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Commit ea28fd56 authored by Vineet Gupta's avatar Vineet Gupta Committed by Greg Kroah-Hartman
Browse files

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: default avatarVineet 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: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d6c0d06b

Documentation/devicetree/bindings/tty/serial/arc-uart.txt

0 → 100644
+26 −0
Original line number Diff line number Diff line 
* 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;

};

drivers/tty/serial/arc_uart.c

+40 −3
Original line number Diff line number Diff line
@@ -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 */



	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,

	 },

};