xref: /netbsd-src/sys/dev/i2c/i2c.c (revision 9aa0541bdf64142d9a27c2cf274394d60182818f) 
1 /*	$NetBSD: i2c.c,v 1.36 2011/10/03 23:53:04 jmcneill 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 1.36 2011/10/03 23:53:04 jmcneill 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 (config_match(parent, cf, &ia) > 0) {
122 		if (ia.ia_addr != (i2c_addr_t)-1 &&
123 		    ia.ia_addr <= I2C_MAX_ADDR &&
124 		    !sc->sc_devices[ia.ia_addr])
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 
225 			buf = NULL;
226 			cdata = prop_dictionary_get(dev, "compatible");
227 			if (cdata)
228 				iic_fill_compat(&ia,
229 				    prop_data_data_nocopy(cdata),
230 				    prop_data_size(cdata), &buf);
231 
232 			if (addr > I2C_MAX_ADDR) {
233 				aprint_error_dev(self,
234 				    "WARNING: ignoring bad device address "
235 				    "@ 0x%02x\n", addr);
236 			} else if (ia.ia_addr == addr) {
237 				aprint_error_dev(self,
238 				    "WARNING: ignoring duplicate device "
239 				    "@ 0x%02x\n", addr);
240 			} else if (sc->sc_devices[addr] == NULL) {
241 				sc->sc_devices[addr] =
242 				    config_found_sm_loc(self, "iic", loc, &ia,
243 					iic_print_direct, NULL);
244 			}
245 
246 			if (ia.ia_compat)
247 				free(ia.ia_compat, M_TEMP);
248 			if (buf)
249 				free(buf, M_TEMP);
250 		}
251 	} else {
252 		/*
253 		 * Attach all i2c devices described in the kernel
254 		 * configuration file.
255 		 */
256 		iic_rescan(self, "iic", NULL);
257 	}
258 }
259 
260 static int
261 iic_detach(device_t self, int flags)
262 {
263 	struct iic_softc *sc = device_private(self);
264 	i2c_tag_t ic = sc->sc_tag;
265 	int i, error;
266 	void *hdl;
267 
268 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
269 		if (sc->sc_devices[i]) {
270 			error = config_detach(sc->sc_devices[i], flags);
271 			if (error)
272 				return error;
273 		}
274 	}
275 
276 	if (ic->ic_running) {
277 		ic->ic_running = 0;
278 		wakeup(ic);
279 		kthread_join(ic->ic_intr_thread);
280 	}
281 
282 	if (!LIST_EMPTY(&ic->ic_list)) {
283 		device_printf(self, "WARNING: intr handler list not empty\n");
284 		while (!LIST_EMPTY(&ic->ic_list)) {
285 			hdl = LIST_FIRST(&ic->ic_list);
286 			iic_smbus_intr_disestablish(ic, hdl);
287 		}
288 	}
289 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
290 		device_printf(self, "WARNING: proc handler list not empty\n");
291 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
292 			hdl = LIST_FIRST(&ic->ic_proc_list);
293 			iic_smbus_intr_disestablish_proc(ic, hdl);
294 		}
295 	}
296 
297 	pmf_device_deregister(self);
298 
299 	return 0;
300 }
301 
302 static void
303 iic_smbus_intr_thread(void *aux)
304 {
305 	i2c_tag_t ic;
306 	struct ic_intr_list *il;
307 	int rv;
308 
309 	ic = (i2c_tag_t)aux;
310 	ic->ic_running = 1;
311 	ic->ic_pending = 0;
312 
313 	while (ic->ic_running) {
314 		if (ic->ic_pending == 0)
315 			rv = tsleep(ic, PZERO, "iicintr", hz);
316 		if (ic->ic_pending > 0) {
317 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
318 				(*il->il_intr)(il->il_intrarg);
319 			}
320 			ic->ic_pending--;
321 		}
322 	}
323 
324 	kthread_exit(0);
325 }
326 
327 void *
328 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
329 {
330 	struct ic_intr_list *il;
331 
332 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
333 	if (il == NULL)
334 		return NULL;
335 
336 	il->il_intr = intr;
337 	il->il_intrarg = intrarg;
338 
339 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
340 
341 	return il;
342 }
343 
344 void
345 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
346 {
347 	struct ic_intr_list *il;
348 
349 	il = (struct ic_intr_list *)hdl;
350 
351 	LIST_REMOVE(il, il_next);
352 	free(il, M_DEVBUF);
353 
354 	return;
355 }
356 
357 void *
358 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
359 {
360 	struct ic_intr_list *il;
361 
362 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
363 	if (il == NULL)
364 		return NULL;
365 
366 	il->il_intr = intr;
367 	il->il_intrarg = intrarg;
368 
369 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
370 
371 	return il;
372 }
373 
374 void
375 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
376 {
377 	struct ic_intr_list *il;
378 
379 	il = (struct ic_intr_list *)hdl;
380 
381 	LIST_REMOVE(il, il_next);
382 	free(il, M_DEVBUF);
383 
384 	return;
385 }
386 
387 int
388 iic_smbus_intr(i2c_tag_t ic)
389 {
390 	struct ic_intr_list *il;
391 
392 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
393 		(*il->il_intr)(il->il_intrarg);
394 	}
395 
396 	ic->ic_pending++;
397 	wakeup(ic);
398 
399 	return 1;
400 }
401 
402 static void
403 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
404 	char **buffer)
405 {
406 	int count, i;
407 	const char *c, *start, **ptr;
408 
409 	*buffer = NULL;
410 	for (i = count = 0, c = compat; i < len; i++, c++)
411 		if (*c == 0)
412 			count++;
413 	count += 2;
414 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
415 	if (!ptr) return;
416 
417 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
418 		if (*c == 0) {
419 			ptr[count++] = start;
420 			start = c+1;
421 		}
422 	}
423 	if (start < compat+len) {
424 		/* last string not 0 terminated */
425 		size_t l = c-start;
426 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
427 		memcpy(*buffer, start, l);
428 		(*buffer)[l] = 0;
429 		ptr[count++] = *buffer;
430 	}
431 	ptr[count] = NULL;
432 
433 	ia->ia_compat = ptr;
434 	ia->ia_ncompat = count;
435 }
436 
437 int
438 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
439 {
440 	int i;
441 
442 	for (; compats && *compats; compats++) {
443 		for (i = 0; i < ia->ia_ncompat; i++) {
444 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
445 				return 1;
446 		}
447 	}
448 	return 0;
449 }
450 
451 static int
452 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
453 {
454 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
455 
456 	if (sc == NULL)
457 		return ENXIO;
458 
459 	return 0;
460 }
461 
462 static int
463 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
464 {
465 	return 0;
466 }
467 
468 static int
469 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
470 {
471 	i2c_tag_t ic = sc->sc_tag;
472 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
473 	void *cmd = NULL;
474 	int error;
475 
476 	/* Validate parameters */
477 	if (iie->iie_addr > I2C_MAX_ADDR)
478 		return EINVAL;
479 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
480 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
481 		return EINVAL;
482 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
483 		return EINVAL;
484 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
485 		return EINVAL;
486 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
487 		return EBADF;
488 
489 #if 0
490 	/* Disallow userspace access to devices that have drivers attached. */
491 	if (sc->sc_devices[iie->iie_addr] != NULL)
492 		return EBUSY;
493 #endif
494 
495 	if (iie->iie_cmd != NULL) {
496 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
497 		if (cmd == NULL)
498 			return ENOMEM;
499 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
500 		if (error) {
501 			kmem_free(cmd, iie->iie_cmdlen);
502 			return error;
503 		}
504 	}
505 
506 	iic_acquire_bus(ic, 0);
507 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
508 	    buf, iie->iie_buflen, 0);
509 	iic_release_bus(ic, 0);
510 
511 	/*
512 	 * Some drivers return error codes on failure, and others return -1.
513 	 */
514 	if (error < 0)
515 		error = EIO;
516 
517 	if (cmd)
518 		kmem_free(cmd, iie->iie_cmdlen);
519 
520 	if (error)
521 		return error;
522 
523 	if (iie->iie_buf)
524 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
525 
526 	return error;
527 }
528 
529 static int
530 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
531 {
532 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
533 
534 	if (sc == NULL)
535 		return ENXIO;
536 
537 	switch (cmd) {
538 	case I2C_IOCTL_EXEC:
539 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
540 	default:
541 		return ENODEV;
542 	}
543 }
544 
545 
546 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
547     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
548 
549 MODULE(MODULE_CLASS_DRIVER, iic, NULL);
550 
551 #ifdef _MODULE
552 #include "ioconf.c"
553 #endif
554 
555 static int
556 iic_modcmd(modcmd_t cmd, void *opaque)
557 {
558 	int error;
559 
560 	error = 0;
561 	switch (cmd) {
562 	case MODULE_CMD_INIT:
563 #ifdef _MODULE
564 		error = config_init_component(cfdriver_ioconf_iic,
565 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
566 		if (error)
567 			aprint_error("%s: unable to init component\n",
568 			    iic_cd.cd_name);
569 #endif
570 		break;
571 	case MODULE_CMD_FINI:
572 #ifdef _MODULE
573 		config_fini_component(cfdriver_ioconf_iic,
574 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
575 #endif
576 		break;
577 	default:
578 		error = ENOTTY;
579 	}
580 	return error;
581 }
582