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