xref: /freebsd/sys/arm/ti/ti_scm.c (revision 11b249f99e4d4891bd2a21ef796d40073ee15508)
1 /*
2  * Copyright (c) 2010
3  *	Ben Gray <ben.r.gray@gmail.com>.
4  * 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  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by Ben Gray.
17  * 4. The name of the company nor the name of the author may be used to
18  *    endorse or promote products derived from this software without specific
19  *    prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY BEN GRAY ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL BEN GRAY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
27  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
30  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /**
34  *	SCM - System Control Module
35  *
36  *	Hopefully in the end this module will contain a bunch of utility functions
37  *	for configuring and querying the general system control registers, but for
38  *	now it only does pin(pad) multiplexing.
39  *
40  *	This is different from the GPIO module in that it is used to configure the
41  *	pins between modules not just GPIO input/output.
42  *
43  *	This file contains the generic top level driver, however it relies on chip
44  *	specific settings and therefore expects an array of ti_scm_padconf structs
45  *	call ti_padconf_devmap to be located somewhere in the kernel.
46  *
47  */
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/kernel.h>
54 #include <sys/module.h>
55 #include <sys/bus.h>
56 #include <sys/resource.h>
57 #include <sys/rman.h>
58 #include <sys/lock.h>
59 #include <sys/mutex.h>
60 
61 #include <machine/bus.h>
62 #include <machine/cpu.h>
63 #include <machine/cpufunc.h>
64 #include <machine/resource.h>
65 
66 #include <dev/fdt/fdt_common.h>
67 #include <dev/fdt/fdt_pinctrl.h>
68 #include <dev/ofw/openfirm.h>
69 #include <dev/ofw/ofw_bus.h>
70 #include <dev/ofw/ofw_bus_subr.h>
71 
72 #include "ti_scm.h"
73 
74 static struct resource_spec ti_scm_res_spec[] = {
75 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },	/* Control memory window */
76 	{ -1, 0 }
77 };
78 
79 static struct ti_scm_softc *ti_scm_sc;
80 
81 #define	ti_scm_read_4(sc, reg)		\
82     bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
83 #define	ti_scm_write_4(sc, reg, val)		\
84     bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
85 
86 /*
87  * Device part of OMAP SCM driver
88  */
89 static int
90 ti_scm_probe(device_t dev)
91 {
92 	if (!ofw_bus_status_okay(dev))
93 		return (ENXIO);
94 
95 	if (!ofw_bus_is_compatible(dev, "syscon"))
96 		return (ENXIO);
97 
98 	if (ti_scm_sc) {
99 		return (EEXIST);
100 	}
101 
102 	device_set_desc(dev, "TI Control Module");
103 	return (BUS_PROBE_DEFAULT);
104 }
105 
106 /**
107  *	ti_scm_attach - attaches the timer to the simplebus
108  *	@dev: new device
109  *
110  *	Reserves memory and interrupt resources, stores the softc structure
111  *	globally and registers both the timecount and eventtimer objects.
112  *
113  *	RETURNS
114  *	Zero on sucess or ENXIO if an error occuried.
115  */
116 static int
117 ti_scm_attach(device_t dev)
118 {
119 	struct ti_scm_softc *sc = device_get_softc(dev);
120 
121 	sc->sc_dev = dev;
122 
123 	if (bus_alloc_resources(dev, ti_scm_res_spec, sc->sc_res)) {
124 		device_printf(dev, "could not allocate resources\n");
125 		return (ENXIO);
126 	}
127 
128 	/* Global timer interface */
129 	sc->sc_bst = rman_get_bustag(sc->sc_res[0]);
130 	sc->sc_bsh = rman_get_bushandle(sc->sc_res[0]);
131 
132 	ti_scm_sc = sc;
133 
134 	return (0);
135 }
136 
137 int
138 ti_scm_reg_read_4(uint32_t reg, uint32_t *val)
139 {
140 	if (!ti_scm_sc)
141 		return (ENXIO);
142 
143 	*val = ti_scm_read_4(ti_scm_sc, reg);
144 	return (0);
145 }
146 
147 int
148 ti_scm_reg_write_4(uint32_t reg, uint32_t val)
149 {
150 	if (!ti_scm_sc)
151 		return (ENXIO);
152 
153 	ti_scm_write_4(ti_scm_sc, reg, val);
154 	return (0);
155 }
156 
157 
158 static device_method_t ti_scm_methods[] = {
159 	DEVMETHOD(device_probe,		ti_scm_probe),
160 	DEVMETHOD(device_attach,	ti_scm_attach),
161 
162 	{ 0, 0 }
163 };
164 
165 static driver_t ti_scm_driver = {
166 	"ti_scm",
167 	ti_scm_methods,
168 	sizeof(struct ti_scm_softc),
169 };
170 
171 static devclass_t ti_scm_devclass;
172 
173 DRIVER_MODULE(ti_scm, simplebus, ti_scm_driver, ti_scm_devclass, 0, 0);
174