xref: /openbsd/sys/dev/fdt/bcm2835_temp.c (revision 73471bf0)
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
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
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
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