git: e07254d1483f - main - riscv: Add driver for the cvitek reboot controller

The branch main has been updated by bnovkov:

URL: https://cgit.FreeBSD.org/src/commit/?id=e07254d1483fad260dec7e2423043f544dfa85f9

commit e07254d1483fad260dec7e2423043f544dfa85f9
Author:     Bojan Novković <bnovkov@FreeBSD.org>
AuthorDate: 2025-01-18 19:11:39 +0000
Commit:     Bojan Novković <bnovkov@FreeBSD.org>
CommitDate: 2025-08-01 12:35:54 +0000

    riscv: Add driver for the cvitek reboot controller
    
    This patch adds support for the cvitek reboot controller.
    This controller is present on the Milk-V riscv SoCs.
    
    Reviewed by:    br, mhorne, jrtc27
    Differential review:    https://reviews.freebsd.org/D48532
---
 sys/riscv/cvitek/cvitek_restart.c | 158 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)

diff --git a/sys/riscv/cvitek/cvitek_restart.c b/sys/riscv/cvitek/cvitek_restart.c
new file mode 100644
index 000000000000..53df126d5171
--- /dev/null
+++ b/sys/riscv/cvitek/cvitek_restart.c
@@ -0,0 +1,158 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2024 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.
+ */
+
+/*
+ * Driver for cvitek's poweroff/restart controller.
+ */
+
+#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 <sys/rman.h>
+
+#include <machine/bus.h>
+#include <machine/resource.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/ofw/openfirm.h>
+
+#define RTC_CTRL0_UNLOCK	0x4
+#define  RTC_CTRL0_UNLOCK_KEY	0xAB18
+
+#define RTC_CTRL0			0x8
+#define  RTC_CTRL0_RESERVED_MASK	0xFFFF0800
+#define  RTC_CTRL0_REQ_SHUTDOWN		0x01
+#define  RTC_CTRL0_REQ_POWERCYCLE	0x08
+#define  RTC_CTRL0_REQ_WARM_RESET	0x10
+
+#define RTC_BASE_OFFSET		0x1000
+#define RTC_EN_SHDN_REQ		(RTC_BASE_OFFSET + 0xC0)
+#define RTC_EN_PWR_CYC_REQ	(RTC_BASE_OFFSET + 0xC8)
+#define RTC_EN_WARM_RST_REQ	(RTC_BASE_OFFSET + 0xCC)
+
+struct cvitek_restart_softc {
+	int reg_rid;
+	struct resource *reg;
+	eventhandler_tag tag;
+};
+
+static void
+cvitek_restart_shutdown_final(device_t dev, int howto)
+{
+	struct cvitek_restart_softc *sc;
+	uint32_t val;
+
+	sc = device_get_softc(dev);
+	val = RTC_CTRL0_RESERVED_MASK;
+	if ((howto & RB_POWEROFF) != 0)
+		val |= RTC_CTRL0_REQ_SHUTDOWN;
+	else if ((howto & RB_POWERCYCLE) != 0)
+		val |= RTC_CTRL0_REQ_POWERCYCLE;
+	else
+		val |= RTC_CTRL0_REQ_WARM_RESET;
+
+	/* Unlock writes to 'rtc_ctrl0'. */
+	bus_write_4(sc->reg, RTC_CTRL0_UNLOCK, RTC_CTRL0_UNLOCK_KEY);
+	bus_write_4(sc->reg, RTC_CTRL0, val);
+	DELAY(1000);
+
+	device_printf(dev, "Poweroff request failed\n");
+}
+
+static int
+cvitek_restart_probe(device_t dev)
+{
+
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+
+	if (ofw_bus_is_compatible(dev, "cvitek,restart")) {
+		device_set_desc(dev, "Cvitek restart controller");
+		return (BUS_PROBE_DEFAULT);
+	}
+	return (ENXIO);
+}
+
+static int
+cvitek_restart_attach(device_t dev)
+{
+	struct cvitek_restart_softc *sc;
+
+	sc = device_get_softc(dev);
+	sc->reg = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->reg_rid,
+	    RF_ACTIVE);
+	if (sc->reg == NULL) {
+		device_printf(dev, "can't map RTC regs\n");
+		return (ENXIO);
+	}
+
+	/* Enable requests for various poweroff methods. */
+	bus_write_4(sc->reg, RTC_EN_SHDN_REQ, 0x1);
+	bus_write_4(sc->reg, RTC_EN_PWR_CYC_REQ, 0x1);
+	bus_write_4(sc->reg, RTC_EN_WARM_RST_REQ, 0x1);
+
+	sc->tag = EVENTHANDLER_REGISTER(shutdown_final,
+	    cvitek_restart_shutdown_final, dev, SHUTDOWN_PRI_LAST);
+
+	return (0);
+}
+
+static int
+cvitek_restart_detach(device_t dev)
+{
+	struct cvitek_restart_softc *sc;
+
+	sc = device_get_softc(dev);
+	if (sc->reg == NULL)
+		return (0);
+
+	bus_write_4(sc->reg, RTC_EN_SHDN_REQ, 0x0);
+	bus_write_4(sc->reg, RTC_EN_PWR_CYC_REQ, 0x0);
+	bus_write_4(sc->reg, RTC_EN_WARM_RST_REQ, 0x0);
+
+	bus_release_resource(dev, SYS_RES_MEMORY, sc->reg_rid, sc->reg);
+	EVENTHANDLER_DEREGISTER(shutdown_final, sc->tag);
+
+	return (0);
+}
+
+static device_method_t cvitek_restart_methods[] = {
+	DEVMETHOD(device_probe,		cvitek_restart_probe),
+	DEVMETHOD(device_attach,	cvitek_restart_attach),
+	DEVMETHOD(device_detach,	cvitek_restart_detach),
+
+	DEVMETHOD_END
+};
+
+DEFINE_CLASS_0(cvitek_restart, cvitek_restart_driver, cvitek_restart_methods,
+    sizeof(struct cvitek_restart_softc));
+DRIVER_MODULE(cvitek_restart, simplebus, cvitek_restart_driver, NULL, NULL);