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freebsd/sys/arm/xscale/pxa/uart_bus_pxa.c
Stanislav Sedov 208cf1fbc3 - Add new ARM kernel option QEMU_WORKAROUNDS which can be
used in the code which needs to implement some specific
  behaviour when being run under QEMU.
- Make PXA UART probe code to work under QEMU gumstix, which
  doesn't emulate all the ports properly.
2012-04-07 23:47:08 +00:00

104 lines
3.3 KiB
C

/*-
* Copyright (c) 2006 Benno Rice. 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>
#include <dev/pci/pcivar.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_cpu.h>
#include <dev/ic/ns16550.h>
#include <arm/xscale/pxa/pxavar.h>
#include <arm/xscale/pxa/pxareg.h>
#include "uart_if.h"
#define PXA_UART_UUE 0x40 /* UART Unit Enable */
static int uart_pxa_probe(device_t dev);
static device_method_t uart_pxa_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, uart_pxa_probe),
DEVMETHOD(device_attach, uart_bus_attach),
DEVMETHOD(device_detach, uart_bus_detach),
{ 0, 0 }
};
static driver_t uart_pxa_driver = {
uart_driver_name,
uart_pxa_methods,
sizeof(struct uart_softc),
};
static int
uart_pxa_probe(device_t dev)
{
bus_space_handle_t base;
struct uart_softc *sc;
base = (bus_space_handle_t)pxa_get_base(dev);
#ifdef QEMU_WORKAROUNDS
/*
* QEMU really exposes only the first uart unless
* you specify several of them in the configuration.
* Otherwise all the rest of UARTs stay unconnected,
* which causes problems in the ns16550 attach routine.
* Unfortunately, even if you provide qemu with 4 uarts
* on the command line, it has a bug where it segfaults
* trying to enable bluetooth on the HWUART. So we just
* allow the FFUART to be attached.
* Also, don't check the UUE (UART Unit Enable) bit, as
* the gumstix bootloader doesn't set it.
*/
if (base != PXA2X0_FFUART_BASE)
return (ENXIO);
#else
/* Check to see if the enable bit's on. */
if ((bus_space_read_4(obio_tag, base,
(REG_IER << 2)) & PXA_UART_UUE) == 0)
return (ENXIO);
#endif
sc = device_get_softc(dev);
sc->sc_class = &uart_ns8250_class;
return(uart_bus_probe(dev, 2, PXA2X0_COM_FREQ, 0, 0));
}
DRIVER_MODULE(uart, pxa, uart_pxa_driver, uart_devclass, 0, 0);