xref: /netbsd-src/sys/dev/i2c/i2c.c (revision ba65fde2d7fefa7d39838fa5fa855e62bd606b5e) 
1 /*	$NetBSD: i2c.c,v 1.39 2013/02/03 16:28:51 jdc Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: i2c.c,v 1.39 2013/02/03 16:28:51 jdc Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/device.h>
44 #include <sys/event.h>
45 #include <sys/conf.h>
46 #include <sys/malloc.h>
47 #include <sys/kmem.h>
48 #include <sys/kthread.h>
49 #include <sys/proc.h>
50 #include <sys/kernel.h>
51 #include <sys/fcntl.h>
52 #include <sys/module.h>
53 
54 #include <dev/i2c/i2cvar.h>
55 
56 #include "locators.h"
57 
58 #define I2C_MAX_ADDR	0x3ff	/* 10-bit address, max */
59 
60 struct iic_softc {
61 	i2c_tag_t sc_tag;
62 	int sc_type;
63 	device_t sc_devices[I2C_MAX_ADDR + 1];
64 };
65 
66 static dev_type_open(iic_open);
67 static dev_type_close(iic_close);
68 static dev_type_ioctl(iic_ioctl);
69 
70 const struct cdevsw iic_cdevsw = {
71 	iic_open, iic_close, noread, nowrite, iic_ioctl,
72 	nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
73 };
74 
75 extern struct cfdriver iic_cd;
76 
77 static void	iic_smbus_intr_thread(void *);
78 static void	iic_fill_compat(struct i2c_attach_args*, const char*,
79 			size_t, char **);
80 
81 static int
82 iic_print_direct(void *aux, const char *pnp)
83 {
84 	struct i2c_attach_args *ia = aux;
85 
86 	if (pnp != NULL)
87 		aprint_normal("%s at %s addr 0x%02x", ia->ia_name, pnp,
88 			ia->ia_addr);
89 	else
90 		aprint_normal(" addr 0x%02x", ia->ia_addr);
91 
92 	return UNCONF;
93 }
94 
95 static int
96 iic_print(void *aux, const char *pnp)
97 {
98 	struct i2c_attach_args *ia = aux;
99 
100 	if (ia->ia_addr != (i2c_addr_t)-1)
101 		aprint_normal(" addr 0x%x", ia->ia_addr);
102 
103 	return UNCONF;
104 }
105 
106 static int
107 iic_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
108 {
109 	struct iic_softc *sc = device_private(parent);
110 	struct i2c_attach_args ia;
111 
112 	ia.ia_tag = sc->sc_tag;
113 	ia.ia_addr = cf->cf_loc[IICCF_ADDR];
114 	ia.ia_size = cf->cf_loc[IICCF_SIZE];
115 	ia.ia_type = sc->sc_type;
116 
117 	ia.ia_name = NULL;
118 	ia.ia_ncompat = 0;
119 	ia.ia_compat = NULL;
120 
121 	if (ia.ia_addr != (i2c_addr_t)-1 &&
122 	    ia.ia_addr <= I2C_MAX_ADDR &&
123 	    !sc->sc_devices[ia.ia_addr])
124 		if (config_match(parent, cf, &ia) > 0) {
125 			sc->sc_devices[ia.ia_addr] =
126 			    config_attach(parent, cf, &ia, iic_print);
127 	}
128 	return 0;
129 }
130 
131 static void
132 iic_child_detach(device_t parent, device_t child)
133 {
134 	struct iic_softc *sc = device_private(parent);
135 	int i;
136 
137 	for (i = 0; i <= I2C_MAX_ADDR; i++)
138 		if (sc->sc_devices[i] == child) {
139 			sc->sc_devices[i] = NULL;
140 			break;
141 	}
142 }
143 
144 static int
145 iic_rescan(device_t self, const char *ifattr, const int *locators)
146 {
147 	config_search_ia(iic_search, self, ifattr, NULL);
148 	return 0;
149 }
150 
151 static int
152 iic_match(device_t parent, cfdata_t cf, void *aux)
153 {
154 
155 	return 1;
156 }
157 
158 static void
159 iic_attach(device_t parent, device_t self, void *aux)
160 {
161 	struct iic_softc *sc = device_private(self);
162 	struct i2cbus_attach_args *iba = aux;
163 	prop_array_t child_devices;
164 	char *buf;
165 	i2c_tag_t ic;
166 	int rv;
167 
168 	aprint_naive("\n");
169 	aprint_normal(": I2C bus\n");
170 
171 	sc->sc_tag = iba->iba_tag;
172 	sc->sc_type = iba->iba_type;
173 	ic = sc->sc_tag;
174 	ic->ic_devname = device_xname(self);
175 
176 	LIST_INIT(&(sc->sc_tag->ic_list));
177 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
178 
179 	rv = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
180 	    iic_smbus_intr_thread, ic, &ic->ic_intr_thread,
181 	    "%s", ic->ic_devname);
182 	if (rv)
183 		aprint_error_dev(self, "unable to create intr thread\n");
184 
185 	if (!pmf_device_register(self, NULL, NULL))
186 		aprint_error_dev(self, "couldn't establish power handler\n");
187 
188 	child_devices = prop_dictionary_get(device_properties(parent),
189 		"i2c-child-devices");
190 	if (child_devices) {
191 		unsigned int i, count;
192 		prop_dictionary_t dev;
193 		prop_data_t cdata;
194 		uint32_t addr, size;
195 		uint64_t cookie;
196 		const char *name;
197 		struct i2c_attach_args ia;
198 		int loc[2];
199 
200 		memset(loc, 0, sizeof loc);
201 		count = prop_array_count(child_devices);
202 		for (i = 0; i < count; i++) {
203 			dev = prop_array_get(child_devices, i);
204 			if (!dev) continue;
205  			if (!prop_dictionary_get_cstring_nocopy(
206 			    dev, "name", &name))
207 				continue;
208 			if (!prop_dictionary_get_uint32(dev, "addr", &addr))
209 				continue;
210 			if (!prop_dictionary_get_uint64(dev, "cookie", &cookie))
211 				cookie = 0;
212 			loc[0] = addr;
213 			if (prop_dictionary_get_uint32(dev, "size", &size))
214 				loc[1] = size;
215 			else
216 				loc[1] = -1;
217 
218 			memset(&ia, 0, sizeof ia);
219 			ia.ia_addr = addr;
220 			ia.ia_type = sc->sc_type;
221 			ia.ia_tag = ic;
222 			ia.ia_name = name;
223 			ia.ia_cookie = cookie;
224 			ia.ia_size = size;
225 
226 			buf = NULL;
227 			cdata = prop_dictionary_get(dev, "compatible");
228 			if (cdata)
229 				iic_fill_compat(&ia,
230 				    prop_data_data_nocopy(cdata),
231 				    prop_data_size(cdata), &buf);
232 
233 			if (addr > I2C_MAX_ADDR) {
234 				aprint_error_dev(self,
235 				    "WARNING: ignoring bad device address "
236 				    "@ 0x%02x\n", addr);
237 			} else if (sc->sc_devices[addr] == NULL) {
238 				sc->sc_devices[addr] =
239 				    config_found_sm_loc(self, "iic", loc, &ia,
240 					iic_print_direct, NULL);
241 			}
242 
243 			if (ia.ia_compat)
244 				free(ia.ia_compat, M_TEMP);
245 			if (buf)
246 				free(buf, M_TEMP);
247 		}
248 	} else {
249 		/*
250 		 * Attach all i2c devices described in the kernel
251 		 * configuration file.
252 		 */
253 		iic_rescan(self, "iic", NULL);
254 	}
255 }
256 
257 static int
258 iic_detach(device_t self, int flags)
259 {
260 	struct iic_softc *sc = device_private(self);
261 	i2c_tag_t ic = sc->sc_tag;
262 	int i, error;
263 	void *hdl;
264 
265 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
266 		if (sc->sc_devices[i]) {
267 			error = config_detach(sc->sc_devices[i], flags);
268 			if (error)
269 				return error;
270 		}
271 	}
272 
273 	if (ic->ic_running) {
274 		ic->ic_running = 0;
275 		wakeup(ic);
276 		kthread_join(ic->ic_intr_thread);
277 	}
278 
279 	if (!LIST_EMPTY(&ic->ic_list)) {
280 		device_printf(self, "WARNING: intr handler list not empty\n");
281 		while (!LIST_EMPTY(&ic->ic_list)) {
282 			hdl = LIST_FIRST(&ic->ic_list);
283 			iic_smbus_intr_disestablish(ic, hdl);
284 		}
285 	}
286 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
287 		device_printf(self, "WARNING: proc handler list not empty\n");
288 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
289 			hdl = LIST_FIRST(&ic->ic_proc_list);
290 			iic_smbus_intr_disestablish_proc(ic, hdl);
291 		}
292 	}
293 
294 	pmf_device_deregister(self);
295 
296 	return 0;
297 }
298 
299 static void
300 iic_smbus_intr_thread(void *aux)
301 {
302 	i2c_tag_t ic;
303 	struct ic_intr_list *il;
304 	int rv;
305 
306 	ic = (i2c_tag_t)aux;
307 	ic->ic_running = 1;
308 	ic->ic_pending = 0;
309 
310 	while (ic->ic_running) {
311 		if (ic->ic_pending == 0)
312 			rv = tsleep(ic, PZERO, "iicintr", hz);
313 		if (ic->ic_pending > 0) {
314 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
315 				(*il->il_intr)(il->il_intrarg);
316 			}
317 			ic->ic_pending--;
318 		}
319 	}
320 
321 	kthread_exit(0);
322 }
323 
324 void *
325 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
326 {
327 	struct ic_intr_list *il;
328 
329 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
330 	if (il == NULL)
331 		return NULL;
332 
333 	il->il_intr = intr;
334 	il->il_intrarg = intrarg;
335 
336 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
337 
338 	return il;
339 }
340 
341 void
342 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
343 {
344 	struct ic_intr_list *il;
345 
346 	il = (struct ic_intr_list *)hdl;
347 
348 	LIST_REMOVE(il, il_next);
349 	free(il, M_DEVBUF);
350 
351 	return;
352 }
353 
354 void *
355 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
356 {
357 	struct ic_intr_list *il;
358 
359 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
360 	if (il == NULL)
361 		return NULL;
362 
363 	il->il_intr = intr;
364 	il->il_intrarg = intrarg;
365 
366 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
367 
368 	return il;
369 }
370 
371 void
372 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
373 {
374 	struct ic_intr_list *il;
375 
376 	il = (struct ic_intr_list *)hdl;
377 
378 	LIST_REMOVE(il, il_next);
379 	free(il, M_DEVBUF);
380 
381 	return;
382 }
383 
384 int
385 iic_smbus_intr(i2c_tag_t ic)
386 {
387 	struct ic_intr_list *il;
388 
389 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
390 		(*il->il_intr)(il->il_intrarg);
391 	}
392 
393 	ic->ic_pending++;
394 	wakeup(ic);
395 
396 	return 1;
397 }
398 
399 static void
400 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
401 	char **buffer)
402 {
403 	int count, i;
404 	const char *c, *start, **ptr;
405 
406 	*buffer = NULL;
407 	for (i = count = 0, c = compat; i < len; i++, c++)
408 		if (*c == 0)
409 			count++;
410 	count += 2;
411 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
412 	if (!ptr) return;
413 
414 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
415 		if (*c == 0) {
416 			ptr[count++] = start;
417 			start = c+1;
418 		}
419 	}
420 	if (start < compat+len) {
421 		/* last string not 0 terminated */
422 		size_t l = c-start;
423 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
424 		memcpy(*buffer, start, l);
425 		(*buffer)[l] = 0;
426 		ptr[count++] = *buffer;
427 	}
428 	ptr[count] = NULL;
429 
430 	ia->ia_compat = ptr;
431 	ia->ia_ncompat = count;
432 }
433 
434 int
435 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
436 {
437 	int i;
438 
439 	for (; compats && *compats; compats++) {
440 		for (i = 0; i < ia->ia_ncompat; i++) {
441 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
442 				return 1;
443 		}
444 	}
445 	return 0;
446 }
447 
448 static int
449 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
450 {
451 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
452 
453 	if (sc == NULL)
454 		return ENXIO;
455 
456 	return 0;
457 }
458 
459 static int
460 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
461 {
462 	return 0;
463 }
464 
465 static int
466 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
467 {
468 	i2c_tag_t ic = sc->sc_tag;
469 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
470 	void *cmd = NULL;
471 	int error;
472 
473 	/* Validate parameters */
474 	if (iie->iie_addr > I2C_MAX_ADDR)
475 		return EINVAL;
476 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
477 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
478 		return EINVAL;
479 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
480 		return EINVAL;
481 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
482 		return EINVAL;
483 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
484 		return EBADF;
485 
486 #if 0
487 	/* Disallow userspace access to devices that have drivers attached. */
488 	if (sc->sc_devices[iie->iie_addr] != NULL)
489 		return EBUSY;
490 #endif
491 
492 	if (iie->iie_cmd != NULL) {
493 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
494 		if (cmd == NULL)
495 			return ENOMEM;
496 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
497 		if (error) {
498 			kmem_free(cmd, iie->iie_cmdlen);
499 			return error;
500 		}
501 	}
502 
503 	iic_acquire_bus(ic, 0);
504 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
505 	    buf, iie->iie_buflen, 0);
506 	iic_release_bus(ic, 0);
507 
508 	/*
509 	 * Some drivers return error codes on failure, and others return -1.
510 	 */
511 	if (error < 0)
512 		error = EIO;
513 
514 	if (cmd)
515 		kmem_free(cmd, iie->iie_cmdlen);
516 
517 	if (error)
518 		return error;
519 
520 	if (iie->iie_buf)
521 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
522 
523 	return error;
524 }
525 
526 static int
527 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
528 {
529 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
530 
531 	if (sc == NULL)
532 		return ENXIO;
533 
534 	switch (cmd) {
535 	case I2C_IOCTL_EXEC:
536 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
537 	default:
538 		return ENODEV;
539 	}
540 }
541 
542 
543 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
544     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
545 
546 MODULE(MODULE_CLASS_DRIVER, iic, NULL);
547 
548 #ifdef _MODULE
549 #include "ioconf.c"
550 #endif
551 
552 static int
553 iic_modcmd(modcmd_t cmd, void *opaque)
554 {
555 	int error;
556 
557 	error = 0;
558 	switch (cmd) {
559 	case MODULE_CMD_INIT:
560 #ifdef _MODULE
561 		error = config_init_component(cfdriver_ioconf_iic,
562 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
563 		if (error)
564 			aprint_error("%s: unable to init component\n",
565 			    iic_cd.cd_name);
566 #endif
567 		break;
568 	case MODULE_CMD_FINI:
569 #ifdef _MODULE
570 		config_fini_component(cfdriver_ioconf_iic,
571 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
572 #endif
573 		break;
574 	default:
575 		error = ENOTTY;
576 	}
577 	return error;
578 }
579