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1// SPDX-License-Identifier: GPL-2.02/*3 * I2C multiplexer4 *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/switch9 * 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 controlled15 * 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 MAX736919 *20 * These chips are all controlled via the I2C bus itself, and all have a21 * single 8-bit register. The upstream "parent" bus fans out to two,22 * four, or eight downstream busses or channels; which of these23 * are selected is determined by the chip type and register contents. A24 * mux can select only one sub-bus at a time; a switch can select any25 * combination simultaneously.26 *27 * Based on:28 * pca954x.c from Kumar Gala <galak@kernel.crashing.org>29 * Copyright (C) 200630 *31 * Based on:32 * pca954x.c from Ken Harrenstien33 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)34 *35 * Based on:36 * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>37 * and38 * 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 858 59#define PCA954X_IRQ_OFFSET 460 61/*62 * MAX7357's configuration register is writeable after POR, but63 * can be locked by setting the basic mode bit. MAX7358 configuration64 * 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_ENABLE74 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_isswi103 } 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 interrupt138 * 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 interrupt147 * 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(adap, client->addr, client->flags,306 I2C_SMBUS_WRITE, val,307 I2C_SMBUS_BYTE, &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 else316 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(muxc->parent, client, 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, 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 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, "%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(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 new393 * 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 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(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 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_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 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(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 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, data->idle_state);488 else489 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 the496 * 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 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(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-gpios536 */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 546static void pca954x_reset_deassert(struct pca954x *data)547{548 if (data->reset_cont)549 reset_control_deassert(data->reset_cont);550 else551 gpiod_set_value_cansleep(data->reset_gpio, 0);552}553 554/*555 * I2C init/probing/exit functions556 */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(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 verify630 * that the mux is in fact present. This also631 * initializes the mux to a channel632 * 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_ismux669 ? "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(&client->dev, &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