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1/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15 * 02110-1301, USA.
16 */
17#include <linux/gpio.h>
18#include <linux/i2c.h>
19#include <linux/init.h>
20#include <linux/interrupt.h>
21#include <linux/irq.h>
22#include <linux/module.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25#include <linux/workqueue.h>
26#include <linux/i2c/sx150x.h>
27
28#define NO_UPDATE_PENDING -1
29
30struct sx150x_device_data {
31 u8 reg_pullup;
32 u8 reg_pulldn;
33 u8 reg_drain;
34 u8 reg_polarity;
35 u8 reg_dir;
36 u8 reg_data;
37 u8 reg_irq_mask;
38 u8 reg_irq_src;
39 u8 reg_sense;
40 u8 reg_clock;
41 u8 reg_misc;
42 u8 reg_reset;
43 u8 ngpios;
44};
45
46struct sx150x_chip {
47 struct gpio_chip gpio_chip;
48 struct i2c_client *client;
49 const struct sx150x_device_data *dev_cfg;
50 int irq_summary;
51 int irq_base;
52 int irq_update;
53 u32 irq_sense;
54 u32 irq_masked;
55 u32 dev_sense;
56 u32 dev_masked;
57 struct irq_chip irq_chip;
58 struct mutex lock;
59};
60
61static const struct sx150x_device_data sx150x_devices[] = {
62 [0] = { /* sx1508q */
63 .reg_pullup = 0x03,
64 .reg_pulldn = 0x04,
65 .reg_drain = 0x05,
66 .reg_polarity = 0x06,
67 .reg_dir = 0x07,
68 .reg_data = 0x08,
69 .reg_irq_mask = 0x09,
70 .reg_irq_src = 0x0c,
71 .reg_sense = 0x0b,
72 .reg_clock = 0x0f,
73 .reg_misc = 0x10,
74 .reg_reset = 0x7d,
75 .ngpios = 8
76 },
77 [1] = { /* sx1509q */
78 .reg_pullup = 0x07,
79 .reg_pulldn = 0x09,
80 .reg_drain = 0x0b,
81 .reg_polarity = 0x0d,
82 .reg_dir = 0x0f,
83 .reg_data = 0x11,
84 .reg_irq_mask = 0x13,
85 .reg_irq_src = 0x19,
86 .reg_sense = 0x17,
87 .reg_clock = 0x1e,
88 .reg_misc = 0x1f,
89 .reg_reset = 0x7d,
90 .ngpios = 16
91 },
92};
93
94static const struct i2c_device_id sx150x_id[] = {
95 {"sx1508q", 0},
96 {"sx1509q", 1},
97 {}
98};
99MODULE_DEVICE_TABLE(i2c, sx150x_id);
100
101static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
102{
103 s32 err = i2c_smbus_write_byte_data(client, reg, val);
104
105 if (err < 0)
106 dev_warn(&client->dev,
107 "i2c write fail: can't write %02x to %02x: %d\n",
108 val, reg, err);
109 return err;
110}
111
112static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
113{
114 s32 err = i2c_smbus_read_byte_data(client, reg);
115
116 if (err >= 0)
117 *val = err;
118 else
119 dev_warn(&client->dev,
120 "i2c read fail: can't read from %02x: %d\n",
121 reg, err);
122 return err;
123}
124
125static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
126{
127 return (chip->dev_cfg->ngpios == offset);
128}
129
130/*
131 * These utility functions solve the common problem of locating and setting
132 * configuration bits. Configuration bits are grouped into registers
133 * whose indexes increase downwards. For example, with eight-bit registers,
134 * sixteen gpios would have their config bits grouped in the following order:
135 * REGISTER N-1 [ f e d c b a 9 8 ]
136 * N [ 7 6 5 4 3 2 1 0 ]
137 *
138 * For multi-bit configurations, the pattern gets wider:
139 * REGISTER N-3 [ f f e e d d c c ]
140 * N-2 [ b b a a 9 9 8 8 ]
141 * N-1 [ 7 7 6 6 5 5 4 4 ]
142 * N [ 3 3 2 2 1 1 0 0 ]
143 *
144 * Given the address of the starting register 'N', the index of the gpio
145 * whose configuration we seek to change, and the width in bits of that
146 * configuration, these functions allow us to locate the correct
147 * register and mask the correct bits.
148 */
149static inline void sx150x_find_cfg(u8 offset, u8 width,
150 u8 *reg, u8 *mask, u8 *shift)
151{
152 *reg -= offset * width / 8;
153 *mask = (1 << width) - 1;
154 *shift = (offset * width) % 8;
155 *mask <<= *shift;
156}
157
158static s32 sx150x_write_cfg(struct sx150x_chip *chip,
159 u8 offset, u8 width, u8 reg, u8 val)
160{
161 u8 mask;
162 u8 data;
163 u8 shift;
164 s32 err;
165
166 sx150x_find_cfg(offset, width, ®, &mask, &shift);
167 err = sx150x_i2c_read(chip->client, reg, &data);
168 if (err < 0)
169 return err;
170
171 data &= ~mask;
172 data |= (val << shift) & mask;
173 return sx150x_i2c_write(chip->client, reg, data);
174}
175
176static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
177{
178 u8 reg = chip->dev_cfg->reg_data;
179 u8 mask;
180 u8 data;
181 u8 shift;
182 s32 err;
183
184 sx150x_find_cfg(offset, 1, ®, &mask, &shift);
185 err = sx150x_i2c_read(chip->client, reg, &data);
186 if (err >= 0)
187 err = (data & mask) != 0 ? 1 : 0;
188
189 return err;
190}
191
192static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
193{
194 sx150x_i2c_write(chip->client,
195 chip->dev_cfg->reg_clock,
196 (val ? 0x1f : 0x10));
197}
198
199static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
200{
201 sx150x_write_cfg(chip,
202 offset,
203 1,
204 chip->dev_cfg->reg_data,
205 (val ? 1 : 0));
206}
207
208static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
209{
210 return sx150x_write_cfg(chip,
211 offset,
212 1,
213 chip->dev_cfg->reg_dir,
214 1);
215}
216
217static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
218{
219 int err;
220
221 err = sx150x_write_cfg(chip,
222 offset,
223 1,
224 chip->dev_cfg->reg_data,
225 (val ? 1 : 0));
226 if (err >= 0)
227 err = sx150x_write_cfg(chip,
228 offset,
229 1,
230 chip->dev_cfg->reg_dir,
231 0);
232 return err;
233}
234
235static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
236{
237 struct sx150x_chip *chip;
238 int status = -EINVAL;
239
240 chip = container_of(gc, struct sx150x_chip, gpio_chip);
241
242 if (!offset_is_oscio(chip, offset)) {
243 mutex_lock(&chip->lock);
244 status = sx150x_get_io(chip, offset);
245 mutex_unlock(&chip->lock);
246 }
247
248 return status;
249}
250
251static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
252{
253 struct sx150x_chip *chip;
254
255 chip = container_of(gc, struct sx150x_chip, gpio_chip);
256
257 mutex_lock(&chip->lock);
258 if (offset_is_oscio(chip, offset))
259 sx150x_set_oscio(chip, val);
260 else
261 sx150x_set_io(chip, offset, val);
262 mutex_unlock(&chip->lock);
263}
264
265static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
266{
267 struct sx150x_chip *chip;
268 int status = -EINVAL;
269
270 chip = container_of(gc, struct sx150x_chip, gpio_chip);
271
272 if (!offset_is_oscio(chip, offset)) {
273 mutex_lock(&chip->lock);
274 status = sx150x_io_input(chip, offset);
275 mutex_unlock(&chip->lock);
276 }
277 return status;
278}
279
280static int sx150x_gpio_direction_output(struct gpio_chip *gc,
281 unsigned offset,
282 int val)
283{
284 struct sx150x_chip *chip;
285 int status = 0;
286
287 chip = container_of(gc, struct sx150x_chip, gpio_chip);
288
289 if (!offset_is_oscio(chip, offset)) {
290 mutex_lock(&chip->lock);
291 status = sx150x_io_output(chip, offset, val);
292 mutex_unlock(&chip->lock);
293 }
294 return status;
295}
296
297static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
298{
299 struct sx150x_chip *chip;
300
301 chip = container_of(gc, struct sx150x_chip, gpio_chip);
302
303 if (offset >= chip->dev_cfg->ngpios)
304 return -EINVAL;
305
306 if (chip->irq_base < 0)
307 return -EINVAL;
308
309 return chip->irq_base + offset;
310}
311
312static void sx150x_irq_mask(struct irq_data *d)
313{
314 struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
315 unsigned n;
316
317 n = d->irq - chip->irq_base;
318 chip->irq_masked |= (1 << n);
319 chip->irq_update = n;
320}
321
322static void sx150x_irq_unmask(struct irq_data *d)
323{
324 struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
325 unsigned n;
326
327 n = d->irq - chip->irq_base;
328 chip->irq_masked &= ~(1 << n);
329 chip->irq_update = n;
330}
331
332static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
333{
334 struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
335 unsigned n, val = 0;
336
337 if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
338 return -EINVAL;
339
340 n = d->irq - chip->irq_base;
341
342 if (flow_type & IRQ_TYPE_EDGE_RISING)
343 val |= 0x1;
344 if (flow_type & IRQ_TYPE_EDGE_FALLING)
345 val |= 0x2;
346
347 chip->irq_sense &= ~(3UL << (n * 2));
348 chip->irq_sense |= val << (n * 2);
349 chip->irq_update = n;
350 return 0;
351}
352
353static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
354{
355 struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
356 unsigned nhandled = 0;
357 unsigned sub_irq;
358 unsigned n;
359 s32 err;
360 u8 val;
361 int i;
362
363 for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
364 err = sx150x_i2c_read(chip->client,
365 chip->dev_cfg->reg_irq_src - i,
366 &val);
367 if (err < 0)
368 continue;
369
370 sx150x_i2c_write(chip->client,
371 chip->dev_cfg->reg_irq_src - i,
372 val);
373 for (n = 0; n < 8; ++n) {
374 if (val & (1 << n)) {
375 sub_irq = chip->irq_base + (i * 8) + n;
376 handle_nested_irq(sub_irq);
377 ++nhandled;
378 }
379 }
380 }
381
382 return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
383}
384
385static void sx150x_irq_bus_lock(struct irq_data *d)
386{
387 struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
388
389 mutex_lock(&chip->lock);
390}
391
392static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
393{
394 struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
395 unsigned n;
396
397 if (chip->irq_update == NO_UPDATE_PENDING)
398 goto out;
399
400 n = chip->irq_update;
401 chip->irq_update = NO_UPDATE_PENDING;
402
403 /* Avoid updates if nothing changed */
404 if (chip->dev_sense == chip->irq_sense &&
405 chip->dev_sense == chip->irq_masked)
406 goto out;
407
408 chip->dev_sense = chip->irq_sense;
409 chip->dev_masked = chip->irq_masked;
410
411 if (chip->irq_masked & (1 << n)) {
412 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
413 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
414 } else {
415 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
416 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
417 chip->irq_sense >> (n * 2));
418 }
419out:
420 mutex_unlock(&chip->lock);
421}
422
423static void sx150x_init_chip(struct sx150x_chip *chip,
424 struct i2c_client *client,
425 kernel_ulong_t driver_data,
426 struct sx150x_platform_data *pdata)
427{
428 mutex_init(&chip->lock);
429
430 chip->client = client;
431 chip->dev_cfg = &sx150x_devices[driver_data];
432 chip->gpio_chip.label = client->name;
433 chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
434 chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
435 chip->gpio_chip.get = sx150x_gpio_get;
436 chip->gpio_chip.set = sx150x_gpio_set;
437 chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
438 chip->gpio_chip.base = pdata->gpio_base;
439 chip->gpio_chip.can_sleep = true;
440 chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
441 if (pdata->oscio_is_gpo)
442 ++chip->gpio_chip.ngpio;
443
444 chip->irq_chip.name = client->name;
445 chip->irq_chip.irq_mask = sx150x_irq_mask;
446 chip->irq_chip.irq_unmask = sx150x_irq_unmask;
447 chip->irq_chip.irq_set_type = sx150x_irq_set_type;
448 chip->irq_chip.irq_bus_lock = sx150x_irq_bus_lock;
449 chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
450 chip->irq_summary = -1;
451 chip->irq_base = -1;
452 chip->irq_masked = ~0;
453 chip->irq_sense = 0;
454 chip->dev_masked = ~0;
455 chip->dev_sense = 0;
456 chip->irq_update = NO_UPDATE_PENDING;
457}
458
459static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
460{
461 int err = 0;
462 unsigned n;
463
464 for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
465 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
466 return err;
467}
468
469static int sx150x_reset(struct sx150x_chip *chip)
470{
471 int err;
472
473 err = i2c_smbus_write_byte_data(chip->client,
474 chip->dev_cfg->reg_reset,
475 0x12);
476 if (err < 0)
477 return err;
478
479 err = i2c_smbus_write_byte_data(chip->client,
480 chip->dev_cfg->reg_reset,
481 0x34);
482 return err;
483}
484
485static int sx150x_init_hw(struct sx150x_chip *chip,
486 struct sx150x_platform_data *pdata)
487{
488 int err = 0;
489
490 if (pdata->reset_during_probe) {
491 err = sx150x_reset(chip);
492 if (err < 0)
493 return err;
494 }
495
496 err = sx150x_i2c_write(chip->client,
497 chip->dev_cfg->reg_misc,
498 0x01);
499 if (err < 0)
500 return err;
501
502 err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
503 pdata->io_pullup_ena);
504 if (err < 0)
505 return err;
506
507 err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
508 pdata->io_pulldn_ena);
509 if (err < 0)
510 return err;
511
512 err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
513 pdata->io_open_drain_ena);
514 if (err < 0)
515 return err;
516
517 err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
518 pdata->io_polarity);
519 if (err < 0)
520 return err;
521
522 if (pdata->oscio_is_gpo)
523 sx150x_set_oscio(chip, 0);
524
525 return err;
526}
527
528static int sx150x_install_irq_chip(struct sx150x_chip *chip,
529 int irq_summary,
530 int irq_base)
531{
532 int err;
533 unsigned n;
534 unsigned irq;
535
536 chip->irq_summary = irq_summary;
537 chip->irq_base = irq_base;
538
539 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
540 irq = irq_base + n;
541 irq_set_chip_data(irq, chip);
542 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
543 irq_set_nested_thread(irq, 1);
544#ifdef CONFIG_ARM
545 set_irq_flags(irq, IRQF_VALID);
546#else
547 irq_set_noprobe(irq);
548#endif
549 }
550
551 err = devm_request_threaded_irq(&chip->client->dev,
552 irq_summary,
553 NULL,
554 sx150x_irq_thread_fn,
555 IRQF_SHARED | IRQF_TRIGGER_FALLING,
556 chip->irq_chip.name,
557 chip);
558 if (err < 0) {
559 chip->irq_summary = -1;
560 chip->irq_base = -1;
561 }
562
563 return err;
564}
565
566static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
567{
568 unsigned n;
569 unsigned irq;
570
571 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
572 irq = chip->irq_base + n;
573 irq_set_chip_and_handler(irq, NULL, NULL);
574 }
575}
576
577static int sx150x_probe(struct i2c_client *client,
578 const struct i2c_device_id *id)
579{
580 static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
581 I2C_FUNC_SMBUS_WRITE_WORD_DATA;
582 struct sx150x_platform_data *pdata;
583 struct sx150x_chip *chip;
584 int rc;
585
586 pdata = dev_get_platdata(&client->dev);
587 if (!pdata)
588 return -EINVAL;
589
590 if (!i2c_check_functionality(client->adapter, i2c_funcs))
591 return -ENOSYS;
592
593 chip = devm_kzalloc(&client->dev,
594 sizeof(struct sx150x_chip), GFP_KERNEL);
595 if (!chip)
596 return -ENOMEM;
597
598 sx150x_init_chip(chip, client, id->driver_data, pdata);
599 rc = sx150x_init_hw(chip, pdata);
600 if (rc < 0)
601 return rc;
602
603 rc = gpiochip_add(&chip->gpio_chip);
604 if (rc)
605 return rc;
606
607 if (pdata->irq_summary >= 0) {
608 rc = sx150x_install_irq_chip(chip,
609 pdata->irq_summary,
610 pdata->irq_base);
611 if (rc < 0)
612 goto probe_fail_post_gpiochip_add;
613 }
614
615 i2c_set_clientdata(client, chip);
616
617 return 0;
618probe_fail_post_gpiochip_add:
619 WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
620 return rc;
621}
622
623static int sx150x_remove(struct i2c_client *client)
624{
625 struct sx150x_chip *chip;
626 int rc;
627
628 chip = i2c_get_clientdata(client);
629 rc = gpiochip_remove(&chip->gpio_chip);
630 if (rc < 0)
631 return rc;
632
633 if (chip->irq_summary >= 0)
634 sx150x_remove_irq_chip(chip);
635
636 return 0;
637}
638
639static struct i2c_driver sx150x_driver = {
640 .driver = {
641 .name = "sx150x",
642 .owner = THIS_MODULE
643 },
644 .probe = sx150x_probe,
645 .remove = sx150x_remove,
646 .id_table = sx150x_id,
647};
648
649static int __init sx150x_init(void)
650{
651 return i2c_add_driver(&sx150x_driver);
652}
653subsys_initcall(sx150x_init);
654
655static void __exit sx150x_exit(void)
656{
657 return i2c_del_driver(&sx150x_driver);
658}
659module_exit(sx150x_exit);
660
661MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
662MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
663MODULE_LICENSE("GPL v2");
664MODULE_ALIAS("i2c:sx150x");