xref: /netbsd-src/sys/dev/i2c/i2c.c (revision 200d779b75dbeafa7bc01fd0f60bc61185f6967b) 
1 /*	$NetBSD: i2c.c,v 1.49 2015/04/13 22:26:20 pgoyette 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 #ifdef _KERNEL_OPT
39 #include "opt_i2c.h"
40 #endif
41 
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(0, "$NetBSD: i2c.c,v 1.49 2015/04/13 22:26:20 pgoyette Exp $");
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/device.h>
48 #include <sys/event.h>
49 #include <sys/conf.h>
50 #include <sys/malloc.h>
51 #include <sys/kmem.h>
52 #include <sys/kthread.h>
53 #include <sys/proc.h>
54 #include <sys/kernel.h>
55 #include <sys/fcntl.h>
56 #include <sys/module.h>
57 
58 #include <dev/i2c/i2cvar.h>
59 
60 #include "locators.h"
61 
62 #ifndef I2C_MAX_ADDR
63 #define I2C_MAX_ADDR	0x3ff	/* 10-bit address, max */
64 #endif
65 
66 struct iic_softc {
67 	i2c_tag_t sc_tag;
68 	int sc_type;
69 	device_t sc_devices[I2C_MAX_ADDR + 1];
70 };
71 
72 static dev_type_open(iic_open);
73 static dev_type_close(iic_close);
74 static dev_type_ioctl(iic_ioctl);
75 
76 const struct cdevsw iic_cdevsw = {
77 	.d_open = iic_open,
78 	.d_close = iic_close,
79 	.d_read = noread,
80 	.d_write = nowrite,
81 	.d_ioctl = iic_ioctl,
82 	.d_stop = nostop,
83 	.d_tty = notty,
84 	.d_poll = nopoll,
85 	.d_mmap = nommap,
86 	.d_kqfilter = nokqfilter,
87 	.d_discard = nodiscard,
88 	.d_flag = D_OTHER
89 };
90 
91 extern struct cfdriver iic_cd;
92 
93 static void	iic_smbus_intr_thread(void *);
94 static void	iic_fill_compat(struct i2c_attach_args*, const char*,
95 			size_t, char **);
96 
97 static int
98 iic_print_direct(void *aux, const char *pnp)
99 {
100 	struct i2c_attach_args *ia = aux;
101 
102 	if (pnp != NULL)
103 		aprint_normal("%s at %s addr 0x%02x", ia->ia_name, pnp,
104 			ia->ia_addr);
105 	else
106 		aprint_normal(" addr 0x%02x", ia->ia_addr);
107 
108 	return UNCONF;
109 }
110 
111 static int
112 iic_print(void *aux, const char *pnp)
113 {
114 	struct i2c_attach_args *ia = aux;
115 
116 	if (ia->ia_addr != (i2c_addr_t)-1)
117 		aprint_normal(" addr 0x%x", ia->ia_addr);
118 
119 	return UNCONF;
120 }
121 
122 static int
123 iic_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
124 {
125 	struct iic_softc *sc = device_private(parent);
126 	struct i2c_attach_args ia;
127 
128 	ia.ia_tag = sc->sc_tag;
129 	ia.ia_size = cf->cf_loc[IICCF_SIZE];
130 	ia.ia_type = sc->sc_type;
131 
132 	ia.ia_name = NULL;
133 	ia.ia_ncompat = 0;
134 	ia.ia_compat = NULL;
135 
136 	for (ia.ia_addr = 0; ia.ia_addr <= I2C_MAX_ADDR; ia.ia_addr++) {
137 		if (sc->sc_devices[ia.ia_addr] != NULL)
138 			continue;
139 
140 		if (cf->cf_loc[IICCF_ADDR] != -1 &&
141 		    cf->cf_loc[IICCF_ADDR] != ia.ia_addr)
142 			continue;
143 
144 		if (config_match(parent, cf, &ia) > 0)
145 			sc->sc_devices[ia.ia_addr] =
146 			    config_attach(parent, cf, &ia, iic_print);
147 	}
148 
149 	return 0;
150 }
151 
152 static void
153 iic_child_detach(device_t parent, device_t child)
154 {
155 	struct iic_softc *sc = device_private(parent);
156 	int i;
157 
158 	for (i = 0; i <= I2C_MAX_ADDR; i++)
159 		if (sc->sc_devices[i] == child) {
160 			sc->sc_devices[i] = NULL;
161 			break;
162 		}
163 }
164 
165 static int
166 iic_rescan(device_t self, const char *ifattr, const int *locators)
167 {
168 	config_search_ia(iic_search, self, ifattr, NULL);
169 	return 0;
170 }
171 
172 static int
173 iic_match(device_t parent, cfdata_t cf, void *aux)
174 {
175 
176 	return 1;
177 }
178 
179 static void
180 iic_attach(device_t parent, device_t self, void *aux)
181 {
182 	struct iic_softc *sc = device_private(self);
183 	struct i2cbus_attach_args *iba = aux;
184 	prop_array_t child_devices;
185 	prop_dictionary_t props;
186 	char *buf;
187 	i2c_tag_t ic;
188 	int rv;
189 	bool indirect_config;
190 
191 	aprint_naive("\n");
192 	aprint_normal(": I2C bus\n");
193 
194 	sc->sc_tag = iba->iba_tag;
195 	sc->sc_type = iba->iba_type;
196 	ic = sc->sc_tag;
197 	ic->ic_devname = device_xname(self);
198 
199 	LIST_INIT(&(sc->sc_tag->ic_list));
200 	LIST_INIT(&(sc->sc_tag->ic_proc_list));
201 
202 	rv = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
203 	    iic_smbus_intr_thread, ic, &ic->ic_intr_thread,
204 	    "%s", ic->ic_devname);
205 	if (rv)
206 		aprint_error_dev(self, "unable to create intr thread\n");
207 
208 	if (!pmf_device_register(self, NULL, NULL))
209 		aprint_error_dev(self, "couldn't establish power handler\n");
210 
211 	props = device_properties(parent);
212 	if (!prop_dictionary_get_bool(props, "i2c-indirect-config",
213 	    &indirect_config))
214 		indirect_config = true;
215 	child_devices = prop_dictionary_get(props, "i2c-child-devices");
216 	if (child_devices) {
217 		unsigned int i, count;
218 		prop_dictionary_t dev;
219 		prop_data_t cdata;
220 		uint32_t addr, size;
221 		uint64_t cookie;
222 		const char *name;
223 		struct i2c_attach_args ia;
224 		int loc[2];
225 
226 		memset(loc, 0, sizeof loc);
227 		count = prop_array_count(child_devices);
228 		for (i = 0; i < count; i++) {
229 			dev = prop_array_get(child_devices, i);
230 			if (!dev) continue;
231  			if (!prop_dictionary_get_cstring_nocopy(
232 			    dev, "name", &name))
233 				continue;
234 			if (!prop_dictionary_get_uint32(dev, "addr", &addr))
235 				continue;
236 			if (!prop_dictionary_get_uint64(dev, "cookie", &cookie))
237 				cookie = 0;
238 			loc[0] = addr;
239 			if (prop_dictionary_get_uint32(dev, "size", &size))
240 				loc[1] = size;
241 			else
242 				loc[1] = -1;
243 
244 			memset(&ia, 0, sizeof ia);
245 			ia.ia_addr = addr;
246 			ia.ia_type = sc->sc_type;
247 			ia.ia_tag = ic;
248 			ia.ia_name = name;
249 			ia.ia_cookie = cookie;
250 			ia.ia_size = size;
251 
252 			buf = NULL;
253 			cdata = prop_dictionary_get(dev, "compatible");
254 			if (cdata)
255 				iic_fill_compat(&ia,
256 				    prop_data_data_nocopy(cdata),
257 				    prop_data_size(cdata), &buf);
258 
259 			if (addr > I2C_MAX_ADDR) {
260 				aprint_error_dev(self,
261 				    "WARNING: ignoring bad device address "
262 				    "@ 0x%02x\n", addr);
263 			} else if (sc->sc_devices[addr] == NULL) {
264 				sc->sc_devices[addr] =
265 				    config_found_sm_loc(self, "iic", loc, &ia,
266 					iic_print_direct, NULL);
267 			}
268 
269 			if (ia.ia_compat)
270 				free(ia.ia_compat, M_TEMP);
271 			if (buf)
272 				free(buf, M_TEMP);
273 		}
274 	} else if (indirect_config) {
275 		/*
276 		 * Attach all i2c devices described in the kernel
277 		 * configuration file.
278 		 */
279 		iic_rescan(self, "iic", NULL);
280 	}
281 }
282 
283 static int
284 iic_detach(device_t self, int flags)
285 {
286 	struct iic_softc *sc = device_private(self);
287 	i2c_tag_t ic = sc->sc_tag;
288 	int i, error;
289 	void *hdl;
290 
291 	for (i = 0; i <= I2C_MAX_ADDR; i++) {
292 		if (sc->sc_devices[i]) {
293 			error = config_detach(sc->sc_devices[i], flags);
294 			if (error)
295 				return error;
296 		}
297 	}
298 
299 	if (ic->ic_running) {
300 		ic->ic_running = 0;
301 		wakeup(ic);
302 		kthread_join(ic->ic_intr_thread);
303 	}
304 
305 	if (!LIST_EMPTY(&ic->ic_list)) {
306 		device_printf(self, "WARNING: intr handler list not empty\n");
307 		while (!LIST_EMPTY(&ic->ic_list)) {
308 			hdl = LIST_FIRST(&ic->ic_list);
309 			iic_smbus_intr_disestablish(ic, hdl);
310 		}
311 	}
312 	if (!LIST_EMPTY(&ic->ic_proc_list)) {
313 		device_printf(self, "WARNING: proc handler list not empty\n");
314 		while (!LIST_EMPTY(&ic->ic_proc_list)) {
315 			hdl = LIST_FIRST(&ic->ic_proc_list);
316 			iic_smbus_intr_disestablish_proc(ic, hdl);
317 		}
318 	}
319 
320 	pmf_device_deregister(self);
321 
322 	return 0;
323 }
324 
325 static void
326 iic_smbus_intr_thread(void *aux)
327 {
328 	i2c_tag_t ic;
329 	struct ic_intr_list *il;
330 
331 	ic = (i2c_tag_t)aux;
332 	ic->ic_running = 1;
333 	ic->ic_pending = 0;
334 
335 	while (ic->ic_running) {
336 		if (ic->ic_pending == 0)
337 			tsleep(ic, PZERO, "iicintr", hz);
338 		if (ic->ic_pending > 0) {
339 			LIST_FOREACH(il, &(ic->ic_proc_list), il_next) {
340 				(*il->il_intr)(il->il_intrarg);
341 			}
342 			ic->ic_pending--;
343 		}
344 	}
345 
346 	kthread_exit(0);
347 }
348 
349 void *
350 iic_smbus_intr_establish(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
351 {
352 	struct ic_intr_list *il;
353 
354 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
355 	if (il == NULL)
356 		return NULL;
357 
358 	il->il_intr = intr;
359 	il->il_intrarg = intrarg;
360 
361 	LIST_INSERT_HEAD(&(ic->ic_list), il, il_next);
362 
363 	return il;
364 }
365 
366 void
367 iic_smbus_intr_disestablish(i2c_tag_t ic, void *hdl)
368 {
369 	struct ic_intr_list *il;
370 
371 	il = (struct ic_intr_list *)hdl;
372 
373 	LIST_REMOVE(il, il_next);
374 	free(il, M_DEVBUF);
375 
376 	return;
377 }
378 
379 void *
380 iic_smbus_intr_establish_proc(i2c_tag_t ic, int (*intr)(void *), void *intrarg)
381 {
382 	struct ic_intr_list *il;
383 
384 	il = malloc(sizeof(struct ic_intr_list), M_DEVBUF, M_WAITOK);
385 	if (il == NULL)
386 		return NULL;
387 
388 	il->il_intr = intr;
389 	il->il_intrarg = intrarg;
390 
391 	LIST_INSERT_HEAD(&(ic->ic_proc_list), il, il_next);
392 
393 	return il;
394 }
395 
396 void
397 iic_smbus_intr_disestablish_proc(i2c_tag_t ic, void *hdl)
398 {
399 	struct ic_intr_list *il;
400 
401 	il = (struct ic_intr_list *)hdl;
402 
403 	LIST_REMOVE(il, il_next);
404 	free(il, M_DEVBUF);
405 
406 	return;
407 }
408 
409 int
410 iic_smbus_intr(i2c_tag_t ic)
411 {
412 	struct ic_intr_list *il;
413 
414 	LIST_FOREACH(il, &(ic->ic_list), il_next) {
415 		(*il->il_intr)(il->il_intrarg);
416 	}
417 
418 	ic->ic_pending++;
419 	wakeup(ic);
420 
421 	return 1;
422 }
423 
424 static void
425 iic_fill_compat(struct i2c_attach_args *ia, const char *compat, size_t len,
426 	char **buffer)
427 {
428 	int count, i;
429 	const char *c, *start, **ptr;
430 
431 	*buffer = NULL;
432 	for (i = count = 0, c = compat; i < len; i++, c++)
433 		if (*c == 0)
434 			count++;
435 	count += 2;
436 	ptr = malloc(sizeof(char*)*count, M_TEMP, M_WAITOK);
437 	if (!ptr) return;
438 
439 	for (i = count = 0, start = c = compat; i < len; i++, c++) {
440 		if (*c == 0) {
441 			ptr[count++] = start;
442 			start = c+1;
443 		}
444 	}
445 	if (start < compat+len) {
446 		/* last string not 0 terminated */
447 		size_t l = c-start;
448 		*buffer = malloc(l+1, M_TEMP, M_WAITOK);
449 		memcpy(*buffer, start, l);
450 		(*buffer)[l] = 0;
451 		ptr[count++] = *buffer;
452 	}
453 	ptr[count] = NULL;
454 
455 	ia->ia_compat = ptr;
456 	ia->ia_ncompat = count;
457 }
458 
459 int
460 iic_compat_match(struct i2c_attach_args *ia, const char ** compats)
461 {
462 	int i;
463 
464 	for (; compats && *compats; compats++) {
465 		for (i = 0; i < ia->ia_ncompat; i++) {
466 			if (strcmp(*compats, ia->ia_compat[i]) == 0)
467 				return 1;
468 		}
469 	}
470 	return 0;
471 }
472 
473 static int
474 iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
475 {
476 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
477 
478 	if (sc == NULL)
479 		return ENXIO;
480 
481 	return 0;
482 }
483 
484 static int
485 iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
486 {
487 	return 0;
488 }
489 
490 static int
491 iic_ioctl_exec(struct iic_softc *sc, i2c_ioctl_exec_t *iie, int flag)
492 {
493 	i2c_tag_t ic = sc->sc_tag;
494 	uint8_t buf[I2C_EXEC_MAX_BUFLEN];
495 	void *cmd = NULL;
496 	int error;
497 
498 	/* Validate parameters */
499 	if (iie->iie_addr > I2C_MAX_ADDR)
500 		return EINVAL;
501 	if (iie->iie_cmdlen > I2C_EXEC_MAX_CMDLEN ||
502 	    iie->iie_buflen > I2C_EXEC_MAX_BUFLEN)
503 		return EINVAL;
504 	if (iie->iie_cmd != NULL && iie->iie_cmdlen == 0)
505 		return EINVAL;
506 	if (iie->iie_buf != NULL && iie->iie_buflen == 0)
507 		return EINVAL;
508 	if (I2C_OP_WRITE_P(iie->iie_op) && (flag & FWRITE) == 0)
509 		return EBADF;
510 
511 #if 0
512 	/* Disallow userspace access to devices that have drivers attached. */
513 	if (sc->sc_devices[iie->iie_addr] != NULL)
514 		return EBUSY;
515 #endif
516 
517 	if (iie->iie_cmd != NULL) {
518 		cmd = kmem_alloc(iie->iie_cmdlen, KM_SLEEP);
519 		if (cmd == NULL)
520 			return ENOMEM;
521 		error = copyin(iie->iie_cmd, cmd, iie->iie_cmdlen);
522 		if (error)
523 			goto out;
524 	}
525 
526 	if (iie->iie_buf != NULL && I2C_OP_WRITE_P(iie->iie_op)) {
527 		error = copyin(iie->iie_buf, buf, iie->iie_buflen);
528 		if (error)
529 			goto out;
530 	}
531 
532 	iic_acquire_bus(ic, 0);
533 	error = iic_exec(ic, iie->iie_op, iie->iie_addr, cmd, iie->iie_cmdlen,
534 	    buf, iie->iie_buflen, 0);
535 	iic_release_bus(ic, 0);
536 
537 	/*
538 	 * Some drivers return error codes on failure, and others return -1.
539 	 */
540 	if (error < 0)
541 		error = EIO;
542 
543 out:
544 	if (cmd)
545 		kmem_free(cmd, iie->iie_cmdlen);
546 
547 	if (error)
548 		return error;
549 
550 	if (iie->iie_buf != NULL && I2C_OP_READ_P(iie->iie_op))
551 		error = copyout(buf, iie->iie_buf, iie->iie_buflen);
552 
553 	return error;
554 }
555 
556 static int
557 iic_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
558 {
559 	struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
560 
561 	if (sc == NULL)
562 		return ENXIO;
563 
564 	switch (cmd) {
565 	case I2C_IOCTL_EXEC:
566 		return iic_ioctl_exec(sc, (i2c_ioctl_exec_t *)data, flag);
567 	default:
568 		return ENODEV;
569 	}
570 }
571 
572 
573 CFATTACH_DECL2_NEW(iic, sizeof(struct iic_softc),
574     iic_match, iic_attach, iic_detach, NULL, iic_rescan, iic_child_detach);
575 
576 MODULE(MODULE_CLASS_DRIVER, iic, "i2cexec");
577 
578 #ifdef _MODULE
579 #include "ioconf.c"
580 #endif
581 
582 static int
583 iic_modcmd(modcmd_t cmd, void *opaque)
584 {
585 	int error;
586 
587 	error = 0;
588 	switch (cmd) {
589 	case MODULE_CMD_INIT:
590 #ifdef _MODULE
591 		error = config_init_component(cfdriver_ioconf_iic,
592 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
593 		if (error)
594 			aprint_error("%s: unable to init component\n",
595 			    iic_cd.cd_name);
596 #endif
597 		break;
598 	case MODULE_CMD_FINI:
599 #ifdef _MODULE
600 		config_fini_component(cfdriver_ioconf_iic,
601 		    cfattach_ioconf_iic, cfdata_ioconf_iic);
602 #endif
603 		break;
604 	default:
605 		error = ENOTTY;
606 	}
607 	return error;
608 }
609