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freebsd/sys/dev/uart/uart_cpu_x86.c
Andrew Turner a931b85a09 uart: Add uart_cpu_acpi_setup to setup the uart
In preperation for adding debug port support add a generic function
to setup the uart from ACPI tables.

Reviewed by:	imp
Sponsored by:	Arm Ltd
Differential Revision:	https://reviews.freebsd.org/D44358
2024-03-18 16:20:52 +00:00

122 lines
3.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2003, 2004 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_cpu_acpi.h>
bus_space_tag_t uart_bus_space_io = X86_BUS_SPACE_IO;
bus_space_tag_t uart_bus_space_mem = X86_BUS_SPACE_MEM;
extern int late_console;
int
uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
{
return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
}
int
uart_cpu_getdev(int devtype, struct uart_devinfo *di)
{
struct uart_class *class;
unsigned int i, ivar;
class = &uart_ns8250_class;
if (class == NULL)
return (ENXIO);
/* Check the environment. */
if (uart_getenv(devtype, di, class) == 0)
return (0);
#ifdef DEV_ACPI
/*
* Check if SPCR can tell us what console to use. If running with
* !late_console, we haven't set up our own page tables yet, so we
* can't map ACPI tables to look at them.
*/
if (late_console && uart_cpu_acpi_setup(devtype, di) == 0)
return (0);
#endif
/*
* Scan the hints. We only try units 0 to 3 (inclusive). This
* covers the ISA legacy where 4 UARTs had their resources
* predefined.
*/
for (i = 0; i < 4; i++) {
if (resource_int_value("uart", i, "flags", &ivar))
continue;
if (devtype == UART_DEV_CONSOLE && !UART_FLAGS_CONSOLE(ivar))
continue;
if (devtype == UART_DEV_DBGPORT && !UART_FLAGS_DBGPORT(ivar))
continue;
/*
* We have a possible device. Make sure it's enabled and
* that we have an I/O port.
*/
if (resource_int_value("uart", i, "disabled", &ivar) == 0 &&
ivar != 0)
continue;
if (resource_int_value("uart", i, "port", &ivar) != 0 ||
ivar == 0)
continue;
/*
* Got it. Fill in the instance and return it. We only have
* ns8250 and successors on i386.
*/
di->ops = uart_getops(class);
di->bas.chan = 0;
di->bas.bst = uart_bus_space_io;
if (bus_space_map(di->bas.bst, ivar, uart_getrange(class), 0,
&di->bas.bsh) != 0)
continue;
di->bas.regshft = 0;
di->bas.rclk = 0;
if (resource_int_value("uart", i, "baud", &ivar) != 0)
ivar = 0;
di->baudrate = ivar;
di->databits = 8;
di->stopbits = 1;
di->parity = UART_PARITY_NONE;
return (0);
}
return (ENXIO);
}