xref: /netbsd-src/sys/arch/arm/apple/apple_wdog.c (revision 8aa5950677e00fd37740ebea83b48dbe2a3d350b)
1 /* $NetBSD: apple_wdog.c,v 1.3 2022/04/05 05:04:04 skrll Exp $ */
2 
3 /*-
4  * Copyright (c) 2021 Jared McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: apple_wdog.c,v 1.3 2022/04/05 05:04:04 skrll Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/device.h>
35 #include <sys/intr.h>
36 #include <sys/kernel.h>
37 #include <sys/lwp.h>
38 #include <sys/systm.h>
39 
40 #include <dev/fdt/fdtvar.h>
41 
42 #define	WDOG_CHIP_CTL		0x000c
43 #define	WDOG_SYS_TMR		0x0010
44 #define	WDOG_SYS_RST		0x0014
45 #define	WDOG_SYS_CTL		0x001c
46 #define	 WDOG_SYS_CTL_ENABLE	__BIT(2)
47 
48 static const struct device_compatible_entry compat_data[] = {
49 	{ .compat = "apple,wdt" },
50 	{ .compat = "apple,reboot-v0" },
51 	DEVICE_COMPAT_EOL
52 };
53 
54 struct apple_wdog_softc {
55 	device_t sc_dev;
56 	bus_space_tag_t sc_bst;
57 	bus_space_handle_t sc_bsh;
58 };
59 
60 #define WDOG_READ(sc, reg) \
61 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
62 #define	WDOG_WRITE(sc, reg, val) \
63 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
64 
65 static void
apple_wdog_reset(device_t dev)66 apple_wdog_reset(device_t dev)
67 {
68 	struct apple_wdog_softc * const sc = device_private(dev);
69 
70 	WDOG_WRITE(sc, WDOG_SYS_RST, 1);
71 	WDOG_WRITE(sc, WDOG_SYS_CTL, WDOG_SYS_CTL_ENABLE);
72 	WDOG_WRITE(sc, WDOG_SYS_TMR, 0);
73 }
74 
75 static struct fdtbus_power_controller_func apple_wdog_power_funcs = {
76 	.reset = apple_wdog_reset,
77 };
78 
79 static int
apple_wdog_match(device_t parent,cfdata_t cf,void * aux)80 apple_wdog_match(device_t parent, cfdata_t cf, void *aux)
81 {
82 	struct fdt_attach_args * const faa = aux;
83 
84 	return of_compatible_match(faa->faa_phandle, compat_data);
85 }
86 
87 static void
apple_wdog_attach(device_t parent,device_t self,void * aux)88 apple_wdog_attach(device_t parent, device_t self, void *aux)
89 {
90 	struct apple_wdog_softc * const sc = device_private(self);
91 	struct fdt_attach_args * const faa = aux;
92 	const int phandle = faa->faa_phandle;
93 	bus_addr_t addr;
94 	bus_size_t size;
95 
96 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
97 		aprint_error(": couldn't get registers\n");
98 		return;
99 	}
100 
101 	sc->sc_dev = self;
102 	sc->sc_bst = faa->faa_bst;
103 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
104 		aprint_error(": couldn't map registers\n");
105 		return;
106 	}
107 
108 	aprint_naive("\n");
109 	aprint_normal(": Apple Watchdog\n");
110 
111 	WDOG_WRITE(sc, WDOG_CHIP_CTL, 0);
112 	WDOG_WRITE(sc, WDOG_SYS_CTL, 0);
113 
114 	fdtbus_register_power_controller(self, phandle,
115 	    &apple_wdog_power_funcs);
116 }
117 
118 CFATTACH_DECL_NEW(apple_wdog, sizeof(struct apple_wdog_softc),
119 	apple_wdog_match, apple_wdog_attach, NULL, NULL);
120