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: stable/11/sys/dev/spibus/spibus.c 346557 2019-04-22 15:04:11Z ian $");
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
49static int
50spibus_probe(device_t dev)
51{
52
53	device_set_desc(dev, "SPI bus");
54	return (BUS_PROBE_DEFAULT);
55}
56
57static int
58spibus_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 */
71static int
72spibus_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
83static int
84spibus_suspend(device_t dev)
85{
86	return (bus_generic_suspend(dev));
87}
88
89static
90int
91spibus_resume(device_t dev)
92{
93	return (bus_generic_resume(dev));
94}
95
96static int
97spibus_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
110static void
111spibus_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
120static int
121spibus_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
132static int
133spibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
134    size_t buflen)
135{
136	*buf = '\0';
137	return (0);
138}
139
140static int
141spibus_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
161static int
162spibus_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
192static device_t
193spibus_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
210static void
211spibus_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
224static int
225spibus_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
230static 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
255driver_t spibus_driver = {
256	"spibus",
257	spibus_methods,
258	sizeof(struct spibus_softc)
259};
260
261devclass_t	spibus_devclass;
262
263DRIVER_MODULE(spibus, spi, spibus_driver, spibus_devclass, 0, 0);
264MODULE_VERSION(spibus, 1);
265