Re: [PATCH v4 3/5] mfd: p3h2x4x: Add driver for NXP P3H2x4x i3c hub and on-die regulator
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2026-01-14 08:28:55
Also in:
linux-i3c, lkml
On Tue, Jan 13, 2026 at 01:45:27PM +0200, Aman Kumar Pandey wrote:
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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.hdiff --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
What?
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+F: drivers/mfd/p3h2840.c +F: include/linux/mfd/p3h2840.h NXP SGTL5000 DRIVER M: Fabio Estevam [off-list ref]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
Do not add at the end of Makefile or Kconfig. P < R if you wanted to order it around here, but probably should be placed much earlier.
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+ obj-$(CONFIG_MFD_UPBOARD_FPGA) += upboard-fpga.o obj-$(CONFIG_MFD_LOONGSON_SE) += loongson-se.odiff --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),
Look here...
+ "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);And here! Drop. This is completely redundant. How is it that in one place you use one syntax and in other place completely different syntax?
+ 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;
Best regards, Krzysztof