[PATCH v6 04/12] mfd: zx297520v3: Add a clock and reset MFD driver.

["Stefan Dösinger" <stefandoesinger@gmail.com>]

This driver registers child devices for the zx297520v3 clock and reset
controllers. The clk-zx297520v3 and reset-zte-zx297520v3 submitted in
the next patches will drive the respective functionalities.

Signed-off-by: Stefan Dösinger <stefandoesinger@gmail.com>

---

Changes v6: Make the ZTE SoC driver section depend on HAS_IOMEM
(Sashiko). The entire MFD section, which contains MFD_CORE, depends on
HAS_IOMEM even with COMPILE_TEST.

Add a NULL ptr check for of_device_get_match_data (Sashiko). While not
uniform, rave-sp, rohm-bd9576, atc260x, da9052-i2c protect against
incorrect manual attachment that way.

Add lspclk here as well in an attempt to satisfy both Conor Dooley, who
asks for MFD for top and matrix, and Philipp Zabel, who prefers aux but
or at least use only one type.

Changes v5: Use MFD instead of Aux bus for top and matrix crm because of
extra functionality: Reboot in top, hwlock in Matrix.

LSP clocks stay with the aux bus and are thus not handled in this
driver. The clk driver will bind directly to the lspcrm node.
---
 MAINTAINERS                      |  1 +
 drivers/soc/Kconfig              |  1 +
 drivers/soc/Makefile             |  1 +
 drivers/soc/zte/Kconfig          | 20 +++++++++
 drivers/soc/zte/Makefile         |  3 ++
 drivers/soc/zte/zx297520v3-crm.c | 95 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 121 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index ceedfa359d47..6502d343fe44 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3882,6 +3882,7 @@ F:	Documentation/devicetree/bindings/clock/zte,zx297520v3-lspcrm.yaml
 F:	Documentation/devicetree/bindings/soc/zte/
 F:	arch/arm/boot/dts/zte/
 F:	arch/arm/mach-zte/
+F:	drivers/soc/zte/
 F:	include/dt-bindings/clock/zte,zx297520v3-clk.h
 F:	include/dt-bindings/reset/zte,zx297520v3-reset.h
 
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index a2d65adffb80..5cc1ade4ce52 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -31,5 +31,6 @@ source "drivers/soc/ux500/Kconfig"
 source "drivers/soc/versatile/Kconfig"
 source "drivers/soc/vt8500/Kconfig"
 source "drivers/soc/xilinx/Kconfig"
+source "drivers/soc/zte/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index c9e689080ceb..63b3f340256c 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_ARCH_U8500)	+= ux500/
 obj-y				+= versatile/
 obj-y				+= vt8500/
 obj-y				+= xilinx/
+obj-y				+= zte/
diff --git a/drivers/soc/zte/Kconfig b/drivers/soc/zte/Kconfig
new file mode 100644
index 000000000000..0e954e6ce2a9
--- /dev/null
+++ b/drivers/soc/zte/Kconfig
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if HAS_IOMEM && (ARCH_ZTE || COMPILE_TEST)
+
+menu "ZTE SoC drivers"
+
+config ZTE_ZX297520V3_CRM
+	tristate "ZTE zx297520v3 Clock and Reset Manager"
+	select MFD_CORE
+	default SOC_ZX297520V3
+	help
+	  Say yes here to enable the driver for the ZTE zx297520v3 clock and
+	  reset manager MFD driver. This driver provides the host device for
+	  the clock and reset drivers and is required to boot the SoC. You
+	  will also need to enable CLK_ZTE_ZX297520V3 and RESET_ZTE_ZX297520V3
+	  to build the actual clock and reset submodule drivers.
+
+endmenu
+
+endif
diff --git a/drivers/soc/zte/Makefile b/drivers/soc/zte/Makefile
new file mode 100644
index 000000000000..090ba8aa06c1
--- /dev/null
+++ b/drivers/soc/zte/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_ZTE_ZX297520V3_CRM) += zx297520v3-crm.o
diff --git a/drivers/soc/zte/zx297520v3-crm.c b/drivers/soc/zte/zx297520v3-crm.c
new file mode 100644
index 000000000000..9d0790b9350b
--- /dev/null
+++ b/drivers/soc/zte/zx297520v3-crm.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 Stefan Dösinger
+ */
+
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/of.h>
+
+struct zx297520v3_crm_data {
+	const struct mfd_cell *cells;
+	unsigned int num_cells;
+};
+
+static const struct mfd_cell zx297520v3_topcrm_devs[] = {
+	{
+		.name = "zx297520v3-topclk",
+	},
+	{
+		.name = "zx297520v3-topreset",
+	},
+	{
+		.name = "syscon-reboot",
+		.of_compatible = "syscon-reboot",
+	},
+};
+
+static const struct zx297520v3_crm_data zx297520v3_topcrm_data = {
+	zx297520v3_topcrm_devs,
+	ARRAY_SIZE(zx297520v3_topcrm_devs),
+};
+
+static const struct mfd_cell zx297520v3_matrixcrm_devs[] = {
+	{
+		.name = "zx297520v3-matrixclk",
+	},
+	{
+		.name = "zx297520v3-matrixreset",
+	},
+	/* A set of hwlock controllers is found here as well, but no driver is implemented yet */
+};
+
+static const struct zx297520v3_crm_data zx297520v3_matrixcrm_data = {
+	zx297520v3_matrixcrm_devs,
+	ARRAY_SIZE(zx297520v3_matrixcrm_devs),
+};
+
+static const struct mfd_cell zx297520v3_lspcrm_devs[] = {
+	{
+		.name = "zx297520v3-lspclk",
+	},
+	{
+		.name = "zx297520v3-lspreset",
+	},
+};
+
+static const struct zx297520v3_crm_data zx297520v3_lspcrm_data = {
+	zx297520v3_lspcrm_devs,
+	ARRAY_SIZE(zx297520v3_lspcrm_devs),
+};
+
+static int zx297520v3_crm_probe(struct platform_device *pdev)
+{
+	const struct zx297520v3_crm_data *data;
+
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -ENODEV;
+
+	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, data->cells,
+				    data->num_cells, NULL, 0, NULL);
+}
+
+static const struct of_device_id of_match_zx297520v3_crm[] = {
+	{ .compatible = "zte,zx297520v3-topcrm", .data = &zx297520v3_topcrm_data },
+	{ .compatible = "zte,zx297520v3-matrixcrm", .data = &zx297520v3_matrixcrm_data },
+	{ .compatible = "zte,zx297520v3-lspcrm", .data = &zx297520v3_lspcrm_data },
+	{ }
+};
+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 MFD host driver");
+MODULE_LICENSE("GPL");

-- 
2.54.0