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authorJohn Linn <john.linn@xilinx.com>2008-04-03 10:22:19 +1100
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2008-04-24 13:32:46 -0500
commitb912b5e2cfb35c02c9c79d3f6e31753f3be4dd83 (patch)
treef9b09696b097dc85cb69d0b28c321cdc92c6afe4
parent2f0b45f846735b486c0383740d3959941c4721a4 (diff)
[POWERPC] Xilinx: of_serial support for Xilinx uart 16550.
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 <john.linn@xilinx.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
-rw-r--r--Documentation/powerpc/booting-without-of.txt11
-rw-r--r--drivers/serial/of_serial.c14
2 files changed, 24 insertions, 1 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 4cc780024e6..cf89e8cfd5b 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -2601,6 +2601,17 @@ platforms are moved over to use the flattened-device-tree model.
differ between different families. May be
'virtex2p', 'virtex4', or 'virtex5'.
+ vi) Xilinx Uart 16550
+
+ Xilinx UART 16550 devices are very similar to the NS16550 but with
+ different register spacing and an offset from the base address.
+
+ Requred properties:
+ - clock-frequency : Frequency of the clock input
+ - reg-offset : A value of 3 is required
+ - reg-shift : A value of 2 is required
+
+
p) Freescale Synchronous Serial Interface
The SSI is a serial device that communicates with audio codecs. It can
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 8aacfb78dea..25029c7570b 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;
+
+ /* 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;