From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 9105633F58D; Wed, 9 Sep 2026 15:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788967231; cv=none; b=Fj5f0wJqBvK0QtcZJd6oISwTwbFPwQ4MeCyFa5hgtZC1Z1Z6r4rKm7wPTYGlH69fJF8L6r9mFjrnIroEMRtbrGw/JlnNzeY6ptwq2nabce6Tn+oIVdcFDkw4cBJ+HUyekh2tj+Ai30oVxE98KCK2b2Ig/3vtiuaFiGbnz6FYPBM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788967231; c=relaxed/simple; bh=Co5zOMjQTCyErtwY7oOxqYQ7eK0SAUY4lWzBiHS49SI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oG42wDZU/Ahn0Z22ineRQUtNiG9oaFUn0owACDN2+At2p9etnB4KRfCpBrOP6Q7htoxs8yBNssEw6zWFKs5uJNFQJ9yzI0jqMAjUA8VZaogXJFuUVEwqWSL6Ev0hzJxFwL5wC+7Yhvub77DcCdrXqCmD/jMgX1/vR3MktrAi0Is= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=X9Y1Q3gX; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="X9Y1Q3gX" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 389CD1A1A65; Wed, 9 Sep 2026 15:20:28 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 0C09060448; Wed, 9 Sep 2026 15:20:28 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id B516D11C7AF93; Wed, 9 Sep 2026 17:20:19 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1788967223; h=from:subject:date:message-id:to:cc:mime-version:content-type: in-reply-to:references; bh=kesk8yMquyK/iFqs9zh4zemiMGA4tCXi/axrzkwTfrU=; b=X9Y1Q3gXqwnZba7FRw4u/4bu8grOnVHyrYtMX92BP0M6QqBuZk33WUtiLCqJ38mzJcUupF 5dkqUkAHKjy8dMwoShJauU50tmOvxReIpD6nvCEIdA+vE1/4fMGt43BpXGivi9oYJG7CmT uOqjYKAWgyI2PucmA2cMfnK2g2TJWBjgEfFJvi3X9p/7CbQUyCowUX2FyRIi8JOhj4TAzy WGUARjKIRxckSGljMF6oEZhvrS64VpnUxDimMnz5Gp/rs2zS69GyV9aEFihtB4UnT1iu3J M28spE9sdGY/TevV/3HwBdF7IXq+JtY/xiLC771c596qPcrzLyiZG5qsS6xuKg== Date: Wed, 9 Sep 2026 17:20:19 +0200 From: Alexandre Belloni To: Sander Speetjens Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , Jonathan Bell , Stefan Wahren , linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Dom Cobley Subject: Re: [PATCH 2/3] rtc: Add Raspberry Pi 5 RTC driver Message-ID: <202609091520190d6592ee@mail.local> References: <20260909141300.1368790-1-sander.speetjens@gmail.com> <20260909141300.1368790-3-sander.speetjens@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260909141300.1368790-3-sander.speetjens@gmail.com> X-Last-TLS-Session-Version: TLSv1.3 On 09/09/2026 16:12:59+0200, Sander Speetjens wrote: > From: Jonathan Bell > > Upstreaming the downstream Raspberry Pi 5 RTC driver. > This driver supports the custom DA9091, which is accessed through the firmware mailbox. > > Co-developed-by: Dom Cobley > Signed-off-by: Sander Speetjens > --- > drivers/rtc/Kconfig | 11 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-rpi.c | 277 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 289 insertions(+) > create mode 100644 drivers/rtc/rtc-rpi.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 05b9233b9418..382973d46e06 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1999,6 +1999,17 @@ config RTC_DRV_R7301 > This driver can also be built as a module. If so, the module > will be called rtc-r7301. > > +config RTC_DRV_RPI > + tristate "Raspberry Pi RTC" > + depends on ARCH_BRCMSTB || COMPILE_TEST > + default ARCH_BRCMSTB > + help > + If you say yes here you get support for the RTC found on > + Raspberry Pi devices. > + > + This driver can also be built as a module. If so, the module > + will be called rtc-rpi. > + > config RTC_DRV_STM32 > tristate "STM32 RTC" > select REGMAP_MMIO > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 0347645b021f..78551bb04c5c 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -148,6 +148,7 @@ obj-$(CONFIG_RTC_DRV_RC5T583) += rtc-rc5t583.o > obj-$(CONFIG_RTC_DRV_RC5T619) += rtc-rc5t619.o > obj-$(CONFIG_RTC_DRV_RK808) += rtc-rk808.o > obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o > +obj-$(CONFIG_RTC_DRV_RPI) += rtc-rpi.o > obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o > obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o > obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o > diff --git a/drivers/rtc/rtc-rpi.c b/drivers/rtc/rtc-rpi.c > new file mode 100644 > index 000000000000..e455b4116957 > --- /dev/null > +++ b/drivers/rtc/rtc-rpi.c > @@ -0,0 +1,277 @@ > +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause > +/** > + * rtc-rpi.c > + * > + * RTC driver using firmware mailbox > + * Supports battery backed RTC and wake alarms > + * > + * Based on rtc-meson-vrtc by Neil Armstrong > + * > + * Copyright (c) 2023, Raspberry Pi Ltd. > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +struct rpi_rtc_data { > + struct rtc_device *rtc; > + struct rpi_firmware *fw; > + u32 bbat_vchg_microvolts; > +}; > + > +#define RPI_FIRMWARE_GET_RTC_REG 0x00030087 > +#define RPI_FIRMWARE_SET_RTC_REG 0x00038087 > + > +enum { > + RTC_TIME, > + RTC_ALARM, > + RTC_ALARM_PENDING, > + RTC_ALARM_ENABLE, > + RTC_BBAT_CHG_VOLTS, > + RTC_BBAT_CHG_VOLTS_MIN, > + RTC_BBAT_CHG_VOLTS_MAX, > + RTC_BBAT_VOLTS > +}; > + > +static int rpi_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_TIME}; > + int err; > + > + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, > + &data, sizeof(data)); > + rtc_time64_to_tm(data[1], tm); > + return err; > +} > + > +static int rpi_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_TIME, rtc_tm_to_time64(tm)}; > + > + return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, > + &data, sizeof(data)); > +} > + > +static int rpi_rtc_alarm_irq_is_enabled(struct device *dev, unsigned char *enabled) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_ALARM_ENABLE}; > + s32 err = 0; > + > + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, > + &data, sizeof(data)); > + *enabled = data[1] & 0x1; > + return err; > +} > + > +static int rpi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_ALARM_ENABLE, enabled}; > + > + return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, > + &data, sizeof(data)); > +} > + > +static int rpi_rtc_alarm_clear_pending(struct device *dev) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_ALARM_PENDING, 1}; > + > + return rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, > + &data, sizeof(data)); > +} > + > +static int rpi_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_ALARM}; > + s32 err = 0; > + > + err = rpi_rtc_alarm_irq_is_enabled(dev, &alarm->enabled); > + if (!err) > + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, > + &data, sizeof(data)); > + rtc_time64_to_tm(data[1], &alarm->time); > + > + return err; > +} > + > +static int rpi_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_ALARM, rtc_tm_to_time64(&alarm->time)}; > + int err; > + > + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, > + &data, sizeof(data)); > + > + if (err == 0) > + err = rpi_rtc_alarm_irq_enable(dev, alarm->enabled); > + > + return err; > +} > + > +static const struct rtc_class_ops rpi_rtc_ops = { > + .read_time = rpi_rtc_read_time, > + .set_time = rpi_rtc_set_time, > + .read_alarm = rpi_rtc_read_alarm, > + .set_alarm = rpi_rtc_set_alarm, > + .alarm_irq_enable = rpi_rtc_alarm_irq_enable, > +}; > + > +static int rpi_rtc_set_charge_voltage(struct device *dev) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); > + u32 data[2] = {RTC_BBAT_CHG_VOLTS, vrtc->bbat_vchg_microvolts}; > + int err; > + > + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_SET_RTC_REG, > + &data, sizeof(data)); > + > + if (err) > + dev_err(dev, "failed to set trickle charge voltage to %uuV: %d\n", > + vrtc->bbat_vchg_microvolts, err); > + else if (vrtc->bbat_vchg_microvolts) > + dev_info(dev, "trickle charging enabled at %uuV\n", > + vrtc->bbat_vchg_microvolts); > + > + return err; > +} > + > +static ssize_t rpi_rtc_print_uint_reg(struct device *dev, char *buf, u32 reg) > +{ > + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev->parent); > + u32 data[2] = {reg, 0}; > + int ret = 0; > + > + ret = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, > + &data, sizeof(data)); > + if (ret < 0) > + return ret; > + > + return sprintf(buf, "%u\n", data[1]); > +} > + > +static ssize_t charging_voltage_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS); > +} > +static DEVICE_ATTR_RO(charging_voltage); > + > +static ssize_t charging_voltage_min_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS_MIN); > +} > +static DEVICE_ATTR_RO(charging_voltage_min); > + > +static ssize_t charging_voltage_max_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_CHG_VOLTS_MAX); > +} > +static DEVICE_ATTR_RO(charging_voltage_max); > + > +static ssize_t battery_voltage_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return rpi_rtc_print_uint_reg(dev, buf, RTC_BBAT_VOLTS); > +} > +static DEVICE_ATTR_RO(battery_voltage); > + > +static struct attribute *rpi_rtc_attrs[] = { > + &dev_attr_charging_voltage.attr, > + &dev_attr_charging_voltage_min.attr, > + &dev_attr_charging_voltage_max.attr, > + &dev_attr_battery_voltage.attr, > + NULL > +}; > + > +static const struct attribute_group rpi_rtc_sysfs_files = { > + .attrs = rpi_rtc_attrs, > +}; This undocumented sysfs interface has to be removed. > + > +static int rpi_rtc_probe(struct platform_device *pdev) > +{ > + struct rpi_rtc_data *vrtc; > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct device_node *fw_node; > + struct rpi_firmware *fw; > + int ret; > + > + fw_node = of_parse_phandle(np, "firmware", 0); > + if (!fw_node) { > + dev_err(dev, "Missing firmware node\n"); > + return -ENOENT; > + } > + > + fw = rpi_firmware_get(fw_node); > + if (!fw) > + return -EPROBE_DEFER; > + > + vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL); > + if (!vrtc) > + return -ENOMEM; > + > + vrtc->fw = fw; > + > + device_init_wakeup(&pdev->dev, 1); > + > + platform_set_drvdata(pdev, vrtc); > + > + vrtc->rtc = devm_rtc_allocate_device(&pdev->dev); > + if (IS_ERR(vrtc->rtc)) > + return PTR_ERR(vrtc->rtc); > + > + set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, vrtc->rtc->features); > + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, vrtc->rtc->features); > + > + vrtc->rtc->ops = &rpi_rtc_ops; > + ret = rtc_add_group(vrtc->rtc, &rpi_rtc_sysfs_files); > + if (ret) > + return ret; > + > + rpi_rtc_alarm_clear_pending(dev); > + > + /* > + * Optionally enable trickle charging - if the property isn't > + * present (or set to zero), trickle charging is disabled. > + */ > + of_property_read_u32(np, "trickle-charge-microvolt", > + &vrtc->bbat_vchg_microvolts); > + > + rpi_rtc_set_charge_voltage(dev); > + > + return devm_rtc_register_device(vrtc->rtc); > +} > + > +static const struct of_device_id rpi_rtc_dt_match[] = { > + { .compatible = "raspberrypi,rpi-rtc"}, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, rpi_rtc_dt_match); > + > +static struct platform_driver rpi_rtc_driver = { > + .probe = rpi_rtc_probe, > + .driver = { > + .name = "rpi-rtc", > + .of_match_table = rpi_rtc_dt_match, > + }, > +}; > + > +module_platform_driver(rpi_rtc_driver); > + > +MODULE_DESCRIPTION("Raspberry Pi RTC driver"); > +MODULE_LICENSE("GPL"); > \ No newline at end of file > -- > 2.55.0 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com