1 /*-
2  * Copyright (c) 2018-2020 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * This software was developed by BAE Systems, the University of Cambridge
6  * Computer Laboratory, and Memorial University under DARPA/AFRL contract
7  * FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent Computing
8  * (TC) research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/rman.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <machine/bus.h>
42 
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <arm64/coresight/coresight.h>
47 
48 #include "coresight_if.h"
49 
50 #define	EDPCSR				0x0a0
51 #define	EDCIDSR				0x0a4
52 #define	EDVIDSR				0x0a8
53 #define	EDPCSR_HI			0x0ac
54 #define	EDOSLAR				0x300
55 #define	EDPRCR				0x310
56 #define	 EDPRCR_COREPURQ		(1 << 3)
57 #define	 EDPRCR_CORENPDRQ		(1 << 0)
58 #define	EDPRSR				0x314
59 #define	EDDEVID1			0xfc4
60 #define	EDDEVID				0xfc8
61 
62 static struct ofw_compat_data compat_data[] = {
63 	{ "arm,coresight-cpu-debug",		1 },
64 	{ NULL,					0 }
65 };
66 
67 struct debug_softc {
68 	struct resource			*res;
69 	struct coresight_platform_data	*pdata;
70 };
71 
72 static struct resource_spec debug_spec[] = {
73 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
74 	{ -1, 0 }
75 };
76 
77 static int
78 debug_init(device_t dev)
79 {
80 	struct debug_softc *sc;
81 	uint32_t reg;
82 
83 	sc = device_get_softc(dev);
84 
85 	/* Unlock Coresight */
86 	bus_write_4(sc->res, CORESIGHT_LAR, CORESIGHT_UNLOCK);
87 
88 	/* Unlock Debug */
89 	bus_write_4(sc->res, EDOSLAR, 0);
90 
91 	/* Already initialized? */
92 	reg = bus_read_4(sc->res, EDPRCR);
93 	if (reg & EDPRCR_CORENPDRQ)
94 		return (0);
95 
96 	/* Enable power */
97 	reg |= EDPRCR_COREPURQ;
98 	bus_write_4(sc->res, EDPRCR, reg);
99 
100 	do {
101 		reg = bus_read_4(sc->res, EDPRSR);
102 	} while ((reg & EDPRCR_CORENPDRQ) == 0);
103 
104 	return (0);
105 }
106 
107 static int
108 debug_probe(device_t dev)
109 {
110 
111 	if (!ofw_bus_status_okay(dev))
112 		return (ENXIO);
113 
114 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
115 		return (ENXIO);
116 
117 	device_set_desc(dev, "Coresight CPU Debug");
118 
119 	return (BUS_PROBE_DEFAULT);
120 }
121 
122 static int
123 debug_attach(device_t dev)
124 {
125 	struct coresight_desc desc;
126 	struct debug_softc *sc;
127 
128 	sc = device_get_softc(dev);
129 
130 	if (bus_alloc_resources(dev, debug_spec, &sc->res) != 0) {
131 		device_printf(dev, "cannot allocate resources for device\n");
132 		return (ENXIO);
133 	}
134 
135 	sc->pdata = coresight_fdt_get_platform_data(dev);
136 	desc.pdata = sc->pdata;
137 	desc.dev = dev;
138 	desc.dev_type = CORESIGHT_CPU_DEBUG;
139 	coresight_register(&desc);
140 
141 	return (0);
142 }
143 
144 static device_method_t debug_methods[] = {
145 	/* Device interface */
146 	DEVMETHOD(device_probe,		debug_probe),
147 	DEVMETHOD(device_attach,	debug_attach),
148 
149 	/* Coresight interface */
150 	DEVMETHOD(coresight_init,	debug_init),
151 	DEVMETHOD_END
152 };
153 
154 static driver_t debug_driver = {
155 	"debug",
156 	debug_methods,
157 	sizeof(struct debug_softc),
158 };
159 
160 EARLY_DRIVER_MODULE(debug, simplebus, debug_driver, 0, 0,
161     BUS_PASS_BUS + BUS_PASS_ORDER_LATE);
162 MODULE_VERSION(debug, 1);
163