FreeBSD/Linux Kernel Cross Reference
sys/arm/ti/ti_scm.c
1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 2010
5 * Ben Gray <ben.r.gray@gmail.com>.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Ben Gray.
19 * 4. The name of the company nor the name of the author may be used to
20 * endorse or promote products derived from this software without specific
21 * prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY BEN GRAY ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL BEN GRAY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 /**
36 * SCM - System Control Module
37 *
38 * Hopefully in the end this module will contain a bunch of utility functions
39 * for configuring and querying the general system control registers, but for
40 * now it only does pin(pad) multiplexing.
41 *
42 * This is different from the GPIO module in that it is used to configure the
43 * pins between modules not just GPIO input/output.
44 *
45 * This file contains the generic top level driver, however it relies on chip
46 * specific settings and therefore expects an array of ti_scm_padconf structs
47 * call ti_padconf_devmap to be located somewhere in the kernel.
48 *
49 */
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
52
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/module.h>
57 #include <sys/bus.h>
58 #include <sys/resource.h>
59 #include <sys/rman.h>
60 #include <sys/lock.h>
61 #include <sys/mutex.h>
62
63 #include <machine/bus.h>
64 #include <machine/resource.h>
65
66 #include <dev/ofw/openfirm.h>
67 #include <dev/ofw/ofw_bus.h>
68 #include <dev/ofw/ofw_bus_subr.h>
69 #include <dev/fdt/fdt_pinctrl.h>
70
71 #include "ti_scm.h"
72 #include "ti_cpuid.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
93 if (!ti_soc_is_supported())
94 return (ENXIO);
95
96 if (!ofw_bus_status_okay(dev))
97 return (ENXIO);
98
99 if (!ofw_bus_is_compatible(dev, "syscon"))
100 return (ENXIO);
101
102 if (ti_scm_sc) {
103 return (EEXIST);
104 }
105
106 device_set_desc(dev, "TI Control Module");
107 return (BUS_PROBE_DEFAULT);
108 }
109
110 /**
111 * ti_scm_attach - attaches the timer to the simplebus
112 * @dev: new device
113 *
114 * Reserves memory and interrupt resources, stores the softc structure
115 * globally and registers both the timecount and eventtimer objects.
116 *
117 * RETURNS
118 * Zero on success or ENXIO if an error occuried.
119 */
120 static int
121 ti_scm_attach(device_t dev)
122 {
123 struct ti_scm_softc *sc = device_get_softc(dev);
124
125 sc->sc_dev = dev;
126
127 if (bus_alloc_resources(dev, ti_scm_res_spec, sc->sc_res)) {
128 device_printf(dev, "could not allocate resources\n");
129 return (ENXIO);
130 }
131
132 /* Global timer interface */
133 sc->sc_bst = rman_get_bustag(sc->sc_res[0]);
134 sc->sc_bsh = rman_get_bushandle(sc->sc_res[0]);
135
136 ti_scm_sc = sc;
137
138 /* Attach platform extensions, if any. */
139 bus_generic_probe(dev);
140
141 return (bus_generic_attach(dev));
142 }
143
144 int
145 ti_scm_reg_read_4(uint32_t reg, uint32_t *val)
146 {
147 if (!ti_scm_sc)
148 return (ENXIO);
149
150 *val = ti_scm_read_4(ti_scm_sc, reg);
151 return (0);
152 }
153
154 int
155 ti_scm_reg_write_4(uint32_t reg, uint32_t val)
156 {
157 if (!ti_scm_sc)
158 return (ENXIO);
159
160 ti_scm_write_4(ti_scm_sc, reg, val);
161 return (0);
162 }
163
164
165 static device_method_t ti_scm_methods[] = {
166 DEVMETHOD(device_probe, ti_scm_probe),
167 DEVMETHOD(device_attach, ti_scm_attach),
168
169 { 0, 0 }
170 };
171
172 static driver_t ti_scm_driver = {
173 "ti_scm",
174 ti_scm_methods,
175 sizeof(struct ti_scm_softc),
176 };
177
178 static devclass_t ti_scm_devclass;
179
180 EARLY_DRIVER_MODULE(ti_scm, simplebus, ti_scm_driver, ti_scm_devclass, 0, 0,
181 BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
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