From deb4602f40de55a6e9a7401193219e3de3fa92a8 Mon Sep 17 00:00:00 2001
From: kettenis <kettenis@openbsd.org>
Date: Thu, 9 Jun 2022 12:13:56 +0000
Subject: [PATCH] Add gpiorestart(4), a driver that resets a SoC/board/machine
 using a GPIO pin.

ok jsg@
---
 sys/dev/fdt/files.fdt     |   6 ++-
 sys/dev/fdt/gpiorestart.c | 102 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 sys/dev/fdt/gpiorestart.c

diff --git a/sys/dev/fdt/files.fdt b/sys/dev/fdt/files.fdt
index 13c5932f9a1..ca24869c0f1 100644
--- a/sys/dev/fdt/files.fdt
+++ b/sys/dev/fdt/files.fdt
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.fdt,v 1.162 2022/01/30 21:40:50 kettenis Exp $
+#	$OpenBSD: files.fdt,v 1.163 2022/06/09 12:13:56 kettenis Exp $
 #
 # Config file and device description for machine-independent FDT code.
 # Included by ports that need it.
@@ -609,6 +609,10 @@ device	gpiokeys
 attach	gpiokeys at fdt
 file	dev/fdt/gpiokeys.c		gpiokeys
 
+device	gpiorestart
+attach	gpiorestart at fdt
+file	dev/fdt/gpiorestart.c		gpiorestart
+
 device	tascodec
 attach	tascodec at i2c
 file	dev/fdt/tascodec.c		tascodec
diff --git a/sys/dev/fdt/gpiorestart.c b/sys/dev/fdt/gpiorestart.c
new file mode 100644
index 00000000000..832798b80f7
--- /dev/null
+++ b/sys/dev/fdt/gpiorestart.c
@@ -0,0 +1,102 @@
+/*	$OpenBSD: gpiorestart.c,v 1.1 2022/06/09 12:13:56 kettenis Exp $	*/
+/*
+ * Copyright (c) 2022 Mark Kettenis
+ *
+ * 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/malloc.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_gpio.h>
+#include <dev/ofw/fdt.h>
+
+extern void (*cpuresetfn)(void);
+
+struct gpiorestart_softc {
+	struct device	sc_dev;
+	uint32_t	*sc_gpio;
+	uint32_t	sc_active_delay;
+	uint32_t	sc_inactive_delay;
+	uint32_t	sc_wait_delay;
+};
+
+int	gpiorestart_match(struct device *, void *, void *);
+void	gpiorestart_attach(struct device *, struct device *, void *);
+
+const struct cfattach gpiorestart_ca = {
+	sizeof(struct gpiorestart_softc), gpiorestart_match, gpiorestart_attach
+};
+
+struct cfdriver gpiorestart_cd = {
+	NULL, "gpiorestart", DV_DULL
+};
+
+void	gpiorestart_reset(void);
+
+int
+gpiorestart_match(struct device *parent, void *match, void *aux)
+{
+	struct fdt_attach_args *faa = aux;
+
+	return OF_is_compatible(faa->fa_node, "gpio-restart");
+}
+
+void
+gpiorestart_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct gpiorestart_softc *sc = (struct gpiorestart_softc *)self;
+	struct fdt_attach_args *faa = aux;
+	int len;
+
+	len = OF_getproplen(faa->fa_node, "gpios");
+	if (len <= 0) {
+		printf(": no gpio\n");
+		return;
+	}
+
+	sc->sc_gpio = malloc(len, M_DEVBUF, M_WAITOK);
+	OF_getpropintarray(faa->fa_node, "gpios", sc->sc_gpio, len);
+
+	sc->sc_active_delay =
+	    OF_getpropint(faa->fa_node, "active-delay", 100) * 1000;
+	sc->sc_inactive_delay =
+	    OF_getpropint(faa->fa_node, "inactive-delay", 100) * 1000;
+	sc->sc_wait_delay =
+	    OF_getpropint(faa->fa_node, "wait-delay", 3000) * 1000;
+
+	if (cpuresetfn == NULL)
+		cpuresetfn = gpiorestart_reset;
+
+	printf("\n");
+}
+
+void
+gpiorestart_reset(void)
+{
+	struct gpiorestart_softc *sc = gpiorestart_cd.cd_devs[0];
+
+	gpio_controller_config_pin(sc->sc_gpio, GPIO_CONFIG_OUTPUT);
+	gpio_controller_set_pin(sc->sc_gpio, 1);
+	delay(sc->sc_active_delay);
+	gpio_controller_set_pin(sc->sc_gpio, 0);
+	delay(sc->sc_inactive_delay);
+	gpio_controller_set_pin(sc->sc_gpio, 1);
+	delay(sc->sc_wait_delay);
+}
-- 
2.20.1