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      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