2 * max732x.c - 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/i2c.h>
23 #include <linux/i2c/max732x.h>
27 * Each port of MAX732x (including MAX7319) falls into one of the
28 * following three types:
34 * designated by 'O', 'I' and 'P' individually according to MAXIM's
35 * datasheets. 'I' and 'P' ports are interrupt capables, some with
36 * a dedicated interrupt mask.
38 * There are two groups of I/O ports, each group usually includes
39 * up to 8 I/O ports, and is accessed by a specific I2C address:
41 * - Group A : by I2C address 0b'110xxxx
42 * - Group B : by I2C address 0b'101xxxx
44 * where 'xxxx' is decided by the connections of pin AD2/AD0. The
45 * address used also affects the initial state of output signals.
47 * Within each group of ports, there are five known combinations of
48 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
49 * the detailed organization of these ports. Only Goup A is interrupt
52 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
53 * and GPIOs from GROUP_A are numbered before those from GROUP_B
54 * (if there are two groups).
56 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
57 * they are not supported by this driver.
60 #define PORT_NONE 0x0 /* '/' No Port */
61 #define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */
62 #define PORT_INPUT 0x2 /* 'I' Input Only */
63 #define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */
65 #define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */
66 #define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */
67 #define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */
68 #define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */
69 #define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */
71 #define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
72 #define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
74 #define INT_NONE 0x0 /* No interrupt capability */
75 #define INT_NO_MASK 0x1 /* Has interrupts, no mask */
76 #define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */
77 #define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */
79 #define INT_CAPS(x) (((uint64_t)(x)) << 32)
93 static uint64_t max732x_features[] = {
94 [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
95 [MAX7320] = GROUP_B(IO_8O),
96 [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
97 [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
98 [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
99 [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
100 [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
101 [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
102 [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
105 static const struct i2c_device_id max732x_id[] = {
106 { "max7319", MAX7319 },
107 { "max7320", MAX7320 },
108 { "max7321", MAX7321 },
109 { "max7322", MAX7322 },
110 { "max7323", MAX7323 },
111 { "max7324", MAX7324 },
112 { "max7325", MAX7325 },
113 { "max7326", MAX7326 },
114 { "max7327", MAX7327 },
117 MODULE_DEVICE_TABLE(i2c, max732x_id);
119 struct max732x_chip {
120 struct gpio_chip gpio_chip;
122 struct i2c_client *client; /* "main" client */
123 struct i2c_client *client_dummy;
124 struct i2c_client *client_group_a;
125 struct i2c_client *client_group_b;
127 unsigned int mask_group_a;
128 unsigned int dir_input;
129 unsigned int dir_output;
134 #ifdef CONFIG_GPIO_MAX732X_IRQ
135 struct mutex irq_lock;
138 uint8_t irq_mask_cur;
139 uint8_t irq_trig_raise;
140 uint8_t irq_trig_fall;
141 uint8_t irq_features;
145 static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
147 struct i2c_client *client;
150 client = group_a ? chip->client_group_a : chip->client_group_b;
151 ret = i2c_smbus_write_byte(client, val);
153 dev_err(&client->dev, "failed writing\n");
160 static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
162 struct i2c_client *client;
165 client = group_a ? chip->client_group_a : chip->client_group_b;
166 ret = i2c_smbus_read_byte(client);
168 dev_err(&client->dev, "failed reading\n");
176 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
178 return (1u << off) & chip->mask_group_a;
181 static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
183 struct max732x_chip *chip;
187 chip = container_of(gc, struct max732x_chip, gpio_chip);
189 ret = max732x_readb(chip, is_group_a(chip, off), ®_val);
193 return reg_val & (1u << (off & 0x7));
196 static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
198 struct max732x_chip *chip;
199 uint8_t reg_out, mask = 1u << (off & 0x7);
202 chip = container_of(gc, struct max732x_chip, gpio_chip);
204 mutex_lock(&chip->lock);
206 reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
207 reg_out = (val) ? reg_out | mask : reg_out & ~mask;
209 ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
213 /* update the shadow register then */
215 chip->reg_out[1] = reg_out;
217 chip->reg_out[0] = reg_out;
219 mutex_unlock(&chip->lock);
222 static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
224 struct max732x_chip *chip;
225 unsigned int mask = 1u << off;
227 chip = container_of(gc, struct max732x_chip, gpio_chip);
229 if ((mask & chip->dir_input) == 0) {
230 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
231 chip->client->name, off);
238 static int max732x_gpio_direction_output(struct gpio_chip *gc,
239 unsigned off, int val)
241 struct max732x_chip *chip;
242 unsigned int mask = 1u << off;
244 chip = container_of(gc, struct max732x_chip, gpio_chip);
246 if ((mask & chip->dir_output) == 0) {
247 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
248 chip->client->name, off);
252 max732x_gpio_set_value(gc, off, val);
256 #ifdef CONFIG_GPIO_MAX732X_IRQ
257 static int max732x_writew(struct max732x_chip *chip, uint16_t val)
261 val = cpu_to_le16(val);
263 ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
265 dev_err(&chip->client_group_a->dev, "failed writing\n");
272 static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
276 ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
278 dev_err(&chip->client_group_a->dev, "failed reading\n");
282 *val = le16_to_cpu(*val);
286 static void max732x_irq_update_mask(struct max732x_chip *chip)
290 if (chip->irq_mask == chip->irq_mask_cur)
293 chip->irq_mask = chip->irq_mask_cur;
295 if (chip->irq_features == INT_NO_MASK)
298 mutex_lock(&chip->lock);
300 switch (chip->irq_features) {
302 msg = (chip->irq_mask << 8) | chip->reg_out[0];
303 max732x_writew(chip, msg);
306 case INT_MERGED_MASK:
307 msg = chip->irq_mask | chip->reg_out[0];
308 max732x_writeb(chip, 1, (uint8_t)msg);
312 mutex_unlock(&chip->lock);
315 static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
317 struct max732x_chip *chip;
319 chip = container_of(gc, struct max732x_chip, gpio_chip);
320 return chip->irq_base + off;
323 static void max732x_irq_mask(unsigned int irq)
325 struct max732x_chip *chip = get_irq_chip_data(irq);
327 chip->irq_mask_cur &= ~(1 << (irq - chip->irq_base));
330 static void max732x_irq_unmask(unsigned int irq)
332 struct max732x_chip *chip = get_irq_chip_data(irq);
334 chip->irq_mask_cur |= 1 << (irq - chip->irq_base);
337 static void max732x_irq_bus_lock(unsigned int irq)
339 struct max732x_chip *chip = get_irq_chip_data(irq);
341 mutex_lock(&chip->irq_lock);
342 chip->irq_mask_cur = chip->irq_mask;
345 static void max732x_irq_bus_sync_unlock(unsigned int irq)
347 struct max732x_chip *chip = get_irq_chip_data(irq);
349 max732x_irq_update_mask(chip);
350 mutex_unlock(&chip->irq_lock);
353 static int max732x_irq_set_type(unsigned int irq, unsigned int type)
355 struct max732x_chip *chip = get_irq_chip_data(irq);
356 uint16_t off = irq - chip->irq_base;
357 uint16_t mask = 1 << off;
359 if (!(mask & chip->dir_input)) {
360 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
361 chip->client->name, off);
365 if (!(type & IRQ_TYPE_EDGE_BOTH)) {
366 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
371 if (type & IRQ_TYPE_EDGE_FALLING)
372 chip->irq_trig_fall |= mask;
374 chip->irq_trig_fall &= ~mask;
376 if (type & IRQ_TYPE_EDGE_RISING)
377 chip->irq_trig_raise |= mask;
379 chip->irq_trig_raise &= ~mask;
381 return max732x_gpio_direction_input(&chip->gpio_chip, off);
384 static struct irq_chip max732x_irq_chip = {
386 .mask = max732x_irq_mask,
387 .unmask = max732x_irq_unmask,
388 .bus_lock = max732x_irq_bus_lock,
389 .bus_sync_unlock = max732x_irq_bus_sync_unlock,
390 .set_type = max732x_irq_set_type,
393 static uint8_t max732x_irq_pending(struct max732x_chip *chip)
402 ret = max732x_readw(chip, &status);
406 trigger = status >> 8;
407 trigger &= chip->irq_mask;
412 cur_stat = status & 0xFF;
413 cur_stat &= chip->irq_mask;
415 old_stat = cur_stat ^ trigger;
417 pending = (old_stat & chip->irq_trig_fall) |
418 (cur_stat & chip->irq_trig_raise);
424 static irqreturn_t max732x_irq_handler(int irq, void *devid)
426 struct max732x_chip *chip = devid;
430 pending = max732x_irq_pending(chip);
436 level = __ffs(pending);
437 handle_nested_irq(level + chip->irq_base);
439 pending &= ~(1 << level);
445 static int max732x_irq_setup(struct max732x_chip *chip,
446 const struct i2c_device_id *id)
448 struct i2c_client *client = chip->client;
449 struct max732x_platform_data *pdata = client->dev.platform_data;
450 int has_irq = max732x_features[id->driver_data] >> 32;
453 if (pdata->irq_base && has_irq != INT_NONE) {
456 chip->irq_base = pdata->irq_base;
457 chip->irq_features = has_irq;
458 mutex_init(&chip->irq_lock);
460 for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
461 int irq = lvl + chip->irq_base;
463 if (!(chip->dir_input & (1 << lvl)))
466 set_irq_chip_data(irq, chip);
467 set_irq_chip_and_handler(irq, &max732x_irq_chip,
469 set_irq_nested_thread(irq, 1);
471 set_irq_flags(irq, IRQF_VALID);
473 set_irq_noprobe(irq);
477 ret = request_threaded_irq(client->irq,
480 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
481 dev_name(&client->dev), chip);
483 dev_err(&client->dev, "failed to request irq %d\n",
488 chip->gpio_chip.to_irq = max732x_gpio_to_irq;
498 static void max732x_irq_teardown(struct max732x_chip *chip)
501 free_irq(chip->client->irq, chip);
503 #else /* CONFIG_GPIO_MAX732X_IRQ */
504 static int max732x_irq_setup(struct max732x_chip *chip,
505 const struct i2c_device_id *id)
507 struct i2c_client *client = chip->client;
508 struct max732x_platform_data *pdata = client->dev.platform_data;
509 int has_irq = max732x_features[id->driver_data] >> 32;
511 if (pdata->irq_base && has_irq != INT_NONE)
512 dev_warn(&client->dev, "interrupt support not compiled in\n");
517 static void max732x_irq_teardown(struct max732x_chip *chip)
522 static int __devinit max732x_setup_gpio(struct max732x_chip *chip,
523 const struct i2c_device_id *id,
526 struct gpio_chip *gc = &chip->gpio_chip;
527 uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
530 for (i = 0; i < 16; i++, id_data >>= 2) {
531 unsigned int mask = 1 << port;
533 switch (id_data & 0x3) {
535 chip->dir_output |= mask;
538 chip->dir_input |= mask;
541 chip->dir_output |= mask;
542 chip->dir_input |= mask;
549 chip->mask_group_a |= mask;
554 gc->direction_input = max732x_gpio_direction_input;
555 if (chip->dir_output) {
556 gc->direction_output = max732x_gpio_direction_output;
557 gc->set = max732x_gpio_set_value;
559 gc->get = max732x_gpio_get_value;
562 gc->base = gpio_start;
564 gc->label = chip->client->name;
565 gc->owner = THIS_MODULE;
570 static int __devinit max732x_probe(struct i2c_client *client,
571 const struct i2c_device_id *id)
573 struct max732x_platform_data *pdata;
574 struct max732x_chip *chip;
575 struct i2c_client *c;
576 uint16_t addr_a, addr_b;
579 pdata = client->dev.platform_data;
581 dev_dbg(&client->dev, "no platform data\n");
585 chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
588 chip->client = client;
590 nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
592 addr_a = (client->addr & 0x0f) | 0x60;
593 addr_b = (client->addr & 0x0f) | 0x50;
595 switch (client->addr & 0x70) {
597 chip->client_group_a = client;
599 c = i2c_new_dummy(client->adapter, addr_b);
600 chip->client_group_b = chip->client_dummy = c;
604 chip->client_group_b = client;
606 c = i2c_new_dummy(client->adapter, addr_a);
607 chip->client_group_a = chip->client_dummy = c;
611 dev_err(&client->dev, "invalid I2C address specified %02x\n",
617 mutex_init(&chip->lock);
619 max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
621 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
623 ret = max732x_irq_setup(chip, id);
627 ret = gpiochip_add(&chip->gpio_chip);
632 ret = pdata->setup(client, chip->gpio_chip.base,
633 chip->gpio_chip.ngpio, pdata->context);
635 dev_warn(&client->dev, "setup failed, %d\n", ret);
638 i2c_set_clientdata(client, chip);
642 max732x_irq_teardown(chip);
647 static int __devexit max732x_remove(struct i2c_client *client)
649 struct max732x_platform_data *pdata = client->dev.platform_data;
650 struct max732x_chip *chip = i2c_get_clientdata(client);
653 if (pdata->teardown) {
654 ret = pdata->teardown(client, chip->gpio_chip.base,
655 chip->gpio_chip.ngpio, pdata->context);
657 dev_err(&client->dev, "%s failed, %d\n",
663 ret = gpiochip_remove(&chip->gpio_chip);
665 dev_err(&client->dev, "%s failed, %d\n",
666 "gpiochip_remove()", ret);
670 max732x_irq_teardown(chip);
672 /* unregister any dummy i2c_client */
673 if (chip->client_dummy)
674 i2c_unregister_device(chip->client_dummy);
680 static struct i2c_driver max732x_driver = {
683 .owner = THIS_MODULE,
685 .probe = max732x_probe,
686 .remove = __devexit_p(max732x_remove),
687 .id_table = max732x_id,
690 static int __init max732x_init(void)
692 return i2c_add_driver(&max732x_driver);
694 /* register after i2c postcore initcall and before
695 * subsys initcalls that may rely on these GPIOs
697 subsys_initcall(max732x_init);
699 static void __exit max732x_exit(void)
701 i2c_del_driver(&max732x_driver);
703 module_exit(max732x_exit);
705 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
706 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
707 MODULE_LICENSE("GPL");