Merge tag 'stm32-bus-firewall-for-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32 into soc/drivers

STM32 Firewall bus for v7.1, round 1

Highlights:
----------
Stm32 SoCs embed debug peripherals such as Coresight. These peripherals
can monitor the activity of the cores. Because of that, they can be
used only if some features in the debug configuration are enabled.
Else, errors or firewall exceptions can be observed. Similarly to
the ETZPC(on stm32mp1x platforms) or the RIFSC(on stm32mp2x platforms),
debug-related peripherals access can be assessed at bus level to
prevent these issues from happening.

The debug configuration can only be accessed by the secure world.
That means that a service must be implemented in the secure world for
the kernel to check the firewall configuration. On OpenSTLinux, it is
done through a Debug access PTA in OP-TEE [1].
To represent the debug peripherals present on a dedicated debug bus,
create a debug bus node in the device tree and the associated driver
that will interact with this PTA.

Plus some fixes.

* tag 'stm32-bus-firewall-for-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32:
  pinctrl: stm32: add firewall checks before probing the HDP driver
  drivers: bus: add the stm32 debug bus driver
  bus: stm32_firewall: add stm32_firewall_get_grant_all_access() API
  bus: stm32_firewall: allow check on different firewall controllers
  dt-bindings: bus: document the stm32 debug bus
  dt-bindings: pinctrl: document access-controllers property for stm32 HDP
  dt-bindings: document access-controllers property for coresight peripherals
  bus: rifsc: fix RIF configuration check for peripherals
  bus: rifsc: Replace snprintf("%s") with strscpy
  bus: stm32_firewall: Simplify with scoped for each OF child loop
  bus: firewall: move stm32_firewall header file in include folder

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

18 files changed, 472 insertions, 53 deletions

diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-cti.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-cti.yaml
index 2a91670ccb8cd..949444aba1f8b 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-cti.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-cti.yaml
@@ -128,6 +128,9 @@ properties:
   "#address-cells":
     const: 1
 
+  access-controllers:
+    maxItems: 1
+
 patternProperties:
   '^trig-conns@([0-9]+)$':
     type: object
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
index b74db15e5f8af..b0693cd46d27a 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dynamic-funnel.yaml
@@ -78,6 +78,9 @@ properties:
         description: Output connection to CoreSight Trace bus
         $ref: /schemas/graph.yaml#/properties/port
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-etm.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-etm.yaml
index 71f2e1ed27e5b..10ebbbeadf939 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-etm.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-etm.yaml
@@ -118,6 +118,9 @@ properties:
         description: Output connection from the ETM to CoreSight Trace bus.
         $ref: /schemas/graph.yaml#/properties/port
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - clocks
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-stm.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-stm.yaml
index 378380c3f5aab..f243e76f597f8 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-stm.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-stm.yaml
@@ -73,6 +73,9 @@ properties:
         description: Output connection to the CoreSight Trace bus.
         $ref: /schemas/graph.yaml#/properties/port
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
index 96dd5b5f771a3..9dc096698c657 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml
@@ -128,6 +128,9 @@ properties:
       - const: tracedata
       - const: metadata
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-tpiu.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-tpiu.yaml
index a207f6899e675..29bbc3961fdf4 100644
--- a/Documentation/devicetree/bindings/arm/arm,coresight-tpiu.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-tpiu.yaml
@@ -70,6 +70,9 @@ properties:
         description: Input connection from the CoreSight Trace bus.
         $ref: /schemas/graph.yaml#/properties/port
 
+  access-controllers:
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/Documentation/devicetree/bindings/bus/st,stm32mp131-dbg-bus.yaml b/Documentation/devicetree/bindings/bus/st,stm32mp131-dbg-bus.yaml
new file mode 100644
index 0000000000000..6c74433efbe34
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/st,stm32mp131-dbg-bus.yaml
@@ -0,0 +1,76 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/st,stm32mp131-dbg-bus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STM32 Coresight bus
+
+maintainers:
+  - Gatien Chevallier <gatien.chevallier@foss.st.com>
+
+description:
+  The STM32 debug bus is in charge of checking the debug configuration
+  of the platform before probing the peripheral drivers that rely on the debug
+  domain.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - st,stm32mp131-dbg-bus
+          - st,stm32mp151-dbg-bus
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+  ranges:
+    minItems: 1
+    maxItems: 2
+
+  "#access-controller-cells":
+    const: 1
+    description:
+      Contains the debug profile necessary to access the peripheral.
+
+patternProperties:
+  "@[0-9a-f]+$":
+    description: Debug related peripherals
+    type: object
+
+    additionalProperties: true
+
+    required:
+      - access-controllers
+
+required:
+  - "#access-controller-cells"
+  - "#address-cells"
+  - "#size-cells"
+  - compatible
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/stm32mp1-clks.h>
+
+    dbg_bus: bus@50080000 {
+      compatible = "st,stm32mp131-dbg-bus";
+      #address-cells = <1>;
+      #size-cells = <1>;
+      #access-controller-cells = <1>;
+      ranges = <0x50080000 0x50080000 0x3f80000>;
+
+      cti@50094000 {
+        compatible = "arm,coresight-cti", "arm,primecell";
+        reg = <0x50094000 0x1000>;
+        clocks = <&rcc CK_DBG>;
+        clock-names = "apb_pclk";
+        access-controllers = <&dbg_bus 0>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-hdp.yaml b/Documentation/devicetree/bindings/pinctrl/st,stm32-hdp.yaml
index 845b6b7b7552f..8f8b4b68aaa31 100644
--- a/Documentation/devicetree/bindings/pinctrl/st,stm32-hdp.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-hdp.yaml
@@ -27,6 +27,12 @@ properties:
   clocks:
     maxItems: 1
 
+  access-controllers:
+    minItems: 1
+    items:
+      - description: debug configuration access controller
+      - description: access controller that manages the HDP as a peripheral
+
 patternProperties:
   "^hdp[0-7]-pins$":
     type: object
diff --git a/MAINTAINERS b/MAINTAINERS
index 55af015174a54..63f59748d661a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25009,6 +25009,7 @@ F:	drivers/hwmon/pmbus/stef48h28.c
 ST STM32 FIREWALL
 M:	Gatien Chevallier <gatien.chevallier@foss.st.com>
 S:	Maintained
+F:	drivers/bus/stm32_dbg_bus.c
 F:	drivers/bus/stm32_etzpc.c
 F:	drivers/bus/stm32_firewall.c
 F:	drivers/bus/stm32_rifsc.c
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 2a1b46f07080b..7a1b04007efb7 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -169,6 +169,16 @@ config QCOM_SSC_BLOCK_BUS
 	  i2c/spi/uart controllers, a hexagon core, and a clock controller
 	  which provides clocks for the above.
 
+config STM32_DBG_BUS
+	tristate "OP-TEE based debug access bus"
+	depends on OPTEE && STM32_FIREWALL
+	depends on ARCH_STM32 || COMPILE_TEST
+	help
+	  Select this to get the support for the OP-TEE based STM32 debug bus
+	  driver that is used to handle debug-related peripherals on STM32
+	  platforms when the debug configuration is not accessible by the
+	  normal world.
+
 config STM32_FIREWALL
 	bool "STM32 Firewall framework"
 	depends on (ARCH_STM32 || COMPILE_TEST) && OF
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 8e693fe8a03a5..799724cfc2dfc 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_OMAP_INTERCONNECT)	+= omap_l3_smx.o omap_l3_noc.o
 obj-$(CONFIG_OMAP_OCP2SCP)	+= omap-ocp2scp.o
 obj-$(CONFIG_QCOM_EBI2)		+= qcom-ebi2.o
 obj-$(CONFIG_QCOM_SSC_BLOCK_BUS)	+= qcom-ssc-block-bus.o
+obj-$(CONFIG_STM32_DBG_BUS)	+= stm32_dbg_bus.o
 obj-$(CONFIG_STM32_FIREWALL)	+= stm32_firewall.o stm32_rifsc.o stm32_etzpc.o
 obj-$(CONFIG_SUN50I_DE2_BUS)	+= sun50i-de2.o
 obj-$(CONFIG_SUNXI_RSB)		+= sunxi-rsb.o
diff --git a/drivers/bus/stm32_dbg_bus.c b/drivers/bus/stm32_dbg_bus.c
new file mode 100644
index 0000000000000..e30ef3465609e
--- /dev/null
+++ b/drivers/bus/stm32_dbg_bus.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026, STMicroelectronics - All Rights Reserved
+ */
+
+#include <linux/bus/stm32_firewall.h>
+#include <linux/bus/stm32_firewall_device.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/tee_drv.h>
+#include <linux/types.h>
+
+enum stm32_dbg_profile {
+	PERIPHERAL_DBG_PROFILE	= 0,
+	HDP_DBG_PROFILE		= 1,
+};
+
+enum stm32_dbg_pta_command {
+	/*
+	 * PTA_CMD_GRANT_DBG_ACCESS - Verify the debug configuration against the given debug profile
+	 * and grant access or not
+	 *
+	 * [in]     value[0].a  Debug profile to grant access to.
+	 */
+	PTA_CMD_GRANT_DBG_ACCESS,
+};
+
+/**
+ * struct stm32_dbg_bus - OP-TEE based STM32 debug bus private data
+ * @dev: STM32 debug bus device.
+ * @ctx: OP-TEE context handler.
+ */
+struct stm32_dbg_bus {
+	struct device *dev;
+	struct tee_context *ctx;
+};
+
+/* Expect at most 1 instance of this driver */
+static struct stm32_dbg_bus *stm32_dbg_bus_priv;
+
+static int stm32_dbg_pta_open_session(u32 *id)
+{
+	struct tee_client_device *dbg_bus_dev = to_tee_client_device(stm32_dbg_bus_priv->dev);
+	struct tee_ioctl_open_session_arg sess_arg;
+	int ret;
+
+	memset(&sess_arg, 0, sizeof(sess_arg));
+	export_uuid(sess_arg.uuid, &dbg_bus_dev->id.uuid);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+	ret = tee_client_open_session(stm32_dbg_bus_priv->ctx, &sess_arg, NULL);
+	if (ret < 0 || sess_arg.ret) {
+		dev_err(stm32_dbg_bus_priv->dev, "Failed opening tee session, err: %#x\n",
+			sess_arg.ret);
+		return -EOPNOTSUPP;
+	}
+
+	*id = sess_arg.session;
+
+	return 0;
+}
+
+static void stm32_dbg_pta_close_session(u32 id)
+{
+	tee_client_close_session(stm32_dbg_bus_priv->ctx, id);
+}
+
+static int stm32_dbg_bus_grant_access(struct stm32_firewall_controller *ctrl, u32 dbg_profile)
+{
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[1] = {0};
+	u32 session_id;
+	int ret;
+
+	if (dbg_profile != PERIPHERAL_DBG_PROFILE && dbg_profile != HDP_DBG_PROFILE)
+		return -EOPNOTSUPP;
+
+	ret = stm32_dbg_pta_open_session(&session_id);
+	if (ret)
+		return ret;
+
+	inv_arg.func = PTA_CMD_GRANT_DBG_ACCESS;
+	inv_arg.session = session_id;
+	inv_arg.num_params = 1;
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = dbg_profile;
+
+	ret = tee_client_invoke_func(stm32_dbg_bus_priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0) {
+		dev_dbg(stm32_dbg_bus_priv->dev,
+			"When invoking function, err %x, TEE returns: %x\n", ret, inv_arg.ret);
+		if (!ret)
+			ret = -EACCES;
+	}
+
+	stm32_dbg_pta_close_session(session_id);
+
+	return ret;
+}
+
+/* Implement mandatory release_access ops even if it does nothing*/
+static void stm32_dbg_bus_release_access(struct stm32_firewall_controller *ctrl, u32 dbg_profile)
+{
+}
+
+static int stm32_dbg_bus_plat_probe(struct platform_device *pdev)
+{
+	struct stm32_firewall_controller *dbg_controller;
+	int ret;
+
+	/* Defer if OP-TEE service is not yet available */
+	if (!stm32_dbg_bus_priv)
+		return -EPROBE_DEFER;
+
+	dbg_controller = devm_kzalloc(&pdev->dev, sizeof(*dbg_controller), GFP_KERNEL);
+	if (!dbg_controller)
+		return dev_err_probe(&pdev->dev, -ENOMEM, "Couldn't allocate debug controller\n");
+
+	dbg_controller->dev = &pdev->dev;
+	dbg_controller->mmio = NULL;
+	dbg_controller->name = dev_driver_string(dbg_controller->dev);
+	dbg_controller->type = STM32_PERIPHERAL_FIREWALL;
+	dbg_controller->grant_access = stm32_dbg_bus_grant_access;
+	dbg_controller->release_access = stm32_dbg_bus_release_access;
+
+	ret = stm32_firewall_controller_register(dbg_controller);
+	if (ret) {
+		dev_err(dbg_controller->dev, "Couldn't register as a firewall controller: %d", ret);
+		return ret;
+	}
+
+	ret = stm32_firewall_populate_bus(dbg_controller);
+	if (ret) {
+		dev_err(dbg_controller->dev, "Couldn't populate debug bus: %d", ret);
+		stm32_firewall_controller_unregister(dbg_controller);
+		return ret;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+	if (ret) {
+		dev_err(dbg_controller->dev, "Couldn't populate the node: %d", ret);
+		stm32_firewall_controller_unregister(dbg_controller);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id stm32_dbg_bus_of_match[] = {
+	{ .compatible = "st,stm32mp131-dbg-bus", },
+	{ .compatible = "st,stm32mp151-dbg-bus", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, stm32_dbg_bus_of_match);
+
+static struct platform_driver stm32_dbg_bus_driver = {
+	.probe = stm32_dbg_bus_plat_probe,
+	.driver = {
+		.name = "stm32-dbg-bus",
+		.of_match_table = stm32_dbg_bus_of_match,
+	},
+};
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	return (ver->impl_id == TEE_IMPL_ID_OPTEE);
+}
+
+static void stm32_dbg_bus_remove(struct tee_client_device *tee_dev)
+{
+	tee_client_close_context(stm32_dbg_bus_priv->ctx);
+	stm32_dbg_bus_priv = NULL;
+
+	of_platform_depopulate(&tee_dev->dev);
+}
+
+static int stm32_dbg_bus_probe(struct tee_client_device *tee_dev)
+{
+	struct device *dev = &tee_dev->dev;
+	struct stm32_dbg_bus *priv;
+	int ret = 0;
+
+	if (stm32_dbg_bus_priv)
+		return dev_err_probe(dev, -EBUSY,
+				     "A STM32 debug bus device is already initialized\n");
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* Open context with TEE driver */
+	priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
+	if (IS_ERR_OR_NULL(priv->ctx))
+		return dev_err_probe(dev, PTR_ERR_OR_ZERO(priv->ctx), "Cannot open TEE context\n");
+
+	stm32_dbg_bus_priv = priv;
+	stm32_dbg_bus_priv->dev = dev;
+
+	return ret;
+}
+
+static const struct tee_client_device_id optee_dbg_bus_id_table[] = {
+	{UUID_INIT(0xdd05bc8b, 0x9f3b, 0x49f0,
+		   0xb6, 0x49, 0x01, 0xaa, 0x10, 0xc1, 0xc2, 0x10)},
+	{}
+};
+
+static struct tee_client_driver stm32_optee_dbg_bus_driver = {
+	.id_table = optee_dbg_bus_id_table,
+	.probe = stm32_dbg_bus_probe,
+	.remove = stm32_dbg_bus_remove,
+	.driver = {
+		.name = "optee_dbg_bus",
+	},
+};
+
+static void __exit stm32_optee_dbg_bus_driver_exit(void)
+{
+	platform_driver_unregister(&stm32_dbg_bus_driver);
+	tee_client_driver_unregister(&stm32_optee_dbg_bus_driver);
+}
+module_exit(stm32_optee_dbg_bus_driver_exit);
+
+static int __init stm32_optee_dbg_bus_driver_init(void)
+{
+	int err;
+
+	err = tee_client_driver_register(&stm32_optee_dbg_bus_driver);
+	if (err)
+		return err;
+
+	err = platform_driver_register(&stm32_dbg_bus_driver);
+	if (err)
+		tee_client_driver_unregister(&stm32_optee_dbg_bus_driver);
+
+	return err;
+}
+module_init(stm32_optee_dbg_bus_driver_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gatien Chevallier <gatien.chevallier@foss.st.com>");
+MODULE_DESCRIPTION("OP-TEE based STM32 debug access bus driver");
diff --git a/drivers/bus/stm32_etzpc.c b/drivers/bus/stm32_etzpc.c
index 7fc0f16960be3..4918a14e507ef 100644
--- a/drivers/bus/stm32_etzpc.c
+++ b/drivers/bus/stm32_etzpc.c
@@ -5,6 +5,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/bus/stm32_firewall.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -16,8 +17,6 @@
 #include <linux/platform_device.h>
 #include <linux/types.h>
 
-#include "stm32_firewall.h"
-
 /*
  * ETZPC registers
  */
diff --git a/drivers/bus/stm32_firewall.c b/drivers/bus/stm32_firewall.c
index 7e7afe8007dbc..e3619dba8b069 100644
--- a/drivers/bus/stm32_firewall.c
+++ b/drivers/bus/stm32_firewall.c
@@ -5,6 +5,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/bus/stm32_firewall.h>
 #include <linux/bus/stm32_firewall_device.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -18,8 +19,6 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 
-#include "stm32_firewall.h"
-
 /* Corresponds to STM32_FIREWALL_MAX_EXTRA_ARGS + firewall ID */
 #define STM32_FIREWALL_MAX_ARGS		(STM32_FIREWALL_MAX_EXTRA_ARGS + 1)
 
@@ -185,6 +184,48 @@ void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 su
 }
 EXPORT_SYMBOL_GPL(stm32_firewall_release_access_by_id);
 
+int stm32_firewall_get_grant_all_access(struct device *dev, struct stm32_firewall **firewall,
+					int *nb_firewall)
+{
+	struct stm32_firewall *loc_firewall;
+	int err;
+	int i;
+
+	*nb_firewall = of_count_phandle_with_args(dev->of_node, "access-controllers",
+						  "#access-controller-cells");
+	if (*nb_firewall < 0)
+		return *nb_firewall;
+
+	if (!*nb_firewall) {
+		*firewall = NULL;
+		return 0;
+	}
+
+	loc_firewall = devm_kcalloc(dev, *nb_firewall, sizeof(*loc_firewall), GFP_KERNEL);
+	if (!loc_firewall)
+		return -ENOMEM;
+
+	/* Get stm32 firewall information */
+	err = stm32_firewall_get_firewall(dev->of_node, loc_firewall, *nb_firewall);
+	if (err)
+		return err;
+
+	for (i = 0; i < *nb_firewall; i++) {
+		err = stm32_firewall_grant_access(&loc_firewall[i]);
+		if (err) {
+			while (i--)
+				stm32_firewall_release_access(&loc_firewall[i]);
+
+			return err;
+		}
+	}
+
+	*firewall = loc_firewall;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_firewall_get_grant_all_access);
+
 /* Firewall controller API */
 
 int stm32_firewall_controller_register(struct stm32_firewall_controller *firewall_controller)
@@ -241,7 +282,6 @@ EXPORT_SYMBOL_GPL(stm32_firewall_controller_unregister);
 int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_controller)
 {
 	struct stm32_firewall *firewalls;
-	struct device_node *child;
 	struct device *parent;
 	unsigned int i;
 	int len;
@@ -251,30 +291,25 @@ int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_contr
 
 	dev_dbg(parent, "Populating %s system bus\n", dev_name(firewall_controller->dev));
 
-	for_each_available_child_of_node(dev_of_node(parent), child) {
+	for_each_available_child_of_node_scoped(dev_of_node(parent), child) {
 		/* The access-controllers property is mandatory for firewall bus devices */
 		len = of_count_phandle_with_args(child, "access-controllers",
 						 "#access-controller-cells");
-		if (len <= 0) {
-			of_node_put(child);
+		if (len <= 0)
 			return -EINVAL;
-		}
 
 		firewalls = kzalloc_objs(*firewalls, len);
-		if (!firewalls) {
-			of_node_put(child);
+		if (!firewalls)
 			return -ENOMEM;
-		}
 
 		err = stm32_firewall_get_firewall(child, firewalls, (unsigned int)len);
 		if (err) {
 			kfree(firewalls);
-			of_node_put(child);
 			return err;
 		}
 
 		for (i = 0; i < len; i++) {
-			if (firewall_controller->grant_access(firewall_controller,
+			if (firewall_controller->grant_access(firewalls[i].firewall_ctrl,
 							      firewalls[i].firewall_id)) {
 				/*
 				 * Peripheral access not allowed or not defined.
diff --git a/drivers/bus/stm32_rifsc.c b/drivers/bus/stm32_rifsc.c
index debeaf8ea1bd2..19d10379dcefb 100644
--- a/drivers/bus/stm32_rifsc.c
+++ b/drivers/bus/stm32_rifsc.c
@@ -5,6 +5,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bits.h>
+#include <linux/bus/stm32_firewall.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -15,10 +16,9 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/string.h>
 #include <linux/types.h>
 
-#include "stm32_firewall.h"
-
 /*
  * RIFSC offset register
  */
@@ -450,7 +450,7 @@ static void stm32_rifsc_fill_rimu_dbg_entry(struct rifsc_dbg_private *rifsc,
 	const struct stm32_rifsc_resources_names *dbg_names = rifsc->res_names;
 	u32 rimc_attr = readl_relaxed(rifsc->mmio + RIFSC_RIMC_ATTR0 + 0x4 * i);
 
-	snprintf(dbg_entry->m_name, sizeof(dbg_entry->m_name), "%s", dbg_names->initiator_names[i]);
+	strscpy(dbg_entry->m_name, dbg_names->initiator_names[i]);
 	dbg_entry->m_cid = FIELD_GET(RIFSC_RIMC_MCID_MASK, rimc_attr);
 	dbg_entry->cidsel = rimc_attr & RIFSC_RIMC_CIDSEL;
 	dbg_entry->m_sec = rimc_attr & RIFSC_RIMC_MSEC;
@@ -469,8 +469,7 @@ static void stm32_rifsc_fill_dev_dbg_entry(struct rifsc_dbg_private *rifsc,
 	sec_cfgr = readl_relaxed(rifsc->mmio + RIFSC_RISC_SECCFGR0 + 0x4 * reg_id);
 	priv_cfgr = readl_relaxed(rifsc->mmio + RIFSC_RISC_PRIVCFGR0 + 0x4 * reg_id);
 
-	snprintf(dbg_entry->dev_name, sizeof(dbg_entry->dev_name), "%s",
-		 dbg_names->device_names[i]);
+	strscpy(dbg_entry->dev_name, dbg_names->device_names[i]);
 	dbg_entry->dev_id = i;
 	dbg_entry->dev_cid_filt_en = cid_cfgr & CIDCFGR_CFEN;
 	dbg_entry->dev_sem_en = cid_cfgr & CIDCFGR_SEMEN;
@@ -688,34 +687,6 @@ static int stm32_rifsc_grant_access(struct stm32_firewall_controller *ctrl, u32
 	sec_reg_value = readl(rifsc_controller->mmio + RIFSC_RISC_SECCFGR0 + 0x4 * reg_id);
 	cid_reg_value = readl(rifsc_controller->mmio + RIFSC_RISC_PER0_CIDCFGR + 0x8 * firewall_id);
 
-	/* First check conditions for semaphore mode, which doesn't take into account static CID. */
-	if ((cid_reg_value & CIDCFGR_SEMEN) && (cid_reg_value & CIDCFGR_CFEN)) {
-		if (cid_reg_value & BIT(RIF_CID1 + SEMWL_SHIFT)) {
-			/* Static CID is irrelevant if semaphore mode */
-			goto skip_cid_check;
-		} else {
-			dev_dbg(rifsc_controller->dev,
-				"Invalid bus semaphore configuration: index %d\n", firewall_id);
-			return -EACCES;
-		}
-	}
-
-	/*
-	 * Skip CID check if CID filtering isn't enabled or filtering is enabled on CID0, which
-	 * corresponds to whatever CID.
-	 */
-	if (!(cid_reg_value & CIDCFGR_CFEN) ||
-	    FIELD_GET(RIFSC_RISC_SCID_MASK, cid_reg_value) == RIF_CID0)
-		goto skip_cid_check;
-
-	/* Coherency check with the CID configuration */
-	if (FIELD_GET(RIFSC_RISC_SCID_MASK, cid_reg_value) != RIF_CID1) {
-		dev_dbg(rifsc_controller->dev, "Invalid CID configuration for peripheral: %d\n",
-			firewall_id);
-		return -EACCES;
-	}
-
-skip_cid_check:
 	/* Check security configuration */
 	if (sec_reg_value & BIT(reg_offset)) {
 		dev_dbg(rifsc_controller->dev,
@@ -723,19 +694,31 @@ skip_cid_check:
 		return -EACCES;
 	}
 
-	/*
-	 * If the peripheral is in semaphore mode, take the semaphore so that
-	 * the CID1 has the ownership.
-	 */
-	if ((cid_reg_value & CIDCFGR_SEMEN) && (cid_reg_value & CIDCFGR_CFEN)) {
+	/* Skip CID check if CID filtering isn't enabled */
+	if (!(cid_reg_value & CIDCFGR_CFEN))
+		goto skip_cid_check;
+
+	/* First check conditions for semaphore mode, which doesn't take into account static CID. */
+	if (cid_reg_value & CIDCFGR_SEMEN) {
+		if (!(cid_reg_value & BIT(RIF_CID1 + SEMWL_SHIFT))) {
+			dev_dbg(rifsc_controller->dev,
+				"Invalid bus semaphore configuration: index %d\n", firewall_id);
+			return -EACCES;
+		}
+
 		rc = stm32_rif_acquire_semaphore(rifsc_controller, firewall_id);
 		if (rc) {
-			dev_err(rifsc_controller->dev,
+			dev_dbg(rifsc_controller->dev,
 				"Couldn't acquire semaphore for peripheral: %d\n", firewall_id);
 			return rc;
 		}
+	} else if (FIELD_GET(RIFSC_RISC_SCID_MASK, cid_reg_value) != RIF_CID1) {
+		dev_dbg(rifsc_controller->dev, "Invalid CID configuration for peripheral: %d\n",
+			firewall_id);
+		return -EACCES;
 	}
 
+skip_cid_check:
 	return 0;
 }
 
diff --git a/drivers/pinctrl/stm32/pinctrl-stm32-hdp.c b/drivers/pinctrl/stm32/pinctrl-stm32-hdp.c
index 0b1dff01e04c1..cce477e86ef90 100644
--- a/drivers/pinctrl/stm32/pinctrl-stm32-hdp.c
+++ b/drivers/pinctrl/stm32/pinctrl-stm32-hdp.c
@@ -4,6 +4,7 @@
  * Author: Clément Le Goffic <clement.legoffic@foss.st.com> for STMicroelectronics.
  */
 #include <linux/bits.h>
+#include <linux/bus/stm32_firewall_device.h>
 #include <linux/clk.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/generic.h>
@@ -46,9 +47,11 @@ struct stm32_hdp {
 	void __iomem *base;
 	struct clk *clk;
 	struct pinctrl_dev *pctl_dev;
+	struct stm32_firewall *firewall;
 	struct gpio_generic_chip gpio_chip;
 	u32 mux_conf;
 	u32 gposet_conf;
+	int nb_firewall_entries;
 	const char * const *func_name;
 };
 
@@ -615,6 +618,13 @@ static int stm32_hdp_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	hdp->dev = dev;
 
+	if (IS_ENABLED(CONFIG_STM32_FIREWALL)) {
+		err = stm32_firewall_get_grant_all_access(dev, &hdp->firewall,
+							  &hdp->nb_firewall_entries);
+		if (err)
+			return err;
+	}
+
 	platform_set_drvdata(pdev, hdp);
 
 	hdp->base = devm_platform_ioremap_resource(pdev, 0);
@@ -670,8 +680,12 @@ static int stm32_hdp_probe(struct platform_device *pdev)
 static void stm32_hdp_remove(struct platform_device *pdev)
 {
 	struct stm32_hdp *hdp = platform_get_drvdata(pdev);
+	int i;
 
 	writel_relaxed(HDP_CTRL_DISABLE, hdp->base + HDP_CTRL);
+
+	for (i = 0; i < hdp->nb_firewall_entries; i++)
+		stm32_firewall_release_access(&hdp->firewall[i]);
 }
 
 static int stm32_hdp_suspend(struct device *dev)
diff --git a/drivers/bus/stm32_firewall.h b/include/linux/bus/stm32_firewall.h
index e5fac85fe3460..e5fac85fe3460 100644
--- a/drivers/bus/stm32_firewall.h
+++ b/include/linux/bus/stm32_firewall.h
diff --git a/include/linux/bus/stm32_firewall_device.h b/include/linux/bus/stm32_firewall_device.h
index eaa7a3f544507..6c878f3ca86f2 100644
--- a/include/linux/bus/stm32_firewall_device.h
+++ b/include/linux/bus/stm32_firewall_device.h
@@ -112,6 +112,25 @@ int stm32_firewall_grant_access_by_id(struct stm32_firewall *firewall, u32 subsy
  */
 void stm32_firewall_release_access_by_id(struct stm32_firewall *firewall, u32 subsystem_id);
 
+/**
+ * stm32_firewall_get_grant_all_access - Allocate and get all the firewall(s) associated to given
+ *					 device. Then, try to grant access rights for each element.
+ *					 This function is basically a helper function that wraps
+ *					 both stm32_firewall_get_firewall() and
+ *					 stm32_firewall_grant_access() on all firewall references of
+ *					 a device along with the allocation of the array.
+ *					 Realease access using stm32_firewall_release_access* APIs
+ *					 when done.
+ *
+ * @dev:			Device performing the checks
+ * @firewall:			Pointer to the array of firewall references to be allocated
+ * @nb_firewall:		Number of allocated elements in @firewall
+ *
+ * Returns 0 on success, or appropriate errno code if error occurred.
+ */
+int stm32_firewall_get_grant_all_access(struct device *dev, struct stm32_firewall **firewall,
+					int *nb_firewall);
+
 #else /* CONFIG_STM32_FIREWALL */
 
 static inline int stm32_firewall_get_firewall(struct device_node *np,
@@ -141,5 +160,12 @@ static inline void stm32_firewall_release_access_by_id(struct stm32_firewall *fi
 {
 }
 
+static inline int stm32_firewall_get_grant_all_access(struct device *dev,
+						      struct stm32_firewall **firewall,
+						      int *nb_firewall)
+{
+	return -ENODEV;
+}
+
 #endif /* CONFIG_STM32_FIREWALL */
 #endif /* STM32_FIREWALL_DEVICE_H */