1 /*
2  * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  * Redistributions of source code must retain the above copyright notice, this
8  * list of conditions and the following disclaimer.
9  *
10  * Redistributions in binary form must reproduce the above copyright notice,
11  * this list of conditions and the following disclaimer in the documentation
12  * and/or other materials provided with the distribution.
13  *
14  * Neither the name of ARM nor the names of its contributors may be used
15  * to endorse or promote products derived from this software without specific
16  * prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifndef __IO_DRIVER_H__
32 #define __IO_DRIVER_H__
33 
34 #include <io_storage.h>
35 #include <stdint.h>
36 
37 
38 /* Generic IO entity structure,representing an accessible IO construct on the
39  * device, such as a file */
40 typedef struct io_entity {
41 	struct io_dev_info *dev_handle;
42 	uintptr_t info;
43 } io_entity_t;
44 
45 
46 /* Device info structure, providing device-specific functions and a means of
47  * adding driver-specific state */
48 typedef struct io_dev_info {
49 	const struct io_dev_funcs *funcs;
50 	uintptr_t info;
51 } io_dev_info_t;
52 
53 
54 /* Structure used to create a connection to a type of device */
55 typedef struct io_dev_connector {
56 	/* dev_open opens a connection to a particular device driver */
57 	int (*dev_open)(const uintptr_t dev_spec, io_dev_info_t **dev_info);
58 } io_dev_connector_t;
59 
60 
61 /* Structure to hold device driver function pointers */
62 typedef struct io_dev_funcs {
63 	io_type_t (*type)(void);
64 	int (*open)(io_dev_info_t *dev_info, const uintptr_t spec,
65 			io_entity_t *entity);
66 	int (*seek)(io_entity_t *entity, int mode, ssize_t offset);
67 	int (*size)(io_entity_t *entity, size_t *length);
68 	int (*read)(io_entity_t *entity, uintptr_t buffer, size_t length,
69 			size_t *length_read);
70 	int (*write)(io_entity_t *entity, const uintptr_t buffer,
71 			size_t length, size_t *length_written);
72 	int (*close)(io_entity_t *entity);
73 	int (*dev_init)(io_dev_info_t *dev_info, const uintptr_t init_params);
74 	int (*dev_close)(io_dev_info_t *dev_info);
75 } io_dev_funcs_t;
76 
77 
78 /* Operations intended to be performed during platform initialisation */
79 
80 /* Register an IO device */
81 int io_register_device(const io_dev_info_t *dev_info);
82 
83 #endif  /* __IO_DRIVER_H__ */
84