Hello.

John Linn wrote:

The Xilinx 16550 uart core is not a standard 16550 because it uses
word-based addressing rather than byte-based addressing. With
additional properties it is compatible with the open firmware
'ns16550' compatible binding.

This code updates the of_serial driver to handle the reg-offset
and reg-shift properties to enable this core to be used.

Signed-off-by: John Linn <[EMAIL PROTECTED]>
---

diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 2efb892..73c47a5 100644
--- a/drivers/serial/of_serial.c
+++ b/drivers/serial/of_serial.c
@@ -31,7 +31,8 @@ static int __devinit of_platform_serial_setup(struct 
of_device *ofdev,
        struct resource resource;
        struct device_node *np = ofdev->node;
        const unsigned int *clk, *spd;
-       int ret;
+       const u32 *prop;
+       int ret, prop_size;
memset(port, 0, sizeof *port);
        spd = of_get_property(np, "current-speed", NULL);
@@ -49,6 +50,17 @@ static int __devinit of_platform_serial_setup(struct 
of_device *ofdev,
spin_lock_init(&port->lock);
        port->mapbase = resource.start;
+
+       /* Check for shifted address mapping */
+       prop = of_get_property(np, "reg-offset", &prop_size);
+       if (prop && (prop_size == sizeof(u32)))
+               port->mapbase += *prop;

I disagree. That trick leads to I/O resource misaccounting/misreporting. You should teach 8250.c about the offset trick instead, just as it's been taught the shift trick in its time.

+
+       /* Check for registers offset within the devices address range */
+       prop = of_get_property(np, "reg-shift", &prop_size);
+       if (prop && (prop_size == sizeof(u32)))
+               port->regshift = *prop;
+
        port->irq = irq_of_parse_and_map(np, 0);
        port->iotype = UPIO_MEM;
        port->type = type;

WBR, Sergei
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