1 /*
2  * Copyright (c) 2014-2022, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #ifndef __IO_DRIVER_H__
8 #define __IO_DRIVER_H__
9 
10 #include <io_storage.h>
11 #include <stdint.h>
12 
13 /* Generic IO entity structure,representing an accessible IO construct on the
14  * device, such as a file */
15 typedef struct io_entity {
16     struct io_dev_info *dev_handle;
17     uintptr_t info;
18 } io_entity_t;
19 
20 /* Device info structure, providing device-specific functions and a means of
21  * adding driver-specific state */
22 typedef struct io_dev_info {
23     const struct io_dev_funcs *funcs;
24     uintptr_t info;
25 } io_dev_info_t;
26 
27 /* Structure used to create a connection to a type of device */
28 typedef struct io_dev_connector {
29     /* dev_open opens a connection to a particular device driver */
30     int (*dev_open)(const uintptr_t dev_spec, io_dev_info_t **dev_info);
31 } io_dev_connector_t;
32 
33 /* Structure to hold device driver function pointers */
34 typedef struct io_dev_funcs {
35     io_type_t (*type)(void);
36     int (*open)(io_dev_info_t *dev_info, const uintptr_t spec,
37                 io_entity_t *entity);
38     int (*seek)(io_entity_t *entity, int mode, size_t offset);
39     int (*size)(io_entity_t *entity, size_t *length);
40     int (*read)(io_entity_t *entity, uintptr_t buffer, size_t length,
41                 size_t *length_read);
42     int (*write)(io_entity_t *entity, const uintptr_t buffer, size_t length,
43                  size_t *length_written);
44     int (*close)(io_entity_t *entity);
45     int (*dev_init)(io_dev_info_t *dev_info, const uintptr_t init_params);
46     int (*dev_close)(io_dev_info_t *dev_info);
47 } io_dev_funcs_t;
48 
49 /* Operations intended to be performed during platform initialisation */
50 
51 /* Register an IO device */
52 int io_register_device(const io_dev_info_t *dev_info);
53 
54 #endif /* __IO_DRIVER_H__ */
55