drivers/bus/stm32_firewall.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
   4  */
   5
   6 #ifndef _STM32_FIREWALL_H
   7 #define _STM32_FIREWALL_H
   8
   9 #include <linux/kernel.h>
  10 #include <linux/list.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/types.h>
  14
  15 /**
  16  * STM32_PERIPHERAL_FIREWALL:           This type of firewall protects peripherals
  17  * STM32_MEMORY_FIREWALL:               This type of firewall protects memories/subsets of memory
  18  *                                      zones
  19  * STM32_NOTYPE_FIREWALL:               Undefined firewall type
  20  */
  21
  22 #define STM32_PERIPHERAL_FIREWALL       BIT(1)
  23 #define STM32_MEMORY_FIREWALL           BIT(2)
  24 #define STM32_NOTYPE_FIREWALL           BIT(3)
  25
  26 /**
  27  * struct stm32_firewall_controller - Information on firewall controller supplying services
  28  *
  29  * @name:                       Name of the firewall controller
  30  * @dev:                        Device reference of the firewall controller
  31  * @mmio:                       Base address of the firewall controller
  32  * @entry:                      List entry of the firewall controller list
  33  * @type:                       Type of firewall
  34  * @max_entries:                Number of entries covered by the firewall
  35  * @grant_access:               Callback used to grant access for a device access against a
  36  *                              firewall controller
  37  * @release_access:             Callback used to release resources taken by a device when access was
  38  *                              granted
  39  * @grant_memory_range_access:  Callback used to grant access for a device to a given memory region
  40  */
  41 struct stm32_firewall_controller {
  42         const char *name;
  43         struct device *dev;
  44         void __iomem *mmio;
  45         struct list_head entry;
  46         unsigned int type;
  47         unsigned int max_entries;
  48
  49         int (*grant_access)(struct stm32_firewall_controller *ctrl, u32 id);
  50         void (*release_access)(struct stm32_firewall_controller *ctrl, u32 id);
  51         int (*grant_memory_range_access)(struct stm32_firewall_controller *ctrl, phys_addr_t paddr,
  52                                          size_t size);
  53 };
  54
  55 /**
  56  * stm32_firewall_controller_register - Register a firewall controller to the STM32 firewall
  57  *                                      framework
  58  * @firewall_controller:        Firewall controller to register
  59  *
  60  * Returns 0 in case of success or -ENODEV if no controller was given.
  61  */
  62 int stm32_firewall_controller_register(struct stm32_firewall_controller *firewall_controller);
  63
  64 /**
  65  * stm32_firewall_controller_unregister - Unregister a firewall controller from the STM32
  66  *                                        firewall framework
  67  * @firewall_controller:        Firewall controller to unregister
  68  */
  69 void stm32_firewall_controller_unregister(struct stm32_firewall_controller *firewall_controller);
  70
  71 /**
  72  * stm32_firewall_populate_bus - Populate device tree nodes that have a correct firewall
  73  *                               configuration. This is used at boot-time only, as a sanity check
  74  *                               between device tree and firewalls hardware configurations to
  75  *                               prevent a kernel crash when a device driver is not granted access
  76  *
  77  * @firewall_controller:        Firewall controller which nodes will be populated or not
  78  *
  79  * Returns 0 in case of success or appropriate errno code if error occurred.
  80  */
  81 int stm32_firewall_populate_bus(struct stm32_firewall_controller *firewall_controller);
  82
  83 #endif /* _STM32_FIREWALL_H */