xref: /freebsd/sys/arm/freescale/imx/imx6_src.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
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 /*
29  * System Reset Control for iMX6
30  */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/bus.h>
37 #include <sys/rman.h>
38 
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 
42 #include <machine/bus.h>
43 
44 #include <arm/freescale/imx/imx6_src.h>
45 
46 #define	SRC_SCR		0
47 #define		SW_IPU1_RST	(1 << 3)
48 
49 struct src_softc {
50 	device_t	dev;
51 	struct resource	*mem_res;
52 };
53 
54 static struct src_softc *src_sc;
55 
56 static inline uint32_t
57 RD4(struct src_softc *sc, bus_size_t off)
58 {
59 
60 	return (bus_read_4(sc->mem_res, off));
61 }
62 
63 static inline void
64 WR4(struct src_softc *sc, bus_size_t off, uint32_t val)
65 {
66 
67 	bus_write_4(sc->mem_res, off, val);
68 }
69 
70 int
71 src_reset_ipu(void)
72 {
73 	uint32_t reg;
74 	int timeout = 10000;
75 
76 	if (src_sc == NULL)
77 		return (-1);
78 
79 	reg = RD4(src_sc, SRC_SCR);
80 	reg |= SW_IPU1_RST;
81 	WR4(src_sc, SRC_SCR, reg);
82 
83 	while (timeout-- > 0) {
84 		reg = RD4(src_sc, SRC_SCR);
85 		if (reg & SW_IPU1_RST)
86 			DELAY(1);
87 		else
88 			break;
89 	}
90 
91 	if (timeout < 0)
92 		return (-1);
93 	else
94 		return (0);
95 }
96 
97 static int
98 src_detach(device_t dev)
99 {
100 	struct src_softc *sc;
101 
102 	sc = device_get_softc(dev);
103 
104 	if (sc->mem_res != NULL)
105 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
106 
107 	return (0);
108 }
109 
110 static int
111 src_attach(device_t dev)
112 {
113 	struct src_softc *sc;
114 	int err, rid;
115 
116 	sc = device_get_softc(dev);
117 	err = 0;
118 
119 	/* Allocate bus_space resources. */
120 	rid = 0;
121 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
122 	    RF_ACTIVE);
123 	if (sc->mem_res == NULL) {
124 		device_printf(dev, "Cannot allocate memory resources\n");
125 		err = ENXIO;
126 		goto out;
127 	}
128 
129 	src_sc = sc;
130 
131 	err = 0;
132 
133 out:
134 
135 	if (err != 0)
136 		src_detach(dev);
137 
138 	return (err);
139 }
140 
141 static int
142 src_probe(device_t dev)
143 {
144 
145         if ((ofw_bus_is_compatible(dev, "fsl,imx6q-src") == 0) &&
146             (ofw_bus_is_compatible(dev, "fsl,imx6-src") == 0))
147 		return (ENXIO);
148 
149 	device_set_desc(dev, "Freescale i.MX6 System Reset Controller");
150 
151 	return (BUS_PROBE_DEFAULT);
152 }
153 
154 static device_method_t src_methods[] = {
155 	/* Device interface */
156 	DEVMETHOD(device_probe,  src_probe),
157 	DEVMETHOD(device_attach, src_attach),
158 	DEVMETHOD(device_detach, src_detach),
159 
160 	DEVMETHOD_END
161 };
162 
163 static driver_t src_driver = {
164 	"src",
165 	src_methods,
166 	sizeof(struct src_softc)
167 };
168 
169 DRIVER_MODULE(src, simplebus, src_driver, 0, 0);
170