Add bcmdog(4), a watchdog timer for the Raspberry Pi.

Based on code written by patrick@

3 files changed, 163 insertions, 2 deletions

diff --git a/sys/arch/arm64/conf/GENERIC b/sys/arch/arm64/conf/GENERIC
index 12b5067ef2b..0a0f1744688 100644
--- a/sys/arch/arm64/conf/GENERIC
+++ b/sys/arch/arm64/conf/GENERIC
@@ -1,4 +1,4 @@
-# $OpenBSD: GENERIC,v 1.7 2017/01/23 14:00:22 patrick Exp $
+# $OpenBSD: GENERIC,v 1.8 2017/01/23 14:15:16 kettenis Exp $
 #
 # GENERIC machine description file
 #
@@ -63,6 +63,7 @@ wsdisplay*	at simplefb?
 
 # Raspberry Pi 3
 bcmintc*	at fdt?
+bcmdog*		at fdt?
 dwctwo*		at fdt?
 usb*		at dwctwo?
 
diff --git a/sys/dev/fdt/bcm2835_dog.c b/sys/dev/fdt/bcm2835_dog.c
new file mode 100644
index 00000000000..641eb9dda80
--- /dev/null
+++ b/sys/dev/fdt/bcm2835_dog.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2015 Patrick Wildt <patrick@blueri.se>
+ *
+ * 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/queue.h>
+#include <sys/malloc.h>
+#include <sys/device.h>
+#include <sys/evcount.h>
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/fdt.h>
+
+extern void (*cpuresetfn)(void);
+
+/* registers */
+#define PM_RSTC		0x1c
+#define PM_RSTS		0x20
+#define PM_WDOG		0x24
+
+/* bits and bytes */
+#define PM_PASSWORD		0x5a000000
+#define PM_RSTC_CONFIGMASK	0x00000030
+#define PM_RSTC_FULL_RESET	0x00000020
+#define PM_RSTC_RESET		0x00000102
+#define PM_WDOG_TIMEMASK	0x000fffff
+
+#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))
+#define HSET4(sc, reg, bits)						\
+	HWRITE4((sc), (reg), HREAD4((sc), (reg)) | (bits))
+#define HCLR4(sc, reg, bits)						\
+	HWRITE4((sc), (reg), HREAD4((sc), (reg)) & ~(bits))
+
+struct bcmdog_softc {
+	struct device		 sc_dev;
+	bus_space_tag_t		 sc_iot;
+	bus_space_handle_t	 sc_ioh;
+};
+
+struct bcmdog_softc *bcmdog_sc;
+
+int	 bcmdog_match(struct device *, void *, void *);
+void	 bcmdog_attach(struct device *, struct device *, void *);
+int	 bcmdog_activate(struct device *, int);
+int	 bcmdog_wdog_cb(void *, int);
+void	 bcmdog_wdog_reset(void);
+
+struct cfattach	bcmdog_ca = {
+	sizeof (struct bcmdog_softc), bcmdog_match, bcmdog_attach, NULL,
+	bcmdog_activate
+};
+
+struct cfdriver bcmdog_cd = {
+	NULL, "bcmdog", DV_DULL
+};
+
+int
+bcmdog_match(struct device *parent, void *cfdata, void *aux)
+{
+	struct fdt_attach_args *fa = aux;
+
+	return OF_is_compatible(fa->fa_node, "brcm,bcm2835-pm-wdt");
+}
+
+void
+bcmdog_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct bcmdog_softc *sc = (struct bcmdog_softc *)self;
+	struct fdt_attach_args *fa = aux;
+
+	sc->sc_iot = fa->fa_iot;
+
+	if (bus_space_map(sc->sc_iot, fa->fa_reg[0].addr,
+	    fa->fa_reg[0].size, 0, &sc->sc_ioh))
+		panic("%s: bus_space_map failed!", __func__);
+
+	printf("\n");
+
+	bcmdog_sc = sc;
+	cpuresetfn = bcmdog_wdog_reset;
+
+#ifndef SMALL_KERNEL
+	wdog_register(bcmdog_wdog_cb, sc);
+#endif
+}
+
+int
+bcmdog_activate(struct device *self, int act)
+{
+	switch (act) {
+	case DVACT_POWERDOWN:
+#ifndef SMALL_KERNEL
+		wdog_shutdown(self);
+#endif
+		break;
+	}
+
+	return 0;
+}
+
+void
+bcmdog_wdog_set(struct bcmdog_softc *sc, uint32_t period)
+{
+	uint32_t rstc, wdog;
+
+	if (period == 0) {
+		HWRITE4(sc, PM_RSTC, PM_RSTC_RESET | PM_PASSWORD);
+		return;
+	}
+
+	rstc = HREAD4(sc, PM_RSTC) & PM_RSTC_CONFIGMASK;
+	rstc |= PM_RSTC_FULL_RESET;
+	rstc |= PM_PASSWORD;
+
+	wdog = period & PM_WDOG_TIMEMASK;
+	wdog |= PM_PASSWORD;
+
+	HWRITE4(sc, PM_WDOG, wdog);
+	HWRITE4(sc, PM_RSTC, rstc);
+}
+
+int
+bcmdog_wdog_cb(void *self, int period)
+{
+	struct bcmdog_softc *sc = self;
+
+	bcmdog_wdog_set(sc, period << 16);
+	return period;
+}
+
+void
+bcmdog_wdog_reset(void)
+{
+	struct bcmdog_softc *sc = bcmdog_sc;
+
+	bcmdog_wdog_set(sc, 10);
+	delay(100000);
+}
diff --git a/sys/dev/fdt/files.fdt b/sys/dev/fdt/files.fdt
index e96b7100b5c..ebe06fc984b 100644
--- a/sys/dev/fdt/files.fdt
+++ b/sys/dev/fdt/files.fdt
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.fdt,v 1.2 2017/01/21 08:26:49 patrick Exp $
+#	$OpenBSD: files.fdt,v 1.3 2017/01/23 14:15:16 kettenis Exp $
 #
 # Config file and device description for machine-independent FDT code.
 # Included by ports that need it.
@@ -25,3 +25,7 @@ file	dev/fdt/sximmc.c		sximmc
 
 attach	ehci at fdt with sxiehci
 file	dev/fdt/sxiehci.c		sxiehci
+
+device	bcmdog
+attach	bcmdog at fdt
+file	dev/fdt/bcm2835_dog.c		bcmdog