bus: firewall: move stm32_firewall header file in include folder

Other driver than RIFSC and ETZPC can implement firewall ops, such as
RCC.
In order for them to have access to the ops and type of this framework,
we need to get the `stm32_firewall.h` file in the include/ folder.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
Acked-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Link: https://lore.kernel.org/r/20260210-b4-firewall-upstream-v8-1-097c1e47af82@gmail.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/include/linux/bus/stm32_firewall.h b/include/linux/bus/stm32_firewall.h
new file mode 100644
index 000000000000..e5fac85fe346
--- /dev/null
+++ b/include/linux/bus/stm32_firewall.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
+ */
+
+#ifndef _STM32_FIREWALL_H
+#define _STM32_FIREWALL_H
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+/**
+ * STM32_PERIPHERAL_FIREWALL:		This type of firewall protects peripherals
+ * STM32_MEMORY_FIREWALL:		This type of firewall protects memories/subsets of memory
+ *					zones
+ * STM32_NOTYPE_FIREWALL:		Undefined firewall type
+ */
+
+#define STM32_PERIPHERAL_FIREWALL	BIT(1)
+#define STM32_MEMORY_FIREWALL		BIT(2)
+#define STM32_NOTYPE_FIREWALL		BIT(3)
+
+/**
+ * struct stm32_firewall_controller - Information on firewall controller supplying services
+ *
+ * @name:			Name of the firewall controller
+ * @dev:			Device reference of the firewall controller
+ * @mmio:			Base address of the firewall controller
+ * @entry:			List entry of the firewall controller list
+ * @type:			Type of firewall
+ * @max_entries:		Number of entries covered by the firewall
+ * @grant_access:		Callback used to grant access for a device access against a
+ *				firewall controller
+ * @release_access:		Callback used to release resources taken by a device when access was
+ *				granted
+ * @grant_memory_range_access:	Callback used to grant access for a device to a given memory region
+ */
+struct stm32_firewall_controller {
+	const char *name;
+	struct device *dev;
+	void __iomem *mmio;
+	struct list_head entry;
+	unsigned int type;
+	unsigned int max_entries;
+
+	int (*grant_access)(struct stm32_firewall_controller *ctrl, u32 id);
+	void (*release_access)(struct stm32_firewall_controller *ctrl, u32 id);
+	int (*grant_memory_range_access)(struct stm32_firewall_controller *ctrl, phys_addr_t paddr,
+					 size_t size);
+};
+
+/**
+ * stm32_firewall_controller_register - Register a firewall controller to the STM32 firewall
+ *					framework
+ * @firewall_controller:	Firewall controller to register
+ *
+ * Returns 0 in case of success or -ENODEV if no controller was given.
+ */
+int stm32_firewall_controller_register(struct stm32_firewall_controller *firewall_controller);
+
+/**
+ * stm32_firewall_controller_unregister - Unregister a firewall controller from the STM32
+ *					  firewall framework
+ * @firewall_controller:	Firewall controller to unregister
+ */
+void stm32_firewall_controller_unregister(struct stm32_firewall_controller *firewall_controller);
+
+/**
+ * stm32_firewall_populate_bus - Populate device tree nodes that have a correct firewall
+ *				 configuration. This is used at boot-time only, as a sanity check
+ *				 between device tree and firewalls hardware configurations to
+ *				 prevent a kernel crash when a device driver is not granted access
+ *
+ * @firewall_controller:	Firewall controller which nodes will be populated or not
+ *
+ * Returns 0 in case of success or appropriate errno code if error occurred.
+ */
+int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_controller);
+
+#endif /* _STM32_FIREWALL_H */