When early console are registered via device-tree, currently it is assumed
that the console iotype is UPIO_MEM and the regshift is 0. This is not the
case for all devices and so add support for reading the device-tree
properties "reg-io-width" and "reg-shift" so that the appropriate iotype
and regshift can be specified for a given device.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/of/fdt.c | 26 +++++++++++++++++++++++++-
drivers/tty/serial/earlycon.c | 6 ++++--
include/linux/serial_core.h | 3 ++-
3 files changed, 31 insertions(+), 4 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 655f79db7899..f69406e42631 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -827,7 +827,9 @@ static int __init early_init_dt_scan_chosen_serial(void)
return -ENODEV;
while (match->compatible[0]) {
+ const __be32 *prop;
u64 addr;
+ u8 iotype, regshift;
if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
match++;
@@ -838,7 +840,29 @@ static int __init early_init_dt_scan_chosen_serial(void)
if (addr == OF_BAD_ADDR)
return -ENXIO;
- of_setup_earlycon(addr, match->data);
+ prop = fdt_getprop(fdt, offset, "reg-shift", NULL);
+ regshift = prop ? be32_to_cpup(prop) : 0;
+
+ prop = fdt_getprop(fdt, offset, "reg-io-width", NULL);
+ if (prop) {
+ switch (be32_to_cpup(prop)) {
+ case 1:
+ iotype = UPIO_MEM;
+ break;
+ case 2:
+ iotype = UPIO_MEM16;
+ break;
+ case 4:
+ iotype = UPIO_MEM32;
+ break;
+ default:
+ return -EINVAL;
+ }
+ } else {
+ iotype = UPIO_MEM;
+ }
+
+ of_setup_earlycon(addr, iotype, regshift, match->data);
return 0;
}
return -ENODEV;
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 3f2423690d01..2fd2f19d7091 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -204,17 +204,19 @@ 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(unsigned long addr, unsigned char iotype,
+ unsigned char regshift,
int (*setup)(struct earlycon_device *, const char *))
{
int err;
struct uart_port *port = &early_console_dev.port;
spin_lock_init(&port->lock);
- port->iotype = UPIO_MEM;
+ port->iotype = iotype;
port->mapbase = addr;
port->uartclk = BASE_BAUD * 16;
port->membase = earlycon_map(addr, SZ_4K);
+ port->regshift = regshift;
early_console_dev.con->data = &early_console_dev;
err = setup(&early_console_dev, NULL);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index e03d6ba5e5b4..e0e1c7ef2856 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -346,7 +346,8 @@ struct earlycon_id {
} __aligned(32);
extern int setup_earlycon(char *buf);
-extern int of_setup_earlycon(unsigned long addr,
+extern int of_setup_earlycon(unsigned long addr, unsigned char iotype,
+ unsigned char regshift,
int (*setup)(struct earlycon_device *, const char *));
#define EARLYCON_DECLARE(_name, func) \
--
2.1.4
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