1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2013 Ganbold Tsagaankhuu <ganbold@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29/* CPU configuration module for Allwinner A20 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <sys/malloc.h>
37#include <sys/rman.h>
38#include <sys/timeet.h>
39#include <sys/timetc.h>
40#include <sys/watchdog.h>
41#include <machine/bus.h>
42#include <machine/cpu.h>
43#include <machine/intr.h>
44
45#include <dev/ofw/openfirm.h>
46#include <dev/ofw/ofw_bus.h>
47#include <dev/ofw/ofw_bus_subr.h>
48
49#include <machine/bus.h>
50
51#include "a20_cpu_cfg.h"
52
53struct a20_cpu_cfg_softc {
54	struct resource 	*res;
55	bus_space_tag_t 	bst;
56	bus_space_handle_t	bsh;
57};
58
59static struct a20_cpu_cfg_softc *a20_cpu_cfg_sc = NULL;
60
61#define cpu_cfg_read_4(sc, reg) 	\
62	bus_space_read_4((sc)->bst, (sc)->bsh, (reg))
63#define cpu_cfg_write_4(sc, reg, val)	\
64	bus_space_write_4((sc)->bst, (sc)->bsh, (reg), (val))
65
66static int
67a20_cpu_cfg_probe(device_t dev)
68{
69
70	if (!ofw_bus_status_okay(dev))
71		return (ENXIO);
72
73	if (ofw_bus_is_compatible(dev, "allwinner,sun7i-cpu-cfg")) {
74		device_set_desc(dev, "A20 CPU Configuration Module");
75		return(BUS_PROBE_DEFAULT);
76	}
77
78	return (ENXIO);
79}
80
81static int
82a20_cpu_cfg_attach(device_t dev)
83{
84	struct a20_cpu_cfg_softc *sc = device_get_softc(dev);
85	int rid = 0;
86
87	if (a20_cpu_cfg_sc)
88		return (ENXIO);
89
90	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
91	if (!sc->res) {
92		device_printf(dev, "could not allocate resource\n");
93		return (ENXIO);
94	}
95
96	sc->bst = rman_get_bustag(sc->res);
97	sc->bsh = rman_get_bushandle(sc->res);
98
99	a20_cpu_cfg_sc = sc;
100
101	return (0);
102}
103
104static device_method_t a20_cpu_cfg_methods[] = {
105	DEVMETHOD(device_probe, 	a20_cpu_cfg_probe),
106	DEVMETHOD(device_attach,	a20_cpu_cfg_attach),
107	{ 0, 0 }
108};
109
110static driver_t a20_cpu_cfg_driver = {
111	"a20_cpu_cfg",
112	a20_cpu_cfg_methods,
113	sizeof(struct a20_cpu_cfg_softc),
114};
115
116EARLY_DRIVER_MODULE(a20_cpu_cfg, simplebus, a20_cpu_cfg_driver, 0, 0,
117    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
118
119uint64_t
120a20_read_counter64(void)
121{
122	uint32_t lo, hi;
123
124	/* Latch counter, wait for it to be ready to read. */
125	cpu_cfg_write_4(a20_cpu_cfg_sc, OSC24M_CNT64_CTRL_REG, CNT64_RL_EN);
126	while (cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_CTRL_REG) & CNT64_RL_EN)
127		continue;
128
129	hi = cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_HIGH_REG);
130	lo = cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_LOW_REG);
131
132	return (((uint64_t)hi << 32) | lo);
133}
134