xref: /freebsd/sys/dev/spibus/spibus.c (revision e17f5b1d)
1 /*-
2  * Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/module.h>
34 #include <sys/kernel.h>
35 #include <sys/queue.h>
36 #include <sys/sysctl.h>
37 #include <sys/types.h>
38 
39 #include <sys/bus.h>
40 #include <machine/bus.h>
41 #include <sys/rman.h>
42 #include <machine/resource.h>
43 
44 #include <dev/spibus/spibusvar.h>
45 #include <dev/spibus/spi.h>
46 #include "spibus_if.h"
47 
48 static int
49 spibus_probe(device_t dev)
50 {
51 
52 	device_set_desc(dev, "SPI bus");
53 	return (BUS_PROBE_DEFAULT);
54 }
55 
56 static int
57 spibus_attach(device_t dev)
58 {
59 	struct spibus_softc *sc = SPIBUS_SOFTC(dev);
60 
61 	sc->dev = dev;
62 	bus_enumerate_hinted_children(dev);
63 	return (bus_generic_attach(dev));
64 }
65 
66 /*
67  * Since this is not a self-enumerating bus, and since we always add
68  * children in attach, we have to always delete children here.
69  */
70 static int
71 spibus_detach(device_t dev)
72 {
73 	int err;
74 
75 	if ((err = bus_generic_detach(dev)) != 0)
76 		return (err);
77 	device_delete_children(dev);
78 
79 	return (0);
80 }
81 
82 static int
83 spibus_suspend(device_t dev)
84 {
85 	return (bus_generic_suspend(dev));
86 }
87 
88 static
89 int
90 spibus_resume(device_t dev)
91 {
92 	return (bus_generic_resume(dev));
93 }
94 
95 static int
96 spibus_print_child(device_t dev, device_t child)
97 {
98 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
99 	int retval = 0;
100 
101 	retval += bus_print_child_header(dev, child);
102 	retval += printf(" at cs %d", devi->cs);
103 	retval += printf(" mode %d", devi->mode);
104 	retval += bus_print_child_footer(dev, child);
105 
106 	return (retval);
107 }
108 
109 static void
110 spibus_probe_nomatch(device_t bus, device_t child)
111 {
112 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
113 
114 	device_printf(bus, "<unknown card> at cs %d mode %d\n", devi->cs,
115 	    devi->mode);
116 	return;
117 }
118 
119 static int
120 spibus_child_location_str(device_t bus, device_t child, char *buf,
121     size_t buflen)
122 {
123 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
124 	int cs;
125 
126 	cs = devi->cs & ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
127 	snprintf(buf, buflen, "bus=%d cs=%d", device_get_unit(bus), cs);
128 	return (0);
129 }
130 
131 static int
132 spibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
133     size_t buflen)
134 {
135 	*buf = '\0';
136 	return (0);
137 }
138 
139 static int
140 spibus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
141 {
142 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
143 
144 	switch (which) {
145 	default:
146 		return (EINVAL);
147 	case SPIBUS_IVAR_CS:
148 		*(uint32_t *)result = devi->cs;
149 		break;
150 	case SPIBUS_IVAR_MODE:
151 		*(uint32_t *)result = devi->mode;
152 		break;
153 	case SPIBUS_IVAR_CLOCK:
154 		*(uint32_t *)result = devi->clock;
155 		break;
156 	}
157 	return (0);
158 }
159 
160 static int
161 spibus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
162 {
163 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
164 
165 	if (devi == NULL || device_get_parent(child) != bus)
166 		return (EDOOFUS);
167 
168 	switch (which) {
169 	case SPIBUS_IVAR_CLOCK:
170 		/* Any non-zero value is allowed for max clock frequency. */
171 		if (value == 0)
172 			return (EINVAL);
173 		devi->clock = (uint32_t)value;
174 		break;
175 	case SPIBUS_IVAR_CS:
176 		 /* Chip select cannot be changed. */
177 		return (EINVAL);
178 	case SPIBUS_IVAR_MODE:
179 		/* Valid SPI modes are 0-3. */
180 		if (value > 3)
181 			return (EINVAL);
182 		devi->mode = (uint32_t)value;
183 		break;
184 	default:
185 		return (EINVAL);
186 	}
187 
188 	return (0);
189 }
190 
191 static device_t
192 spibus_add_child(device_t dev, u_int order, const char *name, int unit)
193 {
194 	device_t child;
195 	struct spibus_ivar *devi;
196 
197 	child = device_add_child_ordered(dev, order, name, unit);
198 	if (child == NULL)
199 		return (child);
200 	devi = malloc(sizeof(struct spibus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
201 	if (devi == NULL) {
202 		device_delete_child(dev, child);
203 		return (0);
204 	}
205 	device_set_ivars(child, devi);
206 	return (child);
207 }
208 
209 static void
210 spibus_hinted_child(device_t bus, const char *dname, int dunit)
211 {
212 	device_t child;
213 	struct spibus_ivar *devi;
214 
215 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
216 	devi = SPIBUS_IVAR(child);
217 	devi->mode = SPIBUS_MODE_NONE;
218 	resource_int_value(dname, dunit, "clock", &devi->clock);
219 	resource_int_value(dname, dunit, "cs", &devi->cs);
220 	resource_int_value(dname, dunit, "mode", &devi->mode);
221 }
222 
223 static int
224 spibus_transfer_impl(device_t dev, device_t child, struct spi_command *cmd)
225 {
226 	return (SPIBUS_TRANSFER(device_get_parent(dev), child, cmd));
227 }
228 
229 static device_method_t spibus_methods[] = {
230 	/* Device interface */
231 	DEVMETHOD(device_probe,		spibus_probe),
232 	DEVMETHOD(device_attach,	spibus_attach),
233 	DEVMETHOD(device_detach,	spibus_detach),
234 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
235 	DEVMETHOD(device_suspend,	spibus_suspend),
236 	DEVMETHOD(device_resume,	spibus_resume),
237 
238 	/* Bus interface */
239 	DEVMETHOD(bus_add_child,	spibus_add_child),
240 	DEVMETHOD(bus_print_child,	spibus_print_child),
241 	DEVMETHOD(bus_probe_nomatch,	spibus_probe_nomatch),
242 	DEVMETHOD(bus_read_ivar,	spibus_read_ivar),
243 	DEVMETHOD(bus_write_ivar,	spibus_write_ivar),
244 	DEVMETHOD(bus_child_pnpinfo_str, spibus_child_pnpinfo_str),
245 	DEVMETHOD(bus_child_location_str, spibus_child_location_str),
246 	DEVMETHOD(bus_hinted_child,	spibus_hinted_child),
247 
248 	/* spibus interface */
249 	DEVMETHOD(spibus_transfer,	spibus_transfer_impl),
250 
251 	DEVMETHOD_END
252 };
253 
254 driver_t spibus_driver = {
255 	"spibus",
256 	spibus_methods,
257 	sizeof(struct spibus_softc)
258 };
259 
260 devclass_t	spibus_devclass;
261 
262 DRIVER_MODULE(spibus, spi, spibus_driver, spibus_devclass, 0, 0);
263 MODULE_VERSION(spibus, 1);
264