svn commit: r363573 - in head/sys: conf dev/extres/syscon
Jessica Clarke
jrtc27 at FreeBSD.org
Sun Jul 26 18:19:51 UTC 2020
Author: jrtc27
Date: Sun Jul 26 18:19:50 2020
New Revision: 363573
URL: https://svnweb.freebsd.org/changeset/base/363573
Log:
Add syscon power and reset control device driver
This device driver supports both syscon-power and syscon-reset devices,
as specified in [1] and [2]. These provide a very simple interface for
power and reset control, and among other things are used by QEMU's virt
machine on RISC-V. A separate commit will enable this on RISC-V, as that
requires adding a RISC-V-specific riscv_syscon akin to r327936's
aw_syscon.
[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-poweroff.txt
[2] https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
Reviewed by: brooks (mentor), jhb (mentor)
Approved by: brooks (mentor), jhb (mentor)
Obtained from: CheriBSD
Differential Revision: https://reviews.freebsd.org/D25724
Added:
head/sys/dev/extres/syscon/syscon_power.c (contents, props changed)
Modified:
head/sys/conf/files
Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files Sun Jul 26 18:17:36 2020 (r363572)
+++ head/sys/conf/files Sun Jul 26 18:19:50 2020 (r363573)
@@ -1702,6 +1702,7 @@ dev/extres/regulator/regulator_fixed.c optional ext_re
dev/extres/syscon/syscon.c optional ext_resources syscon
dev/extres/syscon/syscon_generic.c optional ext_resources syscon fdt
dev/extres/syscon/syscon_if.m optional ext_resources syscon
+dev/extres/syscon/syscon_power.c optional ext_resources syscon syscon_power fdt
dev/fb/fbd.c optional fbd | vt
dev/fb/fb_if.m standard
dev/fb/splash.c optional sc splash
Added: head/sys/dev/extres/syscon/syscon_power.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/dev/extres/syscon/syscon_power.c Sun Jul 26 18:19:50 2020 (r363573)
@@ -0,0 +1,198 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Jessica Clarke <jrtc27 at FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Driver for simple syscon poweroff and reset devices. The device tree
+ * specifications are fully described at:
+ *
+ * https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-poweroff.txt
+ * https://www.kernel.org/doc/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/types.h>
+#include <sys/eventhandler.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/reboot.h>
+
+#include <machine/bus.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/ofw/openfirm.h>
+
+#include "syscon_if.h"
+#include "syscon.h"
+
+struct syscon_power_softc {
+ struct syscon *regmap;
+ uint32_t offset;
+ uint32_t value;
+ uint32_t mask;
+ bool reboot;
+ eventhandler_tag shutdown_tag;
+};
+
+static void
+syscon_power_shutdown_final(device_t dev, int howto)
+{
+ struct syscon_power_softc *sc;
+ bool write;
+
+ sc = device_get_softc(dev);
+ if (sc->reboot)
+ write = (howto & RB_HALT) == 0;
+ else
+ write = (howto & RB_POWEROFF) != 0;
+
+ if (write)
+ SYSCON_MODIFY_4(sc->regmap, sc->offset, sc->mask,
+ sc->value & sc->mask);
+}
+
+static int
+syscon_power_probe(device_t dev)
+{
+
+ if (!ofw_bus_status_okay(dev))
+ return (ENXIO);
+
+ if (ofw_bus_is_compatible(dev, "syscon-poweroff")) {
+ device_set_desc(dev, "Syscon poweroff");
+ return (BUS_PROBE_DEFAULT);
+ } else if (ofw_bus_is_compatible(dev, "syscon-reboot")) {
+ device_set_desc(dev, "Syscon reboot");
+ return (BUS_PROBE_DEFAULT);
+ }
+
+ return (ENXIO);
+}
+
+static int
+syscon_power_attach(device_t dev)
+{
+ struct syscon_power_softc *sc;
+ phandle_t node;
+ int error, len;
+ bool has_mask;
+
+ sc = device_get_softc(dev);
+ node = ofw_bus_get_node(dev);
+
+ if (!OF_hasprop(node, "regmap")) {
+ device_printf(dev, "could not find regmap\n");
+ return (ENXIO);
+ }
+
+ error = syscon_get_by_ofw_property(dev, node, "regmap", &sc->regmap);
+ if (error != 0) {
+ device_printf(dev, "could not get syscon\n");
+ return (ENXIO);
+ }
+
+ len = OF_getproplen(node, "offset");
+ if (len != 4) {
+ device_printf(dev, "could not get offset\n");
+ return (ENXIO);
+ }
+
+ OF_getencprop(node, "offset", &sc->offset, sizeof(sc->offset));
+
+ /* Optional mask */
+ has_mask = OF_hasprop(node, "mask");
+ if (has_mask) {
+ len = OF_getproplen(node, "mask");
+ if (len != 4) {
+ device_printf(dev, "cannot handle mask\n");
+ return (ENXIO);
+ }
+
+ OF_getencprop(node, "mask", &sc->mask, sizeof(sc->mask));
+ } else {
+ sc->mask = 0xffffffff;
+ }
+
+ /*
+ * From the device tree specification:
+ *
+ * Legacy usage: If a node doesn't contain a value property but
+ * contains a mask property, the mask property is used as the value.
+ */
+ if (!OF_hasprop(node, "value")) {
+ if (!has_mask) {
+ device_printf(dev, "must have a value or a mask\n");
+ return (ENXIO);
+ }
+
+ sc->value = sc->mask;
+ } else {
+ len = OF_getproplen(node, "value");
+ if (len != 4) {
+ device_printf(dev, "cannot handle value\n");
+ return (ENXIO);
+ }
+
+ OF_getencprop(node, "value", &sc->value, sizeof(sc->value));
+ }
+
+ sc->reboot = ofw_bus_is_compatible(dev, "syscon-reboot");
+ sc->shutdown_tag = EVENTHANDLER_REGISTER(shutdown_final,
+ syscon_power_shutdown_final, dev, SHUTDOWN_PRI_LAST);
+
+ return (0);
+}
+
+static int
+syscon_power_detach(device_t dev)
+{
+ struct syscon_power_softc *sc;
+
+ sc = device_get_softc(dev);
+ EVENTHANDLER_DEREGISTER(shutdown_final, sc->shutdown_tag);
+
+ return (0);
+}
+
+static device_method_t syscon_power_methods[] = {
+ DEVMETHOD(device_probe, syscon_power_probe),
+ DEVMETHOD(device_attach, syscon_power_attach),
+ DEVMETHOD(device_detach, syscon_power_detach),
+
+ DEVMETHOD_END
+};
+
+DEFINE_CLASS_0(syscon_power, syscon_power_driver, syscon_power_methods,
+ sizeof(struct syscon_power_softc));
+static devclass_t syscon_power_devclass;
+
+DRIVER_MODULE(syscon_power, simplebus, syscon_power_driver,
+ syscon_power_devclass, NULL, NULL);
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