linux-kernel - [PATCH 4/7] rtc: cmos: Report supported alarm limit to rtc infrastructure

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Message-Id: <20230816133936.2150294-5-linux@roeck-us.net>
Date:   Wed, 16 Aug 2023 06:39:33 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     Alessandro Zummo <a.zummo@...ertech.it>,
        Benson Leung <bleung@...omium.org>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        John Stultz <jstultz@...gle.com>,
        Stephen Boyd <sboyd@...nel.org>, linux-rtc@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Brian Norris <briannorris@...omium.org>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 4/7] rtc: cmos: Report supported alarm limit to rtc infrastructure

The alarm window supported by the cmos RTC depends on the chip
and its configuration. Report the limit to the RTC core.

Cc: Brian Norris <briannorris@...omium.org>
Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/rtc/rtc-cmos.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index c9416fe8542d..c565dc4d5bf5 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -913,6 +913,10 @@ static inline void cmos_check_acpi_rtc_status(struct device *dev,
 #define	INITSECTION	__init
 #endif
 
+#define SECS_PER_DAY	(24 * 60 * 60)
+#define SECS_PER_MONTH	(28 * SECS_PER_DAY)
+#define SECS_PER_YEAR	(365 * SECS_PER_DAY)
+
 static int INITSECTION
 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 {
@@ -1019,6 +1023,13 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 		goto cleanup0;
 	}
 
+	if (cmos_rtc.mon_alrm)
+		cmos_rtc.rtc->range_max_offset = SECS_PER_YEAR - 1;
+	else if (cmos_rtc.day_alrm)
+		cmos_rtc.rtc->range_max_offset = SECS_PER_MONTH - 1;
+	else
+		cmos_rtc.rtc->range_max_offset = SECS_PER_DAY - 1;
+
 	rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
 
 	if (!mc146818_does_rtc_work()) {
-- 
2.39.2