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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D1263CA5FC1 for ; Wed, 30 Sep 2026 08:40:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=NYDOdMZa/wf1LZ8vUW6yy2oMn5XA2+ny/9dTMK4B1Tw=; b=oqSAVfOoHj4J6OKKIyOCEQo600 4Hzu2sDZ4jVAWa59zv6zNLWUnIoDcOxLaU7PpKaveS1uy/ZAst5sZ9j0M8n1hDZv87bq9yYChGDY5 4NdUbYq8F9msyzeMBIAJPo4eV27OcGFpw+9IumdtT1KU+v7QMqXXACblFsblwvcRx8j3e/ihoAR98 5JH0Y0ezQL/lvmJ4WWhAMOxRZGwUDg0I6XwdaH+r0hiMNA2VIqGZgNywmh90jErbsCzgSPEYh60YD koi44JWF359QNwTgrsqUI6mR/4f3tvJpgTCmb625vd8k+/Ti2f+HTCfKCh0IM46JDzXiJPsfGpTJC g5Z1naWA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBprC-00000005SI5-0Jfg; Wed, 30 Sep 2026 08:40:06 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBpr5-00000005SED-0JEG for linux-arm-kernel@bombadil.infradead.org; Wed, 30 Sep 2026 08:39:59 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=NYDOdMZa/wf1LZ8vUW6yy2oMn5XA2+ny/9dTMK4B1Tw=; b=GDlAk1gK63eEqZmua/h0cWrG6e DrmNFFF9wBm8FFqt26Dvqw/kxLoDIX93OeK+t4oihJQOey3kIti5rZPSHTkh/m6DC+HgO+0o5l4i+ SfVqe+1VVO5Biljn2CiClf6Waskvd99pBqHxzNzf1VNLDhhR+Crn2z7G9r8Jn/TIRP8U0smDcLRHC zLjVypOPBFvc6+3eJoomyOvvsiAlwLwIdQBysAiBvpItK7cWtg06OP8+40atDiGck7ZpNI86mmXAY U9mo3YnT5NSHP1+Xv7lx2bvoS7g61No5/h5AgDJaptmr41jyHBubDYSRTuvcUCEHEmL9ecDELKO6s P/KebJ1w==; Received: from mail-wm2-x10.google.com ([2a00:1450:4864:31::10]) by casper.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBpr1-0000000Anrr-3z6l for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2026 08:39:58 +0000 Received: by mail-wm2-x10.google.com with SMTP id 5b1f17b1804b1-4a006bb267eso15760115e9.0 for ; Wed, 30 Sep 2026 01:39:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790757593; x=1791362393; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=NYDOdMZa/wf1LZ8vUW6yy2oMn5XA2+ny/9dTMK4B1Tw=; b=JMNMFZ6h1JOgR+yiPE4riY0goBWqvmLA092vY0yvT/J42wQ3At0yx+AaAxtajlFSFn 1w4OBeDT/+V94PR5JDcucjERGenbgEq4i79srRon2E5920WOVaDnQbXypzqAveVgbBxn ol6zDpKLi/IRIT7fjGmQuHDAsLSwXXZArP8BNev/6DzGwxN5+Cjd5iYVb35c5l8sUlKK kfkZUiCsclS19/1n/XIt/hNe/5CefITL6ScKOV2Nti6+y/zGc6g7piTooGc7MhhpGFDU Q51Uc6eF+T2rZlDNcMDKrLQYVv3mjjKLgrfGbYljdQ1Fyr0p5VpbRBozJOqTGLVWc/tV oEGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790757593; x=1791362393; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=NYDOdMZa/wf1LZ8vUW6yy2oMn5XA2+ny/9dTMK4B1Tw=; b=kSsmImDS/0PHMrWztrIRUSs/OahMBvmmiHvqVSDbxLATrEs8jdxxcA4OdcX00mAMe8 Hx9Ho/8s61hBOThQ2wUzIwO5Wtz+NZ6vj+Jy1wXOopMzQUyEZ2TxHEJ+MAdJu5+jMVeR HA9NINWmxHQzK87c1J8dbUw2HAiaA4Xa53ec0S9DZ/8RPjbvAjSk7DzJF8PlN3h6t0Wd jHR0exsB3dy5CBukfrrTY5n2S6+mLowDqBMXWLBZViem7zWSdp0ZYK5wpy8JXz15p2MA ZG/ais54OKOqK1raPST+U4bMS9ODwOZguVKFJa9ipAm3x9Y80b90h+zLMpkbbKAYs4+z CHqw== X-Forwarded-Encrypted: i=1; AKwUvBxreetWIJVPwLab9WBJwTFtTROH+x7eRNYsG1EGtc2/CWrUKyr8vYw0yvSxbzwTa9wcRlhDSVov5ia0Ohbwwlju@lists.infradead.org X-Gm-Message-State: AFuF++nm6m8UEG/fx4bKVOmDJNjlJETQcwe0A5kPEMGlw5HpUqyZX0zD WhkuPtTh9O3BNCXwpOY72UhWvt6ltiBuuCtyC5ZzM+wHZYJYrFBV7Nq3 X-Gm-Gg: AYBFou1gyFxU4qfwaRerfsLxlZLXPrZHman0c4rW2Q6z4yBD9LZKIMbIJ04yFPfRaiv QxdTMC7ESU9+ngFE1hE3mbg67e4tSU+QOi4RkWlUsRZkKrxqcCV0OAX6/arSdL50R7RM2SKVel6 ShO3Wh4DS8WQ8d6b/aPudx5bKk7HCk2TkQOpZEVBiq3LVtPx76tn0NTnOXuYtj6M+C79KYgtTs8 A5i7k1m2waG3fDgt+I1+0o+kqndwShhm2noeaP+KAV39gFj+1BR+OSRxFJ8/xxD4wzToKKcbNB2 ueCcjyC2cthJsLF/8H0n2B6aIB3uKUgHonj9bzeTTQMGx4p20VxsA3HeK5Y4f9jKSdARC8hCB4N NdqOHTxKusToO+9CMeq9eKrEP5n3lDNLgrDd2pfTuBBYk8Vuikmjo1YWz2K3DMnCvv1CGdQfH7o Uxd9KZEFn3VrNUmnhJLQAy56A+8UnQ03DmDmPAx/DokopQhOZDHJCl1STHSxgTXmlg6AcTAI4bC PNM4YKpo0totkxQybyju/BB46Y87GmL78WJ6wDy/JLygQ== X-Received: by 2002:a05:600c:8b5b:b0:49f:ce73:7aa with SMTP id 5b1f17b1804b1-4a01b00b470mr9631895e9.35.1790757593220; Wed, 30 Sep 2026 01:39:53 -0700 (PDT) Received: from zeus.localdomain (212.71.14.70.adsl.dyn.edpnet.net. [212.71.14.70]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48b029bfd2bsm1757325f8f.11.2026.09.30.01.39.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Sep 2026 01:39:52 -0700 (PDT) From: Sander Speetjens To: Alexandre Belloni 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, sander.speetjens@gmail.com, pbrobinson@gmail.com, Dom Cobley Subject: [PATCH v7 2/2] rtc: Add Raspberry Pi 5 RTC driver Date: Wed, 30 Sep 2026 10:39:22 +0200 Message-ID: <20260930083922.484885-3-sander.speetjens@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930083922.484885-1-sander.speetjens@gmail.com> References: <20260930083922.484885-1-sander.speetjens@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260930_093956_008941_8DF63832 X-CRM114-Status: GOOD ( 35.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Upstreaming the downstream Raspberry Pi 5 RTC driver. This driver supports the custom DA9091, which is accessed through the firmware mailbox. Signed-off-by: Jonathan Bell Signed-off-by: Dom Cobley Signed-off-by: Sander Speetjens --- V6 -> V7: - Move from u32 array to struct - Fix encapsulation as mentioned by sashiko-bot V5 -> V6: - Add MODULE_ALIAS, as mentioned by sashiko-bot - Encapsulate the mailbox data in le32_to_cpu or cpu_to_le32, as mentioned by sashiko-bot. For good practice V4 -> V5: No changes V3 -> V4: - Fix Kconfig depends that disallows having Raspberrypi firmware built as a module while the rtc driver is built in - Remove sysfs - Add limits from firmware properties and check in rpi_rtc_set_charge_voltage V2 -> V3: - Move platform check to firmware and abort before registering a platform device if on another platform - Add a dependency on the Raspberry Pi firmware to Kconfig - Check return value of devm_device_init_wakeup - Fix property name V1 -> V2: Instead of the original driver, which was directly bound to the device tree. This driver is bound to the Raspberry Pi firmware device by creating a child device in the firmware driver probe function. The child device is then bound to this driver, which uses the firmware mailbox to access the RTC. A couple of minor changes have been made to the driver since it was originally written, including: - Checking if the model is a Raspberry Pi 5, as the RTC is only present on that model. - Using the new devm_rpi_firmware_get() and devm_init_wakeup() helper to get the firmware device and avoid leaking memory. - Using millivolts instead of microvolts for the trickle charge voltage, to match the RTC standard. - Instead of setting the trickle charge voltage to 0 to disable trickle charging, the property is now optional. If the property is not present, trickle charging is disabled, per the RTC standard. - Renaming the driver dt match compatible to "raspberrypi,firmware-rtc" to match the other firmware bindings. - Renaming the driver name to "raspberrypi-rtc" to match the other firmware drivers. drivers/firmware/raspberrypi.c | 25 +++ drivers/rtc/Kconfig | 12 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-raspberrypi.c | 279 +++++++++++++++++++++++++++++++++ 4 files changed, 317 insertions(+) create mode 100644 drivers/rtc/rtc-raspberrypi.c diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c index 0aa322e9a2e7..a35f00c6fb2c 100644 --- a/drivers/firmware/raspberrypi.c +++ b/drivers/firmware/raspberrypi.c @@ -24,6 +24,7 @@ static struct platform_device *rpi_hwmon; static struct platform_device *rpi_clk; +static struct platform_device *rpi_rtc; struct rpi_firmware { struct mbox_client cl; @@ -231,6 +232,27 @@ static void rpi_register_clk_driver(struct device *dev) -1, NULL, 0); } +static void rpi_register_rtc_driver(struct device *dev) +{ + struct device_node *firmware; + + // Check if our model is a Raspberry Pi 5, as the RTC is only present on that model. + const char *model = of_get_property(of_root, "model", NULL); + + if (!model || strncmp(model, "Raspberry Pi 5", 14) != 0) + return; + + firmware = of_get_compatible_child(dev->of_node, + "raspberrypi,firmware-rtc"); + if (firmware) { + of_node_put(firmware); + return; + } + + rpi_rtc = platform_device_register_data(dev, "raspberrypi-rtc", + -1, NULL, 0); +} + unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id) { struct rpi_firmware_clk_rate_request msg = @@ -305,6 +327,7 @@ static int rpi_firmware_probe(struct platform_device *pdev) rpi_firmware_print_firmware_revision(fw); rpi_register_hwmon_driver(dev, fw); rpi_register_clk_driver(dev); + rpi_register_rtc_driver(dev); return 0; } @@ -327,6 +350,8 @@ static void rpi_firmware_remove(struct platform_device *pdev) rpi_hwmon = NULL; platform_device_unregister(rpi_clk); rpi_clk = NULL; + platform_device_unregister(rpi_rtc); + rpi_rtc = NULL; rpi_firmware_put(fw); } diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 05b9233b9418..4dbe20bcace8 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1999,6 +1999,18 @@ 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 RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE) + 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-raspberrypi. + config RTC_DRV_STM32 tristate "STM32 RTC" select REGMAP_MMIO diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 0347645b021f..46f1a0fc2416 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -144,6 +144,7 @@ obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o obj-$(CONFIG_RTC_DRV_R7301) += rtc-r7301.o obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o +obj-$(CONFIG_RTC_DRV_RPI) += rtc-raspberrypi.o obj-$(CONFIG_RTC_DRV_RC5T583) += rtc-rc5t583.o obj-$(CONFIG_RTC_DRV_RC5T619) += rtc-rc5t619.o obj-$(CONFIG_RTC_DRV_RK808) += rtc-rk808.o diff --git a/drivers/rtc/rtc-raspberrypi.c b/drivers/rtc/rtc-raspberrypi.c new file mode 100644 index 000000000000..9f3f5d7683be --- /dev/null +++ b/drivers/rtc/rtc-raspberrypi.c @@ -0,0 +1,279 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +/** + * rtc-raspberrypi.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 + +#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 +}; + +struct rpi_rtc_data { + struct rtc_device *rtc; + struct rpi_firmware *fw; + u32 bbat_vchg_millivolts; + u32 bbat_vchg_min_millivolts; + u32 bbat_vchg_max_millivolts; +}; + +struct rpi_rtc_reg { + __le32 reg; + __le32 val; +} __packed; + +static int rpi_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_TIME) + }; + int err; + + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, + &data, sizeof(data)); + rtc_time64_to_tm(le32_to_cpu(data.val), 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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_TIME), + .val = cpu_to_le32(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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_ALARM_ENABLE) + }; + s32 err = 0; + + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, + &data, sizeof(data)); + *enabled = le32_to_cpu(data.val) & 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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_ALARM_ENABLE), + .val = cpu_to_le32(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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_ALARM_PENDING), + .val = cpu_to_le32(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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(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(le32_to_cpu(data.val), &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); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_ALARM), + .val = cpu_to_le32(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 void rpi_rtc_set_limits(struct device *dev) +{ + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_BBAT_CHG_VOLTS_MIN) + }; + + int err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, + &data, sizeof(data)); + if (err == 0) + vrtc->bbat_vchg_min_millivolts = le32_to_cpu(data.val) / 1000U; + + data.reg = cpu_to_le32(RTC_BBAT_CHG_VOLTS_MAX); + data.val = cpu_to_le32(0); + err = rpi_firmware_property(vrtc->fw, RPI_FIRMWARE_GET_RTC_REG, + &data, sizeof(data)); + if (err == 0) + vrtc->bbat_vchg_max_millivolts = le32_to_cpu(data.val) / 1000U; +} + +static int rpi_rtc_set_charge_voltage(struct device *dev) +{ + struct rpi_rtc_data *vrtc = dev_get_drvdata(dev); + struct rpi_rtc_reg data = { + .reg = cpu_to_le32(RTC_BBAT_CHG_VOLTS), + .val = cpu_to_le32(vrtc->bbat_vchg_millivolts * 1000U) + }; + int err; + + if (vrtc->bbat_vchg_millivolts != 0 && + (vrtc->bbat_vchg_millivolts < vrtc->bbat_vchg_min_millivolts || + vrtc->bbat_vchg_millivolts > vrtc->bbat_vchg_max_millivolts)) { + dev_warn(dev, "trickle charge voltage %umV is outside of the supported range (%umV - %umV)\n", + vrtc->bbat_vchg_millivolts, + vrtc->bbat_vchg_min_millivolts, + vrtc->bbat_vchg_max_millivolts); + return -EINVAL; + } + + 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 %umV: %d\n", + vrtc->bbat_vchg_millivolts, err); + else if (vrtc->bbat_vchg_millivolts) + dev_info(dev, "trickle charging enabled at %umV\n", + vrtc->bbat_vchg_millivolts); + + return err; +} + +static int rpi_rtc_probe(struct platform_device *pdev) +{ + struct rpi_rtc_data *vrtc; + struct device *dev = &pdev->dev; + struct rpi_firmware *firmware; + int ret; + + // Get the firmware device from the parent device + firmware = devm_rpi_firmware_get(dev, dev->parent->of_node); + + if (!firmware) + return -EPROBE_DEFER; + + vrtc = devm_kzalloc(dev, sizeof(*vrtc), GFP_KERNEL); + if (!vrtc) + return -ENOMEM; + + vrtc->fw = firmware; + + ret = devm_device_init_wakeup(dev); + if (ret) + return ret; + + platform_set_drvdata(pdev, vrtc); + + vrtc->rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(vrtc->rtc)) + return PTR_ERR(vrtc->rtc); + + vrtc->rtc->range_max = U32_MAX; /* 2106-02-07 */ + + 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; + + rpi_rtc_alarm_clear_pending(dev); + + /* + * The trickle-voltage property lives on the parent firmware node + * because we deliberately do not create a DT child node just to + * instantiate this driver (see DT maintainer guidance). + * The firmware driver registers us as a platform device at runtime. + */ + vrtc->bbat_vchg_millivolts = 0; + of_property_read_u32(dev->parent->of_node, "trickle-voltage-millivolt", + &vrtc->bbat_vchg_millivolts); + + rpi_rtc_set_limits(dev); + 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,firmware-rtc" }, + { } +}; +MODULE_DEVICE_TABLE(of, rpi_rtc_dt_match); + +static struct platform_driver rpi_rtc_driver = { + .driver = { + .name = "raspberrypi-rtc", + .of_match_table = of_match_ptr(rpi_rtc_dt_match), + }, + .probe = rpi_rtc_probe +}; + +module_platform_driver(rpi_rtc_driver); + +MODULE_AUTHOR("Jonathan Bell "); +MODULE_AUTHOR("Sander Speetjens "); +MODULE_DESCRIPTION("Raspberry Pi RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:raspberrypi-rtc"); -- 2.55.0