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Commit e302cd93 authored by Emilio López's avatar Emilio López Committed by Greg Kroah-Hartman
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serial: 8250_dw: add support for clk api 



This commit implements support for using the clk api; this lets us use
the "clocks" property with device tree, instead of having to use
clock-frequency.

Signed-off-by: default avatarEmilio López <emilio@elopez.com.ar>
Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 38adbc54

drivers/tty/serial/8250/8250_dw.c

+24 −9
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/acpi.h>

#include <linux/clk.h>



#include "8250.h"
@@ -57,6 +58,7 @@ 
struct dw8250_data {

	int		last_lcr;

	int		line;

	struct clk	*clk;

};



static void dw8250_serial_out(struct uart_port *p, int offset, int value)
@@ -136,8 +138,13 @@ static int dw8250_probe_of(struct uart_port *p) 
	if (!of_property_read_u32(np, "reg-shift", &val))

		p->regshift = val;



	/* clock got configured through clk api, all done */

	if (p->uartclk)

		return 0;



	/* try to find out clock frequency from DT as fallback */

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

		dev_err(p->dev, "no clock-frequency property set\n");

		dev_err(p->dev, "clk or clock-frequency not defined\n");

		return -EINVAL;

	}

	p->uartclk = val;
@@ -294,9 +301,20 @@ static int dw8250_probe(struct platform_device *pdev) 
	if (!uart.port.membase)

		return -ENOMEM;



	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	data->clk = devm_clk_get(&pdev->dev, NULL);

	if (!IS_ERR(data->clk)) {

		clk_prepare_enable(data->clk);

		uart.port.uartclk = clk_get_rate(data->clk);

	}



	uart.port.iotype = UPIO_MEM;

	uart.port.serial_in = dw8250_serial_in;

	uart.port.serial_out = dw8250_serial_out;

	uart.port.private_data = data;



	dw8250_setup_port(&uart);
@@ -312,12 +330,6 @@ static int dw8250_probe(struct platform_device *pdev) 
		return -ENODEV;

	}



	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	uart.port.private_data = data;



	data->line = serial8250_register_8250_port(&uart);

	if (data->line < 0)

		return data->line;
@@ -333,6 +345,9 @@ static int dw8250_remove(struct platform_device *pdev) 


	serial8250_unregister_port(data->line);



	if (!IS_ERR(data->clk))

		clk_disable_unprepare(data->clk);



	return 0;

}