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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: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Emilio López 2013-03-29 00:15:49 +01:00 committed by Greg Kroah-Hartman
parent 38adbc54ce
commit e302cd9320
1 changed files with 24 additions and 9 deletions
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33
drivers/tty/serial/8250/8250_dw.c
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@ -26,6 +26,7 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/clk.h>
#include "8250.h"
@ -55,8 +56,9 @@
struct dw8250_data {
int last_lcr;
int line;
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;
}