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authorJames Morrissey <james.morrissey@arm.com>2014-02-10 16:18:59 +0000
committerDan Handley <dan.handley@arm.com>2014-02-17 18:51:43 +0000
commitf2f9bb5e712d3ec1d7dda5a5b52c8f8701a93d99 (patch)
treeaa2befa32f7f5cb5cc377df88fce742b63be0608 /drivers/io
parent40a6f64795847f2b96ec24e9b11cb7002f0b48bf (diff)
downloadtrusted-firmware-a-f2f9bb5e712d3ec1d7dda5a5b52c8f8701a93d99.tar.gz
Add IO abstraction framework
This is intended primarily for use as a storage abstraction. It allows operations such as image-loading to be implemented in a platform-independent fashion. Each platform registers a set of IO drivers during initialisation. The platform must also provide a function that will return a device and a specifier that can be used to access specified content. Clients of the API will primarily use device and entity handles. The term "entity" is deliberately vague, to allow for different representations of content accessed using different types of specifier, but will often be interpreted as a "file" where the specifier will normally be its path. This commit builds, but is intended to be paired with a sample implementation of "load_image" using a semi-hosting driver on FVP. Change-Id: Id3b52f1c0eb9ce76b44b99fc6b6460803668cc86
Diffstat (limited to 'drivers/io')
-rw-r--r--drivers/io/io_driver.h93
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/io/io_driver.h b/drivers/io/io_driver.h
new file mode 100644
index 0000000000..82dbbf129c
--- /dev/null
+++ b/drivers/io/io_driver.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __IO_DRIVER_H__
+#define __IO_DRIVER_H__
+
+#include "platform.h" /* For MAX_IO_DEVICES */
+
+
+/* Generic IO entity structure,representing an accessible IO construct on the
+ * device, such as a file */
+struct io_entity {
+ io_dev_handle dev_handle;
+ uintptr_t info;
+};
+
+
+/* Device info structure, providing device-specific functions and a means of
+ * adding driver-specific state */
+struct io_dev_info {
+ struct io_dev_funcs *funcs;
+ uintptr_t info;
+};
+
+
+/* Structure used to create a connection to a type of device */
+struct io_dev_connector {
+ /* dev_open opens a connection to a particular device driver */
+ int (*dev_open)(void *spec, struct io_dev_info **dev_info);
+};
+
+
+/* Structure to hold device driver function pointers */
+struct io_dev_funcs {
+ io_type (*type)(void);
+ int (*open)(struct io_dev_info *dev_info, const void *spec,
+ struct io_entity *entity);
+ int (*seek)(struct io_entity *entity, int mode, ssize_t offset);
+ int (*size)(struct io_entity *entity, size_t *length);
+ int (*read)(struct io_entity *entity, void *buffer, size_t length,
+ size_t *length_read);
+ int (*write)(struct io_entity *entity, const void *buffer,
+ size_t length, size_t *length_written);
+ int (*close)(struct io_entity *entity);
+ int (*dev_init)(struct io_dev_info *dev_info, const void *init_params);
+ int (*dev_close)(struct io_dev_info *dev_info);
+};
+
+
+/* IO platform data - used to track devices registered for a specific
+ * platform */
+struct io_plat_data {
+ struct io_dev_info *devices[MAX_IO_DEVICES];
+ unsigned int dev_count;
+};
+
+
+/* Operations intended to be performed during platform initialisation */
+
+/* Initialise the IO layer */
+void io_init(struct io_plat_data *data);
+
+/* Register a device driver */
+int io_register_device(struct io_dev_info *dev_info);
+
+#endif /* __IO_DRIVER_H__ */