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serial/arc-uart: switch to devicetree based probing 

* 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@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vineet Gupta 2013-01-11 11:50:23 +05:30 committed by Greg Kroah-Hartman
parent d6c0d06b34
commit ea28fd56fc
2 changed files with 66 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
Documentation/devicetree/bindings/tty/serial/arc-uart.txt Normal file
View File

@ -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;
};

43
drivers/tty/serial/arc_uart.c
View File

@ -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,
},
};