2 * MAX732x I2C Port Expander with 8/16 I/O
4 * Copyright (C) 2007 Marvell International Ltd.
5 * Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
6 * Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
8 * Derived from drivers/gpio/pca953x.c
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2 of the License.
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/gpio.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/irqdomain.h>
23 #include <linux/i2c.h>
24 #include <linux/i2c/max732x.h>
29 * Each port of MAX732x (including MAX7319) falls into one of the
30 * following three types:
36 * designated by 'O', 'I' and 'P' individually according to MAXIM's
37 * datasheets. 'I' and 'P' ports are interrupt capables, some with
38 * a dedicated interrupt mask.
40 * There are two groups of I/O ports, each group usually includes
41 * up to 8 I/O ports, and is accessed by a specific I2C address:
43 * - Group A : by I2C address 0b'110xxxx
44 * - Group B : by I2C address 0b'101xxxx
46 * where 'xxxx' is decided by the connections of pin AD2/AD0. The
47 * address used also affects the initial state of output signals.
49 * Within each group of ports, there are five known combinations of
50 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
51 * the detailed organization of these ports. Only Goup A is interrupt
54 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
55 * and GPIOs from GROUP_A are numbered before those from GROUP_B
56 * (if there are two groups).
58 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
59 * they are not supported by this driver.
62 #define PORT_NONE 0x0 /* '/' No Port */
63 #define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */
64 #define PORT_INPUT 0x2 /* 'I' Input Only */
65 #define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */
67 #define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */
68 #define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */
69 #define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */
70 #define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */
71 #define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */
73 #define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
74 #define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
76 #define INT_NONE 0x0 /* No interrupt capability */
77 #define INT_NO_MASK 0x1 /* Has interrupts, no mask */
78 #define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */
79 #define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */
81 #define INT_CAPS(x) (((uint64_t)(x)) << 32)
95 static uint64_t max732x_features[] = {
96 [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
97 [MAX7320] = GROUP_B(IO_8O),
98 [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
99 [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
100 [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
101 [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
102 [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
103 [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
104 [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
107 static const struct i2c_device_id max732x_id[] = {
108 { "max7319", MAX7319 },
109 { "max7320", MAX7320 },
110 { "max7321", MAX7321 },
111 { "max7322", MAX7322 },
112 { "max7323", MAX7323 },
113 { "max7324", MAX7324 },
114 { "max7325", MAX7325 },
115 { "max7326", MAX7326 },
116 { "max7327", MAX7327 },
119 MODULE_DEVICE_TABLE(i2c, max732x_id);
122 static const struct of_device_id max732x_of_table[] = {
123 { .compatible = "maxim,max7319" },
124 { .compatible = "maxim,max7320" },
125 { .compatible = "maxim,max7321" },
126 { .compatible = "maxim,max7322" },
127 { .compatible = "maxim,max7323" },
128 { .compatible = "maxim,max7324" },
129 { .compatible = "maxim,max7325" },
130 { .compatible = "maxim,max7326" },
131 { .compatible = "maxim,max7327" },
134 MODULE_DEVICE_TABLE(of, max732x_of_table);
137 struct max732x_chip {
138 struct gpio_chip gpio_chip;
140 struct i2c_client *client; /* "main" client */
141 struct i2c_client *client_dummy;
142 struct i2c_client *client_group_a;
143 struct i2c_client *client_group_b;
145 unsigned int mask_group_a;
146 unsigned int dir_input;
147 unsigned int dir_output;
152 #ifdef CONFIG_GPIO_MAX732X_IRQ
153 struct irq_domain *irq_domain;
154 struct mutex irq_lock;
157 uint8_t irq_mask_cur;
158 uint8_t irq_trig_raise;
159 uint8_t irq_trig_fall;
160 uint8_t irq_features;
164 static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
166 struct i2c_client *client;
169 client = group_a ? chip->client_group_a : chip->client_group_b;
170 ret = i2c_smbus_write_byte(client, val);
172 dev_err(&client->dev, "failed writing\n");
179 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
181 struct i2c_client *client;
184 client = group_a ? chip->client_group_a : chip->client_group_b;
185 ret = i2c_smbus_read_byte(client);
187 dev_err(&client->dev, "failed reading\n");
195 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
197 return (1u << off) & chip->mask_group_a;
200 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
202 struct max732x_chip *chip;
206 chip = container_of(gc, struct max732x_chip, gpio_chip);
208 ret = max732x_readb(chip, is_group_a(chip, off), ®_val);
212 return reg_val & (1u << (off & 0x7));
215 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
217 struct max732x_chip *chip;
218 uint8_t reg_out, mask = 1u << (off & 0x7);
221 chip = container_of(gc, struct max732x_chip, gpio_chip);
223 mutex_lock(&chip->lock);
225 reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
226 reg_out = (val) ? reg_out | mask : reg_out & ~mask;
228 ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
232 /* update the shadow register then */
234 chip->reg_out[1] = reg_out;
236 chip->reg_out[0] = reg_out;
238 mutex_unlock(&chip->lock);
241 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
243 struct max732x_chip *chip;
244 unsigned int mask = 1u << off;
246 chip = container_of(gc, struct max732x_chip, gpio_chip);
248 if ((mask & chip->dir_input) == 0) {
249 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
250 chip->client->name, off);
255 * Open-drain pins must be set to high impedance (which is
256 * equivalent to output-high) to be turned into an input.
258 if ((mask & chip->dir_output))
259 max732x_gpio_set_value(gc, off, 1);
264 static int max732x_gpio_direction_output(struct gpio_chip *gc,
265 unsigned off, int val)
267 struct max732x_chip *chip;
268 unsigned int mask = 1u << off;
270 chip = container_of(gc, struct max732x_chip, gpio_chip);
272 if ((mask & chip->dir_output) == 0) {
273 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
274 chip->client->name, off);
278 max732x_gpio_set_value(gc, off, val);
282 #ifdef CONFIG_GPIO_MAX732X_IRQ
283 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
287 val = cpu_to_le16(val);
289 ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
291 dev_err(&chip->client_group_a->dev, "failed writing\n");
298 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
302 ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
304 dev_err(&chip->client_group_a->dev, "failed reading\n");
308 *val = le16_to_cpu(*val);
312 static void max732x_irq_update_mask(struct max732x_chip *chip)
316 if (chip->irq_mask == chip->irq_mask_cur)
319 chip->irq_mask = chip->irq_mask_cur;
321 if (chip->irq_features == INT_NO_MASK)
324 mutex_lock(&chip->lock);
326 switch (chip->irq_features) {
328 msg = (chip->irq_mask << 8) | chip->reg_out[0];
329 max732x_writew(chip, msg);
332 case INT_MERGED_MASK:
333 msg = chip->irq_mask | chip->reg_out[0];
334 max732x_writeb(chip, 1, (uint8_t)msg);
338 mutex_unlock(&chip->lock);
341 static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
343 struct max732x_chip *chip;
345 chip = container_of(gc, struct max732x_chip, gpio_chip);
347 if (chip->irq_domain) {
348 return irq_create_mapping(chip->irq_domain,
349 chip->irq_base + off);
355 static void max732x_irq_mask(struct irq_data *d)
357 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
359 chip->irq_mask_cur &= ~(1 << d->hwirq);
362 static void max732x_irq_unmask(struct irq_data *d)
364 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
366 chip->irq_mask_cur |= 1 << d->hwirq;
369 static void max732x_irq_bus_lock(struct irq_data *d)
371 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
373 mutex_lock(&chip->irq_lock);
374 chip->irq_mask_cur = chip->irq_mask;
377 static void max732x_irq_bus_sync_unlock(struct irq_data *d)
379 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
383 max732x_irq_update_mask(chip);
385 new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
387 level = __ffs(new_irqs);
388 max732x_gpio_direction_input(&chip->gpio_chip, level);
389 new_irqs &= ~(1 << level);
392 mutex_unlock(&chip->irq_lock);
395 static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
397 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
398 uint16_t off = d->hwirq;
399 uint16_t mask = 1 << off;
401 if (!(mask & chip->dir_input)) {
402 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
403 chip->client->name, off);
407 if (!(type & IRQ_TYPE_EDGE_BOTH)) {
408 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
413 if (type & IRQ_TYPE_EDGE_FALLING)
414 chip->irq_trig_fall |= mask;
416 chip->irq_trig_fall &= ~mask;
418 if (type & IRQ_TYPE_EDGE_RISING)
419 chip->irq_trig_raise |= mask;
421 chip->irq_trig_raise &= ~mask;
426 static struct irq_chip max732x_irq_chip = {
428 .irq_mask = max732x_irq_mask,
429 .irq_unmask = max732x_irq_unmask,
430 .irq_bus_lock = max732x_irq_bus_lock,
431 .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock,
432 .irq_set_type = max732x_irq_set_type,
435 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
444 ret = max732x_readw(chip, &status);
448 trigger = status >> 8;
449 trigger &= chip->irq_mask;
454 cur_stat = status & 0xFF;
455 cur_stat &= chip->irq_mask;
457 old_stat = cur_stat ^ trigger;
459 pending = (old_stat & chip->irq_trig_fall) |
460 (cur_stat & chip->irq_trig_raise);
466 static irqreturn_t max732x_irq_handler(int irq, void *devid)
468 struct max732x_chip *chip = devid;
472 pending = max732x_irq_pending(chip);
478 level = __ffs(pending);
479 handle_nested_irq(irq_find_mapping(chip->irq_domain, level));
481 pending &= ~(1 << level);
487 static int max732x_irq_map(struct irq_domain *h, unsigned int virq,
490 struct max732x_chip *chip = h->host_data;
492 if (!(chip->dir_input & (1 << hw))) {
493 dev_err(&chip->client->dev,
494 "Attempt to map output line as IRQ line: %lu\n",
499 irq_set_chip_data(virq, chip);
500 irq_set_chip_and_handler(virq, &max732x_irq_chip,
502 irq_set_nested_thread(virq, 1);
504 /* ARM needs us to explicitly flag the IRQ as valid
505 * and will set them noprobe when we do so. */
506 set_irq_flags(virq, IRQF_VALID);
508 irq_set_noprobe(virq);
514 static struct irq_domain_ops max732x_irq_domain_ops = {
515 .map = max732x_irq_map,
516 .xlate = irq_domain_xlate_twocell,
519 static void max732x_irq_teardown(struct max732x_chip *chip)
521 if (chip->client->irq && chip->irq_domain)
522 irq_domain_remove(chip->irq_domain);
525 static int max732x_irq_setup(struct max732x_chip *chip,
526 const struct i2c_device_id *id)
528 struct i2c_client *client = chip->client;
529 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
530 int has_irq = max732x_features[id->driver_data] >> 32;
533 if (((pdata && pdata->irq_base) || client->irq)
534 && has_irq != INT_NONE) {
536 chip->irq_base = pdata->irq_base;
537 chip->irq_features = has_irq;
538 mutex_init(&chip->irq_lock);
540 chip->irq_domain = irq_domain_add_simple(client->dev.of_node,
541 chip->gpio_chip.ngpio, chip->irq_base,
542 &max732x_irq_domain_ops, chip);
543 if (!chip->irq_domain) {
544 dev_err(&client->dev, "Failed to create IRQ domain\n");
548 ret = request_threaded_irq(client->irq,
551 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
552 dev_name(&client->dev), chip);
554 dev_err(&client->dev, "failed to request irq %d\n",
559 chip->gpio_chip.to_irq = max732x_gpio_to_irq;
565 max732x_irq_teardown(chip);
569 #else /* CONFIG_GPIO_MAX732X_IRQ */
570 static int max732x_irq_setup(struct max732x_chip *chip,
571 const struct i2c_device_id *id)
573 struct i2c_client *client = chip->client;
574 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
575 int has_irq = max732x_features[id->driver_data] >> 32;
577 if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE)
578 dev_warn(&client->dev, "interrupt support not compiled in\n");
583 static void max732x_irq_teardown(struct max732x_chip *chip)
588 static int max732x_setup_gpio(struct max732x_chip *chip,
589 const struct i2c_device_id *id,
592 struct gpio_chip *gc = &chip->gpio_chip;
593 uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
596 for (i = 0; i < 16; i++, id_data >>= 2) {
597 unsigned int mask = 1 << port;
599 switch (id_data & 0x3) {
601 chip->dir_output |= mask;
604 chip->dir_input |= mask;
607 chip->dir_output |= mask;
608 chip->dir_input |= mask;
615 chip->mask_group_a |= mask;
620 gc->direction_input = max732x_gpio_direction_input;
621 if (chip->dir_output) {
622 gc->direction_output = max732x_gpio_direction_output;
623 gc->set = max732x_gpio_set_value;
625 gc->get = max732x_gpio_get_value;
626 gc->can_sleep = true;
628 gc->base = gpio_start;
630 gc->label = chip->client->name;
631 gc->owner = THIS_MODULE;
636 static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
638 struct max732x_platform_data *pdata;
640 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
644 pdata->gpio_base = -1;
649 static int max732x_probe(struct i2c_client *client,
650 const struct i2c_device_id *id)
652 struct max732x_platform_data *pdata;
653 struct device_node *node;
654 struct max732x_chip *chip;
655 struct i2c_client *c;
656 uint16_t addr_a, addr_b;
659 pdata = dev_get_platdata(&client->dev);
660 node = client->dev.of_node;
663 pdata = of_gpio_max732x(&client->dev);
666 dev_dbg(&client->dev, "no platform data\n");
670 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
673 chip->client = client;
675 nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
676 chip->gpio_chip.dev = &client->dev;
678 addr_a = (client->addr & 0x0f) | 0x60;
679 addr_b = (client->addr & 0x0f) | 0x50;
681 switch (client->addr & 0x70) {
683 chip->client_group_a = client;
685 c = i2c_new_dummy(client->adapter, addr_b);
686 chip->client_group_b = chip->client_dummy = c;
690 chip->client_group_b = client;
692 c = i2c_new_dummy(client->adapter, addr_a);
693 chip->client_group_a = chip->client_dummy = c;
697 dev_err(&client->dev, "invalid I2C address specified %02x\n",
703 if (nr_port > 8 && !chip->client_dummy) {
704 dev_err(&client->dev,
705 "Failed to allocate second group I2C device\n");
710 mutex_init(&chip->lock);
712 max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
714 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
716 ret = max732x_irq_setup(chip, id);
720 ret = gpiochip_add(&chip->gpio_chip);
724 if (pdata && pdata->setup) {
725 ret = pdata->setup(client, chip->gpio_chip.base,
726 chip->gpio_chip.ngpio, pdata->context);
728 dev_warn(&client->dev, "setup failed, %d\n", ret);
731 i2c_set_clientdata(client, chip);
735 if (chip->client_dummy)
736 i2c_unregister_device(chip->client_dummy);
737 max732x_irq_teardown(chip);
741 static int max732x_remove(struct i2c_client *client)
743 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
744 struct max732x_chip *chip = i2c_get_clientdata(client);
746 if (pdata && pdata->teardown) {
749 ret = pdata->teardown(client, chip->gpio_chip.base,
750 chip->gpio_chip.ngpio, pdata->context);
752 dev_err(&client->dev, "%s failed, %d\n",
758 gpiochip_remove(&chip->gpio_chip);
760 max732x_irq_teardown(chip);
762 /* unregister any dummy i2c_client */
763 if (chip->client_dummy)
764 i2c_unregister_device(chip->client_dummy);
769 static struct i2c_driver max732x_driver = {
772 .owner = THIS_MODULE,
773 .of_match_table = of_match_ptr(max732x_of_table),
775 .probe = max732x_probe,
776 .remove = max732x_remove,
777 .id_table = max732x_id,
780 static int __init max732x_init(void)
782 return i2c_add_driver(&max732x_driver);
784 /* register after i2c postcore initcall and before
785 * subsys initcalls that may rely on these GPIOs
787 subsys_initcall(max732x_init);
789 static void __exit max732x_exit(void)
791 i2c_del_driver(&max732x_driver);
793 module_exit(max732x_exit);
795 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
796 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
797 MODULE_LICENSE("GPL");