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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: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Heikki Krogerus 2013-01-10 11:25:10 +02:00 committed by Greg Kroah-Hartman
parent 30046df261
commit 6a7320c466
2 changed files with 42 additions and 1 deletions
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41
drivers/tty/serial/8250/8250_dw.c
View File

@ -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,

2
drivers/tty/serial/8250/Kconfig
View File

@ -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.