ti_scm.c revision 330897 
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: stable/11/sys/arm/ti/ti_scm.c 330897 2018-03-14 03:19:51Z eadler $");
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/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
74static struct resource_spec ti_scm_res_spec[] = {
75	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },	/* Control memory window */
76	{ -1, 0 }
77};
78
79static 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 */
89static int
90ti_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 success or ENXIO if an error occuried.
115 */
116static int
117ti_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	/* Attach platform extensions, if any. */
135	bus_generic_probe(dev);
136
137	return (bus_generic_attach(dev));
138}
139
140int
141ti_scm_reg_read_4(uint32_t reg, uint32_t *val)
142{
143	if (!ti_scm_sc)
144		return (ENXIO);
145
146	*val = ti_scm_read_4(ti_scm_sc, reg);
147	return (0);
148}
149
150int
151ti_scm_reg_write_4(uint32_t reg, uint32_t val)
152{
153	if (!ti_scm_sc)
154		return (ENXIO);
155
156	ti_scm_write_4(ti_scm_sc, reg, val);
157	return (0);
158}
159
160
161static device_method_t ti_scm_methods[] = {
162	DEVMETHOD(device_probe,		ti_scm_probe),
163	DEVMETHOD(device_attach,	ti_scm_attach),
164
165	{ 0, 0 }
166};
167
168static driver_t ti_scm_driver = {
169	"ti_scm",
170	ti_scm_methods,
171	sizeof(struct ti_scm_softc),
172};
173
174static devclass_t ti_scm_devclass;
175
176EARLY_DRIVER_MODULE(ti_scm, simplebus, ti_scm_driver, ti_scm_devclass, 0, 0,
177    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
178