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Commit 0bbeb3c3 authored by Murali Karicheri's avatar Murali Karicheri Committed by Greg Kroah-Hartman
Browse files

of serial port driver - add clk_get_rate() support 



Currently this driver expects the clock-frequency attribute. This
patch allows getting clock-frequency through clk driver API
clk_get_rate() if clock-frequency attribute is not defined.

So in the device bindings for serial device, one can add clocks
phandle to refer to the clk device to get the rate.

Signed-off-by: default avatarMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cadf7486

drivers/tty/serial/of_serial.c

+26 −6
Original line number Diff line number Diff line
@@ -21,8 +21,10 @@ 
#include <linux/of_serial.h>

#include <linux/of_platform.h>

#include <linux/nwpserial.h>

#include <linux/clk.h>



struct of_serial_info {

	struct clk *clk;

	int type;

	int line;

};
@@ -51,7 +53,8 @@ EXPORT_SYMBOL_GPL(tegra_serial_handle_break); 
 * Fill a struct uart_port for a given device node

 */

static int __devinit of_platform_serial_setup(struct platform_device *ofdev,

					int type, struct uart_port *port)

			int type, struct uart_port *port,

			struct of_serial_info *info)

{

	struct resource resource;

	struct device_node *np = ofdev->dev.of_node;
@@ -60,9 +63,18 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev, 


	memset(port, 0, sizeof *port);

	if (of_property_read_u32(np, "clock-frequency", &clk)) {

		dev_warn(&ofdev->dev, "no clock-frequency property set\n");



		/* Get clk rate through clk driver if present */

		info->clk = clk_get(&ofdev->dev, NULL);

		if (info->clk == NULL) {

			dev_warn(&ofdev->dev,

				"clk or clock-frequency not defined\n");

			return -ENODEV;

		}



		clk_prepare_enable(info->clk);

		clk = clk_get_rate(info->clk);

	}

	/* If current-speed was set, then try not to change it. */

	if (of_property_read_u32(np, "current-speed", &spd) == 0)

		port->custom_divisor = clk / (16 * spd);
@@ -70,7 +82,7 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev, 
	ret = of_address_to_resource(np, 0, &resource);

	if (ret) {

		dev_warn(&ofdev->dev, "invalid address\n");

		return ret;

		goto out;

	}



	spin_lock_init(&port->lock);
@@ -97,7 +109,8 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev, 
		default:

			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",

				 prop);

			return -EINVAL;

			ret = -EINVAL;

			goto out;

		}

	}
@@ -115,6 +128,10 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev, 
		port->handle_break = tegra_serial_handle_break;



	return 0;

out:

	if (info->clk)

		clk_disable_unprepare(info->clk);

	return ret;

}



/*
@@ -141,7 +158,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev) 
		return -ENOMEM;



	port_type = (unsigned long)match->data;

	ret = of_platform_serial_setup(ofdev, port_type, &port);

	ret = of_platform_serial_setup(ofdev, port_type, &port, info);

	if (ret)

		goto out;
@@ -204,6 +221,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev) 
		/* need to add code for these */

		break;

	}



	if (info->clk)

		clk_disable_unprepare(info->clk);

	kfree(info);

	return 0;

}