1 /* $OpenBSD: exmct.c,v 1.7 2024/05/13 01:15:50 jsg Exp $ */
2 /*
3 * Copyright (c) 2012-2013 Patrick Wildt <patrick@blueri.se>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/device.h>
21
22 #include <arm/cpufunc.h>
23
24 #include <machine/intr.h>
25 #include <machine/bus.h>
26 #include <machine/fdt.h>
27
28 #include <dev/ofw/openfirm.h>
29 #include <dev/ofw/fdt.h>
30
31 /* registers */
32 #define MCT_CTRL 0x240
33 #define MCT_WRITE_STAT 0x24C
34
35 /* bits and bytes */
36 #define MCT_CTRL_START (1 << 8)
37
38 struct exmct_softc {
39 struct device sc_dev;
40 bus_space_tag_t sc_iot;
41 bus_space_handle_t sc_ioh;
42 };
43
44 struct exmct_softc *exmct_sc;
45
46 int exmct_match(struct device *, void *, void *);
47 void exmct_attach(struct device *, struct device *, void *);
48
49 const struct cfattach exmct_ca = {
50 sizeof (struct exmct_softc), exmct_match, exmct_attach
51 };
52
53 struct cfdriver exmct_cd = {
54 NULL, "exmct", DV_DULL
55 };
56
57 int
exmct_match(struct device * parent,void * match,void * aux)58 exmct_match(struct device *parent, void *match, void *aux)
59 {
60 struct fdt_attach_args *faa = aux;
61
62 return OF_is_compatible(faa->fa_node, "samsung,exynos4210-mct");
63 }
64
65 void
exmct_attach(struct device * parent,struct device * self,void * aux)66 exmct_attach(struct device *parent, struct device *self, void *aux)
67 {
68 struct exmct_softc *sc = (struct exmct_softc *)self;
69 struct fdt_attach_args *faa = aux;
70 uint32_t i, mask, reg;
71
72 sc->sc_iot = faa->fa_iot;
73
74 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
75 faa->fa_reg[0].size, 0, &sc->sc_ioh))
76 panic("%s: bus_space_map failed!", __func__);
77
78 printf("\n");
79
80 exmct_sc = sc;
81
82 extern void agtimer_delay(u_int);
83 arm_clock_register(NULL, agtimer_delay, NULL, NULL);
84
85 bus_space_write_4(sc->sc_iot, sc->sc_ioh, MCT_CTRL,
86 bus_space_read_4(sc->sc_iot, sc->sc_ioh, MCT_CTRL) | MCT_CTRL_START);
87
88 mask = (1 << 16);
89
90 /* Wait 10 times until written value is applied */
91 for (i = 0; i < 10; i++) {
92 reg = bus_space_read_4(sc->sc_iot, sc->sc_ioh, MCT_WRITE_STAT);
93 if (reg & mask) {
94 bus_space_write_4(sc->sc_iot, sc->sc_ioh,
95 MCT_WRITE_STAT, mask);
96 return;
97 }
98 cpufunc_nullop();
99 }
100
101 /* NOTREACHED */
102
103 panic("%s: can't enable timer!", __func__);
104 }
105