From nobody Mon Sep 28 15:34:26 2026 Received: from mta-65-228.siemens.flowmailer.net (mta-65-228.siemens.flowmailer.net [185.136.65.228]) (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 E11BC4078CD for ; Thu, 20 Aug 2026 11:24:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.65.228 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787225089; cv=none; b=KsDRJqLqGqvlCCn0hrBcR/PIQPqix1cWzS5+22BEDX5E/9lsLWxa3ryvt9/gS+Di5fnhIYsx4N5tgmV1syYwvxjhnNfOC3loLRilBcxhndc+Rupel54bifPrq2bamx+yEocOARkB2KZ+2/SYN2MUbxf08YOZKsKgFCsLNviE2Sc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787225089; c=relaxed/simple; bh=QvPrTyRUxpT5Ko4BRW/xtMybx/yQT6cE7mPgUfuIYiU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MHodSJ8HaR1mreOQh74INe8nwRqds2avn/UTM93CXl1nvNitatW/z+pZqF+cqgS38IzD8cp598jNNkr/1W8myrYBpB+6OU83fpL4Jug6YTe99LAY/YeSNkw4zOWmHCM24Dm6XCwfq0gh88I7vrSLJZZoJpRlTqOv606FaY0nN7o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=alexander.sverdlin@siemens.com header.b=AoMGh1yM; arc=none smtp.client-ip=185.136.65.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=alexander.sverdlin@siemens.com header.b="AoMGh1yM" Received: by mta-65-228.siemens.flowmailer.net with ESMTPSA id 20260820112441c0de868a220002072d for ; Thu, 20 Aug 2026 13:24:42 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm2; d=siemens.com; i=alexander.sverdlin@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc; bh=OatxJyygaql0HoMqS6F78jQWSQvpRPQ1GtRa0JOfUs4=; b=AoMGh1yMBn3A4fLmuroPD3tVZr/l4hZx4NzOxzqOtLX+U2rIMc7osYYPriMCnFkNhjTjbv XDb4RoLnhNix41WJzbFXFvGyByW3teKVOjMznXdb1eT3lOCArTRKAmHe4QfHttDls07oDFtk FBinGtWOHi7b7393pSIfqBdxgKm9Cb4ETfMJwQ4hbo8BoDYWOLCsB5nqWKbfW+HzONUqHW+y J2lEEyb1DugIdnBS52dNkT7qVjZ68mE+ICpfECAtZKw1n14mirrpcMBEe9V9C32kxVfS6Lmw ILf0vB9HLrLBUbuObv0pYYJXtGWXDc5B4MQblKNFgwlcZ/r8h7U1Pneg==; From: "A. Sverdlin" To: linux-rtc@vger.kernel.org Cc: Alexander Sverdlin , Alexandre Belloni , linux-kernel@vger.kernel.org, Adrian Freihofer Subject: [PATCH v2] rtc: pcf85063: add 1 Hz update interrupt (UIE) support Date: Thu, 20 Aug 2026 13:24:33 +0200 Message-ID: <20260820112437.3715237-1-alexander.sverdlin@siemens.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-456497:519-21489:flowmailer Content-Type: text/plain; charset="utf-8" From: Alexander Sverdlin The PCF85063A/RV8263 have no dedicated 1 Hz update interrupt, but their countdown timer can be sourced from a 1 Hz clock (TCF =3D 1 Hz, T =3D 1) to generate a periodic interrupt on the INT pin. Use it to offload UIE to the hardware, following the pattern of other RTC drivers: the timer is enabled from set_alarm()/alarm_irq_enable() whenever uie_rtctimer is active, and the IRQ handler reports RTC_UF when the timer flag (TF) is set. RTC_FEATURE_UPDATE_INTERRUPT is now only cleared when no usable interrupt is wired, preserving the polling emulation for those configurations. Co-developed-by: Adrian Freihofer Signed-off-by: Adrian Freihofer Signed-off-by: Alexander Sverdlin --- Changelog (addressed Sashiko comments): - preserve AF bit in pcf85063_set_timer_1hz() - faster and less racy (regarding AF flag) pcf85063_rtc_handle_irq() drivers/rtc/rtc-pcf85063.c | 100 ++++++++++++++++++++++++++++++++++--- 1 file changed, 92 insertions(+), 8 deletions(-) diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c index 01e209d88f5f3..e10e6aaa37d52 100644 --- a/drivers/rtc/rtc-pcf85063.c +++ b/drivers/rtc/rtc-pcf85063.c @@ -44,6 +44,7 @@ #define PCF85063_REG_CTRL2 0x01 #define PCF85063_CTRL2_AF BIT(6) #define PCF85063_CTRL2_AIE BIT(7) +#define PCF85063_CTRL2_TF BIT(3) =20 #define PCF85063_REG_OFFSET 0x02 #define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */ @@ -63,6 +64,14 @@ #define PCF85063_REG_ALM_S 0x0b #define PCF85063_AEN BIT(7) =20 +#define PCF85063_REG_TIMER_VALUE 0x10 +#define PCF85063_REG_TIMER_MODE 0x11 +#define PCF85063_TIMER_MODE_TI_TP BIT(0) +#define PCF85063_TIMER_MODE_TIE BIT(1) +#define PCF85063_TIMER_MODE_TE BIT(2) +#define PCF85063_TIMER_MODE_TCF_MASK GENMASK(4, 3) +#define PCF85063_TIMER_MODE_TCF_1HZ (2 << 3) + struct pcf85063_config { struct regmap_config regmap; unsigned has_alarms:1; @@ -188,12 +197,65 @@ static int pcf85063_rtc_read_alarm(struct device *dev= , struct rtc_wkalrm *alrm) return 0; } =20 +/* + * The chip has no dedicated 1 Hz update interrupt. Drive the countdown ti= mer + * at 1 Hz to emulate it, so the RTC core can offload UIE to the hardware + * instead of polling. A free-running timer is left untouched to preserve = its + * phase across the per-second re-arming done by the core. + */ +static int pcf85063_set_timer_1hz(struct pcf85063 *pcf85063, bool enable) +{ + unsigned int mask =3D PCF85063_TIMER_MODE_TCF_MASK | + PCF85063_TIMER_MODE_TIE | + PCF85063_TIMER_MODE_TI_TP | + PCF85063_TIMER_MODE_TE; + unsigned int mode =3D 0; + unsigned int cur; + int ret; + + if (enable) + mode =3D PCF85063_TIMER_MODE_TCF_1HZ | PCF85063_TIMER_MODE_TIE | + PCF85063_TIMER_MODE_TI_TP | PCF85063_TIMER_MODE_TE; + + ret =3D regmap_read(pcf85063->regmap, PCF85063_REG_TIMER_MODE, &cur); + if (ret) + return ret; + + if ((cur & mask) =3D=3D mode) + return 0; + + /* Stop the counter before changing its reload value. */ + ret =3D regmap_update_bits(pcf85063->regmap, PCF85063_REG_TIMER_MODE, + PCF85063_TIMER_MODE_TE, 0); + if (ret) + return ret; + + if (enable) { + ret =3D regmap_write(pcf85063->regmap, PCF85063_REG_TIMER_VALUE, 1); + if (ret) + return ret; + + /* Clear TF but preserve AF */ + ret =3D regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, + PCF85063_CTRL2_TF | PCF85063_CTRL2_AF, PCF85063_CTRL2_AF); + if (ret) + return ret; + } + + return regmap_update_bits(pcf85063->regmap, PCF85063_REG_TIMER_MODE, + mask, mode); +} + static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *a= lrm) { struct pcf85063 *pcf85063 =3D dev_get_drvdata(dev); u8 buf[5]; int ret; =20 + ret =3D pcf85063_set_timer_1hz(pcf85063, pcf85063->rtc->uie_rtctimer.enab= led); + if (ret) + return ret; + buf[0] =3D bin2bcd(alrm->time.tm_sec); buf[1] =3D bin2bcd(alrm->time.tm_min); buf[2] =3D bin2bcd(alrm->time.tm_hour); @@ -212,22 +274,31 @@ static int pcf85063_rtc_set_alarm(struct device *dev,= struct rtc_wkalrm *alrm) =20 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, - alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CT= RL2_AF); + pcf85063->rtc->aie_timer.enabled ? + PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF); } =20 static int pcf85063_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct pcf85063 *pcf85063 =3D dev_get_drvdata(dev); + int ret; + + ret =3D pcf85063_set_timer_1hz(pcf85063, pcf85063->rtc->uie_rtctimer.enab= led); + if (ret) + return ret; =20 return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, PCF85063_CTRL2_AIE, - enabled ? PCF85063_CTRL2_AIE : 0); + pcf85063->rtc->aie_timer.enabled ? + PCF85063_CTRL2_AIE : 0); } =20 static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id) { struct pcf85063 *pcf85063 =3D dev_id; + unsigned long events =3D RTC_IRQF; + irqreturn_t ret =3D IRQ_NONE; unsigned int val; int err; =20 @@ -236,14 +307,26 @@ static irqreturn_t pcf85063_rtc_handle_irq(int irq, v= oid *dev_id) return IRQ_NONE; =20 if (val & PCF85063_CTRL2_AF) { - rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF); - regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2, - PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, - 0); - return IRQ_HANDLED; + events |=3D RTC_AF; + val &=3D ~(PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF); + ret =3D IRQ_HANDLED; + } else { + /* Preserve AF if it comes after the above regmap_read() */ + val |=3D PCF85063_CTRL2_AF; + } + + if (val & PCF85063_CTRL2_TF) { + events |=3D RTC_UF; + val &=3D ~PCF85063_CTRL2_TF; + ret =3D IRQ_HANDLED; + } + + if (ret =3D=3D IRQ_HANDLED) { + regmap_write(pcf85063->regmap, PCF85063_REG_CTRL2, val); + rtc_update_irq(pcf85063->rtc, 1, events); } =20 - return IRQ_NONE; + return ret; } =20 static int pcf85063_read_offset(struct device *dev, long *offset) @@ -607,6 +690,7 @@ static int pcf85063_probe(struct device *dev, struct re= gmap *regmap, int irq, dev_warn(&pcf85063->rtc->dev, "unable to request IRQ, alarms disabled\n"); } else { + set_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf85063->rtc->features); set_bit(RTC_FEATURE_ALARM, pcf85063->rtc->features); device_init_wakeup(dev, true); err =3D dev_pm_set_wake_irq(dev, irq); --=20 2.55.0