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
75enum 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
96struct 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
107struct 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 */
126static 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
252static 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};
273MODULE_DEVICE_TABLE(i2c, pca954x_id);
274
275static 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};
296MODULE_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 */
300static 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(adapter: adap, addr: client->addr, flags: client->flags,
306 I2C_SMBUS_WRITE, command: val,
307 I2C_SMBUS_BYTE, data: &dummy);
308}
309
310static 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
319static 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(adap: muxc->parent, client, val: regval);
330 data->last_chan = ret < 0 ? 0 : regval;
331 }
332
333 return ret;
334}
335
336static 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, chan: idle_state);
346
347 if (idle_state == MUX_IDLE_DISCONNECT) {
348 /* Deselect active channel */
349 data->last_chan = 0;
350 return pca954x_reg_write(adap: muxc->parent, client,
351 val: data->last_chan);
352 }
353
354 /* otherwise leave as-is */
355
356 return 0;
357}
358
359static 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, fmt: "%d\n", READ_ONCE(data->idle_state));
368}
369
370static 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(s: buf, base: 0, res: &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(adapter: 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, chan: 0);
397
398 i2c_unlock_bus(adapter: muxc->parent, I2C_LOCK_SEGMENT);
399
400 return ret < 0 ? ret : count;
401}
402
403static DEVICE_ATTR_RW(idle_state);
404
405static 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(client: 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: irq_find_mapping(domain: data->irq, hwirq: i));
418
419 return IRQ_RETVAL(pending);
420}
421
422static 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
429static struct irq_chip pca954x_irq_chip = {
430 .name = "i2c-mux-pca954x",
431 .irq_set_type = pca954x_irq_set_type,
432};
433
434static 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_create_linear(of_fwnode_handle(client->dev.of_node),
446 size: data->chip->nchans,
447 ops: &irq_domain_simple_ops, host_data: data);
448 if (!data->irq)
449 return -ENODEV;
450
451 for (c = 0; c < data->chip->nchans; c++) {
452 irq = irq_create_mapping(domain: data->irq, hwirq: 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, chip: &pca954x_irq_chip,
459 handle: handle_simple_irq);
460 }
461
462 return 0;
463}
464
465static 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(regulator: data->supply);
471
472 if (data->irq) {
473 for (c = 0; c < data->chip->nchans; c++) {
474 irq = irq_find_mapping(domain: data->irq, hwirq: c);
475 irq_dispose_mapping(virq: irq);
476 }
477 irq_domain_remove(domain: data->irq);
478 }
479 i2c_mux_del_adapters(muxc);
480}
481
482static 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, chan: data->idle_state);
488 else
489 data->last_chan = 0; /* Disconnect multiplexer */
490
491 if (device_is_compatible(dev: &client->dev, compat: "maxim,max7357")) {
492 if (i2c_check_functionality(adap: 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(dev: &client->dev, propname: "maxim,isolate-stuck-channel"))
501 conf |= MAX7357_CONF_DISCON_SINGLE_CHAN;
502 if (device_property_read_bool(dev: &client->dev,
503 propname: "maxim,send-flush-out-sequence"))
504 conf |= MAX7357_CONF_FLUSH_OUT;
505 if (device_property_read_bool(dev: &client->dev,
506 propname: "maxim,preconnection-wiggle-test-enable"))
507 conf |= MAX7357_CONF_PRECONNECT_TEST;
508
509 ret = i2c_smbus_write_byte_data(client, command: data->last_chan, value: 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, value: data->last_chan);
514 }
515 } else {
516 ret = i2c_smbus_write_byte(client, value: data->last_chan);
517 }
518
519 if (ret < 0)
520 data->last_chan = 0;
521
522 return ret;
523}
524
525static 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(ptr: data->reset_cont))
529 return dev_err_probe(dev, err: PTR_ERR(ptr: data->reset_cont),
530 fmt: "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, con_id: "reset", flags: GPIOD_OUT_HIGH);
538 if (IS_ERR(ptr: data->reset_gpio)) {
539 return dev_err_probe(dev, err: PTR_ERR(ptr: data->reset_gpio),
540 fmt: "Failed to get reset gpio");
541 }
542
543 return 0;
544}
545
546static void pca954x_reset_deassert(struct pca954x *data)
547{
548 if (data->reset_cont)
549 reset_control_deassert(rstc: data->reset_cont);
550 else
551 gpiod_set_value_cansleep(desc: data->reset_gpio, value: 0);
552}
553
554/*
555 * I2C init/probing/exit functions
556 */
557static 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(parent: adap, dev, PCA954X_MAX_NCHANS, sizeof_priv: sizeof(*data), flags: 0,
571 select: pca954x_select_chan, deselect: pca954x_deselect_mux);
572 if (!muxc)
573 return -ENOMEM;
574 data = i2c_mux_priv(muxc);
575
576 i2c_set_clientdata(client, data: muxc);
577 data->client = client;
578
579 data->supply = devm_regulator_get(dev, id: "vdd");
580 if (IS_ERR(ptr: data->supply))
581 return dev_err_probe(dev, err: PTR_ERR(ptr: data->supply),
582 fmt: "Failed to request regulator\n");
583
584 ret = regulator_enable(regulator: data->supply);
585 if (ret)
586 return dev_err_probe(dev, err: ret,
587 fmt: "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(usec: 1);
595 pca954x_reset_deassert(data);
596 /* Give the chip some time to recover. */
597 udelay(usec: 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: &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, propname: "idle-state", val: &data->idle_state)) {
624 if (device_property_read_bool(dev, propname: "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, force_nr: 0, chan_id: num);
648 if (ret)
649 goto fail_cleanup;
650 }
651
652 if (data->irq) {
653 ret = devm_request_threaded_irq(dev, irq: data->client->irq,
654 NULL, thread_fn: pca954x_irq_handler,
655 IRQF_ONESHOT | IRQF_SHARED,
656 devname: "pca954x", dev_id: 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(device: dev, entry: &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
673fail_cleanup:
674 pca954x_cleanup(muxc);
675 return ret;
676}
677
678static void pca954x_remove(struct i2c_client *client)
679{
680 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
681
682 device_remove_file(dev: &client->dev, attr: &dev_attr_idle_state);
683
684 pca954x_cleanup(muxc);
685}
686
687static 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
701static DEFINE_SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
702
703static 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
714module_i2c_driver(pca954x_driver);
715
716MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
717MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
718MODULE_LICENSE("GPL v2");
719

source code of linux/drivers/i2c/muxes/i2c-mux-pca954x.c