xref: /linux/drivers/i2c/muxes/i2c-mux-pca954x.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * I2C multiplexer
4  *
5  * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
6  * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
7  *
8  * This module supports the PCA954x and PCA984x series of I2C multiplexer/switch
9  * chips made by NXP Semiconductors.
10  * This includes the:
11  *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547,
12  *	 PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849.
13  *
14  * It's also compatible to Maxims MAX735x I2C switch chips, which are controlled
15  * as the NXP PCA9548 and the MAX736x chips that act like the PCA9544.
16  *
17  * This includes the:
18  *	 MAX7356, MAX7357, MAX7358, MAX7367, MAX7368 and MAX7369
19  *
20  * These chips are all controlled via the I2C bus itself, and all have a
21  * single 8-bit register. The upstream "parent" bus fans out to two,
22  * four, or eight downstream busses or channels; which of these
23  * are selected is determined by the chip type and register contents. A
24  * mux can select only one sub-bus at a time; a switch can select any
25  * combination simultaneously.
26  *
27  * Based on:
28  *	pca954x.c from Kumar Gala <galak@kernel.crashing.org>
29  * Copyright (C) 2006
30  *
31  * Based on:
32  *	pca954x.c from Ken Harrenstien
33  * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
34  *
35  * Based on:
36  *	i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
37  * and
38  *	pca9540.c from Jean Delvare <jdelvare@suse.de>.
39  */
40 
41 #include <linux/device.h>
42 #include <linux/delay.h>
43 #include <linux/gpio/consumer.h>
44 #include <linux/i2c.h>
45 #include <linux/i2c-mux.h>
46 #include <linux/interrupt.h>
47 #include <linux/irq.h>
48 #include <linux/module.h>
49 #include <linux/pm.h>
50 #include <linux/property.h>
51 #include <linux/regulator/consumer.h>
52 #include <linux/reset.h>
53 #include <linux/slab.h>
54 #include <linux/spinlock.h>
55 #include <dt-bindings/mux/mux.h>
56 
57 #define PCA954X_MAX_NCHANS 8
58 
59 #define PCA954X_IRQ_OFFSET 4
60 
61 /*
62  * MAX7357's configuration register is writeable after POR, but
63  * can be locked by setting the basic mode bit. MAX7358 configuration
64  * register is locked by default and needs to be unlocked first.
65  * The configuration register holds the following settings:
66  */
67 #define MAX7357_CONF_INT_ENABLE			BIT(0)
68 #define MAX7357_CONF_FLUSH_OUT			BIT(1)
69 #define MAX7357_CONF_RELEASE_INT		BIT(2)
70 #define MAX7357_CONF_DISCON_SINGLE_CHAN		BIT(4)
71 #define MAX7357_CONF_PRECONNECT_TEST		BIT(7)
72 
73 #define MAX7357_POR_DEFAULT_CONF		MAX7357_CONF_INT_ENABLE
74 
75 enum pca_type {
76 	max_7356,
77 	max_7357,
78 	max_7358,
79 	max_7367,
80 	max_7368,
81 	max_7369,
82 	pca_9540,
83 	pca_9542,
84 	pca_9543,
85 	pca_9544,
86 	pca_9545,
87 	pca_9546,
88 	pca_9547,
89 	pca_9548,
90 	pca_9846,
91 	pca_9847,
92 	pca_9848,
93 	pca_9849,
94 };
95 
96 struct chip_desc {
97 	u8 nchans;
98 	u8 enable;	/* used for muxes only */
99 	u8 has_irq;
100 	enum muxtype {
101 		pca954x_ismux = 0,
102 		pca954x_isswi
103 	} muxtype;
104 	struct i2c_device_identity id;
105 };
106 
107 struct pca954x {
108 	const struct chip_desc *chip;
109 
110 	u8 last_chan;		/* last register value */
111 	/* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
112 	s32 idle_state;
113 
114 	struct i2c_client *client;
115 
116 	struct irq_domain *irq;
117 	unsigned int irq_mask;
118 	raw_spinlock_t lock;
119 	struct regulator *supply;
120 
121 	struct gpio_desc *reset_gpio;
122 	struct reset_control *reset_cont;
123 };
124 
125 /* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */
126 static const struct chip_desc chips[] = {
127 	[max_7356] = {
128 		.nchans = 8,
129 		.muxtype = pca954x_isswi,
130 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
131 	},
132 	[max_7357] = {
133 		.nchans = 8,
134 		.muxtype = pca954x_isswi,
135 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
136 		/*
137 		 * No interrupt controller support. The interrupt
138 		 * provides information about stuck channels.
139 		 */
140 	},
141 	[max_7358] = {
142 		.nchans = 8,
143 		.muxtype = pca954x_isswi,
144 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
145 		/*
146 		 * No interrupt controller support. The interrupt
147 		 * provides information about stuck channels.
148 		 */
149 	},
150 	[max_7367] = {
151 		.nchans = 4,
152 		.muxtype = pca954x_isswi,
153 		.has_irq = 1,
154 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
155 	},
156 	[max_7368] = {
157 		.nchans = 4,
158 		.muxtype = pca954x_isswi,
159 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
160 	},
161 	[max_7369] = {
162 		.nchans = 4,
163 		.enable = 0x4,
164 		.muxtype = pca954x_ismux,
165 		.has_irq = 1,
166 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
167 	},
168 	[pca_9540] = {
169 		.nchans = 2,
170 		.enable = 0x4,
171 		.muxtype = pca954x_ismux,
172 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
173 	},
174 	[pca_9542] = {
175 		.nchans = 2,
176 		.enable = 0x4,
177 		.has_irq = 1,
178 		.muxtype = pca954x_ismux,
179 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
180 	},
181 	[pca_9543] = {
182 		.nchans = 2,
183 		.has_irq = 1,
184 		.muxtype = pca954x_isswi,
185 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
186 	},
187 	[pca_9544] = {
188 		.nchans = 4,
189 		.enable = 0x4,
190 		.has_irq = 1,
191 		.muxtype = pca954x_ismux,
192 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
193 	},
194 	[pca_9545] = {
195 		.nchans = 4,
196 		.has_irq = 1,
197 		.muxtype = pca954x_isswi,
198 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
199 	},
200 	[pca_9546] = {
201 		.nchans = 4,
202 		.muxtype = pca954x_isswi,
203 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
204 	},
205 	[pca_9547] = {
206 		.nchans = 8,
207 		.enable = 0x8,
208 		.muxtype = pca954x_ismux,
209 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
210 	},
211 	[pca_9548] = {
212 		.nchans = 8,
213 		.muxtype = pca954x_isswi,
214 		.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
215 	},
216 	[pca_9846] = {
217 		.nchans = 4,
218 		.muxtype = pca954x_isswi,
219 		.id = {
220 			.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
221 			.part_id = 0x10b,
222 		},
223 	},
224 	[pca_9847] = {
225 		.nchans = 8,
226 		.enable = 0x8,
227 		.muxtype = pca954x_ismux,
228 		.id = {
229 			.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
230 			.part_id = 0x108,
231 		},
232 	},
233 	[pca_9848] = {
234 		.nchans = 8,
235 		.muxtype = pca954x_isswi,
236 		.id = {
237 			.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
238 			.part_id = 0x10a,
239 		},
240 	},
241 	[pca_9849] = {
242 		.nchans = 4,
243 		.enable = 0x4,
244 		.muxtype = pca954x_ismux,
245 		.id = {
246 			.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
247 			.part_id = 0x109,
248 		},
249 	},
250 };
251 
252 static const struct i2c_device_id pca954x_id[] = {
253 	{ "max7356", max_7356 },
254 	{ "max7357", max_7357 },
255 	{ "max7358", max_7358 },
256 	{ "max7367", max_7367 },
257 	{ "max7368", max_7368 },
258 	{ "max7369", max_7369 },
259 	{ "pca9540", pca_9540 },
260 	{ "pca9542", pca_9542 },
261 	{ "pca9543", pca_9543 },
262 	{ "pca9544", pca_9544 },
263 	{ "pca9545", pca_9545 },
264 	{ "pca9546", pca_9546 },
265 	{ "pca9547", pca_9547 },
266 	{ "pca9548", pca_9548 },
267 	{ "pca9846", pca_9846 },
268 	{ "pca9847", pca_9847 },
269 	{ "pca9848", pca_9848 },
270 	{ "pca9849", pca_9849 },
271 	{ }
272 };
273 MODULE_DEVICE_TABLE(i2c, pca954x_id);
274 
275 static const struct of_device_id pca954x_of_match[] = {
276 	{ .compatible = "maxim,max7356", .data = &chips[max_7356] },
277 	{ .compatible = "maxim,max7357", .data = &chips[max_7357] },
278 	{ .compatible = "maxim,max7358", .data = &chips[max_7358] },
279 	{ .compatible = "maxim,max7367", .data = &chips[max_7367] },
280 	{ .compatible = "maxim,max7368", .data = &chips[max_7368] },
281 	{ .compatible = "maxim,max7369", .data = &chips[max_7369] },
282 	{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
283 	{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
284 	{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
285 	{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
286 	{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
287 	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
288 	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
289 	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
290 	{ .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
291 	{ .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
292 	{ .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
293 	{ .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
294 	{}
295 };
296 MODULE_DEVICE_TABLE(of, pca954x_of_match);
297 
298 /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
299    for this as they will try to lock adapter a second time */
300 static int pca954x_reg_write(struct i2c_adapter *adap,
301 			     struct i2c_client *client, u8 val)
302 {
303 	union i2c_smbus_data dummy;
304 
305 	return __i2c_smbus_xfer(adap, client->addr, client->flags,
306 				I2C_SMBUS_WRITE, val,
307 				I2C_SMBUS_BYTE, &dummy);
308 }
309 
310 static u8 pca954x_regval(struct pca954x *data, u8 chan)
311 {
312 	/* We make switches look like muxes, not sure how to be smarter. */
313 	if (data->chip->muxtype == pca954x_ismux)
314 		return chan | data->chip->enable;
315 	else
316 		return 1 << chan;
317 }
318 
319 static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
320 {
321 	struct pca954x *data = i2c_mux_priv(muxc);
322 	struct i2c_client *client = data->client;
323 	u8 regval;
324 	int ret = 0;
325 
326 	regval = pca954x_regval(data, chan);
327 	/* Only select the channel if its different from the last channel */
328 	if (data->last_chan != regval) {
329 		ret = pca954x_reg_write(muxc->parent, client, regval);
330 		data->last_chan = ret < 0 ? 0 : regval;
331 	}
332 
333 	return ret;
334 }
335 
336 static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
337 {
338 	struct pca954x *data = i2c_mux_priv(muxc);
339 	struct i2c_client *client = data->client;
340 	s32 idle_state;
341 
342 	idle_state = READ_ONCE(data->idle_state);
343 	if (idle_state >= 0)
344 		/* Set the mux back to a predetermined channel */
345 		return pca954x_select_chan(muxc, idle_state);
346 
347 	if (idle_state == MUX_IDLE_DISCONNECT) {
348 		/* Deselect active channel */
349 		data->last_chan = 0;
350 		return pca954x_reg_write(muxc->parent, client,
351 					 data->last_chan);
352 	}
353 
354 	/* otherwise leave as-is */
355 
356 	return 0;
357 }
358 
359 static ssize_t idle_state_show(struct device *dev,
360 				    struct device_attribute *attr,
361 				    char *buf)
362 {
363 	struct i2c_client *client = to_i2c_client(dev);
364 	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
365 	struct pca954x *data = i2c_mux_priv(muxc);
366 
367 	return sprintf(buf, "%d\n", READ_ONCE(data->idle_state));
368 }
369 
370 static ssize_t idle_state_store(struct device *dev,
371 				struct device_attribute *attr,
372 				const char *buf, size_t count)
373 {
374 	struct i2c_client *client = to_i2c_client(dev);
375 	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
376 	struct pca954x *data = i2c_mux_priv(muxc);
377 	int val;
378 	int ret;
379 
380 	ret = kstrtoint(buf, 0, &val);
381 	if (ret < 0)
382 		return ret;
383 
384 	if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT &&
385 	    (val < 0 || val >= data->chip->nchans))
386 		return -EINVAL;
387 
388 	i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT);
389 
390 	WRITE_ONCE(data->idle_state, val);
391 	/*
392 	 * Set the mux into a state consistent with the new
393 	 * idle_state.
394 	 */
395 	if (data->last_chan || val != MUX_IDLE_DISCONNECT)
396 		ret = pca954x_deselect_mux(muxc, 0);
397 
398 	i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT);
399 
400 	return ret < 0 ? ret : count;
401 }
402 
403 static DEVICE_ATTR_RW(idle_state);
404 
405 static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
406 {
407 	struct pca954x *data = dev_id;
408 	unsigned long pending;
409 	int ret, i;
410 
411 	ret = i2c_smbus_read_byte(data->client);
412 	if (ret < 0)
413 		return IRQ_NONE;
414 
415 	pending = (ret >> PCA954X_IRQ_OFFSET) & (BIT(data->chip->nchans) - 1);
416 	for_each_set_bit(i, &pending, data->chip->nchans)
417 		handle_nested_irq(irq_linear_revmap(data->irq, i));
418 
419 	return IRQ_RETVAL(pending);
420 }
421 
422 static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
423 {
424 	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
425 		return -EINVAL;
426 	return 0;
427 }
428 
429 static struct irq_chip pca954x_irq_chip = {
430 	.name = "i2c-mux-pca954x",
431 	.irq_set_type = pca954x_irq_set_type,
432 };
433 
434 static int pca954x_irq_setup(struct i2c_mux_core *muxc)
435 {
436 	struct pca954x *data = i2c_mux_priv(muxc);
437 	struct i2c_client *client = data->client;
438 	int c, irq;
439 
440 	if (!data->chip->has_irq || client->irq <= 0)
441 		return 0;
442 
443 	raw_spin_lock_init(&data->lock);
444 
445 	data->irq = irq_domain_add_linear(client->dev.of_node,
446 					  data->chip->nchans,
447 					  &irq_domain_simple_ops, data);
448 	if (!data->irq)
449 		return -ENODEV;
450 
451 	for (c = 0; c < data->chip->nchans; c++) {
452 		irq = irq_create_mapping(data->irq, c);
453 		if (!irq) {
454 			dev_err(&client->dev, "failed irq create map\n");
455 			return -EINVAL;
456 		}
457 		irq_set_chip_data(irq, data);
458 		irq_set_chip_and_handler(irq, &pca954x_irq_chip,
459 			handle_simple_irq);
460 	}
461 
462 	return 0;
463 }
464 
465 static void pca954x_cleanup(struct i2c_mux_core *muxc)
466 {
467 	struct pca954x *data = i2c_mux_priv(muxc);
468 	int c, irq;
469 
470 	regulator_disable(data->supply);
471 
472 	if (data->irq) {
473 		for (c = 0; c < data->chip->nchans; c++) {
474 			irq = irq_find_mapping(data->irq, c);
475 			irq_dispose_mapping(irq);
476 		}
477 		irq_domain_remove(data->irq);
478 	}
479 	i2c_mux_del_adapters(muxc);
480 }
481 
482 static int pca954x_init(struct i2c_client *client, struct pca954x *data)
483 {
484 	int ret;
485 
486 	if (data->idle_state >= 0)
487 		data->last_chan = pca954x_regval(data, data->idle_state);
488 	else
489 		data->last_chan = 0; /* Disconnect multiplexer */
490 
491 	if (device_is_compatible(&client->dev, "maxim,max7357")) {
492 		if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
493 			u8 conf = MAX7357_POR_DEFAULT_CONF;
494 			/*
495 			 * The interrupt signal is shared with the reset pin. Release the
496 			 * interrupt after 1.6 seconds to allow using the pin as reset.
497 			 */
498 			conf |= MAX7357_CONF_RELEASE_INT;
499 
500 			if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel"))
501 				conf |= MAX7357_CONF_DISCON_SINGLE_CHAN;
502 			if (device_property_read_bool(&client->dev,
503 						      "maxim,send-flush-out-sequence"))
504 				conf |= MAX7357_CONF_FLUSH_OUT;
505 			if (device_property_read_bool(&client->dev,
506 						      "maxim,preconnection-wiggle-test-enable"))
507 				conf |= MAX7357_CONF_PRECONNECT_TEST;
508 
509 			ret = i2c_smbus_write_byte_data(client, data->last_chan, conf);
510 		} else {
511 			dev_warn(&client->dev, "Write byte data not supported."
512 				 "Cannot enable enhanced mode features\n");
513 			ret = i2c_smbus_write_byte(client, data->last_chan);
514 		}
515 	} else {
516 		ret = i2c_smbus_write_byte(client, data->last_chan);
517 	}
518 
519 	if (ret < 0)
520 		data->last_chan = 0;
521 
522 	return ret;
523 }
524 
525 static int pca954x_get_reset(struct device *dev, struct pca954x *data)
526 {
527 	data->reset_cont = devm_reset_control_get_optional_shared(dev, NULL);
528 	if (IS_ERR(data->reset_cont))
529 		return dev_err_probe(dev, PTR_ERR(data->reset_cont),
530 				     "Failed to get reset\n");
531 	else if (data->reset_cont)
532 		return 0;
533 
534 	/*
535 	 * fallback to legacy reset-gpios
536 	 */
537 	data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
538 	if (IS_ERR(data->reset_gpio)) {
539 		return dev_err_probe(dev, PTR_ERR(data->reset_gpio),
540 				     "Failed to get reset gpio");
541 	}
542 
543 	return 0;
544 }
545 
546 static void pca954x_reset_deassert(struct pca954x *data)
547 {
548 	if (data->reset_cont)
549 		reset_control_deassert(data->reset_cont);
550 	else
551 		gpiod_set_value_cansleep(data->reset_gpio, 0);
552 }
553 
554 /*
555  * I2C init/probing/exit functions
556  */
557 static int pca954x_probe(struct i2c_client *client)
558 {
559 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
560 	struct i2c_adapter *adap = client->adapter;
561 	struct device *dev = &client->dev;
562 	struct i2c_mux_core *muxc;
563 	struct pca954x *data;
564 	int num;
565 	int ret;
566 
567 	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
568 		return -ENODEV;
569 
570 	muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0,
571 			     pca954x_select_chan, pca954x_deselect_mux);
572 	if (!muxc)
573 		return -ENOMEM;
574 	data = i2c_mux_priv(muxc);
575 
576 	i2c_set_clientdata(client, muxc);
577 	data->client = client;
578 
579 	data->supply = devm_regulator_get(dev, "vdd");
580 	if (IS_ERR(data->supply))
581 		return dev_err_probe(dev, PTR_ERR(data->supply),
582 				"Failed to request regulator\n");
583 
584 	ret = regulator_enable(data->supply);
585 	if (ret)
586 		return dev_err_probe(dev, ret,
587 				     "Failed to enable vdd supply\n");
588 
589 	ret = pca954x_get_reset(dev, data);
590 	if (ret)
591 		goto fail_cleanup;
592 
593 	if (data->reset_cont || data->reset_gpio) {
594 		udelay(1);
595 		pca954x_reset_deassert(data);
596 		/* Give the chip some time to recover. */
597 		udelay(1);
598 	}
599 
600 	data->chip = device_get_match_data(dev);
601 	if (!data->chip)
602 		data->chip = &chips[id->driver_data];
603 
604 	if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
605 		struct i2c_device_identity id;
606 
607 		ret = i2c_get_device_id(client, &id);
608 		if (ret && ret != -EOPNOTSUPP)
609 			goto fail_cleanup;
610 
611 		if (!ret &&
612 		    (id.manufacturer_id != data->chip->id.manufacturer_id ||
613 		     id.part_id != data->chip->id.part_id)) {
614 			dev_warn(dev, "unexpected device id %03x-%03x-%x\n",
615 				 id.manufacturer_id, id.part_id,
616 				 id.die_revision);
617 			ret = -ENODEV;
618 			goto fail_cleanup;
619 		}
620 	}
621 
622 	data->idle_state = MUX_IDLE_AS_IS;
623 	if (device_property_read_u32(dev, "idle-state", &data->idle_state)) {
624 		if (device_property_read_bool(dev, "i2c-mux-idle-disconnect"))
625 			data->idle_state = MUX_IDLE_DISCONNECT;
626 	}
627 
628 	/*
629 	 * Write the mux register at addr to verify
630 	 * that the mux is in fact present. This also
631 	 * initializes the mux to a channel
632 	 * or disconnected state.
633 	 */
634 	ret = pca954x_init(client, data);
635 	if (ret < 0) {
636 		dev_warn(dev, "probe failed\n");
637 		ret = -ENODEV;
638 		goto fail_cleanup;
639 	}
640 
641 	ret = pca954x_irq_setup(muxc);
642 	if (ret)
643 		goto fail_cleanup;
644 
645 	/* Now create an adapter for each channel */
646 	for (num = 0; num < data->chip->nchans; num++) {
647 		ret = i2c_mux_add_adapter(muxc, 0, num);
648 		if (ret)
649 			goto fail_cleanup;
650 	}
651 
652 	if (data->irq) {
653 		ret = devm_request_threaded_irq(dev, data->client->irq,
654 						NULL, pca954x_irq_handler,
655 						IRQF_ONESHOT | IRQF_SHARED,
656 						"pca954x", data);
657 		if (ret)
658 			goto fail_cleanup;
659 	}
660 
661 	/*
662 	 * The attr probably isn't going to be needed in most cases,
663 	 * so don't fail completely on error.
664 	 */
665 	device_create_file(dev, &dev_attr_idle_state);
666 
667 	dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
668 		 num, data->chip->muxtype == pca954x_ismux
669 				? "mux" : "switch", client->name);
670 
671 	return 0;
672 
673 fail_cleanup:
674 	pca954x_cleanup(muxc);
675 	return ret;
676 }
677 
678 static void pca954x_remove(struct i2c_client *client)
679 {
680 	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
681 
682 	device_remove_file(&client->dev, &dev_attr_idle_state);
683 
684 	pca954x_cleanup(muxc);
685 }
686 
687 static int pca954x_resume(struct device *dev)
688 {
689 	struct i2c_client *client = to_i2c_client(dev);
690 	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
691 	struct pca954x *data = i2c_mux_priv(muxc);
692 	int ret;
693 
694 	ret = pca954x_init(client, data);
695 	if (ret < 0)
696 		dev_err(&client->dev, "failed to verify mux presence\n");
697 
698 	return ret;
699 }
700 
701 static DEFINE_SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
702 
703 static struct i2c_driver pca954x_driver = {
704 	.driver		= {
705 		.name	= "pca954x",
706 		.pm	= pm_sleep_ptr(&pca954x_pm),
707 		.of_match_table = pca954x_of_match,
708 	},
709 	.probe		= pca954x_probe,
710 	.remove		= pca954x_remove,
711 	.id_table	= pca954x_id,
712 };
713 
714 module_i2c_driver(pca954x_driver);
715 
716 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
717 MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
718 MODULE_LICENSE("GPL v2");
719