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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * MAX732x I2C Port Expander with 8/16 I/O
4 *
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.c
11 */
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 the
24 * following three types:
25 *
26 * - Push Pull Output
27 * - Input
28 * - Open Drain I/O
29 *
30 * designated by 'O', 'I' and 'P' individually according to MAXIM's
31 * datasheets. 'I' and 'P' ports are interrupt capables, some with
32 * a dedicated interrupt mask.
33 *
34 * There are two groups of I/O ports, each group usually includes
35 * up to 8 I/O ports, and is accessed by a specific I2C address:
36 *
37 * - Group A : by I2C address 0b'110xxxx
38 * - Group B : by I2C address 0b'101xxxx
39 *
40 * where 'xxxx' is decided by the connections of pin AD2/AD0. The
41 * address used also affects the initial state of output signals.
42 *
43 * Within each group of ports, there are five known combinations of
44 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
45 * the detailed organization of these ports. Only Goup A is interrupt
46 * 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_B
50 * (if there are two groups).
51 *
52 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
53 * 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_IRQ
145 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#endif
152};
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 else
223 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 is
261 * 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_IRQ
286static 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 else
412 chip->irq_trig_fall &= ~mask;
413
414 if (type & IRQ_TYPE_EDGE_RISING)
415 chip->irq_trig_raise |= mask;
416 else
417 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#endif
547
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 before
719 * subsys initcalls that may rely on these GPIOs
720 */
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");
1/*
2 * MAX732x I2C Port Expander with 8/16 I/O
3 *
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>
7 *
8 * Derived from drivers/gpio/pca953x.c
9 *
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.
13 */
14
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>
24
25
26/*
27 * Each port of MAX732x (including MAX7319) falls into one of the
28 * following three types:
29 *
30 * - Push Pull Output
31 * - Input
32 * - Open Drain I/O
33 *
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.
37 *
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:
40 *
41 * - Group A : by I2C address 0b'110xxxx
42 * - Group B : by I2C address 0b'101xxxx
43 *
44 * where 'xxxx' is decided by the connections of pin AD2/AD0. The
45 * address used also affects the initial state of output signals.
46 *
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
50 * capable.
51 *
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).
55 *
56 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
57 * they are not supported by this driver.
58 */
59
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 */
64
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 */
70
71#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
72#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
73
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 */
78
79#define INT_CAPS(x) (((uint64_t)(x)) << 32)
80
81enum {
82 MAX7319,
83 MAX7320,
84 MAX7321,
85 MAX7322,
86 MAX7323,
87 MAX7324,
88 MAX7325,
89 MAX7326,
90 MAX7327,
91};
92
93static 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),
103};
104
105static 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 },
115 { },
116};
117MODULE_DEVICE_TABLE(i2c, max732x_id);
118
119struct max732x_chip {
120 struct gpio_chip gpio_chip;
121
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;
126
127 unsigned int mask_group_a;
128 unsigned int dir_input;
129 unsigned int dir_output;
130
131 struct mutex lock;
132 uint8_t reg_out[2];
133
134#ifdef CONFIG_GPIO_MAX732X_IRQ
135 struct mutex irq_lock;
136 int irq_base;
137 uint8_t irq_mask;
138 uint8_t irq_mask_cur;
139 uint8_t irq_trig_raise;
140 uint8_t irq_trig_fall;
141 uint8_t irq_features;
142#endif
143};
144
145static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
146{
147 struct i2c_client *client;
148 int ret;
149
150 client = group_a ? chip->client_group_a : chip->client_group_b;
151 ret = i2c_smbus_write_byte(client, val);
152 if (ret < 0) {
153 dev_err(&client->dev, "failed writing\n");
154 return ret;
155 }
156
157 return 0;
158}
159
160static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
161{
162 struct i2c_client *client;
163 int ret;
164
165 client = group_a ? chip->client_group_a : chip->client_group_b;
166 ret = i2c_smbus_read_byte(client);
167 if (ret < 0) {
168 dev_err(&client->dev, "failed reading\n");
169 return ret;
170 }
171
172 *val = (uint8_t)ret;
173 return 0;
174}
175
176static inline int is_group_a(struct max732x_chip *chip, unsigned off)
177{
178 return (1u << off) & chip->mask_group_a;
179}
180
181static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
182{
183 struct max732x_chip *chip;
184 uint8_t reg_val;
185 int ret;
186
187 chip = container_of(gc, struct max732x_chip, gpio_chip);
188
189 ret = max732x_readb(chip, is_group_a(chip, off), ®_val);
190 if (ret < 0)
191 return 0;
192
193 return reg_val & (1u << (off & 0x7));
194}
195
196static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
197{
198 struct max732x_chip *chip;
199 uint8_t reg_out, mask = 1u << (off & 0x7);
200 int ret;
201
202 chip = container_of(gc, struct max732x_chip, gpio_chip);
203
204 mutex_lock(&chip->lock);
205
206 reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
207 reg_out = (val) ? reg_out | mask : reg_out & ~mask;
208
209 ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
210 if (ret < 0)
211 goto out;
212
213 /* update the shadow register then */
214 if (off > 7)
215 chip->reg_out[1] = reg_out;
216 else
217 chip->reg_out[0] = reg_out;
218out:
219 mutex_unlock(&chip->lock);
220}
221
222static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
223{
224 struct max732x_chip *chip;
225 unsigned int mask = 1u << off;
226
227 chip = container_of(gc, struct max732x_chip, gpio_chip);
228
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);
232 return -EACCES;
233 }
234
235 /*
236 * Open-drain pins must be set to high impedance (which is
237 * equivalent to output-high) to be turned into an input.
238 */
239 if ((mask & chip->dir_output))
240 max732x_gpio_set_value(gc, off, 1);
241
242 return 0;
243}
244
245static int max732x_gpio_direction_output(struct gpio_chip *gc,
246 unsigned off, int val)
247{
248 struct max732x_chip *chip;
249 unsigned int mask = 1u << off;
250
251 chip = container_of(gc, struct max732x_chip, gpio_chip);
252
253 if ((mask & chip->dir_output) == 0) {
254 dev_dbg(&chip->client->dev, "%s port %d is input only\n",
255 chip->client->name, off);
256 return -EACCES;
257 }
258
259 max732x_gpio_set_value(gc, off, val);
260 return 0;
261}
262
263#ifdef CONFIG_GPIO_MAX732X_IRQ
264static int max732x_writew(struct max732x_chip *chip, uint16_t val)
265{
266 int ret;
267
268 val = cpu_to_le16(val);
269
270 ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
271 if (ret < 0) {
272 dev_err(&chip->client_group_a->dev, "failed writing\n");
273 return ret;
274 }
275
276 return 0;
277}
278
279static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
280{
281 int ret;
282
283 ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
284 if (ret < 0) {
285 dev_err(&chip->client_group_a->dev, "failed reading\n");
286 return ret;
287 }
288
289 *val = le16_to_cpu(*val);
290 return 0;
291}
292
293static void max732x_irq_update_mask(struct max732x_chip *chip)
294{
295 uint16_t msg;
296
297 if (chip->irq_mask == chip->irq_mask_cur)
298 return;
299
300 chip->irq_mask = chip->irq_mask_cur;
301
302 if (chip->irq_features == INT_NO_MASK)
303 return;
304
305 mutex_lock(&chip->lock);
306
307 switch (chip->irq_features) {
308 case INT_INDEP_MASK:
309 msg = (chip->irq_mask << 8) | chip->reg_out[0];
310 max732x_writew(chip, msg);
311 break;
312
313 case INT_MERGED_MASK:
314 msg = chip->irq_mask | chip->reg_out[0];
315 max732x_writeb(chip, 1, (uint8_t)msg);
316 break;
317 }
318
319 mutex_unlock(&chip->lock);
320}
321
322static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
323{
324 struct max732x_chip *chip;
325
326 chip = container_of(gc, struct max732x_chip, gpio_chip);
327 return chip->irq_base + off;
328}
329
330static void max732x_irq_mask(struct irq_data *d)
331{
332 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
333
334 chip->irq_mask_cur &= ~(1 << (d->irq - chip->irq_base));
335}
336
337static void max732x_irq_unmask(struct irq_data *d)
338{
339 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
340
341 chip->irq_mask_cur |= 1 << (d->irq - chip->irq_base);
342}
343
344static void max732x_irq_bus_lock(struct irq_data *d)
345{
346 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
347
348 mutex_lock(&chip->irq_lock);
349 chip->irq_mask_cur = chip->irq_mask;
350}
351
352static void max732x_irq_bus_sync_unlock(struct irq_data *d)
353{
354 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
355
356 max732x_irq_update_mask(chip);
357 mutex_unlock(&chip->irq_lock);
358}
359
360static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
361{
362 struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
363 uint16_t off = d->irq - chip->irq_base;
364 uint16_t mask = 1 << off;
365
366 if (!(mask & chip->dir_input)) {
367 dev_dbg(&chip->client->dev, "%s port %d is output only\n",
368 chip->client->name, off);
369 return -EACCES;
370 }
371
372 if (!(type & IRQ_TYPE_EDGE_BOTH)) {
373 dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
374 d->irq, type);
375 return -EINVAL;
376 }
377
378 if (type & IRQ_TYPE_EDGE_FALLING)
379 chip->irq_trig_fall |= mask;
380 else
381 chip->irq_trig_fall &= ~mask;
382
383 if (type & IRQ_TYPE_EDGE_RISING)
384 chip->irq_trig_raise |= mask;
385 else
386 chip->irq_trig_raise &= ~mask;
387
388 return max732x_gpio_direction_input(&chip->gpio_chip, off);
389}
390
391static struct irq_chip max732x_irq_chip = {
392 .name = "max732x",
393 .irq_mask = max732x_irq_mask,
394 .irq_unmask = max732x_irq_unmask,
395 .irq_bus_lock = max732x_irq_bus_lock,
396 .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock,
397 .irq_set_type = max732x_irq_set_type,
398};
399
400static uint8_t max732x_irq_pending(struct max732x_chip *chip)
401{
402 uint8_t cur_stat;
403 uint8_t old_stat;
404 uint8_t trigger;
405 uint8_t pending;
406 uint16_t status;
407 int ret;
408
409 ret = max732x_readw(chip, &status);
410 if (ret)
411 return 0;
412
413 trigger = status >> 8;
414 trigger &= chip->irq_mask;
415
416 if (!trigger)
417 return 0;
418
419 cur_stat = status & 0xFF;
420 cur_stat &= chip->irq_mask;
421
422 old_stat = cur_stat ^ trigger;
423
424 pending = (old_stat & chip->irq_trig_fall) |
425 (cur_stat & chip->irq_trig_raise);
426 pending &= trigger;
427
428 return pending;
429}
430
431static irqreturn_t max732x_irq_handler(int irq, void *devid)
432{
433 struct max732x_chip *chip = devid;
434 uint8_t pending;
435 uint8_t level;
436
437 pending = max732x_irq_pending(chip);
438
439 if (!pending)
440 return IRQ_HANDLED;
441
442 do {
443 level = __ffs(pending);
444 handle_nested_irq(level + chip->irq_base);
445
446 pending &= ~(1 << level);
447 } while (pending);
448
449 return IRQ_HANDLED;
450}
451
452static int max732x_irq_setup(struct max732x_chip *chip,
453 const struct i2c_device_id *id)
454{
455 struct i2c_client *client = chip->client;
456 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
457 int has_irq = max732x_features[id->driver_data] >> 32;
458 int ret;
459
460 if (pdata->irq_base && has_irq != INT_NONE) {
461 int lvl;
462
463 chip->irq_base = pdata->irq_base;
464 chip->irq_features = has_irq;
465 mutex_init(&chip->irq_lock);
466
467 for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
468 int irq = lvl + chip->irq_base;
469
470 if (!(chip->dir_input & (1 << lvl)))
471 continue;
472
473 irq_set_chip_data(irq, chip);
474 irq_set_chip_and_handler(irq, &max732x_irq_chip,
475 handle_edge_irq);
476 irq_set_nested_thread(irq, 1);
477#ifdef CONFIG_ARM
478 set_irq_flags(irq, IRQF_VALID);
479#else
480 irq_set_noprobe(irq);
481#endif
482 }
483
484 ret = request_threaded_irq(client->irq,
485 NULL,
486 max732x_irq_handler,
487 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
488 dev_name(&client->dev), chip);
489 if (ret) {
490 dev_err(&client->dev, "failed to request irq %d\n",
491 client->irq);
492 goto out_failed;
493 }
494
495 chip->gpio_chip.to_irq = max732x_gpio_to_irq;
496 }
497
498 return 0;
499
500out_failed:
501 chip->irq_base = 0;
502 return ret;
503}
504
505static void max732x_irq_teardown(struct max732x_chip *chip)
506{
507 if (chip->irq_base)
508 free_irq(chip->client->irq, chip);
509}
510#else /* CONFIG_GPIO_MAX732X_IRQ */
511static int max732x_irq_setup(struct max732x_chip *chip,
512 const struct i2c_device_id *id)
513{
514 struct i2c_client *client = chip->client;
515 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
516 int has_irq = max732x_features[id->driver_data] >> 32;
517
518 if (pdata->irq_base && has_irq != INT_NONE)
519 dev_warn(&client->dev, "interrupt support not compiled in\n");
520
521 return 0;
522}
523
524static void max732x_irq_teardown(struct max732x_chip *chip)
525{
526}
527#endif
528
529static int max732x_setup_gpio(struct max732x_chip *chip,
530 const struct i2c_device_id *id,
531 unsigned gpio_start)
532{
533 struct gpio_chip *gc = &chip->gpio_chip;
534 uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
535 int i, port = 0;
536
537 for (i = 0; i < 16; i++, id_data >>= 2) {
538 unsigned int mask = 1 << port;
539
540 switch (id_data & 0x3) {
541 case PORT_OUTPUT:
542 chip->dir_output |= mask;
543 break;
544 case PORT_INPUT:
545 chip->dir_input |= mask;
546 break;
547 case PORT_OPENDRAIN:
548 chip->dir_output |= mask;
549 chip->dir_input |= mask;
550 break;
551 default:
552 continue;
553 }
554
555 if (i < 8)
556 chip->mask_group_a |= mask;
557 port++;
558 }
559
560 if (chip->dir_input)
561 gc->direction_input = max732x_gpio_direction_input;
562 if (chip->dir_output) {
563 gc->direction_output = max732x_gpio_direction_output;
564 gc->set = max732x_gpio_set_value;
565 }
566 gc->get = max732x_gpio_get_value;
567 gc->can_sleep = true;
568
569 gc->base = gpio_start;
570 gc->ngpio = port;
571 gc->label = chip->client->name;
572 gc->owner = THIS_MODULE;
573
574 return port;
575}
576
577static int max732x_probe(struct i2c_client *client,
578 const struct i2c_device_id *id)
579{
580 struct max732x_platform_data *pdata;
581 struct max732x_chip *chip;
582 struct i2c_client *c;
583 uint16_t addr_a, addr_b;
584 int ret, nr_port;
585
586 pdata = dev_get_platdata(&client->dev);
587 if (pdata == NULL) {
588 dev_dbg(&client->dev, "no platform data\n");
589 return -EINVAL;
590 }
591
592 chip = devm_kzalloc(&client->dev, sizeof(struct max732x_chip),
593 GFP_KERNEL);
594 if (chip == NULL)
595 return -ENOMEM;
596 chip->client = client;
597
598 nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
599
600 addr_a = (client->addr & 0x0f) | 0x60;
601 addr_b = (client->addr & 0x0f) | 0x50;
602
603 switch (client->addr & 0x70) {
604 case 0x60:
605 chip->client_group_a = client;
606 if (nr_port > 8) {
607 c = i2c_new_dummy(client->adapter, addr_b);
608 chip->client_group_b = chip->client_dummy = c;
609 }
610 break;
611 case 0x50:
612 chip->client_group_b = client;
613 if (nr_port > 8) {
614 c = i2c_new_dummy(client->adapter, addr_a);
615 chip->client_group_a = chip->client_dummy = c;
616 }
617 break;
618 default:
619 dev_err(&client->dev, "invalid I2C address specified %02x\n",
620 client->addr);
621 ret = -EINVAL;
622 goto out_failed;
623 }
624
625 if (nr_port > 8 && !chip->client_dummy) {
626 dev_err(&client->dev,
627 "Failed to allocate second group I2C device\n");
628 ret = -ENODEV;
629 goto out_failed;
630 }
631
632 mutex_init(&chip->lock);
633
634 max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
635 if (nr_port > 8)
636 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
637
638 ret = max732x_irq_setup(chip, id);
639 if (ret)
640 goto out_failed;
641
642 ret = gpiochip_add(&chip->gpio_chip);
643 if (ret)
644 goto out_failed;
645
646 if (pdata->setup) {
647 ret = pdata->setup(client, chip->gpio_chip.base,
648 chip->gpio_chip.ngpio, pdata->context);
649 if (ret < 0)
650 dev_warn(&client->dev, "setup failed, %d\n", ret);
651 }
652
653 i2c_set_clientdata(client, chip);
654 return 0;
655
656out_failed:
657 if (chip->client_dummy)
658 i2c_unregister_device(chip->client_dummy);
659 max732x_irq_teardown(chip);
660 return ret;
661}
662
663static int max732x_remove(struct i2c_client *client)
664{
665 struct max732x_platform_data *pdata = dev_get_platdata(&client->dev);
666 struct max732x_chip *chip = i2c_get_clientdata(client);
667 int ret;
668
669 if (pdata->teardown) {
670 ret = pdata->teardown(client, chip->gpio_chip.base,
671 chip->gpio_chip.ngpio, pdata->context);
672 if (ret < 0) {
673 dev_err(&client->dev, "%s failed, %d\n",
674 "teardown", ret);
675 return ret;
676 }
677 }
678
679 ret = gpiochip_remove(&chip->gpio_chip);
680 if (ret) {
681 dev_err(&client->dev, "%s failed, %d\n",
682 "gpiochip_remove()", ret);
683 return ret;
684 }
685
686 max732x_irq_teardown(chip);
687
688 /* unregister any dummy i2c_client */
689 if (chip->client_dummy)
690 i2c_unregister_device(chip->client_dummy);
691
692 return 0;
693}
694
695static struct i2c_driver max732x_driver = {
696 .driver = {
697 .name = "max732x",
698 .owner = THIS_MODULE,
699 },
700 .probe = max732x_probe,
701 .remove = max732x_remove,
702 .id_table = max732x_id,
703};
704
705static int __init max732x_init(void)
706{
707 return i2c_add_driver(&max732x_driver);
708}
709/* register after i2c postcore initcall and before
710 * subsys initcalls that may rely on these GPIOs
711 */
712subsys_initcall(max732x_init);
713
714static void __exit max732x_exit(void)
715{
716 i2c_del_driver(&max732x_driver);
717}
718module_exit(max732x_exit);
719
720MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
721MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
722MODULE_LICENSE("GPL");