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_H__
32 #define __IO_H__
33 
34 #include <stdint.h>
35 #include <stdio.h> /* For ssize_t */
36 
37 
38 /* Device type which can be used to enable policy decisions about which device
39  * to access */
40 typedef enum {
41 	IO_TYPE_INVALID,
42 	IO_TYPE_SEMIHOSTING,
43 	IO_TYPE_MEMMAP,
44 	IO_TYPE_FIRMWARE_IMAGE_PACKAGE,
45 	IO_TYPE_BLOCK,
46 	IO_TYPE_MAX
47 } io_type_t;
48 
49 
50 /* Modes used when seeking data on a supported device */
51 typedef enum {
52 	IO_SEEK_INVALID,
53 	IO_SEEK_SET,
54 	IO_SEEK_END,
55 	IO_SEEK_CUR,
56 	IO_SEEK_MAX
57 } io_seek_mode_t;
58 
59 
60 /* Connector type, providing a means of identifying a device to open */
61 struct io_dev_connector;
62 
63 
64 /* File specification - used to refer to data on a device supporting file-like
65  * entities */
66 typedef struct io_file_spec {
67 	const char *path;
68 	unsigned int mode;
69 } io_file_spec_t;
70 
71 
72 /* Block specification - used to refer to data on a device supporting
73  * block-like entities */
74 typedef struct io_block_spec {
75 	size_t offset;
76 	size_t length;
77 } io_block_spec_t;
78 
79 
80 /* Access modes used when accessing data on a device */
81 #define IO_MODE_INVALID (0)
82 #define IO_MODE_RO	(1 << 0)
83 #define IO_MODE_RW	(1 << 1)
84 
85 
86 /* Return codes reported by 'io_*' APIs */
87 #define IO_SUCCESS		(0)
88 #define IO_FAIL			(-1)
89 #define IO_NOT_SUPPORTED	(-2)
90 #define IO_RESOURCES_EXHAUSTED	(-3)
91 
92 
93 /* Open a connection to a device */
94 int io_dev_open(const struct io_dev_connector *dev_con,
95 		const uintptr_t dev_spec,
96 		uintptr_t *dev_handle);
97 
98 
99 /* Initialise a device explicitly - to permit lazy initialisation or
100  * re-initialisation */
101 int io_dev_init(uintptr_t dev_handle, const uintptr_t init_params);
102 
103 /* TODO: Consider whether an explicit "shutdown" API should be included */
104 
105 /* Close a connection to a device */
106 int io_dev_close(uintptr_t dev_handle);
107 
108 
109 /* Synchronous operations */
110 int io_open(uintptr_t dev_handle, const uintptr_t spec, uintptr_t *handle);
111 
112 int io_seek(uintptr_t handle, io_seek_mode_t mode, ssize_t offset);
113 
114 int io_size(uintptr_t handle, size_t *length);
115 
116 int io_read(uintptr_t handle, uintptr_t buffer, size_t length,
117 		size_t *length_read);
118 
119 int io_write(uintptr_t handle, const uintptr_t buffer, size_t length,
120 		size_t *length_written);
121 
122 int io_close(uintptr_t handle);
123 
124 
125 #endif /* __IO_H__ */
126