xref: /netbsd-src/sys/dev/i2c/i2c.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55) 
1 /*	$NetBSD: i2c.c,v 1.43 2014/03/16 05:20:27 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 1.43 2014/03/16 05:20:27 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_flag = D_OTHER
82 };
83 
84 extern struct cfdriver iic_cd;
85 
86 static void	iic_smbus_intr_thread(void *);
87 static void	iic_fill_compat(struct i2c_attach_args*, const char*,
88 			size_t, char **);
89 
90 static int
91 iic_print_direct(void *aux, const char *pnp)
92 {
93 	struct i2c_attach_args *ia = aux;
94 
95 	if (pnp != NULL)
96 		aprint_normal("%s at %s addr 0x%02x", ia->ia_name, pnp,
97 			ia->ia_addr);
98 	else
99 		aprint_normal(" addr 0x%02x", ia->ia_addr);
100 
101 	return UNCONF;
102 }
103 
104 static int
105 iic_print(void *aux, const char *pnp)
106 {
107 	struct i2c_attach_args *ia = aux;
108 
109 	if (ia->ia_addr != (i2c_addr_t)-1)
110 		aprint_normal(" addr 0x%x", ia->ia_addr);
111 
112 	return UNCONF;
113 }
114 
115 static int
116 iic_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
117 {
118 	struct iic_softc *sc = device_private(parent);
119 	struct i2c_attach_args ia;
120 
121 	ia.ia_tag = sc->sc_tag;
122 	ia.ia_size = cf->cf_loc[IICCF_SIZE];
123 	ia.ia_type = sc->sc_type;
124 
125 	ia.ia_name = NULL;
126 	ia.ia_ncompat = 0;
127 	ia.ia_compat = NULL;
128 
129 	for (ia.ia_addr = 0; ia.ia_addr <= I2C_MAX_ADDR; ia.ia_addr++) {
130 		if (sc->sc_devices[ia.ia_addr] != NULL)
131 			continue;
132 
133 		if (cf->cf_loc[IICCF_ADDR] != -1 &&
134 		    cf->cf_loc[IICCF_ADDR] != ia.ia_addr)
135 			continue;
136 
137 		if (config_match(parent, cf, &ia) > 0)
138 			sc->sc_devices[ia.ia_addr] =
139 			    config_attach(parent, cf, &ia, iic_print);
140 	}
141 
142 	return 0;
143 }
144 
145 static void
146 iic_child_detach(device_t parent, device_t child)
147 {
148 	struct iic_softc *sc = device_private(parent);
149 	int i;
150 
151 	for (i = 0; i <= I2C_MAX_ADDR; i++)
152 		if (sc->sc_devices[i] == child) {
153 			sc->sc_devices[i] = NULL;
154 			break;
155 		}
156 }
157 
158 static int
159 iic_rescan(device_t self, const char *ifattr, const int *locators)
160 {
161 	config_search_ia(iic_search, self, ifattr, NULL);
162 	return 0;
163 }
164 
165 static int
166 iic_match(device_t parent, cfdata_t cf, void *aux)
167 {
168 
169 	return 1;
170 }
171 
172 static void
173 iic_attach(device_t parent, device_t self, void *aux)
174 {
175 	struct iic_softc *sc = device_private(self);
176 	struct i2cbus_attach_args *iba = aux;
177 	prop_array_t child_devices;
178 	prop_dictionary_t props;
179 	char *buf;
180 	i2c_tag_t ic;
181 	int rv;
182 	bool indirect_config;
183 
184 	aprint_naive("\n");
185 	aprint_normal(": I2C bus\n");
186 
187 	sc->sc_tag = iba->iba_tag;
188 	sc->sc_type = iba->iba_type;
189 	ic = sc->sc_tag;
190 	ic->ic_devname = device_xname(self);
191 
192 	LIST_INIT(&(sc->sc_tag->ic_list));
193 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
194 
195 	rv = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
196 	    iic_smbus_intr_thread, ic, &ic->ic_intr_thread,
197 	    "%s", ic->ic_devname);
198 	if (rv)
199 		aprint_error_dev(self, "unable to create intr thread\n");
200 
201 	if (!pmf_device_register(self, NULL, NULL))
202 		aprint_error_dev(self, "couldn't establish power handler\n");
203 
204 	props = device_properties(parent);
205 	if (!prop_dictionary_get_bool(props, "i2c-indirect-config",
206 	    &indirect_config))
207 		indirect_config = true;
208 	child_devices = prop_dictionary_get(props, "i2c-child-devices");
209 	if (child_devices) {
210 		unsigned int i, count;
211 		prop_dictionary_t dev;
212 		prop_data_t cdata;
213 		uint32_t addr, size;
214 		uint64_t cookie;
215 		const char *name;
216 		struct i2c_attach_args ia;
217 		int loc[2];
218 
219 		memset(loc, 0, sizeof loc);
220 		count = prop_array_count(child_devices);
221 		for (i = 0; i < count; i++) {
222 			dev = prop_array_get(child_devices, i);
223 			if (!dev) continue;
224  			if (!prop_dictionary_get_cstring_nocopy(
225 			    dev, "name", &name))
226 				continue;
227 			if (!prop_dictionary_get_uint32(dev, "addr", &addr))
228 				continue;
229 			if (!prop_dictionary_get_uint64(dev, "cookie", &cookie))
230 				cookie = 0;
231 			loc[0] = addr;
232 			if (prop_dictionary_get_uint32(dev, "size", &size))
233 				loc[1] = size;
234 			else
235 				loc[1] = -1;
236 
237 			memset(&ia, 0, sizeof ia);
238 			ia.ia_addr = addr;
239 			ia.ia_type = sc->sc_type;
240 			ia.ia_tag = ic;
241 			ia.ia_name = name;
242 			ia.ia_cookie = cookie;
243 			ia.ia_size = size;
244 
245 			buf = NULL;
246 			cdata = prop_dictionary_get(dev, "compatible");
247 			if (cdata)
248 				iic_fill_compat(&ia,
249 				    prop_data_data_nocopy(cdata),
250 				    prop_data_size(cdata), &buf);
251 
252 			if (addr > I2C_MAX_ADDR) {
253 				aprint_error_dev(self,
254 				    "WARNING: ignoring bad device address "
255 				    "@ 0x%02x\n", addr);
256 			} else if (sc->sc_devices[addr] == NULL) {
257 				sc->sc_devices[addr] =
258 				    config_found_sm_loc(self, "iic", loc, &ia,
259 					iic_print_direct, NULL);
260 			}
261 
262 			if (ia.ia_compat)
263 				free(ia.ia_compat, M_TEMP);
264 			if (buf)
265 				free(buf, M_TEMP);
266 		}
267 	} else if (indirect_config) {
268 		/*
269 		 * Attach all i2c devices described in the kernel
270 		 * configuration file.
271 		 */
272 		iic_rescan(self, "iic", NULL);
273 	}
274 }
275 
276 static int
277 iic_detach(device_t self, int flags)
278 {
279 	struct iic_softc *sc = device_private(self);
280 	i2c_tag_t ic = sc->sc_tag;
281 	int i, error;
282 	void *hdl;
283 
284 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
285 		if (sc->sc_devices[i]) {
286 			error = config_detach(sc->sc_devices[i], flags);
287 			if (error)
288 				return error;
289 		}
290 	}
291 
292 	if (ic->ic_running) {
293 		ic->ic_running = 0;
294 		wakeup(ic);
295 		kthread_join(ic->ic_intr_thread);
296 	}
297 
298 	if (!LIST_EMPTY(&ic->ic_list)) {
299 		device_printf(self, "WARNING: intr handler list not empty\n");
300 		while (!LIST_EMPTY(&ic->ic_list)) {
301 			hdl = LIST_FIRST(&ic->ic_list);
302 			iic_smbus_intr_disestablish(ic, hdl);
303 		}
304 	}
305 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
306 		device_printf(self, "WARNING: proc handler list not empty\n");
307 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
308 			hdl = LIST_FIRST(&ic->ic_proc_list);
309 			iic_smbus_intr_disestablish_proc(ic, hdl);
310 		}
311 	}
312 
313 	pmf_device_deregister(self);
314 
315 	return 0;
316 }
317 
318 static void
319 iic_smbus_intr_thread(void *aux)
320 {
321 	i2c_tag_t ic;
322 	struct ic_intr_list *il;
323 
324 	ic = (i2c_tag_t)aux;
325 	ic->ic_running = 1;
326 	ic->ic_pending = 0;
327 
328 	while (ic->ic_running) {
329 		if (ic->ic_pending == 0)
330 			tsleep(ic, PZERO, "iicintr", hz);
331 		if (ic->ic_pending > 0) {
332 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
333 				(*il->il_intr)(il->il_intrarg);
334 			}
335 			ic->ic_pending--;
336 		}
337 	}
338 
339 	kthread_exit(0);
340 }
341 
342 void *
343 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
344 {
345 	struct ic_intr_list *il;
346 
347 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
348 	if (il == NULL)
349 		return NULL;
350 
351 	il->il_intr = intr;
352 	il->il_intrarg = intrarg;
353 
354 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
355 
356 	return il;
357 }
358 
359 void
360 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
361 {
362 	struct ic_intr_list *il;
363 
364 	il = (struct ic_intr_list *)hdl;
365 
366 	LIST_REMOVE(il, il_next);
367 	free(il, M_DEVBUF);
368 
369 	return;
370 }
371 
372 void *
373 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
374 {
375 	struct ic_intr_list *il;
376 
377 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
378 	if (il == NULL)
379 		return NULL;
380 
381 	il->il_intr = intr;
382 	il->il_intrarg = intrarg;
383 
384 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
385 
386 	return il;
387 }
388 
389 void
390 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
391 {
392 	struct ic_intr_list *il;
393 
394 	il = (struct ic_intr_list *)hdl;
395 
396 	LIST_REMOVE(il, il_next);
397 	free(il, M_DEVBUF);
398 
399 	return;
400 }
401 
402 int
403 iic_smbus_intr(i2c_tag_t ic)
404 {
405 	struct ic_intr_list *il;
406 
407 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
408 		(*il->il_intr)(il->il_intrarg);
409 	}
410 
411 	ic->ic_pending++;
412 	wakeup(ic);
413 
414 	return 1;
415 }
416 
417 static void
418 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
419 	char **buffer)
420 {
421 	int count, i;
422 	const char *c, *start, **ptr;
423 
424 	*buffer = NULL;
425 	for (i = count = 0, c = compat; i < len; i++, c++)
426 		if (*c == 0)
427 			count++;
428 	count += 2;
429 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
430 	if (!ptr) return;
431 
432 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
433 		if (*c == 0) {
434 			ptr[count++] = start;
435 			start = c+1;
436 		}
437 	}
438 	if (start < compat+len) {
439 		/* last string not 0 terminated */
440 		size_t l = c-start;
441 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
442 		memcpy(*buffer, start, l);
443 		(*buffer)[l] = 0;
444 		ptr[count++] = *buffer;
445 	}
446 	ptr[count] = NULL;
447 
448 	ia->ia_compat = ptr;
449 	ia->ia_ncompat = count;
450 }
451 
452 int
453 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
454 {
455 	int i;
456 
457 	for (; compats && *compats; compats++) {
458 		for (i = 0; i < ia->ia_ncompat; i++) {
459 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
460 				return 1;
461 		}
462 	}
463 	return 0;
464 }
465 
466 static int
467 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
468 {
469 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
470 
471 	if (sc == NULL)
472 		return ENXIO;
473 
474 	return 0;
475 }
476 
477 static int
478 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
479 {
480 	return 0;
481 }
482 
483 static int
484 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
485 {
486 	i2c_tag_t ic = sc->sc_tag;
487 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
488 	void *cmd = NULL;
489 	int error;
490 
491 	/* Validate parameters */
492 	if (iie->iie_addr > I2C_MAX_ADDR)
493 		return EINVAL;
494 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
495 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
496 		return EINVAL;
497 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
498 		return EINVAL;
499 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
500 		return EINVAL;
501 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
502 		return EBADF;
503 
504 #if 0
505 	/* Disallow userspace access to devices that have drivers attached. */
506 	if (sc->sc_devices[iie->iie_addr] != NULL)
507 		return EBUSY;
508 #endif
509 
510 	if (iie->iie_cmd != NULL) {
511 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
512 		if (cmd == NULL)
513 			return ENOMEM;
514 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
515 		if (error) {
516 			kmem_free(cmd, iie->iie_cmdlen);
517 			return error;
518 		}
519 	}
520 
521 	iic_acquire_bus(ic, 0);
522 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
523 	    buf, iie->iie_buflen, 0);
524 	iic_release_bus(ic, 0);
525 
526 	/*
527 	 * Some drivers return error codes on failure, and others return -1.
528 	 */
529 	if (error < 0)
530 		error = EIO;
531 
532 	if (cmd)
533 		kmem_free(cmd, iie->iie_cmdlen);
534 
535 	if (error)
536 		return error;
537 
538 	if (iie->iie_buf)
539 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
540 
541 	return error;
542 }
543 
544 static int
545 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
546 {
547 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
548 
549 	if (sc == NULL)
550 		return ENXIO;
551 
552 	switch (cmd) {
553 	case I2C_IOCTL_EXEC:
554 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
555 	default:
556 		return ENODEV;
557 	}
558 }
559 
560 
561 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
562     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
563 
564 MODULE(MODULE_CLASS_DRIVER, iic, NULL);
565 
566 #ifdef _MODULE
567 #include "ioconf.c"
568 #endif
569 
570 static int
571 iic_modcmd(modcmd_t cmd, void *opaque)
572 {
573 	int error;
574 
575 	error = 0;
576 	switch (cmd) {
577 	case MODULE_CMD_INIT:
578 #ifdef _MODULE
579 		error = config_init_component(cfdriver_ioconf_iic,
580 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
581 		if (error)
582 			aprint_error("%s: unable to init component\n",
583 			    iic_cd.cd_name);
584 #endif
585 		break;
586 	case MODULE_CMD_FINI:
587 #ifdef _MODULE
588 		config_fini_component(cfdriver_ioconf_iic,
589 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
590 #endif
591 		break;
592 	default:
593 		error = ENOTTY;
594 	}
595 	return error;
596 }
597