1 /* $OpenBSD: bcm2835_temp.c,v 1.2 2021/10/24 17:52:26 mpi Exp $ */
2 /*
3 * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org>
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/sensors.h>
22
23 #include <machine/bus.h>
24 #include <machine/fdt.h>
25
26 #include <dev/ofw/openfirm.h>
27 #include <dev/ofw/fdt.h>
28
29 /* Registers */
30 #define TS_TSENSCTL 0x0000
31 #define TS_TSENSSTAT 0x0004
32 #define TS_TSENSSTAT_VALID (1 << 10)
33 #define TS_TSENSSTAT_DATA(x) ((x) & 0x3ff)
34
35 #define HREAD4(sc, reg) \
36 (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
37 #define HWRITE4(sc, reg, val) \
38 bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
39
40 struct bcmtemp_softc {
41 struct device sc_dev;
42 bus_space_tag_t sc_iot;
43 bus_space_handle_t sc_ioh;
44
45 int32_t sc_slope;
46 int32_t sc_offset;
47
48 struct ksensor sc_sensor;
49 struct ksensordev sc_sensordev;
50 };
51
52 int bcmtemp_match(struct device *, void *, void *);
53 void bcmtemp_attach(struct device *, struct device *, void *);
54
55 const struct cfattach bcmtemp_ca = {
56 sizeof (struct bcmtemp_softc), bcmtemp_match, bcmtemp_attach
57 };
58
59 struct cfdriver bcmtemp_cd = {
60 NULL, "bcmtemp", DV_DULL
61 };
62
63 void bcmtemp_refresh_sensors(void *);
64
65 int
bcmtemp_match(struct device * parent,void * match,void * aux)66 bcmtemp_match(struct device *parent, void *match, void *aux)
67 {
68 struct fdt_attach_args *faa = aux;
69
70 return (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal") ||
71 OF_is_compatible(faa->fa_node, "brcm,bcm2837-thermal"));
72 }
73
74 void
bcmtemp_attach(struct device * parent,struct device * self,void * aux)75 bcmtemp_attach(struct device *parent, struct device *self, void *aux)
76 {
77 struct bcmtemp_softc *sc = (struct bcmtemp_softc *)self;
78 struct fdt_attach_args *faa = aux;
79
80 if (faa->fa_nreg < 1) {
81 printf(": no registers\n");
82 return;
83 }
84
85 sc->sc_iot = faa->fa_iot;
86 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
87 faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
88 printf(": can't map registers\n");
89 return;
90 }
91
92 printf("\n");
93
94 /* XXX fetch these from /thermal-zones. */
95 sc->sc_slope = -538;
96 if (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal"))
97 sc->sc_offset = 407000;
98 else
99 sc->sc_offset = 412000;
100
101 /* Register sensors. */
102 strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
103 sizeof(sc->sc_sensordev.xname));
104 sc->sc_sensor.type = SENSOR_TEMP;
105 sc->sc_sensor.flags = SENSOR_FINVALID;
106 sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
107 sensordev_install(&sc->sc_sensordev);
108 sensor_task_register(sc, bcmtemp_refresh_sensors, 5);
109 }
110
111 void
bcmtemp_refresh_sensors(void * arg)112 bcmtemp_refresh_sensors(void *arg)
113 {
114 struct bcmtemp_softc *sc = arg;
115 int32_t code, temp;
116
117 code = HREAD4(sc, TS_TSENSSTAT);
118 temp = sc->sc_offset + TS_TSENSSTAT_DATA(code) * sc->sc_slope;
119 sc->sc_sensor.value = 273150000 + 1000 * temp;
120 if (code & TS_TSENSSTAT_VALID)
121 sc->sc_sensor.flags &= ~SENSOR_FINVALID;
122 else
123 sc->sc_sensor.flags |= SENSOR_FINVALID;
124 }
125