xref: /netbsd-src/sys/dev/i2c/i2c.c (revision 975a152cfcdb39ae6e496af647af0c7275ca0b61) 
1 /*	$NetBSD: i2c.c,v 1.40 2013/08/07 19:38:45 soren 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 1.40 2013/08/07 19:38:45 soren 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_size = cf->cf_loc[IICCF_SIZE];
114 	ia.ia_type = sc->sc_type;
115 
116 	ia.ia_name = NULL;
117 	ia.ia_ncompat = 0;
118 	ia.ia_compat = NULL;
119 
120 	for (ia.ia_addr = 0; ia.ia_addr <= I2C_MAX_ADDR; ia.ia_addr++) {
121 		if (sc->sc_devices[ia.ia_addr] != NULL)
122 			continue;
123 
124 		if (cf->cf_loc[IICCF_ADDR] != -1 &&
125 		    cf->cf_loc[IICCF_ADDR] != ia.ia_addr)
126 			continue;
127 
128 		if (config_match(parent, cf, &ia) > 0)
129 			sc->sc_devices[ia.ia_addr] =
130 			    config_attach(parent, cf, &ia, iic_print);
131 	}
132 
133 	return 0;
134 }
135 
136 static void
137 iic_child_detach(device_t parent, device_t child)
138 {
139 	struct iic_softc *sc = device_private(parent);
140 	int i;
141 
142 	for (i = 0; i <= I2C_MAX_ADDR; i++)
143 		if (sc->sc_devices[i] == child) {
144 			sc->sc_devices[i] = NULL;
145 			break;
146 		}
147 }
148 
149 static int
150 iic_rescan(device_t self, const char *ifattr, const int *locators)
151 {
152 	config_search_ia(iic_search, self, ifattr, NULL);
153 	return 0;
154 }
155 
156 static int
157 iic_match(device_t parent, cfdata_t cf, void *aux)
158 {
159 
160 	return 1;
161 }
162 
163 static void
164 iic_attach(device_t parent, device_t self, void *aux)
165 {
166 	struct iic_softc *sc = device_private(self);
167 	struct i2cbus_attach_args *iba = aux;
168 	prop_array_t child_devices;
169 	char *buf;
170 	i2c_tag_t ic;
171 	int rv;
172 
173 	aprint_naive("\n");
174 	aprint_normal(": I2C bus\n");
175 
176 	sc->sc_tag = iba->iba_tag;
177 	sc->sc_type = iba->iba_type;
178 	ic = sc->sc_tag;
179 	ic->ic_devname = device_xname(self);
180 
181 	LIST_INIT(&(sc->sc_tag->ic_list));
182 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
183 
184 	rv = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
185 	    iic_smbus_intr_thread, ic, &ic->ic_intr_thread,
186 	    "%s", ic->ic_devname);
187 	if (rv)
188 		aprint_error_dev(self, "unable to create intr thread\n");
189 
190 	if (!pmf_device_register(self, NULL, NULL))
191 		aprint_error_dev(self, "couldn't establish power handler\n");
192 
193 	child_devices = prop_dictionary_get(device_properties(parent),
194 		"i2c-child-devices");
195 	if (child_devices) {
196 		unsigned int i, count;
197 		prop_dictionary_t dev;
198 		prop_data_t cdata;
199 		uint32_t addr, size;
200 		uint64_t cookie;
201 		const char *name;
202 		struct i2c_attach_args ia;
203 		int loc[2];
204 
205 		memset(loc, 0, sizeof loc);
206 		count = prop_array_count(child_devices);
207 		for (i = 0; i < count; i++) {
208 			dev = prop_array_get(child_devices, i);
209 			if (!dev) continue;
210  			if (!prop_dictionary_get_cstring_nocopy(
211 			    dev, "name", &name))
212 				continue;
213 			if (!prop_dictionary_get_uint32(dev, "addr", &addr))
214 				continue;
215 			if (!prop_dictionary_get_uint64(dev, "cookie", &cookie))
216 				cookie = 0;
217 			loc[0] = addr;
218 			if (prop_dictionary_get_uint32(dev, "size", &size))
219 				loc[1] = size;
220 			else
221 				loc[1] = -1;
222 
223 			memset(&ia, 0, sizeof ia);
224 			ia.ia_addr = addr;
225 			ia.ia_type = sc->sc_type;
226 			ia.ia_tag = ic;
227 			ia.ia_name = name;
228 			ia.ia_cookie = cookie;
229 			ia.ia_size = size;
230 
231 			buf = NULL;
232 			cdata = prop_dictionary_get(dev, "compatible");
233 			if (cdata)
234 				iic_fill_compat(&ia,
235 				    prop_data_data_nocopy(cdata),
236 				    prop_data_size(cdata), &buf);
237 
238 			if (addr > I2C_MAX_ADDR) {
239 				aprint_error_dev(self,
240 				    "WARNING: ignoring bad device address "
241 				    "@ 0x%02x\n", addr);
242 			} else if (sc->sc_devices[addr] == NULL) {
243 				sc->sc_devices[addr] =
244 				    config_found_sm_loc(self, "iic", loc, &ia,
245 					iic_print_direct, NULL);
246 			}
247 
248 			if (ia.ia_compat)
249 				free(ia.ia_compat, M_TEMP);
250 			if (buf)
251 				free(buf, M_TEMP);
252 		}
253 	} else {
254 		/*
255 		 * Attach all i2c devices described in the kernel
256 		 * configuration file.
257 		 */
258 		iic_rescan(self, "iic", NULL);
259 	}
260 }
261 
262 static int
263 iic_detach(device_t self, int flags)
264 {
265 	struct iic_softc *sc = device_private(self);
266 	i2c_tag_t ic = sc->sc_tag;
267 	int i, error;
268 	void *hdl;
269 
270 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
271 		if (sc->sc_devices[i]) {
272 			error = config_detach(sc->sc_devices[i], flags);
273 			if (error)
274 				return error;
275 		}
276 	}
277 
278 	if (ic->ic_running) {
279 		ic->ic_running = 0;
280 		wakeup(ic);
281 		kthread_join(ic->ic_intr_thread);
282 	}
283 
284 	if (!LIST_EMPTY(&ic->ic_list)) {
285 		device_printf(self, "WARNING: intr handler list not empty\n");
286 		while (!LIST_EMPTY(&ic->ic_list)) {
287 			hdl = LIST_FIRST(&ic->ic_list);
288 			iic_smbus_intr_disestablish(ic, hdl);
289 		}
290 	}
291 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
292 		device_printf(self, "WARNING: proc handler list not empty\n");
293 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
294 			hdl = LIST_FIRST(&ic->ic_proc_list);
295 			iic_smbus_intr_disestablish_proc(ic, hdl);
296 		}
297 	}
298 
299 	pmf_device_deregister(self);
300 
301 	return 0;
302 }
303 
304 static void
305 iic_smbus_intr_thread(void *aux)
306 {
307 	i2c_tag_t ic;
308 	struct ic_intr_list *il;
309 	int rv;
310 
311 	ic = (i2c_tag_t)aux;
312 	ic->ic_running = 1;
313 	ic->ic_pending = 0;
314 
315 	while (ic->ic_running) {
316 		if (ic->ic_pending == 0)
317 			rv = tsleep(ic, PZERO, "iicintr", hz);
318 		if (ic->ic_pending > 0) {
319 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
320 				(*il->il_intr)(il->il_intrarg);
321 			}
322 			ic->ic_pending--;
323 		}
324 	}
325 
326 	kthread_exit(0);
327 }
328 
329 void *
330 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
331 {
332 	struct ic_intr_list *il;
333 
334 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
335 	if (il == NULL)
336 		return NULL;
337 
338 	il->il_intr = intr;
339 	il->il_intrarg = intrarg;
340 
341 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
342 
343 	return il;
344 }
345 
346 void
347 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
348 {
349 	struct ic_intr_list *il;
350 
351 	il = (struct ic_intr_list *)hdl;
352 
353 	LIST_REMOVE(il, il_next);
354 	free(il, M_DEVBUF);
355 
356 	return;
357 }
358 
359 void *
360 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
361 {
362 	struct ic_intr_list *il;
363 
364 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
365 	if (il == NULL)
366 		return NULL;
367 
368 	il->il_intr = intr;
369 	il->il_intrarg = intrarg;
370 
371 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
372 
373 	return il;
374 }
375 
376 void
377 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
378 {
379 	struct ic_intr_list *il;
380 
381 	il = (struct ic_intr_list *)hdl;
382 
383 	LIST_REMOVE(il, il_next);
384 	free(il, M_DEVBUF);
385 
386 	return;
387 }
388 
389 int
390 iic_smbus_intr(i2c_tag_t ic)
391 {
392 	struct ic_intr_list *il;
393 
394 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
395 		(*il->il_intr)(il->il_intrarg);
396 	}
397 
398 	ic->ic_pending++;
399 	wakeup(ic);
400 
401 	return 1;
402 }
403 
404 static void
405 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
406 	char **buffer)
407 {
408 	int count, i;
409 	const char *c, *start, **ptr;
410 
411 	*buffer = NULL;
412 	for (i = count = 0, c = compat; i < len; i++, c++)
413 		if (*c == 0)
414 			count++;
415 	count += 2;
416 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
417 	if (!ptr) return;
418 
419 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
420 		if (*c == 0) {
421 			ptr[count++] = start;
422 			start = c+1;
423 		}
424 	}
425 	if (start < compat+len) {
426 		/* last string not 0 terminated */
427 		size_t l = c-start;
428 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
429 		memcpy(*buffer, start, l);
430 		(*buffer)[l] = 0;
431 		ptr[count++] = *buffer;
432 	}
433 	ptr[count] = NULL;
434 
435 	ia->ia_compat = ptr;
436 	ia->ia_ncompat = count;
437 }
438 
439 int
440 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
441 {
442 	int i;
443 
444 	for (; compats && *compats; compats++) {
445 		for (i = 0; i < ia->ia_ncompat; i++) {
446 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
447 				return 1;
448 		}
449 	}
450 	return 0;
451 }
452 
453 static int
454 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
455 {
456 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
457 
458 	if (sc == NULL)
459 		return ENXIO;
460 
461 	return 0;
462 }
463 
464 static int
465 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
466 {
467 	return 0;
468 }
469 
470 static int
471 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
472 {
473 	i2c_tag_t ic = sc->sc_tag;
474 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
475 	void *cmd = NULL;
476 	int error;
477 
478 	/* Validate parameters */
479 	if (iie->iie_addr > I2C_MAX_ADDR)
480 		return EINVAL;
481 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
482 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
483 		return EINVAL;
484 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
485 		return EINVAL;
486 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
487 		return EINVAL;
488 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
489 		return EBADF;
490 
491 #if 0
492 	/* Disallow userspace access to devices that have drivers attached. */
493 	if (sc->sc_devices[iie->iie_addr] != NULL)
494 		return EBUSY;
495 #endif
496 
497 	if (iie->iie_cmd != NULL) {
498 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
499 		if (cmd == NULL)
500 			return ENOMEM;
501 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
502 		if (error) {
503 			kmem_free(cmd, iie->iie_cmdlen);
504 			return error;
505 		}
506 	}
507 
508 	iic_acquire_bus(ic, 0);
509 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
510 	    buf, iie->iie_buflen, 0);
511 	iic_release_bus(ic, 0);
512 
513 	/*
514 	 * Some drivers return error codes on failure, and others return -1.
515 	 */
516 	if (error < 0)
517 		error = EIO;
518 
519 	if (cmd)
520 		kmem_free(cmd, iie->iie_cmdlen);
521 
522 	if (error)
523 		return error;
524 
525 	if (iie->iie_buf)
526 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
527 
528 	return error;
529 }
530 
531 static int
532 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
533 {
534 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
535 
536 	if (sc == NULL)
537 		return ENXIO;
538 
539 	switch (cmd) {
540 	case I2C_IOCTL_EXEC:
541 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
542 	default:
543 		return ENODEV;
544 	}
545 }
546 
547 
548 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
549     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
550 
551 MODULE(MODULE_CLASS_DRIVER, iic, NULL);
552 
553 #ifdef _MODULE
554 #include "ioconf.c"
555 #endif
556 
557 static int
558 iic_modcmd(modcmd_t cmd, void *opaque)
559 {
560 	int error;
561 
562 	error = 0;
563 	switch (cmd) {
564 	case MODULE_CMD_INIT:
565 #ifdef _MODULE
566 		error = config_init_component(cfdriver_ioconf_iic,
567 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
568 		if (error)
569 			aprint_error("%s: unable to init component\n",
570 			    iic_cd.cd_name);
571 #endif
572 		break;
573 	case MODULE_CMD_FINI:
574 #ifdef _MODULE
575 		config_fini_component(cfdriver_ioconf_iic,
576 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
577 #endif
578 		break;
579 	default:
580 		error = ENOTTY;
581 	}
582 	return error;
583 }
584