Read the reg-io-width property when earlycon is setup via device tree,
and set the I/O type to UPIO_MEM32 when 4 is read. This behaviour
matches that of the of_serial driver, and is needed for DT configured
earlycon on the MIPS Boston board.
Note that this is only possible when CONFIG_LIBFDT is enabled, but
enabling it everywhere seems like overkill. Thus systems that need this
functionality should select CONFIG_LIBFDT for themselves.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
drivers/of/fdt.c | 2 +-
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/earlycon.c | 15 ++++++++++++++-
include/linux/serial_core.h | 2 +-
4 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index d243029..71c7f0d 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -833,7 +833,7 @@ static int __init early_init_dt_scan_chosen_serial(void)
if (addr == OF_BAD_ADDR)
return -ENXIO;
- of_setup_earlycon(addr, match->data);
+ of_setup_earlycon(fdt, offset, addr, match->data);
return 0;
}
return -ENODEV;
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 5ab4111..1d290d6 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SERIAL_21285) += 21285.o
obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
obj-$(CONFIG_SERIAL_EARLYCON_ARM_SEMIHOST) += earlycon-arm-semihost.o
+CFLAGS_earlycon.o += -I$(srctree)/scripts/dtc/libfdt
# These Sparc drivers have to appear before others such as 8250
# which share ttySx minor node space. Otherwise console device
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index f096360..2b936a7 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/libfdt.h>
#include <linux/serial_core.h>
#include <linux/sizes.h>
#include <linux/mod_devicetable.h>
@@ -196,17 +197,29 @@ static int __init param_setup_earlycon(char *buf)
}
early_param("earlycon", param_setup_earlycon);
-int __init of_setup_earlycon(unsigned long addr,
+int __init of_setup_earlycon(const void *fdt, int offset, unsigned long addr,
int (*setup)(struct earlycon_device *, const char *))
{
int err;
struct uart_port *port = &early_console_dev.port;
+ const __be32 *prop;
port->iotype = UPIO_MEM;
port->mapbase = addr;
port->uartclk = BASE_BAUD * 16;
port->membase = earlycon_map(addr, SZ_4K);
+ if (config_enabled(CONFIG_LIBFDT)) {
+ prop = fdt_getprop(fdt, offset, "reg-io-width", NULL);
+ if (prop) {
+ switch (be32_to_cpup(prop)) {
+ case 4:
+ port->iotype = UPIO_MEM32;
+ break;
+ }
+ }
+ }
+
early_console_dev.con->data = &early_console_dev;
err = setup(&early_console_dev, NULL);
if (err < 0)
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 297d4fa..aa375f1 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -345,7 +345,7 @@ struct earlycon_id {
} __aligned(32);
extern int setup_earlycon(char *buf);
-extern int of_setup_earlycon(unsigned long addr,
+extern int of_setup_earlycon(const void *fdt, int offset, unsigned long addr,
int (*setup)(struct earlycon_device *, const char *));
#define EARLYCON_DECLARE(_name, func) \
--
2.6.2
