Add bcmtemp(4), a driver for the temperature sensor on the Raspberry Pi.

diff --git a/sys/dev/fdt/bcm2835_temp.c b/sys/dev/fdt/bcm2835_temp.c
new file mode 100644 (file)
index 0000000..c5aab99
--- /dev/null
+++ b/sys/dev/fdt/bcm2835_temp.c
@@ -0,0 +1,124 @@
+/*     $OpenBSD: bcm2835_temp.c,v 1.1 2018/02/24 11:06:59 kettenis Exp $       */
+/*
+ * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/sensors.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/fdt.h>
+
+/* Registers */
+#define TS_TSENSCTL            0x0000
+#define TS_TSENSSTAT           0x0004
+#define  TS_TSENSSTAT_VALID    (1 << 10)
+#define  TS_TSENSSTAT_DATA(x)  ((x) & 0x3ff)
+
+#define HREAD4(sc, reg)                                                        \
+       (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
+#define HWRITE4(sc, reg, val)                                          \
+       bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
+
+struct bcmtemp_softc {
+       struct device           sc_dev;
+       bus_space_tag_t         sc_iot;
+       bus_space_handle_t      sc_ioh;
+
+       int32_t                 sc_slope;
+       int32_t                 sc_offset;
+
+       struct ksensor          sc_sensor;
+       struct ksensordev       sc_sensordev;
+};
+
+int    bcmtemp_match(struct device *, void *, void *);
+void   bcmtemp_attach(struct device *, struct device *, void *);
+
+struct cfattach        bcmtemp_ca = {
+       sizeof (struct bcmtemp_softc), bcmtemp_match, bcmtemp_attach
+};
+
+struct cfdriver bcmtemp_cd = {
+       NULL, "bcmtemp", DV_DULL
+};
+
+void   bcmtemp_refresh_sensors(void *);
+
+int
+bcmtemp_match(struct device *parent, void *match, void *aux)
+{
+       struct fdt_attach_args *faa = aux;
+
+       return (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal") ||
+           OF_is_compatible(faa->fa_node, "brcm,bcm2837-thermal"));
+}
+
+void
+bcmtemp_attach(struct device *parent, struct device *self, void *aux)
+{
+       struct bcmtemp_softc *sc = (struct bcmtemp_softc *)self;
+       struct fdt_attach_args *faa = aux;
+
+       if (faa->fa_nreg < 1) {
+               printf(": no registers\n");
+               return;
+       }
+
+       sc->sc_iot = faa->fa_iot;
+       if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
+           faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
+               printf(": can't map registers\n");
+               return;
+       }
+
+       printf("\n");
+
+       /* XXX fetch these from /thermal-zones. */
+       sc->sc_slope = -538;
+       if (OF_is_compatible(faa->fa_node, "brcm,bcm2836-thermal"))
+               sc->sc_offset = 407000;
+       else
+               sc->sc_offset = 412000;
+
+       /* Register sensors. */
+       strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
+           sizeof(sc->sc_sensordev.xname));
+       sc->sc_sensor.type = SENSOR_TEMP;
+       sc->sc_sensor.flags = SENSOR_FINVALID;
+       sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
+       sensordev_install(&sc->sc_sensordev);
+       sensor_task_register(sc, bcmtemp_refresh_sensors, 5);
+}
+
+void
+bcmtemp_refresh_sensors(void *arg)
+{
+       struct bcmtemp_softc *sc = arg;
+       int32_t code, temp;
+
+       code = HREAD4(sc, TS_TSENSSTAT);
+       temp = sc->sc_offset + TS_TSENSSTAT_DATA(code) * sc->sc_slope;
+       sc->sc_sensor.value = 273150000 + 1000 * temp;
+       if (code & TS_TSENSSTAT_VALID)
+               sc->sc_sensor.flags &= ~SENSOR_FINVALID;
+       else
+               sc->sc_sensor.flags |= SENSOR_FINVALID;
+}

diff --git a/sys/dev/fdt/files.fdt b/sys/dev/fdt/files.fdt
index 65286f9..d5d71a7 100644 (file)
--- a/sys/dev/fdt/files.fdt
+++ b/sys/dev/fdt/files.fdt
@@ -1,4 +1,4 @@
-#      $OpenBSD: files.fdt,v 1.37 2018/01/17 10:17:33 kettenis Exp $
+#      $OpenBSD: files.fdt,v 1.38 2018/02/24 11:06:59 kettenis Exp $
 #
 # Config file and device description for machine-independent FDT code.
 # Included by ports that need it.
@@ -57,6 +57,10 @@ device       bcmdog
 attach bcmdog at fdt
 file   dev/fdt/bcm2835_dog.c           bcmdog
 
+device bcmtemp
+attach bcmtemp at fdt
+file   dev/fdt/bcm2835_temp.c          bcmdog
+
 device exrtc
 attach exrtc at fdt
 file   dev/fdt/exrtc.c                 exrtc