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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * MAX732x I2C Port Expander with 8/16 I/O4 *5 * Copyright (C) 2007 Marvell International Ltd.6 * Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>7 * Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>8 * Copyright (C) 2015 Linus Walleij <linus.walleij@linaro.org>9 *10 * Derived from drivers/gpio/pca953x.c11 */12 13#include <linux/module.h>14#include <linux/init.h>15#include <linux/slab.h>16#include <linux/string.h>17#include <linux/gpio/driver.h>18#include <linux/interrupt.h>19#include <linux/i2c.h>20#include <linux/platform_data/max732x.h>21 22/*23 * Each port of MAX732x (including MAX7319) falls into one of the24 * following three types:25 *26 * - Push Pull Output27 * - Input28 * - Open Drain I/O29 *30 * designated by 'O', 'I' and 'P' individually according to MAXIM's31 * datasheets. 'I' and 'P' ports are interrupt capables, some with32 * a dedicated interrupt mask.33 *34 * There are two groups of I/O ports, each group usually includes35 * up to 8 I/O ports, and is accessed by a specific I2C address:36 *37 * - Group A : by I2C address 0b'110xxxx38 * - Group B : by I2C address 0b'101xxxx39 *40 * where 'xxxx' is decided by the connections of pin AD2/AD0. The41 * address used also affects the initial state of output signals.42 *43 * Within each group of ports, there are five known combinations of44 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for45 * the detailed organization of these ports. Only Goup A is interrupt46 * capable.47 *48 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',49 * and GPIOs from GROUP_A are numbered before those from GROUP_B50 * (if there are two groups).51 *52 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so53 * they are not supported by this driver.54 */55 56#define PORT_NONE 0x0 /* '/' No Port */57#define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */58#define PORT_INPUT 0x2 /* 'I' Input Only */59#define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */60 61#define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */62#define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */63#define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */64#define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */65#define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */66 67#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */68#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */69 70#define INT_NONE 0x0 /* No interrupt capability */71#define INT_NO_MASK 0x1 /* Has interrupts, no mask */72#define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */73#define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */74 75#define INT_CAPS(x) (((uint64_t)(x)) << 32)76 77enum {78 MAX7319,79 MAX7320,80 MAX7321,81 MAX7322,82 MAX7323,83 MAX7324,84 MAX7325,85 MAX7326,86 MAX7327,87};88 89static uint64_t max732x_features[] = {90 [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),91 [MAX7320] = GROUP_B(IO_8O),92 [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),93 [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),94 [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),95 [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),96 [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),97 [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),98 [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),99};100 101static const struct i2c_device_id max732x_id[] = {102 { "max7319", MAX7319 },103 { "max7320", MAX7320 },104 { "max7321", MAX7321 },105 { "max7322", MAX7322 },106 { "max7323", MAX7323 },107 { "max7324", MAX7324 },108 { "max7325", MAX7325 },109 { "max7326", MAX7326 },110 { "max7327", MAX7327 },111 { },112};113MODULE_DEVICE_TABLE(i2c, max732x_id);114 115static const struct of_device_id max732x_of_table[] = {116 { .compatible = "maxim,max7319" },117 { .compatible = "maxim,max7320" },118 { .compatible = "maxim,max7321" },119 { .compatible = "maxim,max7322" },120 { .compatible = "maxim,max7323" },121 { .compatible = "maxim,max7324" },122 { .compatible = "maxim,max7325" },123 { .compatible = "maxim,max7326" },124 { .compatible = "maxim,max7327" },125 { }126};127MODULE_DEVICE_TABLE(of, max732x_of_table);128 129struct max732x_chip {130 struct gpio_chip gpio_chip;131 132 struct i2c_client *client; /* "main" client */133 struct i2c_client *client_dummy;134 struct i2c_client *client_group_a;135 struct i2c_client *client_group_b;136 137 unsigned int mask_group_a;138 unsigned int dir_input;139 unsigned int dir_output;140 141 struct mutex lock;142 uint8_t reg_out[2];143 144#ifdef CONFIG_GPIO_MAX732X_IRQ145 struct mutex irq_lock;146 uint8_t irq_mask;147 uint8_t irq_mask_cur;148 uint8_t irq_trig_raise;149 uint8_t irq_trig_fall;150 uint8_t irq_features;151#endif152};153 154static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)155{156 struct i2c_client *client;157 int ret;158 159 client = group_a ? chip->client_group_a : chip->client_group_b;160 ret = i2c_smbus_write_byte(client, val);161 if (ret < 0) {162 dev_err(&client->dev, "failed writing\n");163 return ret;164 }165 166 return 0;167}168 169static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)170{171 struct i2c_client *client;172 int ret;173 174 client = group_a ? chip->client_group_a : chip->client_group_b;175 ret = i2c_smbus_read_byte(client);176 if (ret < 0) {177 dev_err(&client->dev, "failed reading\n");178 return ret;179 }180 181 *val = (uint8_t)ret;182 return 0;183}184 185static inline int is_group_a(struct max732x_chip *chip, unsigned off)186{187 return (1u << off) & chip->mask_group_a;188}189 190static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)191{192 struct max732x_chip *chip = gpiochip_get_data(gc);193 uint8_t reg_val;194 int ret;195 196 ret = max732x_readb(chip, is_group_a(chip, off), ®_val);197 if (ret < 0)198 return ret;199 200 return !!(reg_val & (1u << (off & 0x7)));201}202 203static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,204 int val)205{206 struct max732x_chip *chip = gpiochip_get_data(gc);207 uint8_t reg_out;208 int ret;209 210 mutex_lock(&chip->lock);211 212 reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];213 reg_out = (reg_out & ~mask) | (val & mask);214 215 ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);216 if (ret < 0)217 goto out;218 219 /* update the shadow register then */220 if (off > 7)221 chip->reg_out[1] = reg_out;222 else223 chip->reg_out[0] = reg_out;224out:225 mutex_unlock(&chip->lock);226}227 228static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)229{230 unsigned base = off & ~0x7;231 uint8_t mask = 1u << (off & 0x7);232 233 max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));234}235 236static void max732x_gpio_set_multiple(struct gpio_chip *gc,237 unsigned long *mask, unsigned long *bits)238{239 unsigned mask_lo = mask[0] & 0xff;240 unsigned mask_hi = (mask[0] >> 8) & 0xff;241 242 if (mask_lo)243 max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);244 if (mask_hi)245 max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);246}247 248static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)249{250 struct max732x_chip *chip = gpiochip_get_data(gc);251 unsigned int mask = 1u << off;252 253 if ((mask & chip->dir_input) == 0) {254 dev_dbg(&chip->client->dev, "%s port %d is output only\n",255 chip->client->name, off);256 return -EACCES;257 }258 259 /*260 * Open-drain pins must be set to high impedance (which is261 * equivalent to output-high) to be turned into an input.262 */263 if ((mask & chip->dir_output))264 max732x_gpio_set_value(gc, off, 1);265 266 return 0;267}268 269static int max732x_gpio_direction_output(struct gpio_chip *gc,270 unsigned off, int val)271{272 struct max732x_chip *chip = gpiochip_get_data(gc);273 unsigned int mask = 1u << off;274 275 if ((mask & chip->dir_output) == 0) {276 dev_dbg(&chip->client->dev, "%s port %d is input only\n",277 chip->client->name, off);278 return -EACCES;279 }280 281 max732x_gpio_set_value(gc, off, val);282 return 0;283}284 285#ifdef CONFIG_GPIO_MAX732X_IRQ286static int max732x_writew(struct max732x_chip *chip, uint16_t val)287{288 int ret;289 290 val = cpu_to_le16(val);291 292 ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);293 if (ret < 0) {294 dev_err(&chip->client_group_a->dev, "failed writing\n");295 return ret;296 }297 298 return 0;299}300 301static int max732x_readw(struct max732x_chip *chip, uint16_t *val)302{303 int ret;304 305 ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);306 if (ret < 0) {307 dev_err(&chip->client_group_a->dev, "failed reading\n");308 return ret;309 }310 311 *val = le16_to_cpu(*val);312 return 0;313}314 315static void max732x_irq_update_mask(struct max732x_chip *chip)316{317 uint16_t msg;318 319 if (chip->irq_mask == chip->irq_mask_cur)320 return;321 322 chip->irq_mask = chip->irq_mask_cur;323 324 if (chip->irq_features == INT_NO_MASK)325 return;326 327 mutex_lock(&chip->lock);328 329 switch (chip->irq_features) {330 case INT_INDEP_MASK:331 msg = (chip->irq_mask << 8) | chip->reg_out[0];332 max732x_writew(chip, msg);333 break;334 335 case INT_MERGED_MASK:336 msg = chip->irq_mask | chip->reg_out[0];337 max732x_writeb(chip, 1, (uint8_t)msg);338 break;339 }340 341 mutex_unlock(&chip->lock);342}343 344static void max732x_irq_mask(struct irq_data *d)345{346 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);347 struct max732x_chip *chip = gpiochip_get_data(gc);348 349 chip->irq_mask_cur &= ~(1 << d->hwirq);350 gpiochip_disable_irq(gc, irqd_to_hwirq(d));351}352 353static void max732x_irq_unmask(struct irq_data *d)354{355 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);356 struct max732x_chip *chip = gpiochip_get_data(gc);357 358 gpiochip_enable_irq(gc, irqd_to_hwirq(d));359 chip->irq_mask_cur |= 1 << d->hwirq;360}361 362static void max732x_irq_bus_lock(struct irq_data *d)363{364 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);365 struct max732x_chip *chip = gpiochip_get_data(gc);366 367 mutex_lock(&chip->irq_lock);368 chip->irq_mask_cur = chip->irq_mask;369}370 371static void max732x_irq_bus_sync_unlock(struct irq_data *d)372{373 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);374 struct max732x_chip *chip = gpiochip_get_data(gc);375 uint16_t new_irqs;376 uint16_t level;377 378 max732x_irq_update_mask(chip);379 380 new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;381 while (new_irqs) {382 level = __ffs(new_irqs);383 max732x_gpio_direction_input(&chip->gpio_chip, level);384 new_irqs &= ~(1 << level);385 }386 387 mutex_unlock(&chip->irq_lock);388}389 390static int max732x_irq_set_type(struct irq_data *d, unsigned int type)391{392 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);393 struct max732x_chip *chip = gpiochip_get_data(gc);394 uint16_t off = d->hwirq;395 uint16_t mask = 1 << off;396 397 if (!(mask & chip->dir_input)) {398 dev_dbg(&chip->client->dev, "%s port %d is output only\n",399 chip->client->name, off);400 return -EACCES;401 }402 403 if (!(type & IRQ_TYPE_EDGE_BOTH)) {404 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",405 d->irq, type);406 return -EINVAL;407 }408 409 if (type & IRQ_TYPE_EDGE_FALLING)410 chip->irq_trig_fall |= mask;411 else412 chip->irq_trig_fall &= ~mask;413 414 if (type & IRQ_TYPE_EDGE_RISING)415 chip->irq_trig_raise |= mask;416 else417 chip->irq_trig_raise &= ~mask;418 419 return 0;420}421 422static int max732x_irq_set_wake(struct irq_data *data, unsigned int on)423{424 struct max732x_chip *chip = irq_data_get_irq_chip_data(data);425 426 irq_set_irq_wake(chip->client->irq, on);427 return 0;428}429 430static const struct irq_chip max732x_irq_chip = {431 .name = "max732x",432 .irq_mask = max732x_irq_mask,433 .irq_unmask = max732x_irq_unmask,434 .irq_bus_lock = max732x_irq_bus_lock,435 .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock,436 .irq_set_type = max732x_irq_set_type,437 .irq_set_wake = max732x_irq_set_wake,438 .flags = IRQCHIP_IMMUTABLE,439 GPIOCHIP_IRQ_RESOURCE_HELPERS,440};441 442static uint8_t max732x_irq_pending(struct max732x_chip *chip)443{444 uint8_t cur_stat;445 uint8_t old_stat;446 uint8_t trigger;447 uint8_t pending;448 uint16_t status;449 int ret;450 451 ret = max732x_readw(chip, &status);452 if (ret)453 return 0;454 455 trigger = status >> 8;456 trigger &= chip->irq_mask;457 458 if (!trigger)459 return 0;460 461 cur_stat = status & 0xFF;462 cur_stat &= chip->irq_mask;463 464 old_stat = cur_stat ^ trigger;465 466 pending = (old_stat & chip->irq_trig_fall) |467 (cur_stat & chip->irq_trig_raise);468 pending &= trigger;469 470 return pending;471}472 473static irqreturn_t max732x_irq_handler(int irq, void *devid)474{475 struct max732x_chip *chip = devid;476 uint8_t pending;477 uint8_t level;478 479 pending = max732x_irq_pending(chip);480 481 if (!pending)482 return IRQ_HANDLED;483 484 do {485 level = __ffs(pending);486 handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,487 level));488 489 pending &= ~(1 << level);490 } while (pending);491 492 return IRQ_HANDLED;493}494 495static int max732x_irq_setup(struct max732x_chip *chip,496 const struct i2c_device_id *id)497{498 struct i2c_client *client = chip->client;499 int has_irq = max732x_features[id->driver_data] >> 32;500 int irq_base = 0;501 int ret;502 503 if (client->irq && has_irq != INT_NONE) {504 struct gpio_irq_chip *girq;505 506 chip->irq_features = has_irq;507 mutex_init(&chip->irq_lock);508 509 ret = devm_request_threaded_irq(&client->dev, client->irq,510 NULL, max732x_irq_handler, IRQF_ONESHOT |511 IRQF_TRIGGER_FALLING | IRQF_SHARED,512 dev_name(&client->dev), chip);513 if (ret) {514 dev_err(&client->dev, "failed to request irq %d\n",515 client->irq);516 return ret;517 }518 519 girq = &chip->gpio_chip.irq;520 gpio_irq_chip_set_chip(girq, &max732x_irq_chip);521 /* This will let us handle the parent IRQ in the driver */522 girq->parent_handler = NULL;523 girq->num_parents = 0;524 girq->parents = NULL;525 girq->default_type = IRQ_TYPE_NONE;526 girq->handler = handle_simple_irq;527 girq->threaded = true;528 girq->first = irq_base; /* FIXME: get rid of this */529 }530 531 return 0;532}533 534#else /* CONFIG_GPIO_MAX732X_IRQ */535static int max732x_irq_setup(struct max732x_chip *chip,536 const struct i2c_device_id *id)537{538 struct i2c_client *client = chip->client;539 int has_irq = max732x_features[id->driver_data] >> 32;540 541 if (client->irq && has_irq != INT_NONE)542 dev_warn(&client->dev, "interrupt support not compiled in\n");543 544 return 0;545}546#endif547 548static int max732x_setup_gpio(struct max732x_chip *chip,549 const struct i2c_device_id *id,550 unsigned gpio_start)551{552 struct gpio_chip *gc = &chip->gpio_chip;553 uint32_t id_data = (uint32_t)max732x_features[id->driver_data];554 int i, port = 0;555 556 for (i = 0; i < 16; i++, id_data >>= 2) {557 unsigned int mask = 1 << port;558 559 switch (id_data & 0x3) {560 case PORT_OUTPUT:561 chip->dir_output |= mask;562 break;563 case PORT_INPUT:564 chip->dir_input |= mask;565 break;566 case PORT_OPENDRAIN:567 chip->dir_output |= mask;568 chip->dir_input |= mask;569 break;570 default:571 continue;572 }573 574 if (i < 8)575 chip->mask_group_a |= mask;576 port++;577 }578 579 if (chip->dir_input)580 gc->direction_input = max732x_gpio_direction_input;581 if (chip->dir_output) {582 gc->direction_output = max732x_gpio_direction_output;583 gc->set = max732x_gpio_set_value;584 gc->set_multiple = max732x_gpio_set_multiple;585 }586 gc->get = max732x_gpio_get_value;587 gc->can_sleep = true;588 589 gc->base = gpio_start;590 gc->ngpio = port;591 gc->label = chip->client->name;592 gc->parent = &chip->client->dev;593 gc->owner = THIS_MODULE;594 595 return port;596}597 598static struct max732x_platform_data *of_gpio_max732x(struct device *dev)599{600 struct max732x_platform_data *pdata;601 602 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);603 if (!pdata)604 return NULL;605 606 pdata->gpio_base = -1;607 608 return pdata;609}610 611static int max732x_probe(struct i2c_client *client)612{613 const struct i2c_device_id *id = i2c_client_get_device_id(client);614 struct max732x_platform_data *pdata;615 struct device_node *node;616 struct max732x_chip *chip;617 struct i2c_client *c;618 uint16_t addr_a, addr_b;619 int ret, nr_port;620 621 pdata = dev_get_platdata(&client->dev);622 node = client->dev.of_node;623 624 if (!pdata && node)625 pdata = of_gpio_max732x(&client->dev);626 627 if (!pdata) {628 dev_dbg(&client->dev, "no platform data\n");629 return -EINVAL;630 }631 632 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);633 if (chip == NULL)634 return -ENOMEM;635 chip->client = client;636 637 nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);638 chip->gpio_chip.parent = &client->dev;639 640 addr_a = (client->addr & 0x0f) | 0x60;641 addr_b = (client->addr & 0x0f) | 0x50;642 643 switch (client->addr & 0x70) {644 case 0x60:645 chip->client_group_a = client;646 if (nr_port > 8) {647 c = devm_i2c_new_dummy_device(&client->dev,648 client->adapter, addr_b);649 if (IS_ERR(c)) {650 dev_err(&client->dev,651 "Failed to allocate I2C device\n");652 return PTR_ERR(c);653 }654 chip->client_group_b = chip->client_dummy = c;655 }656 break;657 case 0x50:658 chip->client_group_b = client;659 if (nr_port > 8) {660 c = devm_i2c_new_dummy_device(&client->dev,661 client->adapter, addr_a);662 if (IS_ERR(c)) {663 dev_err(&client->dev,664 "Failed to allocate I2C device\n");665 return PTR_ERR(c);666 }667 chip->client_group_a = chip->client_dummy = c;668 }669 break;670 default:671 dev_err(&client->dev, "invalid I2C address specified %02x\n",672 client->addr);673 return -EINVAL;674 }675 676 if (nr_port > 8 && !chip->client_dummy) {677 dev_err(&client->dev,678 "Failed to allocate second group I2C device\n");679 return -ENODEV;680 }681 682 mutex_init(&chip->lock);683 684 ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);685 if (ret)686 return ret;687 if (nr_port > 8) {688 ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);689 if (ret)690 return ret;691 }692 693 ret = max732x_irq_setup(chip, id);694 if (ret)695 return ret;696 697 ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);698 if (ret)699 return ret;700 701 i2c_set_clientdata(client, chip);702 return 0;703}704 705static struct i2c_driver max732x_driver = {706 .driver = {707 .name = "max732x",708 .of_match_table = max732x_of_table,709 },710 .probe = max732x_probe,711 .id_table = max732x_id,712};713 714static int __init max732x_init(void)715{716 return i2c_add_driver(&max732x_driver);717}718/* register after i2c postcore initcall and before719 * subsys initcalls that may rely on these GPIOs720 */721subsys_initcall(max732x_init);722 723static void __exit max732x_exit(void)724{725 i2c_del_driver(&max732x_driver);726}727module_exit(max732x_exit);728 729MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");730MODULE_DESCRIPTION("GPIO expander driver for MAX732X");731MODULE_LICENSE("GPL");732