xref: /freebsd/sys/arm/freescale/imx/imx6_src.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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("$FreeBSD$");
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 
51 struct src_softc {
52 	device_t	dev;
53 	struct resource	*mem_res;
54 };
55 
56 static struct src_softc *src_sc;
57 
58 static inline uint32_t
59 RD4(struct src_softc *sc, bus_size_t off)
60 {
61 
62 	return (bus_read_4(sc->mem_res, off));
63 }
64 
65 static inline void
66 WR4(struct src_softc *sc, bus_size_t off, uint32_t val)
67 {
68 
69 	bus_write_4(sc->mem_res, off, val);
70 }
71 
72 int
73 src_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 
99 static int
100 src_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 
112 static int
113 src_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 
135 out:
136 
137 	if (err != 0)
138 		src_detach(dev);
139 
140 	return (err);
141 }
142 
143 static int
144 src_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 
156 static 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 
165 static driver_t src_driver = {
166 	"src",
167 	src_methods,
168 	sizeof(struct src_softc)
169 };
170 
171 static devclass_t src_devclass;
172 
173 DRIVER_MODULE(src, simplebus, src_driver, src_devclass, 0, 0);
174