[PATCH v13 04/13] mfd: zx297520v3: Add a clock and reset MFD driver

@@ -2580,5 +2580,17 @@ config MFD_MAX7360
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_ZTE_ZX297520V3_CRM
+	tristate "ZTE zx297520v3 Clock and Reset Manager"
+	depends on ARCH_ZTE || COMPILE_TEST
+	select MFD_CORE
+	default SOC_ZX297520V3
+	help
+	  Say yes here to enable the driver for the ZTE zx297520v3 clock and
+	  reset manager MFD driver. This driver provides the host device for
+	  the clock and reset drivers and is required to boot the SoC. You
+	  will also need to enable CLK_ZTE_ZX297520V3 and RESET_ZTE_ZX297520V3
+	  to build the actual clock and reset child drivers.
+
 endmenu
 endif

@@ -304,3 +304,5 @@ obj-$(CONFIG_MFD_RSMU_SPI)	+= rsmu_spi.o rsmu_core.o
 obj-$(CONFIG_MFD_UPBOARD_FPGA)	+= upboard-fpga.o
 
 obj-$(CONFIG_MFD_LOONGSON_SE)	+= loongson-se.o
+
+obj-$(CONFIG_MFD_ZTE_ZX297520V3_CRM)	+= zte-zx297520v3-crm.o

@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 Stefan Dösinger
+ *
+ * This driver splits the ZTE zx297520v3 SoC's clock and reset management devices into MFD child
+ * nodes that are managed by independent drivers in their respective subsystems.
+ *
+ * ZTE's downstream kernel names the mmio regions "topcrm", "matrixcrm" and "lspcrm". For an
+ * explanation of how the controllers relate please see the DT binding documentation found in
+ * Documentation/devicetree/bindings/clock/zte,zx297520v3-*yaml.
+ *
+ * The controllers are primarily clock controllers, but they all have reset controls as well. Top
+ * and Matrix controllers have further auxiliary functions.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/reset.h>
+
+enum zx_device_type {
+	TYPE_INVALID = 0,
+	TYPE_TOPCRM,
+	TYPE_MATRIXCRM,
+	TYPE_LSPCRM,
+};
+
+static const struct mfd_cell zx297520v3_topcrm_cells[] = {
+	MFD_CELL_NAME("zx297520v3-topclk"),
+	MFD_CELL_NAME("zx297520v3-topreset"),
+	MFD_CELL_OF("reboot", NULL, NULL, 0, 0, "syscon-reboot"),
+	MFD_CELL_NAME("zx297520v3-usb-phy"),
+};
+
+static const struct mfd_cell zx297520v3_matrixcrm_cells[] = {
+	MFD_CELL_NAME("zx297520v3-matrixclk"),
+	MFD_CELL_NAME("zx297520v3-matrixreset"),
+};
+
+static const struct mfd_cell zx297520v3_lspcrm_cells[] = {
+	MFD_CELL_NAME("zx297520v3-lspclk"),
+	MFD_CELL_NAME("zx297520v3-lspreset"),
+};
+
+static int zx297520v3_crm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct mfd_cell *cells;
+	struct reset_control *reset;
+	enum zx_device_type type;
+	unsigned int num_cells;
+	struct clk *pclk;
+
+	type = (enum zx_device_type)(kernel_ulong_t)device_get_match_data(dev);
+	switch (type) {
+	case TYPE_TOPCRM:
+		cells = zx297520v3_topcrm_cells;
+		num_cells = ARRAY_SIZE(zx297520v3_topcrm_cells);
+		break;
+
+	case TYPE_MATRIXCRM:
+		cells = zx297520v3_matrixcrm_cells;
+		num_cells = ARRAY_SIZE(zx297520v3_matrixcrm_cells);
+		break;
+
+	case TYPE_LSPCRM:
+		cells = zx297520v3_lspcrm_cells;
+		num_cells = ARRAY_SIZE(zx297520v3_lspcrm_cells);
+
+		pclk = devm_clk_get_enabled(dev, "pclk");
+		if (IS_ERR(pclk))
+			return dev_err_probe(dev, PTR_ERR(pclk), "Could not get 'pclk'\n");
+
+		reset = devm_reset_control_get_exclusive_deasserted(dev, NULL);
+		if (IS_ERR(reset))
+			return dev_err_probe(dev, PTR_ERR(reset),
+					     "Failed to deassert reset control\n");
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, num_cells, NULL, 0, NULL);
+}
+
+static const struct of_device_id of_match_zx297520v3_crm[] = {
+	{ .compatible = "zte,zx297520v3-topcrm", .data = (void *)TYPE_TOPCRM },
+	{ .compatible = "zte,zx297520v3-matrixcrm", .data = (void *)TYPE_MATRIXCRM },
+	{ .compatible = "zte,zx297520v3-lspcrm", .data = (void *)TYPE_LSPCRM },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, of_match_zx297520v3_crm);
+
+static struct platform_driver zx297520v3_crm = {
+	.probe = zx297520v3_crm_probe,
+	.driver = {
+		.name = "zx297520v3-crm",
+		.of_match_table = of_match_zx297520v3_crm,
+	},
+};
+module_platform_driver(zx297520v3_crm);
+
+MODULE_AUTHOR("Stefan Dösinger <stefandoesinger@gmail.com>");
+MODULE_DESCRIPTION("ZTE zx297520v3 CRM driver");
+MODULE_LICENSE("GPL");