[PATCH v4 3/5] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
From: Aman Kumar Pandey <hidden>
Date: 2026-01-13 11:45:56
Also in:
linux-i3c, lkml
Subsystem:
multifunction devices (mfd), the rest · Maintainers:
Lee Jones, Linus Torvalds
Add core MFD support for the NXP P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841) family of multiport I3C hub devices. These devices connect to a host via I3C/I2C/SMBus and expose multiple downstream target ports. This patch introduces the MFD driver that registers sub-devices for the I3C hub and on-die regulators. Signed-off-by: Aman Kumar Pandey <redacted> Signed-off-by: Vikash Bansal <redacted> --- Changes in v4: - Split the driver into three separate patches(mfd, regulator and I3C hub) - Added support for NXP P3H2x4x MFD functionality --- --- MAINTAINERS | 4 ++ drivers/mfd/Kconfig | 12 ++++ drivers/mfd/Makefile | 2 + drivers/mfd/p3h2840.c | 128 ++++++++++++++++++++++++++++++++++++ include/linux/mfd/p3h2840.h | 22 +++++++ 5 files changed, 168 insertions(+) create mode 100644 drivers/mfd/p3h2840.c create mode 100644 include/linux/mfd/p3h2840.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 03a66efbcc4c..aa7043499223 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS@@ -18931,6 +18931,10 @@ L: linux-kernel@vger.kernel.org L: linux-i3c-owner@lists.infradead.org S: Maintained F: Documentation/devicetree/bindings/mfd/nxp,p3h2840-i3c-hub.yaml +F: drivers/mfd/Kconfig +F: drivers/mfd/Makefile +F: drivers/mfd/p3h2840.c +F: include/linux/mfd/p3h2840.h NXP SGTL5000 DRIVER M: Fabio Estevam <festevam@gmail.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index aace5766b38a..6c41beb0db88 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig@@ -2540,6 +2540,18 @@ config MFD_RSMU_SPI Additional drivers must be enabled in order to use the functionality of the device. +config MFD_P3H2X4X + tristate "NXP P3H2X4X I3C Hub Device" + depends on I3C + select MFD_CORE + select REGMAP_I3C + help + Enable Support for NXP P3H244x/P3H284x I3C HUB device using I3C/I2c + communication interface. + + This driver provides support for I3C Hub and regulator, additional + drivers must be enabled in order to use the functionality of the device. + config MFD_UPBOARD_FPGA tristate "Support for the AAeon UP board FPGA" depends on (X86 && ACPI)
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e75e8045c28a..223142cdd803 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile@@ -301,6 +301,8 @@ obj-$(CONFIG_MFD_QNAP_MCU) += qnap-mcu.o obj-$(CONFIG_MFD_RSMU_I2C) += rsmu_i2c.o rsmu_core.o obj-$(CONFIG_MFD_RSMU_SPI) += rsmu_spi.o rsmu_core.o +obj-$(CONFIG_MFD_P3H2X4X) += p3h2840.o + obj-$(CONFIG_MFD_UPBOARD_FPGA) += upboard-fpga.o obj-$(CONFIG_MFD_LOONGSON_SE) += loongson-se.o
diff --git a/drivers/mfd/p3h2840.c b/drivers/mfd/p3h2840.c
new file mode 100644
index 000000000000..f6a99291c305
--- /dev/null
+++ b/drivers/mfd/p3h2840.c@@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2025 NXP + * P3H2x4x i3c hub and regulator device. + */ + +#include <linux/i3c/master.h> +#include <linux/i2c.h> +#include <linux/mfd/core.h> +#include <linux/regmap.h> +#include <linux/mfd/p3h2840.h> + +static const struct mfd_cell p3h2x4x_devs[] = { + { + .name = "p3h2x4x-regulator", + }, + { + .name = "p3h2x4x-i3c-hub", + }, +}; + +static const struct regmap_config p3h2x4x_regmap_config = { + .reg_bits = P3H2x4x_REG_BITS, + .val_bits = P3H2x4x_VAL_BITS, + .max_register = 0xFF, +}; + +static int p3h2x4x_device_probe_i3c(struct i3c_device *i3cdev) +{ + struct p3h2x4x_dev *p3h2x4x; + int ret; + + p3h2x4x = devm_kzalloc(&i3cdev->dev, sizeof(*p3h2x4x), GFP_KERNEL); + if (!p3h2x4x) + return -ENOMEM; + + i3cdev_set_drvdata(i3cdev, p3h2x4x); + + p3h2x4x->regmap = devm_regmap_init_i3c(i3cdev, &p3h2x4x_regmap_config); + if (IS_ERR(p3h2x4x->regmap)) { + return dev_err_probe(&i3cdev->dev, PTR_ERR(p3h2x4x->regmap), + "Failed to register I3C HUB regmap\n"); + } + + p3h2x4x->is_p3h2x4x_in_i3c = true; + p3h2x4x->i3cdev = i3cdev; + + ret = devm_mfd_add_devices(&i3cdev->dev, PLATFORM_DEVID_NONE, + p3h2x4x_devs, ARRAY_SIZE(p3h2x4x_devs), + NULL, 0, NULL); + if (ret) + return dev_err_probe(&i3cdev->dev, ret, "Failed to add sub devices\n"); + + return 0; +} + +static int p3h2x4x_device_probe_i2c(struct i2c_client *client) +{ + struct p3h2x4x_dev *p3h2x4x; + int ret; + + p3h2x4x = devm_kzalloc(&client->dev, sizeof(*p3h2x4x), GFP_KERNEL); + if (!p3h2x4x) + return -ENOMEM; + + i2c_set_clientdata(client, p3h2x4x); + + p3h2x4x->regmap = devm_regmap_init_i2c(client, &p3h2x4x_regmap_config); + if (IS_ERR(p3h2x4x->regmap)) { + ret = PTR_ERR(p3h2x4x->regmap); + return dev_err_probe(&client->dev, ret, "Failed to register I3C HUB regmap\n"); + } + + p3h2x4x->is_p3h2x4x_in_i3c = false; + p3h2x4x->i2c_client = client; + + ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE, + p3h2x4x_devs, ARRAY_SIZE(p3h2x4x_devs), + NULL, 0, NULL); + if (ret) + return dev_err_probe(&client->dev, ret, "Failed to add sub devices\n"); + + return 0; +} + +/* p3h2x4x ids (i3c) */ +static const struct i3c_device_id p3h2x4x_i3c_ids[] = { + I3C_CLASS(I3C_DCR_HUB, NULL), + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(i3c, p3h2x4x_i3c_ids); + +/* p3h2x4x ids (i2c) */ +static const struct i2c_device_id p3h2x4x_i2c_id_table[] = { + { "nxp-i3c-hub" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, p3h2x4x_i2c_id_table); + +static const struct of_device_id p3h2x4x_i2c_of_match[] = { + { .compatible = "nxp,p3h2840", }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, p3h2x4x_i2c_of_match); +static struct i3c_driver p3h2x4x_i3c = { + .driver = { + .name = "p3h2x4x_i3c_drv", + }, + .probe = p3h2x4x_device_probe_i3c, + .id_table = p3h2x4x_i3c_ids, +}; + +static struct i2c_driver p3h2x4x_i2c = { + .driver = { + .name = "p3h2x4x_i2c_drv", + .of_match_table = p3h2x4x_i2c_of_match, + }, + .probe = p3h2x4x_device_probe_i2c, + .id_table = p3h2x4x_i2c_id_table, +}; + +module_i3c_i2c_driver(p3h2x4x_i3c, &p3h2x4x_i2c); + +MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>"); +MODULE_AUTHOR("vikash Bansal <vikash.bansal@nxp.com>"); +MODULE_DESCRIPTION("P3H2x4x I3C HUB driver"); +MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/p3h2840.h b/include/linux/mfd/p3h2840.h
new file mode 100644
index 000000000000..3c989426bb4d
--- /dev/null
+++ b/include/linux/mfd/p3h2840.h@@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright 2025 NXP + * This header file contain private Reg address and its bit mapping etc. + */ + +#ifndef P3H2840_H +#define P3H2840_H + +#include <linux/types.h> + +/* Reg config for Regmap */ +#define P3H2x4x_REG_BITS 8 +#define P3H2x4x_VAL_BITS 8 + +struct p3h2x4x_dev { + struct i3c_device *i3cdev; + struct i2c_client *i2c_client; + struct regmap *regmap; + bool is_p3h2x4x_in_i3c; +}; +#endif /* P3H2840_H */
--
2.25.1