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TTY: open/hangup race fixup
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / gpio / sx150x.c
blob823559ab0e243610ca8e5ff3b5983aca3d53b7bb
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 struct sx150x_device_data {
29 u8 reg_pullup;
30 u8 reg_pulldn;
31 u8 reg_drain;
32 u8 reg_polarity;
33 u8 reg_dir;
34 u8 reg_data;
35 u8 reg_irq_mask;
36 u8 reg_irq_src;
37 u8 reg_sense;
38 u8 reg_clock;
39 u8 reg_misc;
40 u8 reg_reset;
41 u8 ngpios;
42 };
43
44 struct sx150x_chip {
45 struct gpio_chip gpio_chip;
46 struct i2c_client *client;
47 const struct sx150x_device_data *dev_cfg;
48 int irq_summary;
49 int irq_base;
50 u32 irq_sense;
51 unsigned long irq_set_type_pending;
52 struct irq_chip irq_chip;
53 struct mutex lock;
54 };
55
56 static const struct sx150x_device_data sx150x_devices[] = {
57 [0] = { /* sx1508q */
58 .reg_pullup = 0x03,
59 .reg_pulldn = 0x04,
60 .reg_drain = 0x05,
61 .reg_polarity = 0x06,
62 .reg_dir = 0x07,
63 .reg_data = 0x08,
64 .reg_irq_mask = 0x09,
65 .reg_irq_src = 0x0c,
66 .reg_sense = 0x0b,
67 .reg_clock = 0x0f,
68 .reg_misc = 0x10,
69 .reg_reset = 0x7d,
70 .ngpios = 8
71 },
72 [1] = { /* sx1509q */
73 .reg_pullup = 0x07,
74 .reg_pulldn = 0x09,
75 .reg_drain = 0x0b,
76 .reg_polarity = 0x0d,
77 .reg_dir = 0x0f,
78 .reg_data = 0x11,
79 .reg_irq_mask = 0x13,
80 .reg_irq_src = 0x19,
81 .reg_sense = 0x17,
82 .reg_clock = 0x1e,
83 .reg_misc = 0x1f,
84 .reg_reset = 0x7d,
85 .ngpios = 16
86 },
87 };
88
89 static const struct i2c_device_id sx150x_id[] = {
90 {"sx1508q", 0},
91 {"sx1509q", 1},
92 {}
93 };
94 MODULE_DEVICE_TABLE(i2c, sx150x_id);
95
96 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
97 {
98 s32 err = i2c_smbus_write_byte_data(client, reg, val);
99
100 if (err < 0)
101 dev_warn(&client->dev,
102 "i2c write fail: can't write %02x to %02x: %d\n",
103 val, reg, err);
104 return err;
105 }
106
107 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
108 {
109 s32 err = i2c_smbus_read_byte_data(client, reg);
110
111 if (err >= 0)
112 *val = err;
113 else
114 dev_warn(&client->dev,
115 "i2c read fail: can't read from %02x: %d\n",
116 reg, err);
117 return err;
118 }
119
120 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
121 {
122 return (chip->dev_cfg->ngpios == offset);
123 }
124
125 /*
126 * These utility functions solve the common problem of locating and setting
127 * configuration bits. Configuration bits are grouped into registers
128 * whose indexes increase downwards. For example, with eight-bit registers,
129 * sixteen gpios would have their config bits grouped in the following order:
130 * REGISTER N-1 [ f e d c b a 9 8 ]
131 * N [ 7 6 5 4 3 2 1 0 ]
132 *
133 * For multi-bit configurations, the pattern gets wider:
134 * REGISTER N-3 [ f f e e d d c c ]
135 * N-2 [ b b a a 9 9 8 8 ]
136 * N-1 [ 7 7 6 6 5 5 4 4 ]
137 * N [ 3 3 2 2 1 1 0 0 ]
138 *
139 * Given the address of the starting register 'N', the index of the gpio
140 * whose configuration we seek to change, and the width in bits of that
141 * configuration, these functions allow us to locate the correct
142 * register and mask the correct bits.
143 */
144 static inline void sx150x_find_cfg(u8 offset, u8 width,
145 u8 *reg, u8 *mask, u8 *shift)
146 {
147 *reg -= offset * width / 8;
148 *mask = (1 << width) - 1;
149 *shift = (offset * width) % 8;
150 *mask <<= *shift;
151 }
152
153 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
154 u8 offset, u8 width, u8 reg, u8 val)
155 {
156 u8 mask;
157 u8 data;
158 u8 shift;
159 s32 err;
160
161 sx150x_find_cfg(offset, width, &reg, &mask, &shift);
162 err = sx150x_i2c_read(chip->client, reg, &data);
163 if (err < 0)
164 return err;
165
166 data &= ~mask;
167 data |= (val << shift) & mask;
168 return sx150x_i2c_write(chip->client, reg, data);
169 }
170
171 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
172 {
173 u8 reg = chip->dev_cfg->reg_data;
174 u8 mask;
175 u8 data;
176 u8 shift;
177 s32 err;
178
179 sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
180 err = sx150x_i2c_read(chip->client, reg, &data);
181 if (err >= 0)
182 err = (data & mask) != 0 ? 1 : 0;
183
184 return err;
185 }
186
187 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
188 {
189 sx150x_i2c_write(chip->client,
190 chip->dev_cfg->reg_clock,
191 (val ? 0x1f : 0x10));
192 }
193
194 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
195 {
196 sx150x_write_cfg(chip,
197 offset,
198 1,
199 chip->dev_cfg->reg_data,
200 (val ? 1 : 0));
201 }
202
203 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
204 {
205 return sx150x_write_cfg(chip,
206 offset,
207 1,
208 chip->dev_cfg->reg_dir,
209 1);
210 }
211
212 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
213 {
214 int err;
215
216 err = sx150x_write_cfg(chip,
217 offset,
218 1,
219 chip->dev_cfg->reg_data,
220 (val ? 1 : 0));
221 if (err >= 0)
222 err = sx150x_write_cfg(chip,
223 offset,
224 1,
225 chip->dev_cfg->reg_dir,
226 0);
227 return err;
228 }
229
230 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
231 {
232 struct sx150x_chip *chip;
233 int status = -EINVAL;
234
235 chip = container_of(gc, struct sx150x_chip, gpio_chip);
236
237 if (!offset_is_oscio(chip, offset)) {
238 mutex_lock(&chip->lock);
239 status = sx150x_get_io(chip, offset);
240 mutex_unlock(&chip->lock);
241 }
242
243 return status;
244 }
245
246 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
247 {
248 struct sx150x_chip *chip;
249
250 chip = container_of(gc, struct sx150x_chip, gpio_chip);
251
252 mutex_lock(&chip->lock);
253 if (offset_is_oscio(chip, offset))
254 sx150x_set_oscio(chip, val);
255 else
256 sx150x_set_io(chip, offset, val);
257 mutex_unlock(&chip->lock);
258 }
259
260 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
261 {
262 struct sx150x_chip *chip;
263 int status = -EINVAL;
264
265 chip = container_of(gc, struct sx150x_chip, gpio_chip);
266
267 if (!offset_is_oscio(chip, offset)) {
268 mutex_lock(&chip->lock);
269 status = sx150x_io_input(chip, offset);
270 mutex_unlock(&chip->lock);
271 }
272 return status;
273 }
274
275 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
276 unsigned offset,
277 int val)
278 {
279 struct sx150x_chip *chip;
280 int status = 0;
281
282 chip = container_of(gc, struct sx150x_chip, gpio_chip);
283
284 if (!offset_is_oscio(chip, offset)) {
285 mutex_lock(&chip->lock);
286 status = sx150x_io_output(chip, offset, val);
287 mutex_unlock(&chip->lock);
288 }
289 return status;
290 }
291
292 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
293 {
294 struct sx150x_chip *chip;
295
296 chip = container_of(gc, struct sx150x_chip, gpio_chip);
297
298 if (offset >= chip->dev_cfg->ngpios)
299 return -EINVAL;
300
301 if (chip->irq_base < 0)
302 return -EINVAL;
303
304 return chip->irq_base + offset;
305 }
306
307 static void sx150x_irq_mask(unsigned int irq)
308 {
309 struct irq_chip *ic = get_irq_chip(irq);
310 struct sx150x_chip *chip;
311 unsigned n;
312
313 chip = container_of(ic, struct sx150x_chip, irq_chip);
314 n = irq - chip->irq_base;
315
316 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
317 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
318 }
319
320 static void sx150x_irq_unmask(unsigned int irq)
321 {
322 struct irq_chip *ic = get_irq_chip(irq);
323 struct sx150x_chip *chip;
324 unsigned n;
325
326 chip = container_of(ic, struct sx150x_chip, irq_chip);
327 n = irq - chip->irq_base;
328
329 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
330 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
331 chip->irq_sense >> (n * 2));
332 }
333
334 static int sx150x_irq_set_type(unsigned int irq, unsigned int flow_type)
335 {
336 struct irq_chip *ic = get_irq_chip(irq);
337 struct sx150x_chip *chip;
338 unsigned n, val = 0;
339
340 if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
341 return -EINVAL;
342
343 chip = container_of(ic, struct sx150x_chip, irq_chip);
344 n = irq - chip->irq_base;
345
346 if (flow_type & IRQ_TYPE_EDGE_RISING)
347 val |= 0x1;
348 if (flow_type & IRQ_TYPE_EDGE_FALLING)
349 val |= 0x2;
350
351 chip->irq_sense &= ~(3UL << (n * 2));
352 chip->irq_sense |= val << (n * 2);
353 chip->irq_set_type_pending |= BIT(n);
354 return 0;
355 }
356
357 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
358 {
359 struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
360 unsigned nhandled = 0;
361 unsigned sub_irq;
362 unsigned n;
363 s32 err;
364 u8 val;
365 int i;
366
367 for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
368 err = sx150x_i2c_read(chip->client,
369 chip->dev_cfg->reg_irq_src - i,
370 &val);
371 if (err < 0)
372 continue;
373
374 sx150x_i2c_write(chip->client,
375 chip->dev_cfg->reg_irq_src - i,
376 val);
377 for (n = 0; n < 8; ++n) {
378 if (val & (1 << n)) {
379 sub_irq = chip->irq_base + (i * 8) + n;
380 handle_nested_irq(sub_irq);
381 ++nhandled;
382 }
383 }
384 }
385
386 return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
387 }
388
389 static void sx150x_irq_bus_lock(unsigned int irq)
390 {
391 struct irq_chip *ic = get_irq_chip(irq);
392 struct sx150x_chip *chip;
393
394 chip = container_of(ic, struct sx150x_chip, irq_chip);
395
396 mutex_lock(&chip->lock);
397 }
398
399 static void sx150x_irq_bus_sync_unlock(unsigned int irq)
400 {
401 struct irq_chip *ic = get_irq_chip(irq);
402 struct sx150x_chip *chip;
403 unsigned n;
404
405 chip = container_of(ic, struct sx150x_chip, irq_chip);
406
407 while (chip->irq_set_type_pending) {
408 n = __ffs(chip->irq_set_type_pending);
409 chip->irq_set_type_pending &= ~BIT(n);
410 if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED))
411 sx150x_write_cfg(chip, n, 2,
412 chip->dev_cfg->reg_sense,
413 chip->irq_sense >> (n * 2));
414 }
415
416 mutex_unlock(&chip->lock);
417 }
418
419 static void sx150x_init_chip(struct sx150x_chip *chip,
420 struct i2c_client *client,
421 kernel_ulong_t driver_data,
422 struct sx150x_platform_data *pdata)
423 {
424 mutex_init(&chip->lock);
425
426 chip->client = client;
427 chip->dev_cfg = &sx150x_devices[driver_data];
428 chip->gpio_chip.label = client->name;
429 chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
430 chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
431 chip->gpio_chip.get = sx150x_gpio_get;
432 chip->gpio_chip.set = sx150x_gpio_set;
433 chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
434 chip->gpio_chip.base = pdata->gpio_base;
435 chip->gpio_chip.can_sleep = 1;
436 chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
437 if (pdata->oscio_is_gpo)
438 ++chip->gpio_chip.ngpio;
439
440 chip->irq_chip.name = client->name;
441 chip->irq_chip.mask = sx150x_irq_mask;
442 chip->irq_chip.unmask = sx150x_irq_unmask;
443 chip->irq_chip.set_type = sx150x_irq_set_type;
444 chip->irq_chip.bus_lock = sx150x_irq_bus_lock;
445 chip->irq_chip.bus_sync_unlock = sx150x_irq_bus_sync_unlock;
446 chip->irq_summary = -1;
447 chip->irq_base = -1;
448 chip->irq_sense = 0;
449 chip->irq_set_type_pending = 0;
450 }
451
452 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
453 {
454 int err = 0;
455 unsigned n;
456
457 for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
458 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
459 return err;
460 }
461
462 static int sx150x_reset(struct sx150x_chip *chip)
463 {
464 int err;
465
466 err = i2c_smbus_write_byte_data(chip->client,
467 chip->dev_cfg->reg_reset,
468 0x12);
469 if (err < 0)
470 return err;
471
472 err = i2c_smbus_write_byte_data(chip->client,
473 chip->dev_cfg->reg_reset,
474 0x34);
475 return err;
476 }
477
478 static int sx150x_init_hw(struct sx150x_chip *chip,
479 struct sx150x_platform_data *pdata)
480 {
481 int err = 0;
482
483 if (pdata->reset_during_probe) {
484 err = sx150x_reset(chip);
485 if (err < 0)
486 return err;
487 }
488
489 err = sx150x_i2c_write(chip->client,
490 chip->dev_cfg->reg_misc,
491 0x01);
492 if (err < 0)
493 return err;
494
495 err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
496 pdata->io_pullup_ena);
497 if (err < 0)
498 return err;
499
500 err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
501 pdata->io_pulldn_ena);
502 if (err < 0)
503 return err;
504
505 err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
506 pdata->io_open_drain_ena);
507 if (err < 0)
508 return err;
509
510 err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
511 pdata->io_polarity);
512 if (err < 0)
513 return err;
514
515 if (pdata->oscio_is_gpo)
516 sx150x_set_oscio(chip, 0);
517
518 return err;
519 }
520
521 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
522 int irq_summary,
523 int irq_base)
524 {
525 int err;
526 unsigned n;
527 unsigned irq;
528
529 chip->irq_summary = irq_summary;
530 chip->irq_base = irq_base;
531
532 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
533 irq = irq_base + n;
534 set_irq_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
535 set_irq_nested_thread(irq, 1);
536 #ifdef CONFIG_ARM
537 set_irq_flags(irq, IRQF_VALID);
538 #else
539 set_irq_noprobe(irq);
540 #endif
541 }
542
543 err = request_threaded_irq(irq_summary,
544 NULL,
545 sx150x_irq_thread_fn,
546 IRQF_SHARED | IRQF_TRIGGER_FALLING,
547 chip->irq_chip.name,
548 chip);
549 if (err < 0) {
550 chip->irq_summary = -1;
551 chip->irq_base = -1;
552 }
553
554 return err;
555 }
556
557 static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
558 {
559 unsigned n;
560 unsigned irq;
561
562 free_irq(chip->irq_summary, chip);
563
564 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
565 irq = chip->irq_base + n;
566 set_irq_handler(irq, NULL);
567 set_irq_chip(irq, NULL);
568 }
569 }
570
571 static int __devinit sx150x_probe(struct i2c_client *client,
572 const struct i2c_device_id *id)
573 {
574 static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
575 I2C_FUNC_SMBUS_WRITE_WORD_DATA;
576 struct sx150x_platform_data *pdata;
577 struct sx150x_chip *chip;
578 int rc;
579
580 pdata = client->dev.platform_data;
581 if (!pdata)
582 return -EINVAL;
583
584 if (!i2c_check_functionality(client->adapter, i2c_funcs))
585 return -ENOSYS;
586
587 chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
588 if (!chip)
589 return -ENOMEM;
590
591 sx150x_init_chip(chip, client, id->driver_data, pdata);
592 rc = sx150x_init_hw(chip, pdata);
593 if (rc < 0)
594 goto probe_fail_pre_gpiochip_add;
595
596 rc = gpiochip_add(&chip->gpio_chip);
597 if (rc < 0)
598 goto probe_fail_pre_gpiochip_add;
599
600 if (pdata->irq_summary >= 0) {
601 rc = sx150x_install_irq_chip(chip,
602 pdata->irq_summary,
603 pdata->irq_base);
604 if (rc < 0)
605 goto probe_fail_post_gpiochip_add;
606 }
607
608 i2c_set_clientdata(client, chip);
609
610 return 0;
611 probe_fail_post_gpiochip_add:
612 WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
613 probe_fail_pre_gpiochip_add:
614 kfree(chip);
615 return rc;
616 }
617
618 static int __devexit sx150x_remove(struct i2c_client *client)
619 {
620 struct sx150x_chip *chip;
621 int rc;
622
623 chip = i2c_get_clientdata(client);
624 rc = gpiochip_remove(&chip->gpio_chip);
625 if (rc < 0)
626 return rc;
627
628 if (chip->irq_summary >= 0)
629 sx150x_remove_irq_chip(chip);
630
631 kfree(chip);
632
633 return 0;
634 }
635
636 static struct i2c_driver sx150x_driver = {
637 .driver = {
638 .name = "sx150x",
639 .owner = THIS_MODULE
640 },
641 .probe = sx150x_probe,
642 .remove = __devexit_p(sx150x_remove),
643 .id_table = sx150x_id,
644 };
645
646 static int __init sx150x_init(void)
647 {
648 return i2c_add_driver(&sx150x_driver);
649 }
650 subsys_initcall(sx150x_init);
651
652 static void __exit sx150x_exit(void)
653 {
654 return i2c_del_driver(&sx150x_driver);
655 }
656 module_exit(sx150x_exit);
657
658 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
659 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
660 MODULE_LICENSE("GPL v2");
661 MODULE_ALIAS("i2c:sx150x");
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