* DT binding for arc-uart
* With alll the bits in place we can now use DT probing.
Note that there's a bit of kludge right now because earlyprintk portion
of driver can't use the DT infrastrcuture to get resoures/plat_data.
This requires some infrastructre changes to of_flat_ framework
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: Rob Landley <rob@xxxxxxxxxxx>
Cc: linux-serial@xxxxxxxxxxxxxxx
---
.../devicetree/bindings/tty/serial/arc-uart.txt | 26 ++++++++++++
drivers/tty/serial/arc_uart.c | 43 ++++++++++++++++++-
2 files changed, 66 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/tty/serial/arc-uart.txt
diff --git a/Documentation/devicetree/bindings/tty/serial/arc-uart.txt b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
new file mode 100644
index 0000000..c3bd8f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/arc-uart.txt
@@ -0,0 +1,26 @@
+* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards
+
+Required properties:
+- compatible : "snps,arc-uart"
+- reg : offset and length of the register set for the device.
+- interrupts : device interrupt
+- clock-frequency : the input clock frequency for the UART
+- baud : baud rate for UART
+
+e.g.
+
+arcuart0: serial@c0fc1000 {
+ compatible = "snps,arc-uart";
+ reg = <0xc0fc1000 0x100>;
+ interrupts = <5>;
+ clock-frequency = <80000000>;
+ baud = <115200>;
+ status = "okay";
+};
+
+Note: Each port should have an alias correctly numbered in "aliases" node.
+
+e.g.
+aliases {
+ serial0 = &arcuart0;
+};
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 2db6410..b468601 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -37,6 +37,8 @@
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
/*************************************
* ARC UART Hardware Specs
@@ -537,8 +539,26 @@ arc_uart_init_one(struct platform_device *pdev, int dev_id)
return -ENODEV;
uart->is_emulated = !!plat_data[0]; /* workaround ISS bug */
- uart->port.uartclk = plat_data[1];
- uart->baud = plat_data[2];
+
+ if (is_early_platform_device(pdev)) {
+ uart->port.uartclk = plat_data[1];
+ uart->baud = plat_data[2];
+ } else {
+ struct device_node *np = pdev->dev.of_node;
+ u32 val;
+
+ if (of_property_read_u32(np, "clock-frequency", &val)) {
+ dev_err(&pdev->dev, "clock-frequency property NOTset\n");
+ return -EINVAL;
+ }
+ uart->port.uartclk = val;
+
+ if (of_property_read_u32(np, "baud", &val)) {
+ dev_err(&pdev->dev, "baud property NOT set\n");
+ return -EINVAL;
+ }
+ uart->baud = val;
+ }
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
@@ -673,8 +693,18 @@ static int __init arc_serial_probe_earlyprintk(struct platform_device *pdev)
static int arc_serial_probe(struct platform_device *pdev)
{
int rc, dev_id;
+ struct device_node *np = pdev->dev.of_node;
+
+ /* no device tree device */
+ if (!np)
+ return -ENODEV;
+
+ dev_id = of_alias_get_id(np, "serial");
+ if (dev_id < 0) {
+ dev_err(&pdev->dev, "failed to get alias id: %d\n", dev_id);
+ return dev_id;
+ }
- dev_id = pdev->id < 0 ? 0 : pdev->id;
rc = arc_uart_init_one(pdev, dev_id);
if (rc)
return rc;
@@ -689,12 +719,19 @@ static int arc_serial_remove(struct platform_device *pdev)
return 0;
}
+static const struct of_device_id arc_uart_dt_ids[] = {
+ { .compatible = "snps,arc-uart" },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, arc_uart_dt_ids);
+
static struct platform_driver arc_platform_driver = {
.probe = arc_serial_probe,
.remove = arc_serial_remove,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
+ .of_match_table = arc_uart_dt_ids,
},
};
--
1.7.4.1
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