; b=pkMnPb3fBbyVbH2FfTULH9KQNBuJb+HO2EbtiM4cXhqlj+P2MJ6W+Nc7EVwJsJXgTUas147udZ4ZKyYRV6GfyoofvzD+drFpD6jhMwtNYDJTsI1faEuKtYaCsBpZ09QsRAf1mwwBygHJO3H3bkebYqEfWN4SqWDsvNOBJszhre0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771770072; c=relaxed/simple; bh=Wnb2YfEU6i9cMmpYwUDtZ2E3EJ4153psC3JNN7Xlfy4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GVjs+Ue+4Sw9oy/n3aNa9WPnem28PznyRRs7bwo9/wG79UfqYm4+OghCqCv6PviCJFQMwsO3d3vGlb/c4oGt1s1AUqqj2Ay0O9fVmK63H88BPeJf1hhh9Du0jCYpFcVx5FHc0ezhViGi7EsDP+lO2mABa7J8HnnhtUL7chn29Lc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KT357Ebs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KT357Ebs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53E13C19424; Sun, 22 Feb 2026 14:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771770072; bh=Wnb2YfEU6i9cMmpYwUDtZ2E3EJ4153psC3JNN7Xlfy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KT357EbsehDE+ZP2M84LHEn7wjTf4cGRn6FIs+96mzpQAl0tYdiSiuDXQYRHT3kU7 hnAdxIE7rwCyBSlmY4a0wyMsbswPynl9T2Aa/rxFbh1jDMvVM/M52c5waJE4lF89DZ BVjxGV6XObU4kgVpA3gjKLekRwf4cuTfPQPxfUpL0inqnHaYJ+1uyr3TvcuYkGwSf1 qv4njut8ac/hP+w/d9YnoguPm1o+1Uq9f/I6y2gNEtRg7u5znLwFf8QPefN5uTm1d0 Q1uKZClRToSfXdwzClA0teScOxqZLWRsq/9eCYmLqtONJEoCFx4jb9dalYXSUraGo1 BuoQ9X14W1arw== From: "Rafael J. Wysocki" To: Linux ACPI Cc: Alexandre Belloni , Danilo Krummrich , LKML Subject: [PATCH v0 5/6] ACPI: TAD: Add RTC class device interface Date: Sun, 22 Feb 2026 15:18:29 +0100 Message-ID: <10819001.nUPlyArG6x@rafael.j.wysocki> Organization: Linux Kernel Development In-Reply-To: <4727679.LvFx2qVVIh@rafael.j.wysocki> References: <4727679.LvFx2qVVIh@rafael.j.wysocki> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="UTF-8" From: Rafael J. Wysocki Add an RTC class device interface allowing to read and set the real time value and providing a procfs callback to the ACPI TAD driver. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_tad.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 83 insertions(+), 2 deletions(-) --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -25,6 +25,7 @@ #include #include #include +#include #include MODULE_DESCRIPTION("ACPI Time and Alarm (TAD) Device Driver"); @@ -51,6 +52,7 @@ MODULE_AUTHOR("Rafael J. Wysocki"); /* ACPI TAD RTC */ #define ACPI_TAD_TZ_UNSPEC 2047 +#define ACPI_TAD_TIME_ISDST 3 struct acpi_tad_driver_data { u32 capabilities; @@ -164,6 +166,8 @@ static int acpi_tad_get_real_time(struct return 0; } +/* sysfs interface */ + static char *acpi_tad_rt_next_field(char *s, int *val) { char *p; @@ -579,6 +583,77 @@ static const struct attribute_group acpi .is_visible = acpi_tad_attr_is_visible, }; +/* RTC class device interface */ + +static int acpi_tad_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct acpi_tad_rt rt; + + rt.year = tm->tm_year + 1900; + rt.month = tm->tm_mon + 1; + rt.day = tm->tm_mday; + rt.hour = tm->tm_hour; + rt.minute = tm->tm_min; + rt.second = tm->tm_sec; + rt.tz = ACPI_TAD_TZ_UNSPEC; + rt.daylight = ACPI_TAD_TIME_ISDST * !!tm->tm_isdst; + + return acpi_tad_set_real_time(dev, &rt); +} + +static int acpi_tad_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct acpi_tad_rt rt; + int ret; + + ret = acpi_tad_get_real_time(dev, &rt); + if (ret) + return ret; + + tm->tm_year = rt.year - 1900; + tm->tm_mon = rt.month - 1; + tm->tm_mday = rt.day; + tm->tm_hour = rt.hour; + tm->tm_min = rt.minute; + tm->tm_sec = rt.second; + tm->tm_isdst = rt.daylight == ACPI_TAD_TIME_ISDST; + + return 0; +} + +static int acpi_tad_rtc_procfs(struct device *dev, struct seq_file *seq) +{ + struct acpi_tad_rt rt; + int ret; + + ret = acpi_tad_get_real_time(dev, &rt); + if (ret) + return ret; + + seq_printf(seq, + "Time\t\t: %u:%u:%u\n" + "Date\t\t: %u-%u-%u\n" + "Daylight\t: %s\n", + rt.hour, rt.minute, rt.second, + rt.year, rt.month, rt.day, + str_yes_no(rt.daylight == ACPI_TAD_TIME_ISDST)); + + if (rt.tz == ACPI_TAD_TZ_UNSPEC) + seq_puts(seq, "Timezone\t: unspecified\n"); + else + seq_printf(seq, "Timezone\t: %d\n", rt.tz); + + return 0; +} + +static const struct rtc_class_ops acpi_tad_rtc_ops = { + .read_time = acpi_tad_rtc_read_time, + .set_time = acpi_tad_rtc_set_time, + .proc = acpi_tad_rtc_procfs, +}; + +/* Platform driver interface */ + static int acpi_tad_disable_timer(struct device *dev, u32 timer_id) { return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED); @@ -655,10 +730,16 @@ static int acpi_tad_probe(struct platfor pm_runtime_suspend(dev); ret = sysfs_create_group(&dev->kobj, &acpi_tad_attr_group); - if (ret) + if (ret) { acpi_tad_remove(pdev); + return ret; + } - return ret; + if (caps & ACPI_TAD_RT) + devm_rtc_device_register(dev, "acpi-tad-rtc", &acpi_tad_rtc_ops, + THIS_MODULE); + + return 0; } static const struct acpi_device_id acpi_tad_ids[] = {