imx6_src.c revision 314506 
1/*-
2 * Copyright (c) 2015 Oleksandr Tymoshenko <gonzo@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/sys/arm/freescale/imx/imx6_src.c 314506 2017-03-01 19:55:04Z ian $");
29
30/*
31 * System Reset Control for iMX6
32 */
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37#include <sys/module.h>
38#include <sys/bus.h>
39#include <sys/rman.h>
40
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/ofw_bus_subr.h>
43
44#include <machine/bus.h>
45
46#include <arm/freescale/imx/imx6_src.h>
47
48#define	SRC_SCR		0
49#define		SW_IPU1_RST	(1 << 3)
50
51struct src_softc {
52	device_t	dev;
53	struct resource	*mem_res;
54};
55
56static struct src_softc *src_sc;
57
58static inline uint32_t
59RD4(struct src_softc *sc, bus_size_t off)
60{
61
62	return (bus_read_4(sc->mem_res, off));
63}
64
65static inline void
66WR4(struct src_softc *sc, bus_size_t off, uint32_t val)
67{
68
69	bus_write_4(sc->mem_res, off, val);
70}
71
72int
73src_reset_ipu(void)
74{
75	uint32_t reg;
76	int timeout = 10000;
77
78	if (src_sc == NULL)
79		return (-1);
80
81	reg = RD4(src_sc, SRC_SCR);
82	reg |= SW_IPU1_RST;
83	WR4(src_sc, SRC_SCR, reg);
84
85	while (timeout-- > 0) {
86		reg = RD4(src_sc, SRC_SCR);
87		if (reg & SW_IPU1_RST)
88			DELAY(1);
89		else
90			break;
91	}
92
93	if (timeout < 0)
94		return (-1);
95	else
96		return (0);
97}
98
99static int
100src_detach(device_t dev)
101{
102	struct src_softc *sc;
103
104	sc = device_get_softc(dev);
105
106	if (sc->mem_res != NULL)
107		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
108
109	return (0);
110}
111
112static int
113src_attach(device_t dev)
114{
115	struct src_softc *sc;
116	int err, rid;
117
118	sc = device_get_softc(dev);
119	err = 0;
120
121	/* Allocate bus_space resources. */
122	rid = 0;
123	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
124	    RF_ACTIVE);
125	if (sc->mem_res == NULL) {
126		device_printf(dev, "Cannot allocate memory resources\n");
127		err = ENXIO;
128		goto out;
129	}
130
131	src_sc = sc;
132
133	err = 0;
134
135out:
136
137	if (err != 0)
138		src_detach(dev);
139
140	return (err);
141}
142
143static int
144src_probe(device_t dev)
145{
146
147        if ((ofw_bus_is_compatible(dev, "fsl,imx6q-src") == 0) &&
148            (ofw_bus_is_compatible(dev, "fsl,imx6-src") == 0))
149		return (ENXIO);
150
151	device_set_desc(dev, "Freescale i.MX6 System Reset Controller");
152
153	return (BUS_PROBE_DEFAULT);
154}
155
156static device_method_t src_methods[] = {
157	/* Device interface */
158	DEVMETHOD(device_probe,  src_probe),
159	DEVMETHOD(device_attach, src_attach),
160	DEVMETHOD(device_detach, src_detach),
161
162	DEVMETHOD_END
163};
164
165static driver_t src_driver = {
166	"src",
167	src_methods,
168	sizeof(struct src_softc)
169};
170
171static devclass_t src_devclass;
172
173DRIVER_MODULE(src, simplebus, src_driver, src_devclass, 0, 0);
174