git: 25b9b0b6bec9 - main - riscv: Add driver for cvitek reset controller

The branch main has been updated by bnovkov:

URL: https://cgit.FreeBSD.org/src/commit/?id=25b9b0b6bec9b4a382a16586a6eb8e57944e8d25

commit 25b9b0b6bec9b4a382a16586a6eb8e57944e8d25
Author:     Bojan Novković <bnovkov@FreeBSD.org>
AuthorDate: 2025-01-18 19:11:14 +0000
Commit:     Bojan Novković <bnovkov@FreeBSD.org>
CommitDate: 2025-08-01 12:35:54 +0000

    riscv: Add driver for cvitek reset controller
    
    This patch adds support for the cvitek reset controller.
    This controller is present on the Milk-V riscv SoCs. The controller is
    currently only used by the if_dwc driver.
    
    Differential Revision:  https://reviews.freebsd.org/D48531
    Reviewed by:    jrtc27, br
---
 sys/riscv/cvitek/cvitek_reset.c | 132 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/sys/riscv/cvitek/cvitek_reset.c b/sys/riscv/cvitek/cvitek_reset.c
new file mode 100644
index 000000000000..348bbc85c9a9
--- /dev/null
+++ b/sys/riscv/cvitek/cvitek_reset.c
@@ -0,0 +1,132 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 Bojan Novković <bnovkov@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.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/module.h>
+#include <sys/mutex.h>
+#include <sys/rman.h>
+
+#include <machine/bus.h>
+#include <machine/cpu.h>
+#include <machine/bus.h>
+#include <machine/resource.h>
+
+#include <dev/hwreset/hwreset.h>
+#include <dev/syscon/syscon.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/ofw/openfirm.h>
+
+#include "syscon_if.h"
+#include "hwreset_if.h"
+
+struct cvitek_reset_softc {
+	device_t		dev;
+	struct mtx		mtx;
+	struct syscon	*syscon;
+};
+
+static int
+cvitek_reset_probe(device_t dev)
+{
+
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+
+	if (ofw_bus_is_compatible(dev, "cvitek,reset")) {
+		device_set_desc(dev, "CVITEK reset controller");
+		return (BUS_PROBE_DEFAULT);
+	}
+
+	return (ENXIO);
+}
+
+static int
+cvitek_reset_attach(device_t dev)
+{
+	struct cvitek_reset_softc *sc;
+	int error;
+
+	sc = device_get_softc(dev);
+	sc->dev = dev;
+
+	error = syscon_get_by_ofw_property(dev, ofw_bus_get_node(dev),
+	    "syscon", &sc->syscon);
+	if (error != 0) {
+		device_printf(dev, "Couldn't get syscon handle\n");
+		return (error);
+	}
+	mtx_init(&sc->mtx, device_get_nameunit(sc->dev), NULL, MTX_DEF);
+
+	hwreset_register_ofw_provider(dev);
+
+	return (0);
+}
+
+static int
+cvitek_reset_assert(device_t dev, intptr_t id, bool reset)
+{
+	struct cvitek_reset_softc *sc;
+	uint32_t offset, val;
+	uint32_t bit;
+
+	sc = device_get_softc(dev);
+	bit = id % 32;
+	offset = id / 32;
+
+	mtx_lock(&sc->mtx);
+	val = SYSCON_READ_4(sc->syscon, offset);
+	if (reset)
+		val &= ~(1 << bit);
+	else
+		val |= (1 << bit);
+	SYSCON_WRITE_4(sc->syscon, offset, val);
+	mtx_unlock(&sc->mtx);
+
+	return (0);
+}
+
+static device_method_t cvitek_reset_methods[] = {
+	DEVMETHOD(device_probe,		cvitek_reset_probe),
+	DEVMETHOD(device_attach,	cvitek_reset_attach),
+
+	DEVMETHOD(hwreset_assert,	cvitek_reset_assert),
+
+	DEVMETHOD_END
+};
+
+static driver_t cvitek_reset_driver = {
+	"cvitek_reset",
+	cvitek_reset_methods,
+	sizeof(struct cvitek_reset_softc)
+};
+
+DRIVER_MODULE(cvitek_reset, simplebus, cvitek_reset_driver, 0, 0);