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1/*
2 * MCP23S08 SPI/GPIO gpio expander driver
3 */
4
5#include <linux/kernel.h>
6#include <linux/device.h>
7#include <linux/mutex.h>
8#include <linux/gpio.h>
9#include <linux/i2c.h>
10#include <linux/spi/spi.h>
11#include <linux/spi/mcp23s08.h>
12#include <linux/slab.h>
13#include <asm/byteorder.h>
14
15/**
16 * MCP types supported by driver
17 */
18#define MCP_TYPE_S08 0
19#define MCP_TYPE_S17 1
20#define MCP_TYPE_008 2
21#define MCP_TYPE_017 3
22
23/* Registers are all 8 bits wide.
24 *
25 * The mcp23s17 has twice as many bits, and can be configured to work
26 * with either 16 bit registers or with two adjacent 8 bit banks.
27 */
28#define MCP_IODIR 0x00 /* init/reset: all ones */
29#define MCP_IPOL 0x01
30#define MCP_GPINTEN 0x02
31#define MCP_DEFVAL 0x03
32#define MCP_INTCON 0x04
33#define MCP_IOCON 0x05
34# define IOCON_SEQOP (1 << 5)
35# define IOCON_HAEN (1 << 3)
36# define IOCON_ODR (1 << 2)
37# define IOCON_INTPOL (1 << 1)
38#define MCP_GPPU 0x06
39#define MCP_INTF 0x07
40#define MCP_INTCAP 0x08
41#define MCP_GPIO 0x09
42#define MCP_OLAT 0x0a
43
44struct mcp23s08;
45
46struct mcp23s08_ops {
47 int (*read)(struct mcp23s08 *mcp, unsigned reg);
48 int (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
49 int (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
50 u16 *vals, unsigned n);
51};
52
53struct mcp23s08 {
54 u8 addr;
55
56 u16 cache[11];
57 /* lock protects the cached values */
58 struct mutex lock;
59
60 struct gpio_chip chip;
61
62 const struct mcp23s08_ops *ops;
63 void *data; /* ops specific data */
64};
65
66/* A given spi_device can represent up to eight mcp23sxx chips
67 * sharing the same chipselect but using different addresses
68 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
69 * Driver data holds all the per-chip data.
70 */
71struct mcp23s08_driver_data {
72 unsigned ngpio;
73 struct mcp23s08 *mcp[8];
74 struct mcp23s08 chip[];
75};
76
77/*----------------------------------------------------------------------*/
78
79#ifdef CONFIG_I2C
80
81static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
82{
83 return i2c_smbus_read_byte_data(mcp->data, reg);
84}
85
86static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
87{
88 return i2c_smbus_write_byte_data(mcp->data, reg, val);
89}
90
91static int
92mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
93{
94 while (n--) {
95 int ret = mcp23008_read(mcp, reg++);
96 if (ret < 0)
97 return ret;
98 *vals++ = ret;
99 }
100
101 return 0;
102}
103
104static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
105{
106 return i2c_smbus_read_word_data(mcp->data, reg << 1);
107}
108
109static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
110{
111 return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
112}
113
114static int
115mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
116{
117 while (n--) {
118 int ret = mcp23017_read(mcp, reg++);
119 if (ret < 0)
120 return ret;
121 *vals++ = ret;
122 }
123
124 return 0;
125}
126
127static const struct mcp23s08_ops mcp23008_ops = {
128 .read = mcp23008_read,
129 .write = mcp23008_write,
130 .read_regs = mcp23008_read_regs,
131};
132
133static const struct mcp23s08_ops mcp23017_ops = {
134 .read = mcp23017_read,
135 .write = mcp23017_write,
136 .read_regs = mcp23017_read_regs,
137};
138
139#endif /* CONFIG_I2C */
140
141/*----------------------------------------------------------------------*/
142
143#ifdef CONFIG_SPI_MASTER
144
145static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
146{
147 u8 tx[2], rx[1];
148 int status;
149
150 tx[0] = mcp->addr | 0x01;
151 tx[1] = reg;
152 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
153 return (status < 0) ? status : rx[0];
154}
155
156static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
157{
158 u8 tx[3];
159
160 tx[0] = mcp->addr;
161 tx[1] = reg;
162 tx[2] = val;
163 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
164}
165
166static int
167mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
168{
169 u8 tx[2], *tmp;
170 int status;
171
172 if ((n + reg) > sizeof mcp->cache)
173 return -EINVAL;
174 tx[0] = mcp->addr | 0x01;
175 tx[1] = reg;
176
177 tmp = (u8 *)vals;
178 status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
179 if (status >= 0) {
180 while (n--)
181 vals[n] = tmp[n]; /* expand to 16bit */
182 }
183 return status;
184}
185
186static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
187{
188 u8 tx[2], rx[2];
189 int status;
190
191 tx[0] = mcp->addr | 0x01;
192 tx[1] = reg << 1;
193 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
194 return (status < 0) ? status : (rx[0] | (rx[1] << 8));
195}
196
197static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
198{
199 u8 tx[4];
200
201 tx[0] = mcp->addr;
202 tx[1] = reg << 1;
203 tx[2] = val;
204 tx[3] = val >> 8;
205 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
206}
207
208static int
209mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
210{
211 u8 tx[2];
212 int status;
213
214 if ((n + reg) > sizeof mcp->cache)
215 return -EINVAL;
216 tx[0] = mcp->addr | 0x01;
217 tx[1] = reg << 1;
218
219 status = spi_write_then_read(mcp->data, tx, sizeof tx,
220 (u8 *)vals, n * 2);
221 if (status >= 0) {
222 while (n--)
223 vals[n] = __le16_to_cpu((__le16)vals[n]);
224 }
225
226 return status;
227}
228
229static const struct mcp23s08_ops mcp23s08_ops = {
230 .read = mcp23s08_read,
231 .write = mcp23s08_write,
232 .read_regs = mcp23s08_read_regs,
233};
234
235static const struct mcp23s08_ops mcp23s17_ops = {
236 .read = mcp23s17_read,
237 .write = mcp23s17_write,
238 .read_regs = mcp23s17_read_regs,
239};
240
241#endif /* CONFIG_SPI_MASTER */
242
243/*----------------------------------------------------------------------*/
244
245static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
246{
247 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
248 int status;
249
250 mutex_lock(&mcp->lock);
251 mcp->cache[MCP_IODIR] |= (1 << offset);
252 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
253 mutex_unlock(&mcp->lock);
254 return status;
255}
256
257static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
258{
259 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
260 int status;
261
262 mutex_lock(&mcp->lock);
263
264 /* REVISIT reading this clears any IRQ ... */
265 status = mcp->ops->read(mcp, MCP_GPIO);
266 if (status < 0)
267 status = 0;
268 else {
269 mcp->cache[MCP_GPIO] = status;
270 status = !!(status & (1 << offset));
271 }
272 mutex_unlock(&mcp->lock);
273 return status;
274}
275
276static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
277{
278 unsigned olat = mcp->cache[MCP_OLAT];
279
280 if (value)
281 olat |= mask;
282 else
283 olat &= ~mask;
284 mcp->cache[MCP_OLAT] = olat;
285 return mcp->ops->write(mcp, MCP_OLAT, olat);
286}
287
288static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
289{
290 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
291 unsigned mask = 1 << offset;
292
293 mutex_lock(&mcp->lock);
294 __mcp23s08_set(mcp, mask, value);
295 mutex_unlock(&mcp->lock);
296}
297
298static int
299mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
300{
301 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
302 unsigned mask = 1 << offset;
303 int status;
304
305 mutex_lock(&mcp->lock);
306 status = __mcp23s08_set(mcp, mask, value);
307 if (status == 0) {
308 mcp->cache[MCP_IODIR] &= ~mask;
309 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
310 }
311 mutex_unlock(&mcp->lock);
312 return status;
313}
314
315/*----------------------------------------------------------------------*/
316
317#ifdef CONFIG_DEBUG_FS
318
319#include <linux/seq_file.h>
320
321/*
322 * This shows more info than the generic gpio dump code:
323 * pullups, deglitching, open drain drive.
324 */
325static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
326{
327 struct mcp23s08 *mcp;
328 char bank;
329 int t;
330 unsigned mask;
331
332 mcp = container_of(chip, struct mcp23s08, chip);
333
334 /* NOTE: we only handle one bank for now ... */
335 bank = '0' + ((mcp->addr >> 1) & 0x7);
336
337 mutex_lock(&mcp->lock);
338 t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
339 if (t < 0) {
340 seq_printf(s, " I/O ERROR %d\n", t);
341 goto done;
342 }
343
344 for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
345 const char *label;
346
347 label = gpiochip_is_requested(chip, t);
348 if (!label)
349 continue;
350
351 seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
352 chip->base + t, bank, t, label,
353 (mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
354 (mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
355 (mcp->cache[MCP_GPPU] & mask) ? " " : "up");
356 /* NOTE: ignoring the irq-related registers */
357 seq_printf(s, "\n");
358 }
359done:
360 mutex_unlock(&mcp->lock);
361}
362
363#else
364#define mcp23s08_dbg_show NULL
365#endif
366
367/*----------------------------------------------------------------------*/
368
369static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
370 void *data, unsigned addr,
371 unsigned type, unsigned base, unsigned pullups)
372{
373 int status;
374
375 mutex_init(&mcp->lock);
376
377 mcp->data = data;
378 mcp->addr = addr;
379
380 mcp->chip.direction_input = mcp23s08_direction_input;
381 mcp->chip.get = mcp23s08_get;
382 mcp->chip.direction_output = mcp23s08_direction_output;
383 mcp->chip.set = mcp23s08_set;
384 mcp->chip.dbg_show = mcp23s08_dbg_show;
385
386 switch (type) {
387#ifdef CONFIG_SPI_MASTER
388 case MCP_TYPE_S08:
389 mcp->ops = &mcp23s08_ops;
390 mcp->chip.ngpio = 8;
391 mcp->chip.label = "mcp23s08";
392 break;
393
394 case MCP_TYPE_S17:
395 mcp->ops = &mcp23s17_ops;
396 mcp->chip.ngpio = 16;
397 mcp->chip.label = "mcp23s17";
398 break;
399#endif /* CONFIG_SPI_MASTER */
400
401#ifdef CONFIG_I2C
402 case MCP_TYPE_008:
403 mcp->ops = &mcp23008_ops;
404 mcp->chip.ngpio = 8;
405 mcp->chip.label = "mcp23008";
406 break;
407
408 case MCP_TYPE_017:
409 mcp->ops = &mcp23017_ops;
410 mcp->chip.ngpio = 16;
411 mcp->chip.label = "mcp23017";
412 break;
413#endif /* CONFIG_I2C */
414
415 default:
416 dev_err(dev, "invalid device type (%d)\n", type);
417 return -EINVAL;
418 }
419
420 mcp->chip.base = base;
421 mcp->chip.can_sleep = 1;
422 mcp->chip.dev = dev;
423 mcp->chip.owner = THIS_MODULE;
424
425 /* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
426 * and MCP_IOCON.HAEN = 1, so we work with all chips.
427 */
428 status = mcp->ops->read(mcp, MCP_IOCON);
429 if (status < 0)
430 goto fail;
431 if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
432 /* mcp23s17 has IOCON twice, make sure they are in sync */
433 status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
434 status |= IOCON_HAEN | (IOCON_HAEN << 8);
435 status = mcp->ops->write(mcp, MCP_IOCON, status);
436 if (status < 0)
437 goto fail;
438 }
439
440 /* configure ~100K pullups */
441 status = mcp->ops->write(mcp, MCP_GPPU, pullups);
442 if (status < 0)
443 goto fail;
444
445 status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
446 if (status < 0)
447 goto fail;
448
449 /* disable inverter on input */
450 if (mcp->cache[MCP_IPOL] != 0) {
451 mcp->cache[MCP_IPOL] = 0;
452 status = mcp->ops->write(mcp, MCP_IPOL, 0);
453 if (status < 0)
454 goto fail;
455 }
456
457 /* disable irqs */
458 if (mcp->cache[MCP_GPINTEN] != 0) {
459 mcp->cache[MCP_GPINTEN] = 0;
460 status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
461 if (status < 0)
462 goto fail;
463 }
464
465 status = gpiochip_add(&mcp->chip);
466fail:
467 if (status < 0)
468 dev_dbg(dev, "can't setup chip %d, --> %d\n",
469 addr, status);
470 return status;
471}
472
473/*----------------------------------------------------------------------*/
474
475#ifdef CONFIG_I2C
476
477static int __devinit mcp230xx_probe(struct i2c_client *client,
478 const struct i2c_device_id *id)
479{
480 struct mcp23s08_platform_data *pdata;
481 struct mcp23s08 *mcp;
482 int status;
483
484 pdata = client->dev.platform_data;
485 if (!pdata || !gpio_is_valid(pdata->base)) {
486 dev_dbg(&client->dev, "invalid or missing platform data\n");
487 return -EINVAL;
488 }
489
490 mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
491 if (!mcp)
492 return -ENOMEM;
493
494 status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
495 id->driver_data, pdata->base,
496 pdata->chip[0].pullups);
497 if (status)
498 goto fail;
499
500 i2c_set_clientdata(client, mcp);
501
502 return 0;
503
504fail:
505 kfree(mcp);
506
507 return status;
508}
509
510static int __devexit mcp230xx_remove(struct i2c_client *client)
511{
512 struct mcp23s08 *mcp = i2c_get_clientdata(client);
513 int status;
514
515 status = gpiochip_remove(&mcp->chip);
516 if (status == 0)
517 kfree(mcp);
518
519 return status;
520}
521
522static const struct i2c_device_id mcp230xx_id[] = {
523 { "mcp23008", MCP_TYPE_008 },
524 { "mcp23017", MCP_TYPE_017 },
525 { },
526};
527MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
528
529static struct i2c_driver mcp230xx_driver = {
530 .driver = {
531 .name = "mcp230xx",
532 .owner = THIS_MODULE,
533 },
534 .probe = mcp230xx_probe,
535 .remove = __devexit_p(mcp230xx_remove),
536 .id_table = mcp230xx_id,
537};
538
539static int __init mcp23s08_i2c_init(void)
540{
541 return i2c_add_driver(&mcp230xx_driver);
542}
543
544static void mcp23s08_i2c_exit(void)
545{
546 i2c_del_driver(&mcp230xx_driver);
547}
548
549#else
550
551static int __init mcp23s08_i2c_init(void) { return 0; }
552static void mcp23s08_i2c_exit(void) { }
553
554#endif /* CONFIG_I2C */
555
556/*----------------------------------------------------------------------*/
557
558#ifdef CONFIG_SPI_MASTER
559
560static int mcp23s08_probe(struct spi_device *spi)
561{
562 struct mcp23s08_platform_data *pdata;
563 unsigned addr;
564 unsigned chips = 0;
565 struct mcp23s08_driver_data *data;
566 int status, type;
567 unsigned base;
568
569 type = spi_get_device_id(spi)->driver_data;
570
571 pdata = spi->dev.platform_data;
572 if (!pdata || !gpio_is_valid(pdata->base)) {
573 dev_dbg(&spi->dev, "invalid or missing platform data\n");
574 return -EINVAL;
575 }
576
577 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
578 if (!pdata->chip[addr].is_present)
579 continue;
580 chips++;
581 if ((type == MCP_TYPE_S08) && (addr > 3)) {
582 dev_err(&spi->dev,
583 "mcp23s08 only supports address 0..3\n");
584 return -EINVAL;
585 }
586 }
587 if (!chips)
588 return -ENODEV;
589
590 data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
591 GFP_KERNEL);
592 if (!data)
593 return -ENOMEM;
594 spi_set_drvdata(spi, data);
595
596 base = pdata->base;
597 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
598 if (!pdata->chip[addr].is_present)
599 continue;
600 chips--;
601 data->mcp[addr] = &data->chip[chips];
602 status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
603 0x40 | (addr << 1), type, base,
604 pdata->chip[addr].pullups);
605 if (status < 0)
606 goto fail;
607
608 base += (type == MCP_TYPE_S17) ? 16 : 8;
609 }
610 data->ngpio = base - pdata->base;
611
612 /* NOTE: these chips have a relatively sane IRQ framework, with
613 * per-signal masking and level/edge triggering. It's not yet
614 * handled here...
615 */
616
617 return 0;
618
619fail:
620 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
621 int tmp;
622
623 if (!data->mcp[addr])
624 continue;
625 tmp = gpiochip_remove(&data->mcp[addr]->chip);
626 if (tmp < 0)
627 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
628 }
629 kfree(data);
630 return status;
631}
632
633static int mcp23s08_remove(struct spi_device *spi)
634{
635 struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
636 unsigned addr;
637 int status = 0;
638
639 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
640 int tmp;
641
642 if (!data->mcp[addr])
643 continue;
644
645 tmp = gpiochip_remove(&data->mcp[addr]->chip);
646 if (tmp < 0) {
647 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
648 status = tmp;
649 }
650 }
651 if (status == 0)
652 kfree(data);
653 return status;
654}
655
656static const struct spi_device_id mcp23s08_ids[] = {
657 { "mcp23s08", MCP_TYPE_S08 },
658 { "mcp23s17", MCP_TYPE_S17 },
659 { },
660};
661MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
662
663static struct spi_driver mcp23s08_driver = {
664 .probe = mcp23s08_probe,
665 .remove = mcp23s08_remove,
666 .id_table = mcp23s08_ids,
667 .driver = {
668 .name = "mcp23s08",
669 .owner = THIS_MODULE,
670 },
671};
672
673static int __init mcp23s08_spi_init(void)
674{
675 return spi_register_driver(&mcp23s08_driver);
676}
677
678static void mcp23s08_spi_exit(void)
679{
680 spi_unregister_driver(&mcp23s08_driver);
681}
682
683#else
684
685static int __init mcp23s08_spi_init(void) { return 0; }
686static void mcp23s08_spi_exit(void) { }
687
688#endif /* CONFIG_SPI_MASTER */
689
690/*----------------------------------------------------------------------*/
691
692static int __init mcp23s08_init(void)
693{
694 int ret;
695
696 ret = mcp23s08_spi_init();
697 if (ret)
698 goto spi_fail;
699
700 ret = mcp23s08_i2c_init();
701 if (ret)
702 goto i2c_fail;
703
704 return 0;
705
706 i2c_fail:
707 mcp23s08_spi_exit();
708 spi_fail:
709 return ret;
710}
711/* register after spi/i2c postcore initcall and before
712 * subsys initcalls that may rely on these GPIOs
713 */
714subsys_initcall(mcp23s08_init);
715
716static void __exit mcp23s08_exit(void)
717{
718 mcp23s08_spi_exit();
719 mcp23s08_i2c_exit();
720}
721module_exit(mcp23s08_exit);
722
723MODULE_LICENSE("GPL");