xref: /netbsd-src/sys/dev/i2c/i2c.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7) 
1 /*	$NetBSD: i2c.c,v 1.44 2014/07/25 08:10:37 dholland 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 1.44 2014/07/25 08:10:37 dholland 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 	.d_open = iic_open,
72 	.d_close = iic_close,
73 	.d_read = noread,
74 	.d_write = nowrite,
75 	.d_ioctl = iic_ioctl,
76 	.d_stop = nostop,
77 	.d_tty = notty,
78 	.d_poll = nopoll,
79 	.d_mmap = nommap,
80 	.d_kqfilter = nokqfilter,
81 	.d_discard = nodiscard,
82 	.d_flag = D_OTHER
83 };
84 
85 extern struct cfdriver iic_cd;
86 
87 static void	iic_smbus_intr_thread(void *);
88 static void	iic_fill_compat(struct i2c_attach_args*, const char*,
89 			size_t, char **);
90 
91 static int
92 iic_print_direct(void *aux, const char *pnp)
93 {
94 	struct i2c_attach_args *ia = aux;
95 
96 	if (pnp != NULL)
97 		aprint_normal("%s at %s addr 0x%02x", ia->ia_name, pnp,
98 			ia->ia_addr);
99 	else
100 		aprint_normal(" addr 0x%02x", ia->ia_addr);
101 
102 	return UNCONF;
103 }
104 
105 static int
106 iic_print(void *aux, const char *pnp)
107 {
108 	struct i2c_attach_args *ia = aux;
109 
110 	if (ia->ia_addr != (i2c_addr_t)-1)
111 		aprint_normal(" addr 0x%x", ia->ia_addr);
112 
113 	return UNCONF;
114 }
115 
116 static int
117 iic_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
118 {
119 	struct iic_softc *sc = device_private(parent);
120 	struct i2c_attach_args ia;
121 
122 	ia.ia_tag = sc->sc_tag;
123 	ia.ia_size = cf->cf_loc[IICCF_SIZE];
124 	ia.ia_type = sc->sc_type;
125 
126 	ia.ia_name = NULL;
127 	ia.ia_ncompat = 0;
128 	ia.ia_compat = NULL;
129 
130 	for (ia.ia_addr = 0; ia.ia_addr <= I2C_MAX_ADDR; ia.ia_addr++) {
131 		if (sc->sc_devices[ia.ia_addr] != NULL)
132 			continue;
133 
134 		if (cf->cf_loc[IICCF_ADDR] != -1 &&
135 		    cf->cf_loc[IICCF_ADDR] != ia.ia_addr)
136 			continue;
137 
138 		if (config_match(parent, cf, &ia) > 0)
139 			sc->sc_devices[ia.ia_addr] =
140 			    config_attach(parent, cf, &ia, iic_print);
141 	}
142 
143 	return 0;
144 }
145 
146 static void
147 iic_child_detach(device_t parent, device_t child)
148 {
149 	struct iic_softc *sc = device_private(parent);
150 	int i;
151 
152 	for (i = 0; i <= I2C_MAX_ADDR; i++)
153 		if (sc->sc_devices[i] == child) {
154 			sc->sc_devices[i] = NULL;
155 			break;
156 		}
157 }
158 
159 static int
160 iic_rescan(device_t self, const char *ifattr, const int *locators)
161 {
162 	config_search_ia(iic_search, self, ifattr, NULL);
163 	return 0;
164 }
165 
166 static int
167 iic_match(device_t parent, cfdata_t cf, void *aux)
168 {
169 
170 	return 1;
171 }
172 
173 static void
174 iic_attach(device_t parent, device_t self, void *aux)
175 {
176 	struct iic_softc *sc = device_private(self);
177 	struct i2cbus_attach_args *iba = aux;
178 	prop_array_t child_devices;
179 	prop_dictionary_t props;
180 	char *buf;
181 	i2c_tag_t ic;
182 	int rv;
183 	bool indirect_config;
184 
185 	aprint_naive("\n");
186 	aprint_normal(": I2C bus\n");
187 
188 	sc->sc_tag = iba->iba_tag;
189 	sc->sc_type = iba->iba_type;
190 	ic = sc->sc_tag;
191 	ic->ic_devname = device_xname(self);
192 
193 	LIST_INIT(&(sc->sc_tag->ic_list));
194 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
195 
196 	rv = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
197 	    iic_smbus_intr_thread, ic, &ic->ic_intr_thread,
198 	    "%s", ic->ic_devname);
199 	if (rv)
200 		aprint_error_dev(self, "unable to create intr thread\n");
201 
202 	if (!pmf_device_register(self, NULL, NULL))
203 		aprint_error_dev(self, "couldn't establish power handler\n");
204 
205 	props = device_properties(parent);
206 	if (!prop_dictionary_get_bool(props, "i2c-indirect-config",
207 	    &indirect_config))
208 		indirect_config = true;
209 	child_devices = prop_dictionary_get(props, "i2c-child-devices");
210 	if (child_devices) {
211 		unsigned int i, count;
212 		prop_dictionary_t dev;
213 		prop_data_t cdata;
214 		uint32_t addr, size;
215 		uint64_t cookie;
216 		const char *name;
217 		struct i2c_attach_args ia;
218 		int loc[2];
219 
220 		memset(loc, 0, sizeof loc);
221 		count = prop_array_count(child_devices);
222 		for (i = 0; i < count; i++) {
223 			dev = prop_array_get(child_devices, i);
224 			if (!dev) continue;
225  			if (!prop_dictionary_get_cstring_nocopy(
226 			    dev, "name", &name))
227 				continue;
228 			if (!prop_dictionary_get_uint32(dev, "addr", &addr))
229 				continue;
230 			if (!prop_dictionary_get_uint64(dev, "cookie", &cookie))
231 				cookie = 0;
232 			loc[0] = addr;
233 			if (prop_dictionary_get_uint32(dev, "size", &size))
234 				loc[1] = size;
235 			else
236 				loc[1] = -1;
237 
238 			memset(&ia, 0, sizeof ia);
239 			ia.ia_addr = addr;
240 			ia.ia_type = sc->sc_type;
241 			ia.ia_tag = ic;
242 			ia.ia_name = name;
243 			ia.ia_cookie = cookie;
244 			ia.ia_size = size;
245 
246 			buf = NULL;
247 			cdata = prop_dictionary_get(dev, "compatible");
248 			if (cdata)
249 				iic_fill_compat(&ia,
250 				    prop_data_data_nocopy(cdata),
251 				    prop_data_size(cdata), &buf);
252 
253 			if (addr > I2C_MAX_ADDR) {
254 				aprint_error_dev(self,
255 				    "WARNING: ignoring bad device address "
256 				    "@ 0x%02x\n", addr);
257 			} else if (sc->sc_devices[addr] == NULL) {
258 				sc->sc_devices[addr] =
259 				    config_found_sm_loc(self, "iic", loc, &ia,
260 					iic_print_direct, NULL);
261 			}
262 
263 			if (ia.ia_compat)
264 				free(ia.ia_compat, M_TEMP);
265 			if (buf)
266 				free(buf, M_TEMP);
267 		}
268 	} else if (indirect_config) {
269 		/*
270 		 * Attach all i2c devices described in the kernel
271 		 * configuration file.
272 		 */
273 		iic_rescan(self, "iic", NULL);
274 	}
275 }
276 
277 static int
278 iic_detach(device_t self, int flags)
279 {
280 	struct iic_softc *sc = device_private(self);
281 	i2c_tag_t ic = sc->sc_tag;
282 	int i, error;
283 	void *hdl;
284 
285 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
286 		if (sc->sc_devices[i]) {
287 			error = config_detach(sc->sc_devices[i], flags);
288 			if (error)
289 				return error;
290 		}
291 	}
292 
293 	if (ic->ic_running) {
294 		ic->ic_running = 0;
295 		wakeup(ic);
296 		kthread_join(ic->ic_intr_thread);
297 	}
298 
299 	if (!LIST_EMPTY(&ic->ic_list)) {
300 		device_printf(self, "WARNING: intr handler list not empty\n");
301 		while (!LIST_EMPTY(&ic->ic_list)) {
302 			hdl = LIST_FIRST(&ic->ic_list);
303 			iic_smbus_intr_disestablish(ic, hdl);
304 		}
305 	}
306 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
307 		device_printf(self, "WARNING: proc handler list not empty\n");
308 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
309 			hdl = LIST_FIRST(&ic->ic_proc_list);
310 			iic_smbus_intr_disestablish_proc(ic, hdl);
311 		}
312 	}
313 
314 	pmf_device_deregister(self);
315 
316 	return 0;
317 }
318 
319 static void
320 iic_smbus_intr_thread(void *aux)
321 {
322 	i2c_tag_t ic;
323 	struct ic_intr_list *il;
324 
325 	ic = (i2c_tag_t)aux;
326 	ic->ic_running = 1;
327 	ic->ic_pending = 0;
328 
329 	while (ic->ic_running) {
330 		if (ic->ic_pending == 0)
331 			tsleep(ic, PZERO, "iicintr", hz);
332 		if (ic->ic_pending > 0) {
333 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
334 				(*il->il_intr)(il->il_intrarg);
335 			}
336 			ic->ic_pending--;
337 		}
338 	}
339 
340 	kthread_exit(0);
341 }
342 
343 void *
344 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
345 {
346 	struct ic_intr_list *il;
347 
348 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
349 	if (il == NULL)
350 		return NULL;
351 
352 	il->il_intr = intr;
353 	il->il_intrarg = intrarg;
354 
355 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
356 
357 	return il;
358 }
359 
360 void
361 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
362 {
363 	struct ic_intr_list *il;
364 
365 	il = (struct ic_intr_list *)hdl;
366 
367 	LIST_REMOVE(il, il_next);
368 	free(il, M_DEVBUF);
369 
370 	return;
371 }
372 
373 void *
374 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
375 {
376 	struct ic_intr_list *il;
377 
378 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
379 	if (il == NULL)
380 		return NULL;
381 
382 	il->il_intr = intr;
383 	il->il_intrarg = intrarg;
384 
385 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
386 
387 	return il;
388 }
389 
390 void
391 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
392 {
393 	struct ic_intr_list *il;
394 
395 	il = (struct ic_intr_list *)hdl;
396 
397 	LIST_REMOVE(il, il_next);
398 	free(il, M_DEVBUF);
399 
400 	return;
401 }
402 
403 int
404 iic_smbus_intr(i2c_tag_t ic)
405 {
406 	struct ic_intr_list *il;
407 
408 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
409 		(*il->il_intr)(il->il_intrarg);
410 	}
411 
412 	ic->ic_pending++;
413 	wakeup(ic);
414 
415 	return 1;
416 }
417 
418 static void
419 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
420 	char **buffer)
421 {
422 	int count, i;
423 	const char *c, *start, **ptr;
424 
425 	*buffer = NULL;
426 	for (i = count = 0, c = compat; i < len; i++, c++)
427 		if (*c == 0)
428 			count++;
429 	count += 2;
430 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
431 	if (!ptr) return;
432 
433 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
434 		if (*c == 0) {
435 			ptr[count++] = start;
436 			start = c+1;
437 		}
438 	}
439 	if (start < compat+len) {
440 		/* last string not 0 terminated */
441 		size_t l = c-start;
442 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
443 		memcpy(*buffer, start, l);
444 		(*buffer)[l] = 0;
445 		ptr[count++] = *buffer;
446 	}
447 	ptr[count] = NULL;
448 
449 	ia->ia_compat = ptr;
450 	ia->ia_ncompat = count;
451 }
452 
453 int
454 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
455 {
456 	int i;
457 
458 	for (; compats && *compats; compats++) {
459 		for (i = 0; i < ia->ia_ncompat; i++) {
460 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
461 				return 1;
462 		}
463 	}
464 	return 0;
465 }
466 
467 static int
468 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
469 {
470 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
471 
472 	if (sc == NULL)
473 		return ENXIO;
474 
475 	return 0;
476 }
477 
478 static int
479 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
480 {
481 	return 0;
482 }
483 
484 static int
485 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
486 {
487 	i2c_tag_t ic = sc->sc_tag;
488 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
489 	void *cmd = NULL;
490 	int error;
491 
492 	/* Validate parameters */
493 	if (iie->iie_addr > I2C_MAX_ADDR)
494 		return EINVAL;
495 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
496 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
497 		return EINVAL;
498 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
499 		return EINVAL;
500 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
501 		return EINVAL;
502 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
503 		return EBADF;
504 
505 #if 0
506 	/* Disallow userspace access to devices that have drivers attached. */
507 	if (sc->sc_devices[iie->iie_addr] != NULL)
508 		return EBUSY;
509 #endif
510 
511 	if (iie->iie_cmd != NULL) {
512 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
513 		if (cmd == NULL)
514 			return ENOMEM;
515 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
516 		if (error) {
517 			kmem_free(cmd, iie->iie_cmdlen);
518 			return error;
519 		}
520 	}
521 
522 	iic_acquire_bus(ic, 0);
523 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
524 	    buf, iie->iie_buflen, 0);
525 	iic_release_bus(ic, 0);
526 
527 	/*
528 	 * Some drivers return error codes on failure, and others return -1.
529 	 */
530 	if (error < 0)
531 		error = EIO;
532 
533 	if (cmd)
534 		kmem_free(cmd, iie->iie_cmdlen);
535 
536 	if (error)
537 		return error;
538 
539 	if (iie->iie_buf)
540 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
541 
542 	return error;
543 }
544 
545 static int
546 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
547 {
548 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
549 
550 	if (sc == NULL)
551 		return ENXIO;
552 
553 	switch (cmd) {
554 	case I2C_IOCTL_EXEC:
555 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
556 	default:
557 		return ENODEV;
558 	}
559 }
560 
561 
562 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
563     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
564 
565 MODULE(MODULE_CLASS_DRIVER, iic, NULL);
566 
567 #ifdef _MODULE
568 #include "ioconf.c"
569 #endif
570 
571 static int
572 iic_modcmd(modcmd_t cmd, void *opaque)
573 {
574 	int error;
575 
576 	error = 0;
577 	switch (cmd) {
578 	case MODULE_CMD_INIT:
579 #ifdef _MODULE
580 		error = config_init_component(cfdriver_ioconf_iic,
581 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
582 		if (error)
583 			aprint_error("%s: unable to init component\n",
584 			    iic_cd.cd_name);
585 #endif
586 		break;
587 	case MODULE_CMD_FINI:
588 #ifdef _MODULE
589 		config_fini_component(cfdriver_ioconf_iic,
590 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
591 #endif
592 		break;
593 	default:
594 		error = ENOTTY;
595 	}
596 	return error;
597 }
598