Added the first steps towards the implementation of the new api.

For this new api, each device will be implemented as a separate backend 
for a common interface. This will make it easier to support multiple 
devices in a single application.

src/Makefile.am

@@ -5,6 +5,7 @@
 libdivecomputerdir = $(includedir)/libdivecomputer
 libdivecomputer_HEADERS = 	\
 	utils.h \
+	device.h \
 	suunto.h \
 	suunto_eon.h \
 	suunto_vyper.h \
@@ -29,6 +30,7 @@ lib_LTLIBRARIES = libdivecomputer.la
 libdivecomputer_la_LDFLAGS = -no-undefined
 
 libdivecomputer_la_SOURCES = \
+	device.h device-private.h device.c \
 	suunto.h \
 	suunto_common.h suunto_common.c \
 	suunto_eon.h suunto_eon.c \

src/device-private.h

@@ -0,0 +1,40 @@
+#ifndef DEVICE_PRIVATE_H
+#define DEVICE_PRIVATE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#include "device.h"
+
+struct device_t;
+struct device_backend_t;
+
+typedef struct device_backend_t device_backend_t;
+
+struct device_t {
+	const device_backend_t *backend;
+};
+
+struct device_backend_t {
+    device_type_t type;
+
+	device_status_t (*handshake) (device_t *device, unsigned char data[], unsigned int size);
+
+	device_status_t (*version) (device_t *device, unsigned char data[], unsigned int size);
+
+	device_status_t (*read) (device_t *device, unsigned int address, unsigned char data[], unsigned int size);
+
+	device_status_t (*write) (device_t *device, unsigned int address, const unsigned char data[], unsigned int size);
+
+	device_status_t (*download) (device_t *device, unsigned char data[], unsigned int size);
+
+	device_status_t (*foreach) (device_t *device, dive_callback_t callback, void *userdata);
+
+	device_status_t (*close) (device_t *device);
+};
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* DEVICE_PRIVATE_H */

src/device.c

@@ -0,0 +1,103 @@
+#include "device-private.h"
+
+#define NULL 0
+
+device_type_t
+device_get_type (device_t *device)
+{
+	if (device == NULL)
+		return DEVICE_TYPE_NULL;
+
+	return device->backend->type;
+}
+
+
+device_status_t
+device_handshake (device_t *device, unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->handshake == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->handshake (device, data, size);
+}
+
+
+device_status_t
+device_version (device_t *device, unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->version == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->version (device, data, size);
+}
+
+
+device_status_t
+device_read (device_t *device, unsigned int address, unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->read == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->read (device, address, data, size);
+}
+
+
+device_status_t
+device_write (device_t *device, unsigned int address, const unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->write == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->write (device, address, data, size);
+}
+
+
+device_status_t
+device_download (device_t *device, unsigned char data[], unsigned int size)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->download == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->download (device, data, size);
+}
+
+
+device_status_t
+device_foreach (device_t *device, dive_callback_t callback, void *userdata)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	if (device->backend->foreach == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->foreach (device, callback, userdata);
+}
+
+
+device_status_t
+device_close (device_t *device)
+{
+	if (device == NULL)
+		return DEVICE_STATUS_SUCCESS;
+
+	if (device->backend->close == NULL)
+		return DEVICE_STATUS_UNSUPPORTED;
+
+	return device->backend->close (device);
+}

src/device.h

@@ -0,0 +1,46 @@
+#ifndef DEVICE_H
+#define DEVICE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef enum device_type_t {
+	DEVICE_TYPE_NULL = 0
+} device_type_t;
+
+typedef enum device_status_t {
+	DEVICE_STATUS_SUCCESS = 0,
+	DEVICE_STATUS_UNSUPPORTED = -1,
+	DEVICE_STATUS_TYPE_MISMATCH = -2,
+	DEVICE_STATUS_ERROR = -3,
+	DEVICE_STATUS_IO = -4,
+	DEVICE_STATUS_TIMEOUT = -5,
+	DEVICE_STATUS_PROTOCOL = -6,
+	DEVICE_STATUS_MEMORY = -7
+} device_status_t;
+
+typedef struct device_t device_t;
+
+typedef void (*dive_callback_t) (const unsigned char *data, unsigned int size, void *userdata);
+
+device_type_t device_get_type (device_t *device);
+
+device_status_t device_handshake (device_t *device, unsigned char data[], unsigned int size);
+
+device_status_t device_version (device_t *device, unsigned char data[], unsigned int size);
+
+device_status_t device_read (device_t *device, unsigned int address, unsigned char data[], unsigned int size);
+
+device_status_t device_write (device_t *device, unsigned int address, const unsigned char data[], unsigned int size);
+
+device_status_t device_download (device_t *device, unsigned char data[], unsigned int size);
+
+device_status_t device_foreach (device_t *device, dive_callback_t callback, void *userdata);
+
+device_status_t device_close (device_t *device);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* DEVICE_H */