xref: /freebsd/sys/dev/spibus/spibus.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * Copyright (c) 2006 M. Warner Losh
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 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 #include <sys/kernel.h>
36 #include <sys/queue.h>
37 #include <sys/sysctl.h>
38 #include <sys/types.h>
39 
40 #include <sys/bus.h>
41 #include <machine/bus.h>
42 #include <sys/rman.h>
43 #include <machine/resource.h>
44 
45 #include <dev/spibus/spibusvar.h>
46 #include <dev/spibus/spi.h>
47 #include "spibus_if.h"
48 
49 static int
50 spibus_probe(device_t dev)
51 {
52 
53 	device_set_desc(dev, "SPI bus");
54 	return (BUS_PROBE_DEFAULT);
55 }
56 
57 static int
58 spibus_attach(device_t dev)
59 {
60 	struct spibus_softc *sc = SPIBUS_SOFTC(dev);
61 
62 	sc->dev = dev;
63 	bus_enumerate_hinted_children(dev);
64 	return (bus_generic_attach(dev));
65 }
66 
67 /*
68  * Since this is not a self-enumerating bus, and since we always add
69  * children in attach, we have to always delete children here.
70  */
71 static int
72 spibus_detach(device_t dev)
73 {
74 	int err;
75 
76 	if ((err = bus_generic_detach(dev)) != 0)
77 		return (err);
78 	device_delete_children(dev);
79 
80 	return (0);
81 }
82 
83 static int
84 spibus_suspend(device_t dev)
85 {
86 	return (bus_generic_suspend(dev));
87 }
88 
89 static
90 int
91 spibus_resume(device_t dev)
92 {
93 	return (bus_generic_resume(dev));
94 }
95 
96 static int
97 spibus_print_child(device_t dev, device_t child)
98 {
99 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
100 	int retval = 0;
101 
102 	retval += bus_print_child_header(dev, child);
103 	retval += printf(" at cs %d", devi->cs);
104 	retval += printf(" mode %d", devi->mode);
105 	retval += bus_print_child_footer(dev, child);
106 
107 	return (retval);
108 }
109 
110 static void
111 spibus_probe_nomatch(device_t bus, device_t child)
112 {
113 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
114 
115 	device_printf(bus, "<unknown card> at cs %d mode %d\n", devi->cs,
116 	    devi->mode);
117 	return;
118 }
119 
120 static int
121 spibus_child_location_str(device_t bus, device_t child, char *buf,
122     size_t buflen)
123 {
124 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
125 	int cs;
126 
127 	cs = devi->cs & ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
128 	snprintf(buf, buflen, "bus=%d cs=%d", device_get_unit(bus), cs);
129 	return (0);
130 }
131 
132 static int
133 spibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
134     size_t buflen)
135 {
136 	*buf = '\0';
137 	return (0);
138 }
139 
140 static int
141 spibus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
142 {
143 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
144 
145 	switch (which) {
146 	default:
147 		return (EINVAL);
148 	case SPIBUS_IVAR_CS:
149 		*(uint32_t *)result = devi->cs;
150 		break;
151 	case SPIBUS_IVAR_MODE:
152 		*(uint32_t *)result = devi->mode;
153 		break;
154 	case SPIBUS_IVAR_CLOCK:
155 		*(uint32_t *)result = devi->clock;
156 		break;
157 	}
158 	return (0);
159 }
160 
161 static int
162 spibus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
163 {
164 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
165 
166 	if (devi == NULL || device_get_parent(child) != bus)
167 		return (EDOOFUS);
168 
169 	switch (which) {
170 	case SPIBUS_IVAR_CLOCK:
171 		/* Any non-zero value is allowed for max clock frequency. */
172 		if (value == 0)
173 			return (EINVAL);
174 		devi->clock = (uint32_t)value;
175 		break;
176 	case SPIBUS_IVAR_CS:
177 		 /* Chip select cannot be changed. */
178 		return (EINVAL);
179 	case SPIBUS_IVAR_MODE:
180 		/* Valid SPI modes are 0-3. */
181 		if (value > 3)
182 			return (EINVAL);
183 		devi->mode = (uint32_t)value;
184 		break;
185 	default:
186 		return (EINVAL);
187 	}
188 
189 	return (0);
190 }
191 
192 static device_t
193 spibus_add_child(device_t dev, u_int order, const char *name, int unit)
194 {
195 	device_t child;
196 	struct spibus_ivar *devi;
197 
198 	child = device_add_child_ordered(dev, order, name, unit);
199 	if (child == NULL)
200 		return (child);
201 	devi = malloc(sizeof(struct spibus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
202 	if (devi == NULL) {
203 		device_delete_child(dev, child);
204 		return (0);
205 	}
206 	device_set_ivars(child, devi);
207 	return (child);
208 }
209 
210 static void
211 spibus_hinted_child(device_t bus, const char *dname, int dunit)
212 {
213 	device_t child;
214 	struct spibus_ivar *devi;
215 
216 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
217 	devi = SPIBUS_IVAR(child);
218 	devi->mode = SPIBUS_MODE_NONE;
219 	resource_int_value(dname, dunit, "clock", &devi->clock);
220 	resource_int_value(dname, dunit, "cs", &devi->cs);
221 	resource_int_value(dname, dunit, "mode", &devi->mode);
222 }
223 
224 static int
225 spibus_transfer_impl(device_t dev, device_t child, struct spi_command *cmd)
226 {
227 	return (SPIBUS_TRANSFER(device_get_parent(dev), child, cmd));
228 }
229 
230 static device_method_t spibus_methods[] = {
231 	/* Device interface */
232 	DEVMETHOD(device_probe,		spibus_probe),
233 	DEVMETHOD(device_attach,	spibus_attach),
234 	DEVMETHOD(device_detach,	spibus_detach),
235 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
236 	DEVMETHOD(device_suspend,	spibus_suspend),
237 	DEVMETHOD(device_resume,	spibus_resume),
238 
239 	/* Bus interface */
240 	DEVMETHOD(bus_add_child,	spibus_add_child),
241 	DEVMETHOD(bus_print_child,	spibus_print_child),
242 	DEVMETHOD(bus_probe_nomatch,	spibus_probe_nomatch),
243 	DEVMETHOD(bus_read_ivar,	spibus_read_ivar),
244 	DEVMETHOD(bus_write_ivar,	spibus_write_ivar),
245 	DEVMETHOD(bus_child_pnpinfo_str, spibus_child_pnpinfo_str),
246 	DEVMETHOD(bus_child_location_str, spibus_child_location_str),
247 	DEVMETHOD(bus_hinted_child,	spibus_hinted_child),
248 
249 	/* spibus interface */
250 	DEVMETHOD(spibus_transfer,	spibus_transfer_impl),
251 
252 	DEVMETHOD_END
253 };
254 
255 driver_t spibus_driver = {
256 	"spibus",
257 	spibus_methods,
258 	sizeof(struct spibus_softc)
259 };
260 
261 devclass_t	spibus_devclass;
262 
263 DRIVER_MODULE(spibus, spi, spibus_driver, spibus_devclass, 0, 0);
264 MODULE_VERSION(spibus, 1);
265