From nobody Mon Feb 9 18:43:38 2026 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (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 472693C199C; Tue, 3 Feb 2026 16:21:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770135705; cv=none; b=EiDgfkNByPf6NFI4M8nFUaIUaNY7PXNxQ2RWPhEPB4Pv8BlHwkySHOoZqWC1qYk7+10rpBJs8s5ueKjiIJVxp6UZ9sI6uYb6gcRjys+2qhPSoAbe35pn+anHsmplwc3bFTHLJDzynXQvTB1Dl44RK0jshne0nuesDw4/nr5UPrM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770135705; c=relaxed/simple; bh=YLJOuvpWZfrp0dIHbGdNR9H/BLU+eWxUoMWIYPVsD8Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=r6oV6C+u2oHlvhJWUe9YuNzHjI/vGQpo3JAau/X/Y8APqS9RuYqSb7t3Ph5xJqUcgxJtv89U+o8RaIQpfkQBnSByS7h+lf8qAElOZjKp767nnwtDNvj/+ey3LcStLeS7H0DcQuBrZUutdc3IljLyL+y1EWypMbCE5RrWrA4xMe0= 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=uxO9zjj8; arc=none smtp.client-ip=185.171.202.116 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="uxO9zjj8" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id C240FC24381; Tue, 3 Feb 2026 16:21:46 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 82EDB60728; Tue, 3 Feb 2026 16:21:41 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 7C8D1119A88EE; Tue, 3 Feb 2026 17:21:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1770135700; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=9pGgY1AXtB3+/bquNYu0YC11KDwnMcvuAwORygeqiBw=; b=uxO9zjj8jMKiToMR0RtzEMAGbfLVKejGFCB745ACtXJcDUoIHsk5rsTgizaWP87oBCvKkg P7dB0pswzHJ1W5QBmgQPDysnNGa/zr0Uf91W+/InwpufEqKWLHnoOi9smMLeF1n49Qrv2M tBbNZ+r1ZyUGTEm9qoZ1SNxBYzVulPIZYUyhR9rLoAj/RLC5+oCEFTg2fjHjUjvmvrVtqc aTzq89taMREwrore8krM0fCxXg9Nl2km7Y+IFMCLAXDSmbQ+FfpqDexJOiMU8b/tcNi2h+ Nrrh9YRGzveHIsSjk4dGbKcXTI4iwTWlnhO4fUoeTY0GTZMqYU6l//D2cNIIkA== From: "Thomas Perrot (Schneider Electric)" Date: Tue, 03 Feb 2026 17:21:12 +0100 Subject: [PATCH v3 3/5] mfd: aaeon: Add SRG-IMX8P MCU driver Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260203-dev-b4-aaeon-mcu-driver-v3-3-0a19432076ac@bootlin.com> References: <20260203-dev-b4-aaeon-mcu-driver-v3-0-0a19432076ac@bootlin.com> In-Reply-To: <20260203-dev-b4-aaeon-mcu-driver-v3-0-0a19432076ac@bootlin.com> To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Linus Walleij , Bartosz Golaszewski , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , =?utf-8?q?J=C3=A9r=C3=A9mie_Dautheribes?= , Wim Van Sebroeck , Guenter Roeck , Lee Jones Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, Thomas Petazzoni , "Thomas Perrot (Schneider Electric)" X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=7217; i=thomas.perrot@bootlin.com; h=from:subject:message-id; bh=YLJOuvpWZfrp0dIHbGdNR9H/BLU+eWxUoMWIYPVsD8Q=; b=owEB7QES/pANAwAKAZ/ACwVx/grtAcsmYgBpgiCH8PeiC/MuCitGeJjLtt0ymvN894AU9vs8y A+qsAhZcZGJAbMEAAEKAB0WIQSHQHfGpqMKIwOoEiGfwAsFcf4K7QUCaYIghwAKCRCfwAsFcf4K 7TdvC/9+XhVjfUkrB3MnoV8QRMPJXFjr7K+MU8oii9i0gy572WMLuruf1xU9jyuA/OPF812etmJ 6WX3F6rWn3kubgfgvSVKVbVLlkake/j6+2xcFAH9w6JLBTwrLd4i3HeQboUdjjfE13BIc7d0IpF GDZtwq0/cZ1WZgX3fV/FWhj2AmWCaCtYAryWFhk7oIOIhLBpntJmGpDK5Ud6GNvmcTNvYD0PyRU vp2PxVMoxld96s87bnW44Mw4LyC+9iHwWRZh22HFoRwgdVgMg6VK7alxKMCm/6T5YtYGb74FoC/ dRmUSHCZr1h6WbJxR6qUDZE3Dkvu63zfQw8iZ4GXvJ8A/iEkEdQ1a4H/WPo5GN/wlF4ipUGQoyv YqNVzm7OFo0jU4S5IBxcT+gzOX6PK3KapMyAl9FrMpcooWTrTZRAMBvZKlQxDQDy+E+edJjR4yU Si+NIpKq7KxePTfy0EHUix77TPpyWhdWR3G8E9b281VImfSEqHAnucv9QiRKsyReAFU90= X-Developer-Key: i=thomas.perrot@bootlin.com; a=openpgp; fpr=874077C6A6A30A2303A812219FC00B0571FE0AED X-Last-TLS-Session-Version: TLSv1.3 Add Multi-Function Device (MFD) driver for the Aaeon SRG-IMX8P embedded controller. This driver provides the core I2C communication interface and registers child devices (GPIO and watchdog controllers). The MCU firmware version is queried during probe and logged for diagnostic purposes. All I2C transactions are serialized using a mutex to ensure proper communication with the microcontroller. Co-developed-by: J=C3=A9r=C3=A9mie Dautheribes (Schneider Electric) Signed-off-by: J=C3=A9r=C3=A9mie Dautheribes (Schneider Electric) Signed-off-by: Thomas Perrot (Schneider Electric) --- MAINTAINERS | 2 + drivers/mfd/Kconfig | 10 +++ drivers/mfd/Makefile | 2 + drivers/mfd/aaeon-mcu.c | 137 ++++++++++++++++++++++++++++++++++++++= ++++ include/linux/mfd/aaeon-mcu.h | 20 ++++++ 5 files changed, 171 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index ea9d55f76f3509c7f6ba6d1bc86ca2e2e71aa954..f91b6a1826d04bef8a0f88221f6= c8e8a3652cd77 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -191,6 +191,8 @@ M: Thomas Perrot R: J=C3=A9r=C3=A9mie Dautheribes S: Maintained F: Documentation/devicetree/bindings/mfd/aaeon,srg-imx8p-mcu.yaml +F: drivers/mfd/aaeon-mcu.c +F: include/linux/mfd/aaeon-mcu.h =20 AAEON UPBOARD FPGA MFD DRIVER M: Thomas Richard diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index aace5766b38aa5e46e32a8a7b42eea238159fbcf..7a1ceedece899faad7a03a1fe7b= 1c91b72253c05 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1574,6 +1574,16 @@ config AB8500_CORE the irq_chip parts for handling the Mixed Signal chip events. This chip embeds various other multimedia functionalities as well. =20 +config MFD_AAEON_MCU + tristate "Aaeon SRG-IMX8P MCU Driver" + depends on I2C || COMPILE_TEST + select MFD_CORE + help + Select this option to enable support for the Aaeon SRG-IMX8P + onboard microcontroller (MCU). This driver provides the core + functionality to communicate with the MCU over I2C. The MCU + provides GPIO and watchdog functionality. + config MFD_DB8500_PRCMU bool "ST-Ericsson DB8500 Power Reset Control Management Unit" depends on UX500_SOC_DB8500 diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index e75e8045c28afae975ac61d282b3b85af5440119..0bc3a10c787c55730131224fc10= 53fe35657dd71 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -304,3 +304,5 @@ obj-$(CONFIG_MFD_RSMU_SPI) +=3D rsmu_spi.o rsmu_core.o obj-$(CONFIG_MFD_UPBOARD_FPGA) +=3D upboard-fpga.o =20 obj-$(CONFIG_MFD_LOONGSON_SE) +=3D loongson-se.o + +obj-$(CONFIG_MFD_AAEON_MCU) +=3D aaeon-mcu.o diff --git a/drivers/mfd/aaeon-mcu.c b/drivers/mfd/aaeon-mcu.c new file mode 100644 index 0000000000000000000000000000000000000000..4f2420668106453549ab42888bb= fd50363bdfc45 --- /dev/null +++ b/drivers/mfd/aaeon-mcu.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Aaeon MCU driver + * + * Copyright (C) 2025 Bootlin + * Author: J=C3=A9r=C3=A9mie Dautheribes + * Author: Thomas Perrot + */ + +#include +#include +#include +#include +#include +#include +#include + +#define AAEON_MCU_FW_VERSION 0x76 + +/** + * struct aaeon_mcu_dev - Internal representation of the Aaeon MCU + * @dev: Pointer to kernel device structure + * @i2c_lock: Mutex to serialize I2C bus access + */ +struct aaeon_mcu_dev { + struct device *dev; + struct mutex i2c_lock; +}; + +static const struct mfd_cell aaeon_mcu_devs[] =3D { + { + .name =3D "aaeon-mcu-wdt", + }, + { + .name =3D "aaeon-mcu-gpio", + }, +}; + +static int aaeon_mcu_read_version(struct device *dev, u8 index, u8 *versio= n) +{ + u8 cmd[3] =3D { AAEON_MCU_FW_VERSION, index, 0x00 }; + + return aaeon_mcu_i2c_xfer(dev, cmd, sizeof(cmd), version, sizeof(*version= )); +} + +static int aaeon_mcu_print_fw_version(struct i2c_client *client) +{ + struct device *dev =3D &client->dev; + u8 major, minor; + int ret; + + ret =3D aaeon_mcu_read_version(dev, 0x00, &major); + if (ret) + return ret; + + ret =3D aaeon_mcu_read_version(dev, 0x01, &minor); + if (ret) + return ret; + + dev_dbg(dev, "firmware version: v%d.%d\n", major, minor); + + return 0; +} + +int aaeon_mcu_i2c_xfer(struct device *dev, + const u8 *cmd, int cmd_len, + u8 *rsp, int rsp_len) +{ + struct i2c_client *client =3D to_i2c_client(dev); + struct aaeon_mcu_dev *mcu =3D i2c_get_clientdata(client); + int ret; + + guard(mutex)(&mcu->i2c_lock); + + ret =3D i2c_master_send(client, cmd, cmd_len); + if (ret < 0) + return ret; + + ret =3D i2c_master_recv(client, rsp, rsp_len); + if (ret < 0) + return ret; + + if (ret !=3D rsp_len) { + dev_err(dev, + "i2c recv count error (expected: %d, actual: %d)\n", + rsp_len, ret); + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(aaeon_mcu_i2c_xfer); + +static int aaeon_mcu_probe(struct i2c_client *client) +{ + struct aaeon_mcu_dev *mcu; + int ret; + + mcu =3D devm_kzalloc(&client->dev, sizeof(*mcu), GFP_KERNEL); + if (!mcu) + return -ENOMEM; + + i2c_set_clientdata(client, mcu); + mcu->dev =3D &client->dev; + + ret =3D devm_mutex_init(&client->dev, &mcu->i2c_lock); + if (ret) + return ret; + + ret =3D aaeon_mcu_print_fw_version(client); + if (ret) { + dev_err(&client->dev, "unable to read firmware version\n"); + return ret; + } + + return devm_mfd_add_devices(mcu->dev, PLATFORM_DEVID_NONE, aaeon_mcu_devs, + ARRAY_SIZE(aaeon_mcu_devs), NULL, 0, NULL); +} + +static const struct of_device_id aaeon_mcu_of_match[] =3D { + { .compatible =3D "aaeon,srg-imx8p-mcu" }, + {}, +}; +MODULE_DEVICE_TABLE(of, aaeon_mcu_of_match); + +static struct i2c_driver aaeon_mcu_driver =3D { + .driver =3D { + .name =3D "aaeon_mcu", + .of_match_table =3D aaeon_mcu_of_match, + }, + .probe =3D aaeon_mcu_probe, +}; +module_i2c_driver(aaeon_mcu_driver); + +MODULE_DESCRIPTION("Aaeon MCU Driver"); +MODULE_AUTHOR("J=C3=A9r=C3=A9mie Dautheribes "); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mfd/aaeon-mcu.h b/include/linux/mfd/aaeon-mcu.h new file mode 100644 index 0000000000000000000000000000000000000000..2e9f5f316f33b70c732faa85057= 6cee596455dab --- /dev/null +++ b/include/linux/mfd/aaeon-mcu.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Aaeon MCU driver definitions + * + * Copyright (C) 2025 Bootlin + * Author: J=C3=A9r=C3=A9mie Dautheribes + * Author: Thomas Perrot + */ + +#ifndef __LINUX_MFD_AAEON_MCU_H +#define __LINUX_MFD_AAEON_MCU_H + +#include +#include + +int aaeon_mcu_i2c_xfer(struct device *dev, + const u8 *cmd, int cmd_len, + u8 *rsp, int rsp_len); + +#endif /* __LINUX_MFD_AAEON_MCU_H */ --=20 2.52.0