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Commit 6a7320c4 authored by Heikki Krogerus's avatar Heikki Krogerus Committed by Greg Kroah-Hartman
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serial: 8250_dw: Add ACPI 5.0 support 



This adds support for ACPI 5.0 enumerated Designware UARTs.
ACPI does not deliver information about uart clk, so
delivering it with the driver_data.

Signed-off-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 30046df2

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

+41 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
 * Synopsys DesignWare 8250 driver.

 *

 * Copyright 2011 Picochip, Jamie Iles.

 * Copyright 2013 Intel Corporation

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by
@@ -24,12 +25,16 @@ 
#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/acpi.h>



/* Offsets for the DesignWare specific registers */

#define DW_UART_USR	0x1f /* UART Status Register */

#define DW_UART_CPR	0xf4 /* Component Parameter Register */

#define DW_UART_UCV	0xf8 /* UART Component Version */



/* Intel Low Power Subsystem specific */

#define LPSS_PRV_CLOCK_PARAMS 0x800



/* Component Parameter Register bits */

#define DW_UART_CPR_ABP_DATA_WIDTH	(3 << 0)

#define DW_UART_CPR_AFCE_MODE		(1 << 4)
@@ -138,6 +143,30 @@ static int dw8250_probe_of(struct uart_port *p) 
	return 0;

}



static int dw8250_probe_acpi(struct uart_port *p)

{

	const struct acpi_device_id *id;

	u32 reg;



	id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev);

	if (!id)

		return -ENODEV;



	p->iotype = UPIO_MEM32;

	p->serial_in = dw8250_serial_in32;

	p->serial_out = dw8250_serial_out32;

	p->regshift = 2;

	p->uartclk = (unsigned int)id->driver_data;



	/* Fix Haswell issue where the clocks do not get enabled */

	if (!strcmp(id->id, "INT33C4") || !strcmp(id->id, "INT33C5")) {

		reg = readl(p->membase + LPSS_PRV_CLOCK_PARAMS);

		writel(reg | 1, p->membase + LPSS_PRV_CLOCK_PARAMS);

	}



	return 0;

}



static void dw8250_setup_port(struct uart_8250_port *up)

{

	struct uart_port	*p = &up->port;
@@ -199,6 +228,10 @@ static int dw8250_probe(struct platform_device *pdev) 
		err = dw8250_probe_of(&uart.port);

		if (err)

			return err;

	} else if (ACPI_HANDLE(&pdev->dev)) {

		err = dw8250_probe_acpi(&uart.port);

		if (err)

			return err;

	} else {

		return -ENODEV;

	}
@@ -258,11 +291,19 @@ static const struct of_device_id dw8250_of_match[] = { 
};

MODULE_DEVICE_TABLE(of, dw8250_of_match);



static const struct acpi_device_id dw8250_acpi_match[] = {

	{ "INT33C4", 100000000 },

	{ "INT33C5", 100000000 },

	{ },

};

MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);



static struct platform_driver dw8250_platform_driver = {

	.driver = {

		.name		= "dw-apb-uart",

		.owner		= THIS_MODULE,

		.of_match_table	= dw8250_of_match,

		.acpi_match_table = ACPI_PTR(dw8250_acpi_match),

	},

	.probe			= dw8250_probe,

	.remove			= dw8250_remove,

drivers/tty/serial/8250/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -256,7 +256,7 @@ config SERIAL_8250_FSL 


config SERIAL_8250_DW

	tristate "Support for Synopsys DesignWare 8250 quirks"

	depends on SERIAL_8250 && OF

	depends on SERIAL_8250

	help

	  Selecting this option will enable handling of the extra features

	  present in the Synopsys DesignWare APB UART.