1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1998, 2001 Nicolas Souchu
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 /*
31 * Autoconfiguration and support routines for the Philips serial I2C bus
32 */
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/rman.h>
42 #include <sys/sysctl.h>
43 #include <sys/bus.h>
44
45 #include <dev/iicbus/iiconf.h>
46 #include <dev/iicbus/iicbus.h>
47
48 #include "iicbus_if.h"
49
50 /* See comments below for why auto-scanning is a bad idea. */
51 #define SCAN_IICBUS 0
52
53 SYSCTL_NODE(_hw, OID_AUTO, i2c, CTLFLAG_RW, 0, "i2c controls");
54
55 static int
iicbus_probe(device_t dev)56 iicbus_probe(device_t dev)
57 {
58
59 device_set_desc(dev, "Philips I2C bus");
60
61 /* Allow other subclasses to override this driver. */
62 return (BUS_PROBE_GENERIC);
63 }
64
65 #if SCAN_IICBUS
66 static int
iic_probe_device(device_t dev,u_char addr)67 iic_probe_device(device_t dev, u_char addr)
68 {
69 int count;
70 char byte;
71
72 if ((addr & 1) == 0) {
73 /* is device writable? */
74 if (!iicbus_start(dev, (u_char)addr, 0)) {
75 iicbus_stop(dev);
76 return (1);
77 }
78 } else {
79 /* is device readable? */
80 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
81 return (1);
82 }
83
84 return (0);
85 }
86 #endif
87
88 /*
89 * We add all the devices which we know about.
90 * The generic attach routine will attach them if they are alive.
91 */
92 int
iicbus_attach_common(device_t dev,u_int bus_freq)93 iicbus_attach_common(device_t dev, u_int bus_freq)
94 {
95 #if SCAN_IICBUS
96 unsigned char addr;
97 #endif
98 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
99 int strict;
100
101 sc->dev = dev;
102 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF);
103 iicbus_init_frequency(dev, bus_freq);
104 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
105 if (resource_int_value(device_get_name(dev),
106 device_get_unit(dev), "strict", &strict) == 0)
107 sc->strict = strict;
108 else
109 sc->strict = 1;
110
111 /* device probing is meaningless since the bus is supposed to be
112 * hot-plug. Moreover, some I2C chips do not appreciate random
113 * accesses like stop after start to fast, reads for less than
114 * x bytes...
115 */
116 #if SCAN_IICBUS
117 printf("Probing for devices on iicbus%d:", device_get_unit(dev));
118
119 /* probe any devices */
120 for (addr = 16; addr < 240; addr++) {
121 if (iic_probe_device(dev, (u_char)addr)) {
122 printf(" <%x>", addr);
123 }
124 }
125 printf("\n");
126 #endif
127 bus_generic_probe(dev);
128 bus_enumerate_hinted_children(dev);
129 bus_generic_attach(dev);
130 return (0);
131 }
132
133 static int
iicbus_attach(device_t dev)134 iicbus_attach(device_t dev)
135 {
136
137 return (iicbus_attach_common(dev, 0));
138 }
139
140 int
iicbus_detach(device_t dev)141 iicbus_detach(device_t dev)
142 {
143 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
144 int err;
145
146 if ((err = device_delete_children(dev)) != 0)
147 return (err);
148 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
149 mtx_destroy(&sc->lock);
150 return (0);
151 }
152
153 static int
iicbus_print_child(device_t dev,device_t child)154 iicbus_print_child(device_t dev, device_t child)
155 {
156 struct iicbus_ivar *devi = IICBUS_IVAR(child);
157 int retval = 0;
158
159 retval += bus_print_child_header(dev, child);
160 if (devi->addr != 0)
161 retval += printf(" at addr %#x", devi->addr);
162 resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd");
163 retval += bus_print_child_footer(dev, child);
164
165 return (retval);
166 }
167
168 void
iicbus_probe_nomatch(device_t bus,device_t child)169 iicbus_probe_nomatch(device_t bus, device_t child)
170 {
171 struct iicbus_ivar *devi = IICBUS_IVAR(child);
172
173 device_printf(bus, "<unknown card> at addr %#x\n", devi->addr);
174 }
175
176 int
iicbus_child_location_str(device_t bus,device_t child,char * buf,size_t buflen)177 iicbus_child_location_str(device_t bus, device_t child, char *buf,
178 size_t buflen)
179 {
180 struct iicbus_ivar *devi = IICBUS_IVAR(child);
181
182 snprintf(buf, buflen, "addr=%#x", devi->addr);
183 return (0);
184 }
185
186 int
iicbus_child_pnpinfo_str(device_t bus,device_t child,char * buf,size_t buflen)187 iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
188 size_t buflen)
189 {
190 *buf = '\0';
191 return (0);
192 }
193
194 int
iicbus_read_ivar(device_t bus,device_t child,int which,uintptr_t * result)195 iicbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
196 {
197 struct iicbus_ivar *devi = IICBUS_IVAR(child);
198
199 switch (which) {
200 default:
201 return (EINVAL);
202 case IICBUS_IVAR_ADDR:
203 *result = devi->addr;
204 break;
205 }
206 return (0);
207 }
208
209 int
iicbus_write_ivar(device_t bus,device_t child,int which,uintptr_t value)210 iicbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
211 {
212 struct iicbus_ivar *devi = IICBUS_IVAR(child);
213
214 switch (which) {
215 default:
216 return (EINVAL);
217 case IICBUS_IVAR_ADDR:
218 if (devi->addr != 0)
219 return (EINVAL);
220 devi->addr = value;
221 }
222 return (0);
223 }
224
225 device_t
iicbus_add_child_common(device_t dev,u_int order,const char * name,int unit,size_t ivars_size)226 iicbus_add_child_common(device_t dev, u_int order, const char *name, int unit,
227 size_t ivars_size)
228 {
229 device_t child;
230 struct iicbus_ivar *devi;
231
232 child = device_add_child_ordered(dev, order, name, unit);
233 if (child == NULL)
234 return (child);
235 devi = malloc(ivars_size, M_DEVBUF, M_NOWAIT | M_ZERO);
236 if (devi == NULL) {
237 device_delete_child(dev, child);
238 return (0);
239 }
240 resource_list_init(&devi->rl);
241 device_set_ivars(child, devi);
242 return (child);
243 }
244
245 static device_t
iicbus_add_child(device_t dev,u_int order,const char * name,int unit)246 iicbus_add_child(device_t dev, u_int order, const char *name, int unit)
247 {
248
249 return (iicbus_add_child_common(
250 dev, order, name, unit, sizeof(struct iicbus_ivar)));
251 }
252
253 static void
iicbus_child_deleted(device_t dev,device_t child)254 iicbus_child_deleted(device_t dev, device_t child)
255 {
256 struct iicbus_ivar *devi;
257
258 devi = device_get_ivars(child);
259 if (devi == NULL)
260 return;
261 resource_list_free(&devi->rl);
262 free(devi, M_DEVBUF);
263 }
264
265 static void
iicbus_hinted_child(device_t bus,const char * dname,int dunit)266 iicbus_hinted_child(device_t bus, const char *dname, int dunit)
267 {
268 device_t child;
269 int irq;
270 struct iicbus_ivar *devi;
271
272 child = BUS_ADD_CHILD(bus, 0, dname, dunit);
273 devi = IICBUS_IVAR(child);
274 resource_int_value(dname, dunit, "addr", &devi->addr);
275 if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
276 if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
277 device_printf(bus,
278 "warning: bus_set_resource() failed\n");
279 }
280 }
281
282 static struct resource_list *
iicbus_get_resource_list(device_t bus __unused,device_t child)283 iicbus_get_resource_list(device_t bus __unused, device_t child)
284 {
285 struct iicbus_ivar *devi;
286
287 devi = IICBUS_IVAR(child);
288 return (&devi->rl);
289 }
290
291 int
iicbus_generic_intr(device_t dev,int event,char * buf)292 iicbus_generic_intr(device_t dev, int event, char *buf)
293 {
294
295 return (0);
296 }
297
298 int
iicbus_null_callback(device_t dev,int index,caddr_t data)299 iicbus_null_callback(device_t dev, int index, caddr_t data)
300 {
301
302 return (0);
303 }
304
305 int
iicbus_null_repeated_start(device_t dev,u_char addr)306 iicbus_null_repeated_start(device_t dev, u_char addr)
307 {
308
309 return (IIC_ENOTSUPP);
310 }
311
312 void
iicbus_init_frequency(device_t dev,u_int bus_freq)313 iicbus_init_frequency(device_t dev, u_int bus_freq)
314 {
315 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
316
317 /*
318 * If a bus frequency value was passed in, use it. Otherwise initialize
319 * it first to the standard i2c 100KHz frequency, then override that
320 * from a hint if one exists.
321 */
322 if (bus_freq > 0)
323 sc->bus_freq = bus_freq;
324 else {
325 sc->bus_freq = 100000;
326 resource_int_value(device_get_name(dev), device_get_unit(dev),
327 "frequency", (int *)&sc->bus_freq);
328 }
329 /*
330 * Set up the sysctl that allows the bus frequency to be changed.
331 * It is flagged as a tunable so that the user can set the value in
332 * loader(8), and that will override any other setting from any source.
333 * The sysctl tunable/value is the one most directly controlled by the
334 * user and thus the one that always takes precedence.
335 */
336 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
337 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
338 OID_AUTO, "frequency", CTLFLAG_RWTUN, &sc->bus_freq,
339 sc->bus_freq, "Bus frequency in Hz");
340 }
341
342 static u_int
iicbus_get_frequency(device_t dev,u_char speed)343 iicbus_get_frequency(device_t dev, u_char speed)
344 {
345 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
346
347 /*
348 * If the frequency has not been configured for the bus, or the request
349 * is specifically for SLOW speed, use the standard 100KHz rate, else
350 * use the configured bus speed.
351 */
352 if (sc->bus_freq == 0 || speed == IIC_SLOW)
353 return (100000);
354 return (sc->bus_freq);
355 }
356
357 static device_method_t iicbus_methods[] = {
358 /* device interface */
359 DEVMETHOD(device_probe, iicbus_probe),
360 DEVMETHOD(device_attach, iicbus_attach),
361 DEVMETHOD(device_detach, iicbus_detach),
362 DEVMETHOD(device_suspend, bus_generic_suspend),
363 DEVMETHOD(device_resume, bus_generic_resume),
364
365 /* bus interface */
366 DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
367 DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
368 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
369 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
370 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource),
371 DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
372 DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource),
373 DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
374 DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource),
375 DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list),
376 DEVMETHOD(bus_add_child, iicbus_add_child),
377 DEVMETHOD(bus_child_deleted, iicbus_child_deleted),
378 DEVMETHOD(bus_print_child, iicbus_print_child),
379 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch),
380 DEVMETHOD(bus_read_ivar, iicbus_read_ivar),
381 DEVMETHOD(bus_write_ivar, iicbus_write_ivar),
382 DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str),
383 DEVMETHOD(bus_child_location_str, iicbus_child_location_str),
384 DEVMETHOD(bus_hinted_child, iicbus_hinted_child),
385
386 /* iicbus interface */
387 DEVMETHOD(iicbus_transfer, iicbus_transfer),
388 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency),
389
390 DEVMETHOD_END
391 };
392
393 driver_t iicbus_driver = {
394 "iicbus",
395 iicbus_methods,
396 sizeof(struct iicbus_softc),
397 };
398
399 devclass_t iicbus_devclass;
400
401 MODULE_VERSION(iicbus, IICBUS_MODVER);
402 DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0);
403