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-rw-r--r--Documentation/devicetree/bindings/tty/serial/of-serial.txt3
-rw-r--r--drivers/tty/serial/of_serial.c17
2 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
index 35e53ae85eec..337a7e51faca 100644
--- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt
+++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
@@ -19,6 +19,9 @@ Optional properties:
- current-speed : the current active speed of the UART.
- reg-offset : offset to apply to the mapbase from the start of the registers.
- reg-shift : quantity to shift the register offsets by.
+- reg-io-width : the size (in bytes) of the IO accesses that should be
+ performed on the device. There are some systems that require 32-bit
+ accesses to the UART (e.g. TI davinci).
- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
RTAS and should not be registered.
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index c911b2419abb..36038ed8f09a 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -65,6 +65,23 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
port->irq = irq_of_parse_and_map(np, 0);
port->iotype = UPIO_MEM;
+ prop = of_get_property(np, "reg-io-width", &prop_size);
+ if (prop && (prop_size == sizeof(u32))) {
+ switch (be32_to_cpup(prop)) {
+ case 1:
+ port->iotype = UPIO_MEM;
+ break;
+ case 4:
+ port->iotype = UPIO_MEM32;
+ break;
+ default:
+ dev_warn(&ofdev->dev,
+ "unsupported io width (%d bytes)\n",
+ be32_to_cpup(prop));
+ return -EINVAL;
+ }
+ }
+
port->type = type;
port->uartclk = be32_to_cpup(clk);
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP