uart_bus_pxa.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2006 Benno Rice.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/sys/arm/xscale/pxa/uart_bus_pxa.c 330897 2018-03-14 03:19:51Z eadler $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/conf.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <machine/bus.h>
37#include <sys/rman.h>
38#include <machine/resource.h>
39
40#include <dev/pci/pcivar.h>
41
42#include <dev/uart/uart.h>
43#include <dev/uart/uart_bus.h>
44#include <dev/uart/uart_cpu.h>
45
46#include <dev/ic/ns16550.h>
47
48#include <arm/xscale/pxa/pxavar.h>
49#include <arm/xscale/pxa/pxareg.h>
50
51#include "uart_if.h"
52
53#define	PXA_UART_UUE	0x40	/* UART Unit Enable */
54
55static int uart_pxa_probe(device_t dev);
56
57static device_method_t uart_pxa_methods[] = {
58	/* Device interface */
59	DEVMETHOD(device_probe,		uart_pxa_probe),
60	DEVMETHOD(device_attach,	uart_bus_attach),
61	DEVMETHOD(device_detach,	uart_bus_detach),
62	{ 0, 0 }
63};
64
65static driver_t uart_pxa_driver = {
66	uart_driver_name,
67	uart_pxa_methods,
68	sizeof(struct uart_softc),
69};
70
71static int
72uart_pxa_probe(device_t dev)
73{
74	bus_space_handle_t	base;
75	struct			uart_softc *sc;
76
77	base = (bus_space_handle_t)pxa_get_base(dev);
78#ifdef QEMU_WORKAROUNDS
79	/*
80	 * QEMU really exposes only the first uart unless
81	 * you specify several of them in the configuration.
82	 * Otherwise all the rest of UARTs stay unconnected,
83	 * which causes problems in the ns16550 attach routine.
84	 * Unfortunately, even if you provide qemu with 4 uarts
85	 * on the command line, it has a bug where it segfaults
86	 * trying to enable bluetooth on the HWUART.  So we just
87	 * allow the FFUART to be attached.
88	 * Also, don't check the UUE (UART Unit Enable) bit, as
89	 * the gumstix bootloader doesn't set it.
90	 */
91	if (base != PXA2X0_FFUART_BASE)
92		return (ENXIO);
93#else
94	/* Check to see if the enable bit's on. */
95	if ((bus_space_read_4(obio_tag, base,
96	    (REG_IER << 2)) & PXA_UART_UUE) == 0)
97		return (ENXIO);
98#endif
99	sc = device_get_softc(dev);
100	sc->sc_class = &uart_ns8250_class;
101
102	return(uart_bus_probe(dev, 2, PXA2X0_COM_FREQ, 0, 0));
103}
104
105DRIVER_MODULE(uart, pxa, uart_pxa_driver, uart_devclass, 0, 0);
106