Merge tag 'sunxi-fixes-for-4.3' of https://git.kernel.org/pub/scm/linux/kernel/git...
[linux-drm-fsl-dcu.git] / drivers / gpio / gpio-sx150x.c
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 #include <linux/of.h>
27 #include <linux/of_address.h>
28 #include <linux/of_irq.h>
29 #include <linux/of_gpio.h>
30 #include <linux/of_device.h>
31
32 #define NO_UPDATE_PENDING       -1
33
34 /* The chip models of sx150x */
35 #define SX150X_456 0
36 #define SX150X_789 1
37
38 struct sx150x_456_pri {
39         u8 reg_pld_mode;
40         u8 reg_pld_table0;
41         u8 reg_pld_table1;
42         u8 reg_pld_table2;
43         u8 reg_pld_table3;
44         u8 reg_pld_table4;
45         u8 reg_advance;
46 };
47
48 struct sx150x_789_pri {
49         u8 reg_drain;
50         u8 reg_polarity;
51         u8 reg_clock;
52         u8 reg_misc;
53         u8 reg_reset;
54         u8 ngpios;
55 };
56
57 struct sx150x_device_data {
58         u8 model;
59         u8 reg_pullup;
60         u8 reg_pulldn;
61         u8 reg_dir;
62         u8 reg_data;
63         u8 reg_irq_mask;
64         u8 reg_irq_src;
65         u8 reg_sense;
66         u8 ngpios;
67         union {
68                 struct sx150x_456_pri x456;
69                 struct sx150x_789_pri x789;
70         } pri;
71 };
72
73 struct sx150x_chip {
74         struct gpio_chip                 gpio_chip;
75         struct i2c_client               *client;
76         const struct sx150x_device_data *dev_cfg;
77         int                              irq_summary;
78         int                              irq_base;
79         int                              irq_update;
80         u32                              irq_sense;
81         u32                              irq_masked;
82         u32                              dev_sense;
83         u32                              dev_masked;
84         struct irq_chip                  irq_chip;
85         struct mutex                     lock;
86 };
87
88 static const struct sx150x_device_data sx150x_devices[] = {
89         [0] = { /* sx1508q */
90                 .model = SX150X_789,
91                 .reg_pullup     = 0x03,
92                 .reg_pulldn     = 0x04,
93                 .reg_dir        = 0x07,
94                 .reg_data       = 0x08,
95                 .reg_irq_mask   = 0x09,
96                 .reg_irq_src    = 0x0c,
97                 .reg_sense      = 0x0b,
98                 .pri.x789 = {
99                         .reg_drain      = 0x05,
100                         .reg_polarity   = 0x06,
101                         .reg_clock      = 0x0f,
102                         .reg_misc       = 0x10,
103                         .reg_reset      = 0x7d,
104                 },
105                 .ngpios = 8,
106         },
107         [1] = { /* sx1509q */
108                 .model = SX150X_789,
109                 .reg_pullup     = 0x07,
110                 .reg_pulldn     = 0x09,
111                 .reg_dir        = 0x0f,
112                 .reg_data       = 0x11,
113                 .reg_irq_mask   = 0x13,
114                 .reg_irq_src    = 0x19,
115                 .reg_sense      = 0x17,
116                 .pri.x789 = {
117                         .reg_drain      = 0x0b,
118                         .reg_polarity   = 0x0d,
119                         .reg_clock      = 0x1e,
120                         .reg_misc       = 0x1f,
121                         .reg_reset      = 0x7d,
122                 },
123                 .ngpios = 16
124         },
125         [2] = { /* sx1506q */
126                 .model = SX150X_456,
127                 .reg_pullup     = 0x05,
128                 .reg_pulldn     = 0x07,
129                 .reg_dir        = 0x03,
130                 .reg_data       = 0x01,
131                 .reg_irq_mask   = 0x09,
132                 .reg_irq_src    = 0x0f,
133                 .reg_sense      = 0x0d,
134                 .pri.x456 = {
135                         .reg_pld_mode   = 0x21,
136                         .reg_pld_table0 = 0x23,
137                         .reg_pld_table1 = 0x25,
138                         .reg_pld_table2 = 0x27,
139                         .reg_pld_table3 = 0x29,
140                         .reg_pld_table4 = 0x2b,
141                         .reg_advance    = 0xad,
142                 },
143                 .ngpios = 16
144         },
145 };
146
147 static const struct i2c_device_id sx150x_id[] = {
148         {"sx1508q", 0},
149         {"sx1509q", 1},
150         {"sx1506q", 2},
151         {}
152 };
153 MODULE_DEVICE_TABLE(i2c, sx150x_id);
154
155 static const struct of_device_id sx150x_of_match[] = {
156         { .compatible = "semtech,sx1508q" },
157         { .compatible = "semtech,sx1509q" },
158         { .compatible = "semtech,sx1506q" },
159         {},
160 };
161 MODULE_DEVICE_TABLE(of, sx150x_of_match);
162
163 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
164 {
165         s32 err = i2c_smbus_write_byte_data(client, reg, val);
166
167         if (err < 0)
168                 dev_warn(&client->dev,
169                         "i2c write fail: can't write %02x to %02x: %d\n",
170                         val, reg, err);
171         return err;
172 }
173
174 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
175 {
176         s32 err = i2c_smbus_read_byte_data(client, reg);
177
178         if (err >= 0)
179                 *val = err;
180         else
181                 dev_warn(&client->dev,
182                         "i2c read fail: can't read from %02x: %d\n",
183                         reg, err);
184         return err;
185 }
186
187 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
188 {
189         return (chip->dev_cfg->ngpios == offset);
190 }
191
192 /*
193  * These utility functions solve the common problem of locating and setting
194  * configuration bits.  Configuration bits are grouped into registers
195  * whose indexes increase downwards.  For example, with eight-bit registers,
196  * sixteen gpios would have their config bits grouped in the following order:
197  * REGISTER N-1 [ f e d c b a 9 8 ]
198  *          N   [ 7 6 5 4 3 2 1 0 ]
199  *
200  * For multi-bit configurations, the pattern gets wider:
201  * REGISTER N-3 [ f f e e d d c c ]
202  *          N-2 [ b b a a 9 9 8 8 ]
203  *          N-1 [ 7 7 6 6 5 5 4 4 ]
204  *          N   [ 3 3 2 2 1 1 0 0 ]
205  *
206  * Given the address of the starting register 'N', the index of the gpio
207  * whose configuration we seek to change, and the width in bits of that
208  * configuration, these functions allow us to locate the correct
209  * register and mask the correct bits.
210  */
211 static inline void sx150x_find_cfg(u8 offset, u8 width,
212                                 u8 *reg, u8 *mask, u8 *shift)
213 {
214         *reg   -= offset * width / 8;
215         *mask   = (1 << width) - 1;
216         *shift  = (offset * width) % 8;
217         *mask <<= *shift;
218 }
219
220 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
221                         u8 offset, u8 width, u8 reg, u8 val)
222 {
223         u8  mask;
224         u8  data;
225         u8  shift;
226         s32 err;
227
228         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
229         err = sx150x_i2c_read(chip->client, reg, &data);
230         if (err < 0)
231                 return err;
232
233         data &= ~mask;
234         data |= (val << shift) & mask;
235         return sx150x_i2c_write(chip->client, reg, data);
236 }
237
238 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
239 {
240         u8  reg = chip->dev_cfg->reg_data;
241         u8  mask;
242         u8  data;
243         u8  shift;
244         s32 err;
245
246         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
247         err = sx150x_i2c_read(chip->client, reg, &data);
248         if (err >= 0)
249                 err = (data & mask) != 0 ? 1 : 0;
250
251         return err;
252 }
253
254 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
255 {
256         sx150x_i2c_write(chip->client,
257                         chip->dev_cfg->pri.x789.reg_clock,
258                         (val ? 0x1f : 0x10));
259 }
260
261 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
262 {
263         sx150x_write_cfg(chip,
264                         offset,
265                         1,
266                         chip->dev_cfg->reg_data,
267                         (val ? 1 : 0));
268 }
269
270 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
271 {
272         return sx150x_write_cfg(chip,
273                                 offset,
274                                 1,
275                                 chip->dev_cfg->reg_dir,
276                                 1);
277 }
278
279 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
280 {
281         int err;
282
283         err = sx150x_write_cfg(chip,
284                         offset,
285                         1,
286                         chip->dev_cfg->reg_data,
287                         (val ? 1 : 0));
288         if (err >= 0)
289                 err = sx150x_write_cfg(chip,
290                                 offset,
291                                 1,
292                                 chip->dev_cfg->reg_dir,
293                                 0);
294         return err;
295 }
296
297 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
298 {
299         struct sx150x_chip *chip;
300         int status = -EINVAL;
301
302         chip = container_of(gc, struct sx150x_chip, gpio_chip);
303
304         if (!offset_is_oscio(chip, offset)) {
305                 mutex_lock(&chip->lock);
306                 status = sx150x_get_io(chip, offset);
307                 mutex_unlock(&chip->lock);
308         }
309
310         return status;
311 }
312
313 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
314 {
315         struct sx150x_chip *chip;
316
317         chip = container_of(gc, struct sx150x_chip, gpio_chip);
318
319         mutex_lock(&chip->lock);
320         if (offset_is_oscio(chip, offset))
321                 sx150x_set_oscio(chip, val);
322         else
323                 sx150x_set_io(chip, offset, val);
324         mutex_unlock(&chip->lock);
325 }
326
327 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
328 {
329         struct sx150x_chip *chip;
330         int status = -EINVAL;
331
332         chip = container_of(gc, struct sx150x_chip, gpio_chip);
333
334         if (!offset_is_oscio(chip, offset)) {
335                 mutex_lock(&chip->lock);
336                 status = sx150x_io_input(chip, offset);
337                 mutex_unlock(&chip->lock);
338         }
339         return status;
340 }
341
342 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
343                                         unsigned offset,
344                                         int val)
345 {
346         struct sx150x_chip *chip;
347         int status = 0;
348
349         chip = container_of(gc, struct sx150x_chip, gpio_chip);
350
351         if (!offset_is_oscio(chip, offset)) {
352                 mutex_lock(&chip->lock);
353                 status = sx150x_io_output(chip, offset, val);
354                 mutex_unlock(&chip->lock);
355         }
356         return status;
357 }
358
359 static void sx150x_irq_mask(struct irq_data *d)
360 {
361         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
362         unsigned n = d->hwirq;
363
364         chip->irq_masked |= (1 << n);
365         chip->irq_update = n;
366 }
367
368 static void sx150x_irq_unmask(struct irq_data *d)
369 {
370         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
371         unsigned n = d->hwirq;
372
373         chip->irq_masked &= ~(1 << n);
374         chip->irq_update = n;
375 }
376
377 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
378 {
379         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
380         unsigned n, val = 0;
381
382         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
383                 return -EINVAL;
384
385         n = d->hwirq;
386
387         if (flow_type & IRQ_TYPE_EDGE_RISING)
388                 val |= 0x1;
389         if (flow_type & IRQ_TYPE_EDGE_FALLING)
390                 val |= 0x2;
391
392         chip->irq_sense &= ~(3UL << (n * 2));
393         chip->irq_sense |= val << (n * 2);
394         chip->irq_update = n;
395         return 0;
396 }
397
398 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
399 {
400         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
401         unsigned nhandled = 0;
402         unsigned sub_irq;
403         unsigned n;
404         s32 err;
405         u8 val;
406         int i;
407
408         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
409                 err = sx150x_i2c_read(chip->client,
410                                       chip->dev_cfg->reg_irq_src - i,
411                                       &val);
412                 if (err < 0)
413                         continue;
414
415                 sx150x_i2c_write(chip->client,
416                                 chip->dev_cfg->reg_irq_src - i,
417                                 val);
418                 for (n = 0; n < 8; ++n) {
419                         if (val & (1 << n)) {
420                                 sub_irq = irq_find_mapping(
421                                         chip->gpio_chip.irqdomain,
422                                         (i * 8) + n);
423                                 handle_nested_irq(sub_irq);
424                                 ++nhandled;
425                         }
426                 }
427         }
428
429         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
430 }
431
432 static void sx150x_irq_bus_lock(struct irq_data *d)
433 {
434         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
435
436         mutex_lock(&chip->lock);
437 }
438
439 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
440 {
441         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
442         unsigned n;
443
444         if (chip->irq_update == NO_UPDATE_PENDING)
445                 goto out;
446
447         n = chip->irq_update;
448         chip->irq_update = NO_UPDATE_PENDING;
449
450         /* Avoid updates if nothing changed */
451         if (chip->dev_sense == chip->irq_sense &&
452             chip->dev_masked == chip->irq_masked)
453                 goto out;
454
455         chip->dev_sense = chip->irq_sense;
456         chip->dev_masked = chip->irq_masked;
457
458         if (chip->irq_masked & (1 << n)) {
459                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
460                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
461         } else {
462                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
463                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
464                                  chip->irq_sense >> (n * 2));
465         }
466 out:
467         mutex_unlock(&chip->lock);
468 }
469
470 static void sx150x_init_chip(struct sx150x_chip *chip,
471                         struct i2c_client *client,
472                         kernel_ulong_t driver_data,
473                         struct sx150x_platform_data *pdata)
474 {
475         mutex_init(&chip->lock);
476
477         chip->client                     = client;
478         chip->dev_cfg                    = &sx150x_devices[driver_data];
479         chip->gpio_chip.dev              = &client->dev;
480         chip->gpio_chip.label            = client->name;
481         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
482         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
483         chip->gpio_chip.get              = sx150x_gpio_get;
484         chip->gpio_chip.set              = sx150x_gpio_set;
485         chip->gpio_chip.base             = pdata->gpio_base;
486         chip->gpio_chip.can_sleep        = true;
487         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
488 #ifdef CONFIG_OF_GPIO
489         chip->gpio_chip.of_node          = client->dev.of_node;
490         chip->gpio_chip.of_gpio_n_cells  = 2;
491 #endif
492         if (pdata->oscio_is_gpo)
493                 ++chip->gpio_chip.ngpio;
494
495         chip->irq_chip.name                = client->name;
496         chip->irq_chip.irq_mask            = sx150x_irq_mask;
497         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
498         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
499         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
500         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
501         chip->irq_summary                  = -1;
502         chip->irq_base                     = -1;
503         chip->irq_masked                   = ~0;
504         chip->irq_sense                    = 0;
505         chip->dev_masked                   = ~0;
506         chip->dev_sense                    = 0;
507         chip->irq_update                   = NO_UPDATE_PENDING;
508 }
509
510 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
511 {
512         int err = 0;
513         unsigned n;
514
515         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
516                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
517         return err;
518 }
519
520 static int sx150x_reset(struct sx150x_chip *chip)
521 {
522         int err;
523
524         err = i2c_smbus_write_byte_data(chip->client,
525                                         chip->dev_cfg->pri.x789.reg_reset,
526                                         0x12);
527         if (err < 0)
528                 return err;
529
530         err = i2c_smbus_write_byte_data(chip->client,
531                                         chip->dev_cfg->pri.x789.reg_reset,
532                                         0x34);
533         return err;
534 }
535
536 static int sx150x_init_hw(struct sx150x_chip *chip,
537                         struct sx150x_platform_data *pdata)
538 {
539         int err = 0;
540
541         if (pdata->reset_during_probe) {
542                 err = sx150x_reset(chip);
543                 if (err < 0)
544                         return err;
545         }
546
547         if (chip->dev_cfg->model == SX150X_789)
548                 err = sx150x_i2c_write(chip->client,
549                                 chip->dev_cfg->pri.x789.reg_misc,
550                                 0x01);
551         else
552                 err = sx150x_i2c_write(chip->client,
553                                 chip->dev_cfg->pri.x456.reg_advance,
554                                 0x04);
555         if (err < 0)
556                 return err;
557
558         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
559                         pdata->io_pullup_ena);
560         if (err < 0)
561                 return err;
562
563         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
564                         pdata->io_pulldn_ena);
565         if (err < 0)
566                 return err;
567
568         if (chip->dev_cfg->model == SX150X_789) {
569                 err = sx150x_init_io(chip,
570                                 chip->dev_cfg->pri.x789.reg_drain,
571                                 pdata->io_open_drain_ena);
572                 if (err < 0)
573                         return err;
574
575                 err = sx150x_init_io(chip,
576                                 chip->dev_cfg->pri.x789.reg_polarity,
577                                 pdata->io_polarity);
578                 if (err < 0)
579                         return err;
580         } else {
581                 /* Set all pins to work in normal mode */
582                 err = sx150x_init_io(chip,
583                                 chip->dev_cfg->pri.x456.reg_pld_mode,
584                                 0);
585                 if (err < 0)
586                         return err;
587         }
588
589
590         if (pdata->oscio_is_gpo)
591                 sx150x_set_oscio(chip, 0);
592
593         return err;
594 }
595
596 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
597                                 int irq_summary,
598                                 int irq_base)
599 {
600         int err;
601
602         chip->irq_summary = irq_summary;
603         chip->irq_base    = irq_base;
604
605         /* Add gpio chip to irq subsystem */
606         err = gpiochip_irqchip_add(&chip->gpio_chip,
607                 &chip->irq_chip, chip->irq_base,
608                 handle_edge_irq, IRQ_TYPE_EDGE_BOTH);
609         if (err) {
610                 dev_err(&chip->client->dev,
611                         "could not connect irqchip to gpiochip\n");
612                 return  err;
613         }
614
615         err = devm_request_threaded_irq(&chip->client->dev,
616                         irq_summary, NULL, sx150x_irq_thread_fn,
617                         IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_FALLING,
618                         chip->irq_chip.name, chip);
619         if (err < 0) {
620                 chip->irq_summary = -1;
621                 chip->irq_base    = -1;
622         }
623
624         return err;
625 }
626
627 static int sx150x_probe(struct i2c_client *client,
628                                 const struct i2c_device_id *id)
629 {
630         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
631                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
632         struct sx150x_platform_data *pdata;
633         struct sx150x_chip *chip;
634         int rc;
635
636         pdata = dev_get_platdata(&client->dev);
637         if (!pdata)
638                 return -EINVAL;
639
640         if (!i2c_check_functionality(client->adapter, i2c_funcs))
641                 return -ENOSYS;
642
643         chip = devm_kzalloc(&client->dev,
644                 sizeof(struct sx150x_chip), GFP_KERNEL);
645         if (!chip)
646                 return -ENOMEM;
647
648         sx150x_init_chip(chip, client, id->driver_data, pdata);
649         rc = sx150x_init_hw(chip, pdata);
650         if (rc < 0)
651                 return rc;
652
653         rc = gpiochip_add(&chip->gpio_chip);
654         if (rc)
655                 return rc;
656
657         if (pdata->irq_summary >= 0) {
658                 rc = sx150x_install_irq_chip(chip,
659                                         pdata->irq_summary,
660                                         pdata->irq_base);
661                 if (rc < 0)
662                         goto probe_fail_post_gpiochip_add;
663         }
664
665         i2c_set_clientdata(client, chip);
666
667         return 0;
668 probe_fail_post_gpiochip_add:
669         gpiochip_remove(&chip->gpio_chip);
670         return rc;
671 }
672
673 static int sx150x_remove(struct i2c_client *client)
674 {
675         struct sx150x_chip *chip;
676
677         chip = i2c_get_clientdata(client);
678         gpiochip_remove(&chip->gpio_chip);
679
680         return 0;
681 }
682
683 static struct i2c_driver sx150x_driver = {
684         .driver = {
685                 .name = "sx150x",
686                 .owner = THIS_MODULE,
687                 .of_match_table = of_match_ptr(sx150x_of_match),
688         },
689         .probe    = sx150x_probe,
690         .remove   = sx150x_remove,
691         .id_table = sx150x_id,
692 };
693
694 static int __init sx150x_init(void)
695 {
696         return i2c_add_driver(&sx150x_driver);
697 }
698 subsys_initcall(sx150x_init);
699
700 static void __exit sx150x_exit(void)
701 {
702         return i2c_del_driver(&sx150x_driver);
703 }
704 module_exit(sx150x_exit);
705
706 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
707 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
708 MODULE_LICENSE("GPL v2");