1/*	$OpenBSD: qcmtx.c,v 1.1 2023/05/17 23:30:58 patrick Exp $	*/
2/*
3 * Copyright (c) 2023 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#include <sys/malloc.h>
22
23#include <machine/bus.h>
24#include <machine/fdt.h>
25
26#include <dev/ofw/openfirm.h>
27#include <dev/ofw/ofw_misc.h>
28#include <dev/ofw/fdt.h>
29
30#define QCMTX_OFF(idx)		((idx) * 0x1000)
31#define QCMTX_NUM_LOCKS		32
32#define QCMTX_APPS_PROC_ID	1
33
34#define HREAD4(sc, reg)							\
35	(bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
36#define HWRITE4(sc, reg, val)						\
37	bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
38
39struct qcmtx_softc {
40	struct device		sc_dev;
41	bus_space_tag_t		sc_iot;
42	bus_space_handle_t	sc_ioh;
43	int			sc_node;
44
45	struct hwlock_device	sc_hd;
46};
47
48int	qcmtx_match(struct device *, void *, void *);
49void	qcmtx_attach(struct device *, struct device *, void *);
50
51int	qcmtx_lock(void *, uint32_t *, int);
52
53const struct cfattach qcmtx_ca = {
54	sizeof (struct qcmtx_softc), qcmtx_match, qcmtx_attach
55};
56
57struct cfdriver qcmtx_cd = {
58	NULL, "qcmtx", DV_DULL
59};
60
61int
62qcmtx_match(struct device *parent, void *match, void *aux)
63{
64	struct fdt_attach_args *faa = aux;
65
66	return OF_is_compatible(faa->fa_node, "qcom,tcsr-mutex");
67}
68
69void
70qcmtx_attach(struct device *parent, struct device *self, void *aux)
71{
72	struct qcmtx_softc *sc = (struct qcmtx_softc *)self;
73	struct fdt_attach_args *faa = aux;
74
75	if (faa->fa_nreg < 1) {
76		printf(": no registers\n");
77		return;
78	}
79
80	sc->sc_node = faa->fa_node;
81	sc->sc_iot = faa->fa_iot;
82	if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
83	    faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
84		printf(": can't map registers\n");
85		return;
86	}
87
88	printf("\n");
89
90	sc->sc_hd.hd_node = faa->fa_node;
91	sc->sc_hd.hd_cookie = sc;
92	sc->sc_hd.hd_lock = qcmtx_lock;
93	hwlock_register(&sc->sc_hd);
94}
95
96int
97qcmtx_lock(void *cookie, uint32_t *cells, int lock)
98{
99	struct qcmtx_softc *sc = cookie;
100	int idx = cells[0];
101
102	if (idx >= QCMTX_NUM_LOCKS)
103		return ENXIO;
104
105	if (lock) {
106		HWRITE4(sc, QCMTX_OFF(idx), QCMTX_APPS_PROC_ID);
107		if (HREAD4(sc, QCMTX_OFF(idx)) !=
108		    QCMTX_APPS_PROC_ID)
109			return EAGAIN;
110		KASSERT(HREAD4(sc, QCMTX_OFF(idx)) == QCMTX_APPS_PROC_ID);
111	} else {
112		KASSERT(HREAD4(sc, QCMTX_OFF(idx)) == QCMTX_APPS_PROC_ID);
113		HWRITE4(sc, QCMTX_OFF(idx), 0);
114	}
115
116	return 0;
117}
118