[PATCH 3/6] serial: earlycon: add DT support

Rob Herring
2014-05-08T22:25:29Z

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>
---
drivers/tty/serial/earlycon.c | 27 +++++++++++++++++++++++++++
include/asm-generic/vmlinux.lds.h | 4 +++-
include/linux/serial_core.h | 6 ++++++
3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index c92e830..021fe5f 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -15,6 +15,7 @@
#include <linux/init.h>
#include <linux/io.h>
#include <linux/serial_core.h>
+#include <linux/mod_devicetable.h>

#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
@@ -32,6 +33,9 @@ static struct earlycon_device early_console_dev = {
.con = &early_con,
};

+static const struct of_device_id __earlycon_of_table_sentinel
+ __used __section(__earlycon_of_table_end);
+
static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
{
void __iomem *base;
@@ -142,3 +146,26 @@ int __init setup_earlycon(char *buf, const char *match,
register_console(early_console_dev.con);
return 0;
}
+
+int __init of_setup_earlycon(unsigned long addr,
+ int (*setup)(struct earlycon_device *, const char *))
+{
+ int err;
+ struct uart_port *port = &early_console_dev.port;
+
+ port->iotype = UPIO_MEM;
+ port->mapbase = addr;
+ port->uartclk = BASE_BAUD * 16;
+ port->membase = earlycon_map(addr, SZ_4K);
+
+ early_console_dev.con->data = &early_console_dev;
+ err = setup(&early_console_dev, NULL);
+ if (err < 0)
+ return err;
+ if (!early_console_dev.con->write)
+ return -ENODEV;
+
+
+ register_console(early_console_dev.con);
+ return 0;
+}
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 120ccb9..f5249c4 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -129,6 +129,7 @@
#define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk)
#define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
#define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method)
+#define EARLYCON_OF_TABLES() OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)

#define KERNEL_DTB() \
STRUCT_ALIGN(); \
@@ -458,7 +459,8 @@
CLKSRC_OF_TABLES() \
CPU_METHOD_OF_TABLES() \
KERNEL_DTB() \
- IRQCHIP_OF_MATCH_TABLE()
+ IRQCHIP_OF_MATCH_TABLE() \
+ EARLYCON_OF_TABLES()

#define INIT_TEXT \
*(.init.text) \
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 7a15b5b..5bbb809 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,
--
1.9.1