xref: /freebsd/sys/dev/p2sb/p2sb.c (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1 /*-
2  * Copyright (c) 2018 Stormshield
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * Implementation of Primary to Sideband bridge (P2SB), the documentation is available here :
29  * https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/c620-series-chipset-datasheet.pdf
30  * section 36.9 P2SB Bridge.
31  * This device exposes a 16MB memory block, this block is composed of 256 64KB blocks called ports.
32  * The indexes of this array (target port ID) can be found on the Table 36-10 of the documentation.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/module.h>
37 #include <sys/systm.h>
38 #include <sys/errno.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/mutex.h>
43 #include <sys/bus.h>
44 
45 #include <machine/bus.h>
46 #include <sys/rman.h>
47 #include <machine/resource.h>
48 
49 #include <dev/pci/pcivar.h>
50 #include <dev/pci/pcireg.h>
51 
52 #include "p2sb.h"
53 
54 #define PCI_PRODUCT_LEWISBURG_P2SB 0xa1a08086
55 
56 #define P2SB_PORT2ADDRESS_SHIFT 16
57 #define P2SB_PORT_ADDRESS(port) ((uint32_t)port << P2SB_PORT2ADDRESS_SHIFT)
58 
59 static const uint8_t lbg_communities[] = {
60 	0xAF, 0xAE, 0xAD, 0xAC, 0xAB, 0x11
61 };
62 
63 /* The softc holds our per-instance data. */
64 struct p2sb_softc {
65 	device_t	dev;
66 	int rid;
67 	struct resource *res;
68 	struct intel_community *communities;
69 	int ncommunities;
70 	struct mtx mutex;
71 };
72 
73 int
74 p2sb_get_port(device_t dev, int unit)
75 {
76 
77 	if (unit >= nitems(lbg_communities))
78 		return (EINVAL);
79 	return (lbg_communities[unit]);
80 }
81 
82 uint32_t
83 p2sb_port_read_4(device_t dev, uint8_t port, uint32_t reg)
84 {
85 	struct p2sb_softc *sc;
86 
87 	KASSERT(reg < (1<<P2SB_PORT2ADDRESS_SHIFT), ("register out of port"));
88 	sc = device_get_softc(dev);
89 	return (bus_read_4(sc->res, P2SB_PORT_ADDRESS(port) + reg));
90 }
91 
92 void
93 p2sb_port_write_4(device_t dev, uint8_t port, uint32_t reg, uint32_t val)
94 {
95 	struct p2sb_softc *sc;
96 
97 	KASSERT(reg < (1<<P2SB_PORT2ADDRESS_SHIFT), ("register out of port"));
98 	sc = device_get_softc(dev);
99 	bus_write_4(sc->res, P2SB_PORT_ADDRESS(port) + reg, val);
100 }
101 
102 void
103 p2sb_lock(device_t dev)
104 {
105 	struct p2sb_softc *sc;
106 
107 	sc = device_get_softc(dev);
108 	mtx_lock_spin(&sc->mutex);
109 }
110 
111 void
112 p2sb_unlock(device_t dev)
113 {
114 	struct p2sb_softc *sc;
115 
116 	sc = device_get_softc(dev);
117 	mtx_unlock_spin(&sc->mutex);
118 }
119 
120 
121 static int
122 p2sb_probe(device_t dev)
123 {
124 
125 	if (pci_get_devid(dev) == PCI_PRODUCT_LEWISBURG_P2SB) {
126 		device_set_desc(dev, "Lewisburg P2SB");
127 		return (BUS_PROBE_DEFAULT);
128 	}
129 	return (ENXIO);
130 }
131 
132 /* Attach function is only called if the probe is successful. */
133 
134 static int
135 p2sb_attach(device_t dev)
136 {
137 	struct p2sb_softc *sc;
138 	int i;
139 
140 	sc = device_get_softc(dev);
141 	sc->dev = dev;
142 	sc->rid = PCIR_BAR(0);
143 	sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->rid, RF_ACTIVE);
144 	if (sc->res == NULL) {
145 		device_printf(dev, "Could not allocate memory.\n");
146 		return (ENXIO);
147 	}
148 	mtx_init(&sc->mutex, device_get_nameunit(dev), NULL, MTX_SPIN);
149 	for (i = 0; i < nitems(lbg_communities); ++i)
150 		device_add_child(dev, "lbggpiocm", i);
151 
152 	return (bus_generic_attach(dev));
153 }
154 
155 /* Detach device. */
156 
157 static int
158 p2sb_detach(device_t dev)
159 {
160 	struct p2sb_softc *sc;
161 
162 	/* Teardown the state in our softc created in our attach routine. */
163 	device_delete_children(dev);
164 	sc = device_get_softc(dev);
165 	mtx_destroy(&sc->mutex);
166 	if (sc->res != NULL)
167 		bus_release_resource(dev, SYS_RES_MEMORY, sc->rid, sc->res);
168 	return (0);
169 }
170 
171 /* Called during system shutdown after sync. */
172 
173 static int
174 p2sb_shutdown(device_t dev)
175 {
176 
177 	return (0);
178 }
179 
180 /*
181  * Device suspend routine.
182  */
183 static int
184 p2sb_suspend(device_t dev)
185 {
186 
187 	return (0);
188 }
189 
190 /*
191  * Device resume routine.
192  */
193 static int
194 p2sb_resume(device_t dev)
195 {
196 
197 	return (0);
198 }
199 
200 static device_method_t p2sb_methods[] = {
201 	/* Device interface */
202 	DEVMETHOD(device_probe,		p2sb_probe),
203 	DEVMETHOD(device_attach,	p2sb_attach),
204 	DEVMETHOD(device_detach,	p2sb_detach),
205 	DEVMETHOD(device_shutdown,	p2sb_shutdown),
206 	DEVMETHOD(device_suspend,	p2sb_suspend),
207 	DEVMETHOD(device_resume,	p2sb_resume),
208 
209 	DEVMETHOD_END
210 };
211 
212 static devclass_t p2sb_devclass;
213 
214 DEFINE_CLASS_0(p2sb, p2sb_driver, p2sb_methods, sizeof(struct p2sb_softc));
215 DRIVER_MODULE(p2sb, pci, p2sb_driver, p2sb_devclass, 0, 0);
216