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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 * These chips are all controlled via the I2C bus itself, and all have a
15 * single 8-bit register. The upstream "parent" bus fans out to two,
16 * four, or eight downstream busses or channels; which of these
17 * are selected is determined by the chip type and register contents. A
18 * mux can select only one sub-bus at a time; a switch can select any
19 * combination simultaneously.
20 *
21 * Based on:
22 * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
23 * Copyright (C) 2006
24 *
25 * Based on:
26 * pca954x.c from Ken Harrenstien
27 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
28 *
29 * Based on:
30 * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
31 * and
32 * pca9540.c from Jean Delvare <jdelvare@suse.de>.
33 */
34
35#include <linux/device.h>
36#include <linux/delay.h>
37#include <linux/gpio/consumer.h>
38#include <linux/i2c.h>
39#include <linux/i2c-mux.h>
40#include <linux/interrupt.h>
41#include <linux/irq.h>
42#include <linux/module.h>
43#include <linux/pm.h>
44#include <linux/property.h>
45#include <linux/slab.h>
46#include <linux/spinlock.h>
47#include <dt-bindings/mux/mux.h>
48
49#define PCA954X_MAX_NCHANS 8
50
51#define PCA954X_IRQ_OFFSET 4
52
53enum pca_type {
54 pca_9540,
55 pca_9542,
56 pca_9543,
57 pca_9544,
58 pca_9545,
59 pca_9546,
60 pca_9547,
61 pca_9548,
62 pca_9846,
63 pca_9847,
64 pca_9848,
65 pca_9849,
66};
67
68struct chip_desc {
69 u8 nchans;
70 u8 enable; /* used for muxes only */
71 u8 has_irq;
72 enum muxtype {
73 pca954x_ismux = 0,
74 pca954x_isswi
75 } muxtype;
76 struct i2c_device_identity id;
77};
78
79struct pca954x {
80 const struct chip_desc *chip;
81
82 u8 last_chan; /* last register value */
83 /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
84 s32 idle_state;
85
86 struct i2c_client *client;
87
88 struct irq_domain *irq;
89 unsigned int irq_mask;
90 raw_spinlock_t lock;
91};
92
93/* Provide specs for the PCA954x types we know about */
94static const struct chip_desc chips[] = {
95 [pca_9540] = {
96 .nchans = 2,
97 .enable = 0x4,
98 .muxtype = pca954x_ismux,
99 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
100 },
101 [pca_9542] = {
102 .nchans = 2,
103 .enable = 0x4,
104 .has_irq = 1,
105 .muxtype = pca954x_ismux,
106 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
107 },
108 [pca_9543] = {
109 .nchans = 2,
110 .has_irq = 1,
111 .muxtype = pca954x_isswi,
112 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
113 },
114 [pca_9544] = {
115 .nchans = 4,
116 .enable = 0x4,
117 .has_irq = 1,
118 .muxtype = pca954x_ismux,
119 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
120 },
121 [pca_9545] = {
122 .nchans = 4,
123 .has_irq = 1,
124 .muxtype = pca954x_isswi,
125 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
126 },
127 [pca_9546] = {
128 .nchans = 4,
129 .muxtype = pca954x_isswi,
130 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
131 },
132 [pca_9547] = {
133 .nchans = 8,
134 .enable = 0x8,
135 .muxtype = pca954x_ismux,
136 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
137 },
138 [pca_9548] = {
139 .nchans = 8,
140 .muxtype = pca954x_isswi,
141 .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
142 },
143 [pca_9846] = {
144 .nchans = 4,
145 .muxtype = pca954x_isswi,
146 .id = {
147 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
148 .part_id = 0x10b,
149 },
150 },
151 [pca_9847] = {
152 .nchans = 8,
153 .enable = 0x8,
154 .muxtype = pca954x_ismux,
155 .id = {
156 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
157 .part_id = 0x108,
158 },
159 },
160 [pca_9848] = {
161 .nchans = 8,
162 .muxtype = pca954x_isswi,
163 .id = {
164 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
165 .part_id = 0x10a,
166 },
167 },
168 [pca_9849] = {
169 .nchans = 4,
170 .enable = 0x4,
171 .muxtype = pca954x_ismux,
172 .id = {
173 .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
174 .part_id = 0x109,
175 },
176 },
177};
178
179static const struct i2c_device_id pca954x_id[] = {
180 { "pca9540", pca_9540 },
181 { "pca9542", pca_9542 },
182 { "pca9543", pca_9543 },
183 { "pca9544", pca_9544 },
184 { "pca9545", pca_9545 },
185 { "pca9546", pca_9546 },
186 { "pca9547", pca_9547 },
187 { "pca9548", pca_9548 },
188 { "pca9846", pca_9846 },
189 { "pca9847", pca_9847 },
190 { "pca9848", pca_9848 },
191 { "pca9849", pca_9849 },
192 { }
193};
194MODULE_DEVICE_TABLE(i2c, pca954x_id);
195
196static const struct of_device_id pca954x_of_match[] = {
197 { .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
198 { .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
199 { .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
200 { .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
201 { .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
202 { .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
203 { .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
204 { .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
205 { .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
206 { .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
207 { .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
208 { .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
209 {}
210};
211MODULE_DEVICE_TABLE(of, pca954x_of_match);
212
213/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
214 for this as they will try to lock adapter a second time */
215static int pca954x_reg_write(struct i2c_adapter *adap,
216 struct i2c_client *client, u8 val)
217{
218 union i2c_smbus_data dummy;
219
220 return __i2c_smbus_xfer(adap, client->addr, client->flags,
221 I2C_SMBUS_WRITE, val,
222 I2C_SMBUS_BYTE, &dummy);
223}
224
225static u8 pca954x_regval(struct pca954x *data, u8 chan)
226{
227 /* We make switches look like muxes, not sure how to be smarter. */
228 if (data->chip->muxtype == pca954x_ismux)
229 return chan | data->chip->enable;
230 else
231 return 1 << chan;
232}
233
234static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
235{
236 struct pca954x *data = i2c_mux_priv(muxc);
237 struct i2c_client *client = data->client;
238 u8 regval;
239 int ret = 0;
240
241 regval = pca954x_regval(data, chan);
242 /* Only select the channel if its different from the last channel */
243 if (data->last_chan != regval) {
244 ret = pca954x_reg_write(muxc->parent, client, regval);
245 data->last_chan = ret < 0 ? 0 : regval;
246 }
247
248 return ret;
249}
250
251static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
252{
253 struct pca954x *data = i2c_mux_priv(muxc);
254 struct i2c_client *client = data->client;
255 s32 idle_state;
256
257 idle_state = READ_ONCE(data->idle_state);
258 if (idle_state >= 0)
259 /* Set the mux back to a predetermined channel */
260 return pca954x_select_chan(muxc, idle_state);
261
262 if (idle_state == MUX_IDLE_DISCONNECT) {
263 /* Deselect active channel */
264 data->last_chan = 0;
265 return pca954x_reg_write(muxc->parent, client,
266 data->last_chan);
267 }
268
269 /* otherwise leave as-is */
270
271 return 0;
272}
273
274static ssize_t idle_state_show(struct device *dev,
275 struct device_attribute *attr,
276 char *buf)
277{
278 struct i2c_client *client = to_i2c_client(dev);
279 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
280 struct pca954x *data = i2c_mux_priv(muxc);
281
282 return sprintf(buf, "%d\n", READ_ONCE(data->idle_state));
283}
284
285static ssize_t idle_state_store(struct device *dev,
286 struct device_attribute *attr,
287 const char *buf, size_t count)
288{
289 struct i2c_client *client = to_i2c_client(dev);
290 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
291 struct pca954x *data = i2c_mux_priv(muxc);
292 int val;
293 int ret;
294
295 ret = kstrtoint(buf, 0, &val);
296 if (ret < 0)
297 return ret;
298
299 if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT &&
300 (val < 0 || val >= data->chip->nchans))
301 return -EINVAL;
302
303 i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT);
304
305 WRITE_ONCE(data->idle_state, val);
306 /*
307 * Set the mux into a state consistent with the new
308 * idle_state.
309 */
310 if (data->last_chan || val != MUX_IDLE_DISCONNECT)
311 ret = pca954x_deselect_mux(muxc, 0);
312
313 i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT);
314
315 return ret < 0 ? ret : count;
316}
317
318static DEVICE_ATTR_RW(idle_state);
319
320static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
321{
322 struct pca954x *data = dev_id;
323 unsigned long pending;
324 int ret, i;
325
326 ret = i2c_smbus_read_byte(data->client);
327 if (ret < 0)
328 return IRQ_NONE;
329
330 pending = (ret >> PCA954X_IRQ_OFFSET) & (BIT(data->chip->nchans) - 1);
331 for_each_set_bit(i, &pending, data->chip->nchans)
332 handle_nested_irq(irq_linear_revmap(data->irq, i));
333
334 return IRQ_RETVAL(pending);
335}
336
337static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
338{
339 if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
340 return -EINVAL;
341 return 0;
342}
343
344static struct irq_chip pca954x_irq_chip = {
345 .name = "i2c-mux-pca954x",
346 .irq_set_type = pca954x_irq_set_type,
347};
348
349static int pca954x_irq_setup(struct i2c_mux_core *muxc)
350{
351 struct pca954x *data = i2c_mux_priv(muxc);
352 struct i2c_client *client = data->client;
353 int c, irq;
354
355 if (!data->chip->has_irq || client->irq <= 0)
356 return 0;
357
358 raw_spin_lock_init(&data->lock);
359
360 data->irq = irq_domain_add_linear(client->dev.of_node,
361 data->chip->nchans,
362 &irq_domain_simple_ops, data);
363 if (!data->irq)
364 return -ENODEV;
365
366 for (c = 0; c < data->chip->nchans; c++) {
367 irq = irq_create_mapping(data->irq, c);
368 if (!irq) {
369 dev_err(&client->dev, "failed irq create map\n");
370 return -EINVAL;
371 }
372 irq_set_chip_data(irq, data);
373 irq_set_chip_and_handler(irq, &pca954x_irq_chip,
374 handle_simple_irq);
375 }
376
377 return 0;
378}
379
380static void pca954x_cleanup(struct i2c_mux_core *muxc)
381{
382 struct pca954x *data = i2c_mux_priv(muxc);
383 int c, irq;
384
385 if (data->irq) {
386 for (c = 0; c < data->chip->nchans; c++) {
387 irq = irq_find_mapping(data->irq, c);
388 irq_dispose_mapping(irq);
389 }
390 irq_domain_remove(data->irq);
391 }
392 i2c_mux_del_adapters(muxc);
393}
394
395static int pca954x_init(struct i2c_client *client, struct pca954x *data)
396{
397 int ret;
398
399 if (data->idle_state >= 0)
400 data->last_chan = pca954x_regval(data, data->idle_state);
401 else
402 data->last_chan = 0; /* Disconnect multiplexer */
403
404 ret = i2c_smbus_write_byte(client, data->last_chan);
405 if (ret < 0)
406 data->last_chan = 0;
407
408 return ret;
409}
410
411/*
412 * I2C init/probing/exit functions
413 */
414static int pca954x_probe(struct i2c_client *client)
415{
416 const struct i2c_device_id *id = i2c_client_get_device_id(client);
417 struct i2c_adapter *adap = client->adapter;
418 struct device *dev = &client->dev;
419 struct gpio_desc *gpio;
420 struct i2c_mux_core *muxc;
421 struct pca954x *data;
422 int num;
423 int ret;
424
425 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
426 return -ENODEV;
427
428 muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0,
429 pca954x_select_chan, pca954x_deselect_mux);
430 if (!muxc)
431 return -ENOMEM;
432 data = i2c_mux_priv(muxc);
433
434 i2c_set_clientdata(client, muxc);
435 data->client = client;
436
437 /* Reset the mux if a reset GPIO is specified. */
438 gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
439 if (IS_ERR(gpio))
440 return PTR_ERR(gpio);
441 if (gpio) {
442 udelay(1);
443 gpiod_set_value_cansleep(gpio, 0);
444 /* Give the chip some time to recover. */
445 udelay(1);
446 }
447
448 data->chip = device_get_match_data(dev);
449 if (!data->chip)
450 data->chip = &chips[id->driver_data];
451
452 if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
453 struct i2c_device_identity id;
454
455 ret = i2c_get_device_id(client, &id);
456 if (ret && ret != -EOPNOTSUPP)
457 return ret;
458
459 if (!ret &&
460 (id.manufacturer_id != data->chip->id.manufacturer_id ||
461 id.part_id != data->chip->id.part_id)) {
462 dev_warn(dev, "unexpected device id %03x-%03x-%x\n",
463 id.manufacturer_id, id.part_id,
464 id.die_revision);
465 return -ENODEV;
466 }
467 }
468
469 data->idle_state = MUX_IDLE_AS_IS;
470 if (device_property_read_u32(dev, "idle-state", &data->idle_state)) {
471 if (device_property_read_bool(dev, "i2c-mux-idle-disconnect"))
472 data->idle_state = MUX_IDLE_DISCONNECT;
473 }
474
475 /*
476 * Write the mux register at addr to verify
477 * that the mux is in fact present. This also
478 * initializes the mux to a channel
479 * or disconnected state.
480 */
481 ret = pca954x_init(client, data);
482 if (ret < 0) {
483 dev_warn(dev, "probe failed\n");
484 return -ENODEV;
485 }
486
487 ret = pca954x_irq_setup(muxc);
488 if (ret)
489 goto fail_cleanup;
490
491 /* Now create an adapter for each channel */
492 for (num = 0; num < data->chip->nchans; num++) {
493 ret = i2c_mux_add_adapter(muxc, 0, num, 0);
494 if (ret)
495 goto fail_cleanup;
496 }
497
498 if (data->irq) {
499 ret = devm_request_threaded_irq(dev, data->client->irq,
500 NULL, pca954x_irq_handler,
501 IRQF_ONESHOT | IRQF_SHARED,
502 "pca954x", data);
503 if (ret)
504 goto fail_cleanup;
505 }
506
507 /*
508 * The attr probably isn't going to be needed in most cases,
509 * so don't fail completely on error.
510 */
511 device_create_file(dev, &dev_attr_idle_state);
512
513 dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
514 num, data->chip->muxtype == pca954x_ismux
515 ? "mux" : "switch", client->name);
516
517 return 0;
518
519fail_cleanup:
520 pca954x_cleanup(muxc);
521 return ret;
522}
523
524static void pca954x_remove(struct i2c_client *client)
525{
526 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
527
528 device_remove_file(&client->dev, &dev_attr_idle_state);
529
530 pca954x_cleanup(muxc);
531}
532
533#ifdef CONFIG_PM_SLEEP
534static int pca954x_resume(struct device *dev)
535{
536 struct i2c_client *client = to_i2c_client(dev);
537 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
538 struct pca954x *data = i2c_mux_priv(muxc);
539 int ret;
540
541 ret = pca954x_init(client, data);
542 if (ret < 0)
543 dev_err(&client->dev, "failed to verify mux presence\n");
544
545 return ret;
546}
547#endif
548
549static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
550
551static struct i2c_driver pca954x_driver = {
552 .driver = {
553 .name = "pca954x",
554 .pm = &pca954x_pm,
555 .of_match_table = pca954x_of_match,
556 },
557 .probe_new = pca954x_probe,
558 .remove = pca954x_remove,
559 .id_table = pca954x_id,
560};
561
562module_i2c_driver(pca954x_driver);
563
564MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
565MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
566MODULE_LICENSE("GPL v2");
1/*
2 * I2C multiplexer
3 *
4 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
6 *
7 * This module supports the PCA954x series of I2C multiplexer/switch chips
8 * made by Philips Semiconductors.
9 * This includes the:
10 * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
11 * and PCA9548.
12 *
13 * These chips are all controlled via the I2C bus itself, and all have a
14 * single 8-bit register. The upstream "parent" bus fans out to two,
15 * four, or eight downstream busses or channels; which of these
16 * are selected is determined by the chip type and register contents. A
17 * mux can select only one sub-bus at a time; a switch can select any
18 * combination simultaneously.
19 *
20 * Based on:
21 * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
22 * Copyright (C) 2006
23 *
24 * Based on:
25 * pca954x.c from Ken Harrenstien
26 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
27 *
28 * Based on:
29 * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
30 * and
31 * pca9540.c from Jean Delvare <jdelvare@suse.de>.
32 *
33 * This file is licensed under the terms of the GNU General Public
34 * License version 2. This program is licensed "as is" without any
35 * warranty of any kind, whether express or implied.
36 */
37
38#include <linux/acpi.h>
39#include <linux/device.h>
40#include <linux/gpio/consumer.h>
41#include <linux/i2c.h>
42#include <linux/i2c-mux.h>
43#include <linux/i2c/pca954x.h>
44#include <linux/module.h>
45#include <linux/of.h>
46#include <linux/of_device.h>
47#include <linux/pm.h>
48#include <linux/slab.h>
49
50#define PCA954X_MAX_NCHANS 8
51
52enum pca_type {
53 pca_9540,
54 pca_9542,
55 pca_9543,
56 pca_9544,
57 pca_9545,
58 pca_9546,
59 pca_9547,
60 pca_9548,
61};
62
63struct chip_desc {
64 u8 nchans;
65 u8 enable; /* used for muxes only */
66 enum muxtype {
67 pca954x_ismux = 0,
68 pca954x_isswi
69 } muxtype;
70};
71
72struct pca954x {
73 const struct chip_desc *chip;
74
75 u8 last_chan; /* last register value */
76 u8 deselect;
77 struct i2c_client *client;
78};
79
80/* Provide specs for the PCA954x types we know about */
81static const struct chip_desc chips[] = {
82 [pca_9540] = {
83 .nchans = 2,
84 .enable = 0x4,
85 .muxtype = pca954x_ismux,
86 },
87 [pca_9543] = {
88 .nchans = 2,
89 .muxtype = pca954x_isswi,
90 },
91 [pca_9544] = {
92 .nchans = 4,
93 .enable = 0x4,
94 .muxtype = pca954x_ismux,
95 },
96 [pca_9545] = {
97 .nchans = 4,
98 .muxtype = pca954x_isswi,
99 },
100 [pca_9547] = {
101 .nchans = 8,
102 .enable = 0x8,
103 .muxtype = pca954x_ismux,
104 },
105 [pca_9548] = {
106 .nchans = 8,
107 .muxtype = pca954x_isswi,
108 },
109};
110
111static const struct i2c_device_id pca954x_id[] = {
112 { "pca9540", pca_9540 },
113 { "pca9542", pca_9540 },
114 { "pca9543", pca_9543 },
115 { "pca9544", pca_9544 },
116 { "pca9545", pca_9545 },
117 { "pca9546", pca_9545 },
118 { "pca9547", pca_9547 },
119 { "pca9548", pca_9548 },
120 { }
121};
122MODULE_DEVICE_TABLE(i2c, pca954x_id);
123
124#ifdef CONFIG_ACPI
125static const struct acpi_device_id pca954x_acpi_ids[] = {
126 { .id = "PCA9540", .driver_data = pca_9540 },
127 { .id = "PCA9542", .driver_data = pca_9540 },
128 { .id = "PCA9543", .driver_data = pca_9543 },
129 { .id = "PCA9544", .driver_data = pca_9544 },
130 { .id = "PCA9545", .driver_data = pca_9545 },
131 { .id = "PCA9546", .driver_data = pca_9545 },
132 { .id = "PCA9547", .driver_data = pca_9547 },
133 { .id = "PCA9548", .driver_data = pca_9548 },
134 { }
135};
136MODULE_DEVICE_TABLE(acpi, pca954x_acpi_ids);
137#endif
138
139#ifdef CONFIG_OF
140static const struct of_device_id pca954x_of_match[] = {
141 { .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
142 { .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
143 { .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
144 { .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
145 { .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
146 { .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
147 { .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
148 { .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
149 {}
150};
151#endif
152
153/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
154 for this as they will try to lock adapter a second time */
155static int pca954x_reg_write(struct i2c_adapter *adap,
156 struct i2c_client *client, u8 val)
157{
158 int ret = -ENODEV;
159
160 if (adap->algo->master_xfer) {
161 struct i2c_msg msg;
162 char buf[1];
163
164 msg.addr = client->addr;
165 msg.flags = 0;
166 msg.len = 1;
167 buf[0] = val;
168 msg.buf = buf;
169 ret = __i2c_transfer(adap, &msg, 1);
170
171 if (ret >= 0 && ret != 1)
172 ret = -EREMOTEIO;
173 } else {
174 union i2c_smbus_data data;
175 ret = adap->algo->smbus_xfer(adap, client->addr,
176 client->flags,
177 I2C_SMBUS_WRITE,
178 val, I2C_SMBUS_BYTE, &data);
179 }
180
181 return ret;
182}
183
184static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
185{
186 struct pca954x *data = i2c_mux_priv(muxc);
187 struct i2c_client *client = data->client;
188 const struct chip_desc *chip = data->chip;
189 u8 regval;
190 int ret = 0;
191
192 /* we make switches look like muxes, not sure how to be smarter */
193 if (chip->muxtype == pca954x_ismux)
194 regval = chan | chip->enable;
195 else
196 regval = 1 << chan;
197
198 /* Only select the channel if its different from the last channel */
199 if (data->last_chan != regval) {
200 ret = pca954x_reg_write(muxc->parent, client, regval);
201 data->last_chan = ret < 0 ? 0 : regval;
202 }
203
204 return ret;
205}
206
207static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
208{
209 struct pca954x *data = i2c_mux_priv(muxc);
210 struct i2c_client *client = data->client;
211
212 if (!(data->deselect & (1 << chan)))
213 return 0;
214
215 /* Deselect active channel */
216 data->last_chan = 0;
217 return pca954x_reg_write(muxc->parent, client, data->last_chan);
218}
219
220/*
221 * I2C init/probing/exit functions
222 */
223static int pca954x_probe(struct i2c_client *client,
224 const struct i2c_device_id *id)
225{
226 struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
227 struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
228 struct device_node *of_node = client->dev.of_node;
229 bool idle_disconnect_dt;
230 struct gpio_desc *gpio;
231 int num, force, class;
232 struct i2c_mux_core *muxc;
233 struct pca954x *data;
234 const struct of_device_id *match;
235 int ret;
236
237 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
238 return -ENODEV;
239
240 muxc = i2c_mux_alloc(adap, &client->dev,
241 PCA954X_MAX_NCHANS, sizeof(*data), 0,
242 pca954x_select_chan, pca954x_deselect_mux);
243 if (!muxc)
244 return -ENOMEM;
245 data = i2c_mux_priv(muxc);
246
247 i2c_set_clientdata(client, muxc);
248 data->client = client;
249
250 /* Get the mux out of reset if a reset GPIO is specified. */
251 gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
252 if (IS_ERR(gpio))
253 return PTR_ERR(gpio);
254
255 /* Write the mux register at addr to verify
256 * that the mux is in fact present. This also
257 * initializes the mux to disconnected state.
258 */
259 if (i2c_smbus_write_byte(client, 0) < 0) {
260 dev_warn(&client->dev, "probe failed\n");
261 return -ENODEV;
262 }
263
264 match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
265 if (match)
266 data->chip = of_device_get_match_data(&client->dev);
267 else if (id)
268 data->chip = &chips[id->driver_data];
269 else {
270 const struct acpi_device_id *acpi_id;
271
272 acpi_id = acpi_match_device(ACPI_PTR(pca954x_acpi_ids),
273 &client->dev);
274 if (!acpi_id)
275 return -ENODEV;
276 data->chip = &chips[acpi_id->driver_data];
277 }
278
279 data->last_chan = 0; /* force the first selection */
280
281 idle_disconnect_dt = of_node &&
282 of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
283
284 /* Now create an adapter for each channel */
285 for (num = 0; num < data->chip->nchans; num++) {
286 bool idle_disconnect_pd = false;
287
288 force = 0; /* dynamic adap number */
289 class = 0; /* no class by default */
290 if (pdata) {
291 if (num < pdata->num_modes) {
292 /* force static number */
293 force = pdata->modes[num].adap_id;
294 class = pdata->modes[num].class;
295 } else
296 /* discard unconfigured channels */
297 break;
298 idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
299 }
300 data->deselect |= (idle_disconnect_pd ||
301 idle_disconnect_dt) << num;
302
303 ret = i2c_mux_add_adapter(muxc, force, num, class);
304
305 if (ret) {
306 dev_err(&client->dev,
307 "failed to register multiplexed adapter"
308 " %d as bus %d\n", num, force);
309 goto virt_reg_failed;
310 }
311 }
312
313 dev_info(&client->dev,
314 "registered %d multiplexed busses for I2C %s %s\n",
315 num, data->chip->muxtype == pca954x_ismux
316 ? "mux" : "switch", client->name);
317
318 return 0;
319
320virt_reg_failed:
321 i2c_mux_del_adapters(muxc);
322 return ret;
323}
324
325static int pca954x_remove(struct i2c_client *client)
326{
327 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
328
329 i2c_mux_del_adapters(muxc);
330 return 0;
331}
332
333#ifdef CONFIG_PM_SLEEP
334static int pca954x_resume(struct device *dev)
335{
336 struct i2c_client *client = to_i2c_client(dev);
337 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
338 struct pca954x *data = i2c_mux_priv(muxc);
339
340 data->last_chan = 0;
341 return i2c_smbus_write_byte(client, 0);
342}
343#endif
344
345static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
346
347static struct i2c_driver pca954x_driver = {
348 .driver = {
349 .name = "pca954x",
350 .pm = &pca954x_pm,
351 .of_match_table = of_match_ptr(pca954x_of_match),
352 .acpi_match_table = ACPI_PTR(pca954x_acpi_ids),
353 },
354 .probe = pca954x_probe,
355 .remove = pca954x_remove,
356 .id_table = pca954x_id,
357};
358
359module_i2c_driver(pca954x_driver);
360
361MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
362MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
363MODULE_LICENSE("GPL v2");