serial: earlycon: add DT support

This adds the infrastructure to generic earlycon for earlycon setup
using DT. The actual setup is not enabled until a following commit to
add the FDT parsing.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Grant Likely <grant.likely@linaro.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 7a15b5b24c0b..5bbb809ee197 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -294,6 +294,9 @@ struct earlycon_device {
 int setup_earlycon(char *buf, const char *match,
                    int (*setup)(struct earlycon_device *, const char *));
 
+extern int of_setup_earlycon(unsigned long addr,
+                             int (*setup)(struct earlycon_device *, const char *));
+
 #define EARLYCON_DECLARE(name, func) \
 static int __init name ## _setup_earlycon(char *buf) \
 { \
@@ -301,6 +304,9 @@ static int __init name ## _setup_earlycon(char *buf) \
 } \
 early_param("earlycon", name ## _setup_earlycon);
 
+#define OF_EARLYCON_DECLARE(name, compat, fn)                           \
+        _OF_DECLARE(earlycon, name, compat, fn, void *)
+
 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
                                    struct console *c);
 void uart_parse_options(char *options, int *baud, int *parity, int *bits,