ratp: implement generic command support

The RATP implementation now allows executing generic commands with a
binary interface: binary requests are received and binary responses
are returned.

Each command can define its own RATP request contents (e.g. to specify
command-specific options) as well as its own RATP response contents
(if any data is to be returned).

Each command is associated with a pair of numeric unique request and
response IDs, and for easy reference these IDs are maintained in the
common ratp_bb header. Modules may override generic implemented
commands or include their own new ones (as long as the numeric IDs
introduced are unique).

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 49 insertions, 0 deletions

diff --git a/include/asm-generic/barebox.lds.h b/include/asm-generic/barebox.lds.h
index c8a919b928..74d3ca4a96 100644
--- a/include/asm-generic/barebox.lds.h
+++ b/include/asm-generic/barebox.lds.h
@@ -44,6 +44,8 @@
 
 #define BAREBOX_CMDS	KEEP(*(SORT_BY_NAME(.barebox_cmd*)))
 
+#define BAREBOX_RATP_CMDS	KEEP(*(SORT_BY_NAME(.barebox_ratp_cmd*)))
+
 #define BAREBOX_SYMS	KEEP(*(__usymtab))
 
 #define BAREBOX_MAGICVARS	KEEP(*(SORT_BY_NAME(.barebox_magicvar*)))
diff --git a/include/ratp_bb.h b/include/ratp_bb.h
index f485f7d8ac..75aabed55e 100644
--- a/include/ratp_bb.h
+++ b/include/ratp_bb.h
@@ -1,6 +1,24 @@
 #ifndef __RATP_BB_H
 #define __RATP_BB_H
 
+#include <linux/stringify.h>
+
+#define BB_RATP_TYPE_COMMAND		1
+#define BB_RATP_TYPE_COMMAND_RETURN	2
+#define BB_RATP_TYPE_CONSOLEMSG		3
+#define BB_RATP_TYPE_PING		4
+#define BB_RATP_TYPE_PONG		5
+#define BB_RATP_TYPE_GETENV		6
+#define BB_RATP_TYPE_GETENV_RETURN	7
+#define BB_RATP_TYPE_FS			8
+#define BB_RATP_TYPE_FS_RETURN		9
+
+struct ratp_bb {
+	uint16_t type;
+	uint16_t flags;
+	uint8_t data[];
+};
+
 struct ratp_bb_pkt {
 	unsigned int len;
 	uint8_t data[];
@@ -11,4 +29,33 @@ void barebox_ratp_command_run(void);
 int  barebox_ratp_fs_call(struct ratp_bb_pkt *tx, struct ratp_bb_pkt **rx);
 int  barebox_ratp_fs_mount(const char *path);
 
+/*
+ * RATP commands definition
+ */
+
+struct ratp_command {
+	struct list_head  list;
+	uint16_t          request_id;
+	uint16_t          response_id;
+	int		(*cmd)(const struct ratp_bb *req,
+			       int req_len,
+			       struct ratp_bb **rsp,
+			       int *rsp_len);
+}
+#ifdef __x86_64__
+/* This is required because the linker will put symbols on a 64 bit alignment */
+__attribute__((aligned(64)))
+#endif
+;
+
+#define BAREBOX_RATP_CMD_START(_name)							\
+extern const struct ratp_command __barebox_ratp_cmd_##_name;				\
+const struct ratp_command __barebox_ratp_cmd_##_name					\
+	__attribute__ ((unused,section (".barebox_ratp_cmd_" __stringify(_name)))) = {
+
+#define BAREBOX_RATP_CMD_END								\
+};
+
+int register_ratp_command(struct ratp_command *cmd);
+
 #endif /* __RATP_BB_H */