tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 irq_chip *ic = irq_data_get_irq_chip(d);
315 struct sx150x_chip *chip;
316 unsigned n;
317
318 chip = container_of(ic, struct sx150x_chip, irq_chip);
319 n = d->irq - chip->irq_base;
320 chip->irq_masked |= (1 << n);
321 chip->irq_update = n;
322}
323
324static void sx150x_irq_unmask(struct irq_data *d)
325{
326 struct irq_chip *ic = irq_data_get_irq_chip(d);
327 struct sx150x_chip *chip;
328 unsigned n;
329
330 chip = container_of(ic, struct sx150x_chip, irq_chip);
331 n = d->irq - chip->irq_base;
332
333 chip->irq_masked &= ~(1 << n);
334 chip->irq_update = n;
335}
336
337static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
338{
339 struct irq_chip *ic = irq_data_get_irq_chip(d);
340 struct sx150x_chip *chip;
341 unsigned n, val = 0;
342
343 if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
344 return -EINVAL;
345
346 chip = container_of(ic, struct sx150x_chip, irq_chip);
347 n = d->irq - chip->irq_base;
348
349 if (flow_type & IRQ_TYPE_EDGE_RISING)
350 val |= 0x1;
351 if (flow_type & IRQ_TYPE_EDGE_FALLING)
352 val |= 0x2;
353
354 chip->irq_sense &= ~(3UL << (n * 2));
355 chip->irq_sense |= val << (n * 2);
356 chip->irq_update = n;
357 return 0;
358}
359
360static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
361{
362 struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
363 unsigned nhandled = 0;
364 unsigned sub_irq;
365 unsigned n;
366 s32 err;
367 u8 val;
368 int i;
369
370 for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
371 err = sx150x_i2c_read(chip->client,
372 chip->dev_cfg->reg_irq_src - i,
373 &val);
374 if (err < 0)
375 continue;
376
377 sx150x_i2c_write(chip->client,
378 chip->dev_cfg->reg_irq_src - i,
379 val);
380 for (n = 0; n < 8; ++n) {
381 if (val & (1 << n)) {
382 sub_irq = chip->irq_base + (i * 8) + n;
383 handle_nested_irq(sub_irq);
384 ++nhandled;
385 }
386 }
387 }
388
389 return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
390}
391
392static void sx150x_irq_bus_lock(struct irq_data *d)
393{
394 struct irq_chip *ic = irq_data_get_irq_chip(d);
395 struct sx150x_chip *chip;
396
397 chip = container_of(ic, struct sx150x_chip, irq_chip);
398
399 mutex_lock(&chip->lock);
400}
401
402static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
403{
404 struct irq_chip *ic = irq_data_get_irq_chip(d);
405 struct sx150x_chip *chip;
406 unsigned n;
407
408 chip = container_of(ic, struct sx150x_chip, irq_chip);
409
410 if (chip->irq_update == NO_UPDATE_PENDING)
411 goto out;
412
413 n = chip->irq_update;
414 chip->irq_update = NO_UPDATE_PENDING;
415
416 /* Avoid updates if nothing changed */
417 if (chip->dev_sense == chip->irq_sense &&
418 chip->dev_sense == chip->irq_masked)
419 goto out;
420
421 chip->dev_sense = chip->irq_sense;
422 chip->dev_masked = chip->irq_masked;
423
424 if (chip->irq_masked & (1 << n)) {
425 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
426 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
427 } else {
428 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
429 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
430 chip->irq_sense >> (n * 2));
431 }
432out:
433 mutex_unlock(&chip->lock);
434}
435
436static void sx150x_init_chip(struct sx150x_chip *chip,
437 struct i2c_client *client,
438 kernel_ulong_t driver_data,
439 struct sx150x_platform_data *pdata)
440{
441 mutex_init(&chip->lock);
442
443 chip->client = client;
444 chip->dev_cfg = &sx150x_devices[driver_data];
445 chip->gpio_chip.label = client->name;
446 chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
447 chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
448 chip->gpio_chip.get = sx150x_gpio_get;
449 chip->gpio_chip.set = sx150x_gpio_set;
450 chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
451 chip->gpio_chip.base = pdata->gpio_base;
452 chip->gpio_chip.can_sleep = 1;
453 chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
454 if (pdata->oscio_is_gpo)
455 ++chip->gpio_chip.ngpio;
456
457 chip->irq_chip.name = client->name;
458 chip->irq_chip.irq_mask = sx150x_irq_mask;
459 chip->irq_chip.irq_unmask = sx150x_irq_unmask;
460 chip->irq_chip.irq_set_type = sx150x_irq_set_type;
461 chip->irq_chip.irq_bus_lock = sx150x_irq_bus_lock;
462 chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
463 chip->irq_summary = -1;
464 chip->irq_base = -1;
465 chip->irq_masked = ~0;
466 chip->irq_sense = 0;
467 chip->dev_masked = ~0;
468 chip->dev_sense = 0;
469 chip->irq_update = NO_UPDATE_PENDING;
470}
471
472static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
473{
474 int err = 0;
475 unsigned n;
476
477 for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
478 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
479 return err;
480}
481
482static int sx150x_reset(struct sx150x_chip *chip)
483{
484 int err;
485
486 err = i2c_smbus_write_byte_data(chip->client,
487 chip->dev_cfg->reg_reset,
488 0x12);
489 if (err < 0)
490 return err;
491
492 err = i2c_smbus_write_byte_data(chip->client,
493 chip->dev_cfg->reg_reset,
494 0x34);
495 return err;
496}
497
498static int sx150x_init_hw(struct sx150x_chip *chip,
499 struct sx150x_platform_data *pdata)
500{
501 int err = 0;
502
503 if (pdata->reset_during_probe) {
504 err = sx150x_reset(chip);
505 if (err < 0)
506 return err;
507 }
508
509 err = sx150x_i2c_write(chip->client,
510 chip->dev_cfg->reg_misc,
511 0x01);
512 if (err < 0)
513 return err;
514
515 err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
516 pdata->io_pullup_ena);
517 if (err < 0)
518 return err;
519
520 err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
521 pdata->io_pulldn_ena);
522 if (err < 0)
523 return err;
524
525 err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
526 pdata->io_open_drain_ena);
527 if (err < 0)
528 return err;
529
530 err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
531 pdata->io_polarity);
532 if (err < 0)
533 return err;
534
535 if (pdata->oscio_is_gpo)
536 sx150x_set_oscio(chip, 0);
537
538 return err;
539}
540
541static int sx150x_install_irq_chip(struct sx150x_chip *chip,
542 int irq_summary,
543 int irq_base)
544{
545 int err;
546 unsigned n;
547 unsigned irq;
548
549 chip->irq_summary = irq_summary;
550 chip->irq_base = irq_base;
551
552 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
553 irq = irq_base + n;
554 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
555 irq_set_nested_thread(irq, 1);
556#ifdef CONFIG_ARM
557 set_irq_flags(irq, IRQF_VALID);
558#else
559 irq_set_noprobe(irq);
560#endif
561 }
562
563 err = request_threaded_irq(irq_summary,
564 NULL,
565 sx150x_irq_thread_fn,
566 IRQF_SHARED | IRQF_TRIGGER_FALLING,
567 chip->irq_chip.name,
568 chip);
569 if (err < 0) {
570 chip->irq_summary = -1;
571 chip->irq_base = -1;
572 }
573
574 return err;
575}
576
577static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
578{
579 unsigned n;
580 unsigned irq;
581
582 free_irq(chip->irq_summary, chip);
583
584 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
585 irq = chip->irq_base + n;
586 irq_set_chip_and_handler(irq, NULL, NULL);
587 }
588}
589
590static int __devinit sx150x_probe(struct i2c_client *client,
591 const struct i2c_device_id *id)
592{
593 static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
594 I2C_FUNC_SMBUS_WRITE_WORD_DATA;
595 struct sx150x_platform_data *pdata;
596 struct sx150x_chip *chip;
597 int rc;
598
599 pdata = client->dev.platform_data;
600 if (!pdata)
601 return -EINVAL;
602
603 if (!i2c_check_functionality(client->adapter, i2c_funcs))
604 return -ENOSYS;
605
606 chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
607 if (!chip)
608 return -ENOMEM;
609
610 sx150x_init_chip(chip, client, id->driver_data, pdata);
611 rc = sx150x_init_hw(chip, pdata);
612 if (rc < 0)
613 goto probe_fail_pre_gpiochip_add;
614
615 rc = gpiochip_add(&chip->gpio_chip);
616 if (rc < 0)
617 goto probe_fail_pre_gpiochip_add;
618
619 if (pdata->irq_summary >= 0) {
620 rc = sx150x_install_irq_chip(chip,
621 pdata->irq_summary,
622 pdata->irq_base);
623 if (rc < 0)
624 goto probe_fail_post_gpiochip_add;
625 }
626
627 i2c_set_clientdata(client, chip);
628
629 return 0;
630probe_fail_post_gpiochip_add:
631 WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
632probe_fail_pre_gpiochip_add:
633 kfree(chip);
634 return rc;
635}
636
637static int __devexit sx150x_remove(struct i2c_client *client)
638{
639 struct sx150x_chip *chip;
640 int rc;
641
642 chip = i2c_get_clientdata(client);
643 rc = gpiochip_remove(&chip->gpio_chip);
644 if (rc < 0)
645 return rc;
646
647 if (chip->irq_summary >= 0)
648 sx150x_remove_irq_chip(chip);
649
650 kfree(chip);
651
652 return 0;
653}
654
655static struct i2c_driver sx150x_driver = {
656 .driver = {
657 .name = "sx150x",
658 .owner = THIS_MODULE
659 },
660 .probe = sx150x_probe,
661 .remove = __devexit_p(sx150x_remove),
662 .id_table = sx150x_id,
663};
664
665static int __init sx150x_init(void)
666{
667 return i2c_add_driver(&sx150x_driver);
668}
669subsys_initcall(sx150x_init);
670
671static void __exit sx150x_exit(void)
672{
673 return i2c_del_driver(&sx150x_driver);
674}
675module_exit(sx150x_exit);
676
677MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
678MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
679MODULE_LICENSE("GPL v2");
680MODULE_ALIAS("i2c:sx150x");