xref: /freebsd/sys/riscv/cvitek/cvitek_restart.c (revision e07254d1483fad260dec7e2423043f544dfa85f9)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2024 Bojan Novković <bnovkov@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 /*
29  * Driver for cvitek's poweroff/restart controller.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/types.h>
35 #include <sys/eventhandler.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/reboot.h>
39 #include <sys/rman.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 #include <dev/ofw/openfirm.h>
47 
48 #define RTC_CTRL0_UNLOCK	0x4
49 #define  RTC_CTRL0_UNLOCK_KEY	0xAB18
50 
51 #define RTC_CTRL0			0x8
52 #define  RTC_CTRL0_RESERVED_MASK	0xFFFF0800
53 #define  RTC_CTRL0_REQ_SHUTDOWN		0x01
54 #define  RTC_CTRL0_REQ_POWERCYCLE	0x08
55 #define  RTC_CTRL0_REQ_WARM_RESET	0x10
56 
57 #define RTC_BASE_OFFSET		0x1000
58 #define RTC_EN_SHDN_REQ		(RTC_BASE_OFFSET + 0xC0)
59 #define RTC_EN_PWR_CYC_REQ	(RTC_BASE_OFFSET + 0xC8)
60 #define RTC_EN_WARM_RST_REQ	(RTC_BASE_OFFSET + 0xCC)
61 
62 struct cvitek_restart_softc {
63 	int reg_rid;
64 	struct resource *reg;
65 	eventhandler_tag tag;
66 };
67 
68 static void
cvitek_restart_shutdown_final(device_t dev,int howto)69 cvitek_restart_shutdown_final(device_t dev, int howto)
70 {
71 	struct cvitek_restart_softc *sc;
72 	uint32_t val;
73 
74 	sc = device_get_softc(dev);
75 	val = RTC_CTRL0_RESERVED_MASK;
76 	if ((howto & RB_POWEROFF) != 0)
77 		val |= RTC_CTRL0_REQ_SHUTDOWN;
78 	else if ((howto & RB_POWERCYCLE) != 0)
79 		val |= RTC_CTRL0_REQ_POWERCYCLE;
80 	else
81 		val |= RTC_CTRL0_REQ_WARM_RESET;
82 
83 	/* Unlock writes to 'rtc_ctrl0'. */
84 	bus_write_4(sc->reg, RTC_CTRL0_UNLOCK, RTC_CTRL0_UNLOCK_KEY);
85 	bus_write_4(sc->reg, RTC_CTRL0, val);
86 	DELAY(1000);
87 
88 	device_printf(dev, "Poweroff request failed\n");
89 }
90 
91 static int
cvitek_restart_probe(device_t dev)92 cvitek_restart_probe(device_t dev)
93 {
94 
95 	if (!ofw_bus_status_okay(dev))
96 		return (ENXIO);
97 
98 	if (ofw_bus_is_compatible(dev, "cvitek,restart")) {
99 		device_set_desc(dev, "Cvitek restart controller");
100 		return (BUS_PROBE_DEFAULT);
101 	}
102 	return (ENXIO);
103 }
104 
105 static int
cvitek_restart_attach(device_t dev)106 cvitek_restart_attach(device_t dev)
107 {
108 	struct cvitek_restart_softc *sc;
109 
110 	sc = device_get_softc(dev);
111 	sc->reg = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->reg_rid,
112 	    RF_ACTIVE);
113 	if (sc->reg == NULL) {
114 		device_printf(dev, "can't map RTC regs\n");
115 		return (ENXIO);
116 	}
117 
118 	/* Enable requests for various poweroff methods. */
119 	bus_write_4(sc->reg, RTC_EN_SHDN_REQ, 0x1);
120 	bus_write_4(sc->reg, RTC_EN_PWR_CYC_REQ, 0x1);
121 	bus_write_4(sc->reg, RTC_EN_WARM_RST_REQ, 0x1);
122 
123 	sc->tag = EVENTHANDLER_REGISTER(shutdown_final,
124 	    cvitek_restart_shutdown_final, dev, SHUTDOWN_PRI_LAST);
125 
126 	return (0);
127 }
128 
129 static int
cvitek_restart_detach(device_t dev)130 cvitek_restart_detach(device_t dev)
131 {
132 	struct cvitek_restart_softc *sc;
133 
134 	sc = device_get_softc(dev);
135 	if (sc->reg == NULL)
136 		return (0);
137 
138 	bus_write_4(sc->reg, RTC_EN_SHDN_REQ, 0x0);
139 	bus_write_4(sc->reg, RTC_EN_PWR_CYC_REQ, 0x0);
140 	bus_write_4(sc->reg, RTC_EN_WARM_RST_REQ, 0x0);
141 
142 	bus_release_resource(dev, SYS_RES_MEMORY, sc->reg_rid, sc->reg);
143 	EVENTHANDLER_DEREGISTER(shutdown_final, sc->tag);
144 
145 	return (0);
146 }
147 
148 static device_method_t cvitek_restart_methods[] = {
149 	DEVMETHOD(device_probe,		cvitek_restart_probe),
150 	DEVMETHOD(device_attach,	cvitek_restart_attach),
151 	DEVMETHOD(device_detach,	cvitek_restart_detach),
152 
153 	DEVMETHOD_END
154 };
155 
156 DEFINE_CLASS_0(cvitek_restart, cvitek_restart_driver, cvitek_restart_methods,
157     sizeof(struct cvitek_restart_softc));
158 DRIVER_MODULE(cvitek_restart, simplebus, cvitek_restart_driver, NULL, NULL);
159