of: earlycon: Initialize port fields from DT properties
Read the optional "reg-offset", "reg-shift", "reg-io-width" and endianness
properties and initialize the respective struct uart_port field if found.
NB: These bindings are common to several drivers and the values merely
indicate the default value; the registering earlycon setup() method can
simply override the values if required.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 7509ee34d..7089667 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -19,6 +19,7 @@
#include <linux/io.h>
#include <linux/serial_core.h>
#include <linux/sizes.h>
+#include <linux/of_fdt.h>
#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
@@ -219,10 +220,13 @@
int __init of_setup_earlycon(unsigned long addr,
const struct earlycon_id *match,
+ unsigned long node,
const char *options)
{
int err;
struct uart_port *port = &early_console_dev.port;
+ const __be32 *val;
+ bool big_endian;
spin_lock_init(&port->lock);
port->iotype = UPIO_MEM;
@@ -230,6 +234,33 @@
port->uartclk = BASE_BAUD * 16;
port->membase = earlycon_map(addr, SZ_4K);
+ val = of_get_flat_dt_prop(node, "reg-offset", NULL);
+ if (val)
+ port->mapbase += be32_to_cpu(*val);
+ val = of_get_flat_dt_prop(node, "reg-shift", NULL);
+ if (val)
+ port->regshift = be32_to_cpu(*val);
+ big_endian = of_get_flat_dt_prop(node, "big-endian", NULL) != NULL ||
+ (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+ of_get_flat_dt_prop(node, "native-endian", NULL) != NULL);
+ val = of_get_flat_dt_prop(node, "reg-io-width", NULL);
+ if (val) {
+ switch (be32_to_cpu(*val)) {
+ case 1:
+ port->iotype = UPIO_MEM;
+ break;
+ case 2:
+ port->iotype = UPIO_MEM16;
+ break;
+ case 4:
+ port->iotype = (big_endian) ? UPIO_MEM32BE : UPIO_MEM32;
+ break;
+ default:
+ pr_warn("[%s] unsupported reg-io-width\n", match->name);
+ return -EINVAL;
+ }
+ }
+
if (options) {
strlcpy(early_console_dev.options, options,
sizeof(early_console_dev.options));