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Linux 3.11-rc3
[cris-mirror.git] / drivers / gpio / gpio-max732x.c
blobd4b51b163b039f9aa6ed93c007a3d0d56160f3e1
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
81 enum {
82 MAX7319,
83 MAX7320,
84 MAX7321,
85 MAX7322,
86 MAX7323,
87 MAX7324,
88 MAX7325,
89 MAX7326,
90 MAX7327,
91 };
92
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),
103 };
104
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 },
115 { },
116 };
117 MODULE_DEVICE_TABLE(i2c, max732x_id);
118
119 struct 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
145 static 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
160 static 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
176 static inline int is_group_a(struct max732x_chip *chip, unsigned off)
177 {
178 return (1u << off) & chip->mask_group_a;
179 }
180
181 static 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), &reg_val);
190 if (ret < 0)
191 return 0;
192
193 return reg_val & (1u << (off & 0x7));
194 }
195
196 static 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;
218 out:
219 mutex_unlock(&chip->lock);
220 }
221
222 static 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
245 static 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
264 static 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
279 static 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
293 static 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
322 static 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
330 static 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
337 static 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
344 static 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
352 static 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
360 static 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
391 static 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
400 static 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
431 static 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
452 static 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 = client->dev.platform_data;
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
500 out_failed:
501 chip->irq_base = 0;
502 return ret;
503 }
504
505 static 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 */
511 static 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 = client->dev.platform_data;
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
524 static void max732x_irq_teardown(struct max732x_chip *chip)
525 {
526 }
527 #endif
528
529 static 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 = 1;
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
577 static 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 = client->dev.platform_data;
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 mutex_init(&chip->lock);
626
627 max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
628 if (nr_port > 8)
629 max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
630
631 ret = max732x_irq_setup(chip, id);
632 if (ret)
633 goto out_failed;
634
635 ret = gpiochip_add(&chip->gpio_chip);
636 if (ret)
637 goto out_failed;
638
639 if (pdata->setup) {
640 ret = pdata->setup(client, chip->gpio_chip.base,
641 chip->gpio_chip.ngpio, pdata->context);
642 if (ret < 0)
643 dev_warn(&client->dev, "setup failed, %d\n", ret);
644 }
645
646 i2c_set_clientdata(client, chip);
647 return 0;
648
649 out_failed:
650 max732x_irq_teardown(chip);
651 return ret;
652 }
653
654 static int max732x_remove(struct i2c_client *client)
655 {
656 struct max732x_platform_data *pdata = client->dev.platform_data;
657 struct max732x_chip *chip = i2c_get_clientdata(client);
658 int ret;
659
660 if (pdata->teardown) {
661 ret = pdata->teardown(client, chip->gpio_chip.base,
662 chip->gpio_chip.ngpio, pdata->context);
663 if (ret < 0) {
664 dev_err(&client->dev, "%s failed, %d\n",
665 "teardown", ret);
666 return ret;
667 }
668 }
669
670 ret = gpiochip_remove(&chip->gpio_chip);
671 if (ret) {
672 dev_err(&client->dev, "%s failed, %d\n",
673 "gpiochip_remove()", ret);
674 return ret;
675 }
676
677 max732x_irq_teardown(chip);
678
679 /* unregister any dummy i2c_client */
680 if (chip->client_dummy)
681 i2c_unregister_device(chip->client_dummy);
682
683 return 0;
684 }
685
686 static struct i2c_driver max732x_driver = {
687 .driver = {
688 .name = "max732x",
689 .owner = THIS_MODULE,
690 },
691 .probe = max732x_probe,
692 .remove = max732x_remove,
693 .id_table = max732x_id,
694 };
695
696 static int __init max732x_init(void)
697 {
698 return i2c_add_driver(&max732x_driver);
699 }
700 /* register after i2c postcore initcall and before
701 * subsys initcalls that may rely on these GPIOs
702 */
703 subsys_initcall(max732x_init);
704
705 static void __exit max732x_exit(void)
706 {
707 i2c_del_driver(&max732x_driver);
708 }
709 module_exit(max732x_exit);
710
711 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
712 MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
713 MODULE_LICENSE("GPL");
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