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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/module.h>
9#include <linux/gpio.h>
10#include <linux/i2c.h>
11#include <linux/spi/spi.h>
12#include <linux/spi/mcp23s08.h>
13#include <linux/slab.h>
14#include <asm/byteorder.h>
15
16/**
17 * MCP types supported by driver
18 */
19#define MCP_TYPE_S08 0
20#define MCP_TYPE_S17 1
21#define MCP_TYPE_008 2
22#define MCP_TYPE_017 3
23
24/* Registers are all 8 bits wide.
25 *
26 * The mcp23s17 has twice as many bits, and can be configured to work
27 * with either 16 bit registers or with two adjacent 8 bit banks.
28 */
29#define MCP_IODIR 0x00 /* init/reset: all ones */
30#define MCP_IPOL 0x01
31#define MCP_GPINTEN 0x02
32#define MCP_DEFVAL 0x03
33#define MCP_INTCON 0x04
34#define MCP_IOCON 0x05
35# define IOCON_SEQOP (1 << 5)
36# define IOCON_HAEN (1 << 3)
37# define IOCON_ODR (1 << 2)
38# define IOCON_INTPOL (1 << 1)
39#define MCP_GPPU 0x06
40#define MCP_INTF 0x07
41#define MCP_INTCAP 0x08
42#define MCP_GPIO 0x09
43#define MCP_OLAT 0x0a
44
45struct mcp23s08;
46
47struct mcp23s08_ops {
48 int (*read)(struct mcp23s08 *mcp, unsigned reg);
49 int (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
50 int (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
51 u16 *vals, unsigned n);
52};
53
54struct mcp23s08 {
55 u8 addr;
56
57 u16 cache[11];
58 /* lock protects the cached values */
59 struct mutex lock;
60
61 struct gpio_chip chip;
62
63 const struct mcp23s08_ops *ops;
64 void *data; /* ops specific data */
65};
66
67/* A given spi_device can represent up to eight mcp23sxx chips
68 * sharing the same chipselect but using different addresses
69 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
70 * Driver data holds all the per-chip data.
71 */
72struct mcp23s08_driver_data {
73 unsigned ngpio;
74 struct mcp23s08 *mcp[8];
75 struct mcp23s08 chip[];
76};
77
78/*----------------------------------------------------------------------*/
79
80#ifdef CONFIG_I2C
81
82static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
83{
84 return i2c_smbus_read_byte_data(mcp->data, reg);
85}
86
87static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
88{
89 return i2c_smbus_write_byte_data(mcp->data, reg, val);
90}
91
92static int
93mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
94{
95 while (n--) {
96 int ret = mcp23008_read(mcp, reg++);
97 if (ret < 0)
98 return ret;
99 *vals++ = ret;
100 }
101
102 return 0;
103}
104
105static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
106{
107 return i2c_smbus_read_word_data(mcp->data, reg << 1);
108}
109
110static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
111{
112 return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
113}
114
115static int
116mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
117{
118 while (n--) {
119 int ret = mcp23017_read(mcp, reg++);
120 if (ret < 0)
121 return ret;
122 *vals++ = ret;
123 }
124
125 return 0;
126}
127
128static const struct mcp23s08_ops mcp23008_ops = {
129 .read = mcp23008_read,
130 .write = mcp23008_write,
131 .read_regs = mcp23008_read_regs,
132};
133
134static const struct mcp23s08_ops mcp23017_ops = {
135 .read = mcp23017_read,
136 .write = mcp23017_write,
137 .read_regs = mcp23017_read_regs,
138};
139
140#endif /* CONFIG_I2C */
141
142/*----------------------------------------------------------------------*/
143
144#ifdef CONFIG_SPI_MASTER
145
146static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
147{
148 u8 tx[2], rx[1];
149 int status;
150
151 tx[0] = mcp->addr | 0x01;
152 tx[1] = reg;
153 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
154 return (status < 0) ? status : rx[0];
155}
156
157static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
158{
159 u8 tx[3];
160
161 tx[0] = mcp->addr;
162 tx[1] = reg;
163 tx[2] = val;
164 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
165}
166
167static int
168mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
169{
170 u8 tx[2], *tmp;
171 int status;
172
173 if ((n + reg) > sizeof mcp->cache)
174 return -EINVAL;
175 tx[0] = mcp->addr | 0x01;
176 tx[1] = reg;
177
178 tmp = (u8 *)vals;
179 status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
180 if (status >= 0) {
181 while (n--)
182 vals[n] = tmp[n]; /* expand to 16bit */
183 }
184 return status;
185}
186
187static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
188{
189 u8 tx[2], rx[2];
190 int status;
191
192 tx[0] = mcp->addr | 0x01;
193 tx[1] = reg << 1;
194 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
195 return (status < 0) ? status : (rx[0] | (rx[1] << 8));
196}
197
198static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
199{
200 u8 tx[4];
201
202 tx[0] = mcp->addr;
203 tx[1] = reg << 1;
204 tx[2] = val;
205 tx[3] = val >> 8;
206 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
207}
208
209static int
210mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
211{
212 u8 tx[2];
213 int status;
214
215 if ((n + reg) > sizeof mcp->cache)
216 return -EINVAL;
217 tx[0] = mcp->addr | 0x01;
218 tx[1] = reg << 1;
219
220 status = spi_write_then_read(mcp->data, tx, sizeof tx,
221 (u8 *)vals, n * 2);
222 if (status >= 0) {
223 while (n--)
224 vals[n] = __le16_to_cpu((__le16)vals[n]);
225 }
226
227 return status;
228}
229
230static const struct mcp23s08_ops mcp23s08_ops = {
231 .read = mcp23s08_read,
232 .write = mcp23s08_write,
233 .read_regs = mcp23s08_read_regs,
234};
235
236static const struct mcp23s08_ops mcp23s17_ops = {
237 .read = mcp23s17_read,
238 .write = mcp23s17_write,
239 .read_regs = mcp23s17_read_regs,
240};
241
242#endif /* CONFIG_SPI_MASTER */
243
244/*----------------------------------------------------------------------*/
245
246static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
247{
248 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
249 int status;
250
251 mutex_lock(&mcp->lock);
252 mcp->cache[MCP_IODIR] |= (1 << offset);
253 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
254 mutex_unlock(&mcp->lock);
255 return status;
256}
257
258static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
259{
260 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
261 int status;
262
263 mutex_lock(&mcp->lock);
264
265 /* REVISIT reading this clears any IRQ ... */
266 status = mcp->ops->read(mcp, MCP_GPIO);
267 if (status < 0)
268 status = 0;
269 else {
270 mcp->cache[MCP_GPIO] = status;
271 status = !!(status & (1 << offset));
272 }
273 mutex_unlock(&mcp->lock);
274 return status;
275}
276
277static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
278{
279 unsigned olat = mcp->cache[MCP_OLAT];
280
281 if (value)
282 olat |= mask;
283 else
284 olat &= ~mask;
285 mcp->cache[MCP_OLAT] = olat;
286 return mcp->ops->write(mcp, MCP_OLAT, olat);
287}
288
289static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
290{
291 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
292 unsigned mask = 1 << offset;
293
294 mutex_lock(&mcp->lock);
295 __mcp23s08_set(mcp, mask, value);
296 mutex_unlock(&mcp->lock);
297}
298
299static int
300mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
301{
302 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
303 unsigned mask = 1 << offset;
304 int status;
305
306 mutex_lock(&mcp->lock);
307 status = __mcp23s08_set(mcp, mask, value);
308 if (status == 0) {
309 mcp->cache[MCP_IODIR] &= ~mask;
310 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
311 }
312 mutex_unlock(&mcp->lock);
313 return status;
314}
315
316/*----------------------------------------------------------------------*/
317
318#ifdef CONFIG_DEBUG_FS
319
320#include <linux/seq_file.h>
321
322/*
323 * This shows more info than the generic gpio dump code:
324 * pullups, deglitching, open drain drive.
325 */
326static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
327{
328 struct mcp23s08 *mcp;
329 char bank;
330 int t;
331 unsigned mask;
332
333 mcp = container_of(chip, struct mcp23s08, chip);
334
335 /* NOTE: we only handle one bank for now ... */
336 bank = '0' + ((mcp->addr >> 1) & 0x7);
337
338 mutex_lock(&mcp->lock);
339 t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
340 if (t < 0) {
341 seq_printf(s, " I/O ERROR %d\n", t);
342 goto done;
343 }
344
345 for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
346 const char *label;
347
348 label = gpiochip_is_requested(chip, t);
349 if (!label)
350 continue;
351
352 seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
353 chip->base + t, bank, t, label,
354 (mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
355 (mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
356 (mcp->cache[MCP_GPPU] & mask) ? "up" : " ");
357 /* NOTE: ignoring the irq-related registers */
358 seq_printf(s, "\n");
359 }
360done:
361 mutex_unlock(&mcp->lock);
362}
363
364#else
365#define mcp23s08_dbg_show NULL
366#endif
367
368/*----------------------------------------------------------------------*/
369
370static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
371 void *data, unsigned addr,
372 unsigned type, unsigned base, unsigned pullups)
373{
374 int status;
375
376 mutex_init(&mcp->lock);
377
378 mcp->data = data;
379 mcp->addr = addr;
380
381 mcp->chip.direction_input = mcp23s08_direction_input;
382 mcp->chip.get = mcp23s08_get;
383 mcp->chip.direction_output = mcp23s08_direction_output;
384 mcp->chip.set = mcp23s08_set;
385 mcp->chip.dbg_show = mcp23s08_dbg_show;
386
387 switch (type) {
388#ifdef CONFIG_SPI_MASTER
389 case MCP_TYPE_S08:
390 mcp->ops = &mcp23s08_ops;
391 mcp->chip.ngpio = 8;
392 mcp->chip.label = "mcp23s08";
393 break;
394
395 case MCP_TYPE_S17:
396 mcp->ops = &mcp23s17_ops;
397 mcp->chip.ngpio = 16;
398 mcp->chip.label = "mcp23s17";
399 break;
400#endif /* CONFIG_SPI_MASTER */
401
402#ifdef CONFIG_I2C
403 case MCP_TYPE_008:
404 mcp->ops = &mcp23008_ops;
405 mcp->chip.ngpio = 8;
406 mcp->chip.label = "mcp23008";
407 break;
408
409 case MCP_TYPE_017:
410 mcp->ops = &mcp23017_ops;
411 mcp->chip.ngpio = 16;
412 mcp->chip.label = "mcp23017";
413 break;
414#endif /* CONFIG_I2C */
415
416 default:
417 dev_err(dev, "invalid device type (%d)\n", type);
418 return -EINVAL;
419 }
420
421 mcp->chip.base = base;
422 mcp->chip.can_sleep = 1;
423 mcp->chip.dev = dev;
424 mcp->chip.owner = THIS_MODULE;
425
426 /* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
427 * and MCP_IOCON.HAEN = 1, so we work with all chips.
428 */
429 status = mcp->ops->read(mcp, MCP_IOCON);
430 if (status < 0)
431 goto fail;
432 if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
433 /* mcp23s17 has IOCON twice, make sure they are in sync */
434 status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
435 status |= IOCON_HAEN | (IOCON_HAEN << 8);
436 status = mcp->ops->write(mcp, MCP_IOCON, status);
437 if (status < 0)
438 goto fail;
439 }
440
441 /* configure ~100K pullups */
442 status = mcp->ops->write(mcp, MCP_GPPU, pullups);
443 if (status < 0)
444 goto fail;
445
446 status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
447 if (status < 0)
448 goto fail;
449
450 /* disable inverter on input */
451 if (mcp->cache[MCP_IPOL] != 0) {
452 mcp->cache[MCP_IPOL] = 0;
453 status = mcp->ops->write(mcp, MCP_IPOL, 0);
454 if (status < 0)
455 goto fail;
456 }
457
458 /* disable irqs */
459 if (mcp->cache[MCP_GPINTEN] != 0) {
460 mcp->cache[MCP_GPINTEN] = 0;
461 status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
462 if (status < 0)
463 goto fail;
464 }
465
466 status = gpiochip_add(&mcp->chip);
467fail:
468 if (status < 0)
469 dev_dbg(dev, "can't setup chip %d, --> %d\n",
470 addr, status);
471 return status;
472}
473
474/*----------------------------------------------------------------------*/
475
476#ifdef CONFIG_I2C
477
478static int __devinit mcp230xx_probe(struct i2c_client *client,
479 const struct i2c_device_id *id)
480{
481 struct mcp23s08_platform_data *pdata;
482 struct mcp23s08 *mcp;
483 int status;
484
485 pdata = client->dev.platform_data;
486 if (!pdata || !gpio_is_valid(pdata->base)) {
487 dev_dbg(&client->dev, "invalid or missing platform data\n");
488 return -EINVAL;
489 }
490
491 mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
492 if (!mcp)
493 return -ENOMEM;
494
495 status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
496 id->driver_data, pdata->base,
497 pdata->chip[0].pullups);
498 if (status)
499 goto fail;
500
501 i2c_set_clientdata(client, mcp);
502
503 return 0;
504
505fail:
506 kfree(mcp);
507
508 return status;
509}
510
511static int __devexit mcp230xx_remove(struct i2c_client *client)
512{
513 struct mcp23s08 *mcp = i2c_get_clientdata(client);
514 int status;
515
516 status = gpiochip_remove(&mcp->chip);
517 if (status == 0)
518 kfree(mcp);
519
520 return status;
521}
522
523static const struct i2c_device_id mcp230xx_id[] = {
524 { "mcp23008", MCP_TYPE_008 },
525 { "mcp23017", MCP_TYPE_017 },
526 { },
527};
528MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
529
530static struct i2c_driver mcp230xx_driver = {
531 .driver = {
532 .name = "mcp230xx",
533 .owner = THIS_MODULE,
534 },
535 .probe = mcp230xx_probe,
536 .remove = __devexit_p(mcp230xx_remove),
537 .id_table = mcp230xx_id,
538};
539
540static int __init mcp23s08_i2c_init(void)
541{
542 return i2c_add_driver(&mcp230xx_driver);
543}
544
545static void mcp23s08_i2c_exit(void)
546{
547 i2c_del_driver(&mcp230xx_driver);
548}
549
550#else
551
552static int __init mcp23s08_i2c_init(void) { return 0; }
553static void mcp23s08_i2c_exit(void) { }
554
555#endif /* CONFIG_I2C */
556
557/*----------------------------------------------------------------------*/
558
559#ifdef CONFIG_SPI_MASTER
560
561static int mcp23s08_probe(struct spi_device *spi)
562{
563 struct mcp23s08_platform_data *pdata;
564 unsigned addr;
565 unsigned chips = 0;
566 struct mcp23s08_driver_data *data;
567 int status, type;
568 unsigned base;
569
570 type = spi_get_device_id(spi)->driver_data;
571
572 pdata = spi->dev.platform_data;
573 if (!pdata || !gpio_is_valid(pdata->base)) {
574 dev_dbg(&spi->dev, "invalid or missing platform data\n");
575 return -EINVAL;
576 }
577
578 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
579 if (!pdata->chip[addr].is_present)
580 continue;
581 chips++;
582 if ((type == MCP_TYPE_S08) && (addr > 3)) {
583 dev_err(&spi->dev,
584 "mcp23s08 only supports address 0..3\n");
585 return -EINVAL;
586 }
587 }
588 if (!chips)
589 return -ENODEV;
590
591 data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
592 GFP_KERNEL);
593 if (!data)
594 return -ENOMEM;
595 spi_set_drvdata(spi, data);
596
597 base = pdata->base;
598 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
599 if (!pdata->chip[addr].is_present)
600 continue;
601 chips--;
602 data->mcp[addr] = &data->chip[chips];
603 status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
604 0x40 | (addr << 1), type, base,
605 pdata->chip[addr].pullups);
606 if (status < 0)
607 goto fail;
608
609 base += (type == MCP_TYPE_S17) ? 16 : 8;
610 }
611 data->ngpio = base - pdata->base;
612
613 /* NOTE: these chips have a relatively sane IRQ framework, with
614 * per-signal masking and level/edge triggering. It's not yet
615 * handled here...
616 */
617
618 return 0;
619
620fail:
621 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
622 int tmp;
623
624 if (!data->mcp[addr])
625 continue;
626 tmp = gpiochip_remove(&data->mcp[addr]->chip);
627 if (tmp < 0)
628 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
629 }
630 kfree(data);
631 return status;
632}
633
634static int mcp23s08_remove(struct spi_device *spi)
635{
636 struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
637 unsigned addr;
638 int status = 0;
639
640 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
641 int tmp;
642
643 if (!data->mcp[addr])
644 continue;
645
646 tmp = gpiochip_remove(&data->mcp[addr]->chip);
647 if (tmp < 0) {
648 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
649 status = tmp;
650 }
651 }
652 if (status == 0)
653 kfree(data);
654 return status;
655}
656
657static const struct spi_device_id mcp23s08_ids[] = {
658 { "mcp23s08", MCP_TYPE_S08 },
659 { "mcp23s17", MCP_TYPE_S17 },
660 { },
661};
662MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
663
664static struct spi_driver mcp23s08_driver = {
665 .probe = mcp23s08_probe,
666 .remove = mcp23s08_remove,
667 .id_table = mcp23s08_ids,
668 .driver = {
669 .name = "mcp23s08",
670 .owner = THIS_MODULE,
671 },
672};
673
674static int __init mcp23s08_spi_init(void)
675{
676 return spi_register_driver(&mcp23s08_driver);
677}
678
679static void mcp23s08_spi_exit(void)
680{
681 spi_unregister_driver(&mcp23s08_driver);
682}
683
684#else
685
686static int __init mcp23s08_spi_init(void) { return 0; }
687static void mcp23s08_spi_exit(void) { }
688
689#endif /* CONFIG_SPI_MASTER */
690
691/*----------------------------------------------------------------------*/
692
693static int __init mcp23s08_init(void)
694{
695 int ret;
696
697 ret = mcp23s08_spi_init();
698 if (ret)
699 goto spi_fail;
700
701 ret = mcp23s08_i2c_init();
702 if (ret)
703 goto i2c_fail;
704
705 return 0;
706
707 i2c_fail:
708 mcp23s08_spi_exit();
709 spi_fail:
710 return ret;
711}
712/* register after spi/i2c postcore initcall and before
713 * subsys initcalls that may rely on these GPIOs
714 */
715subsys_initcall(mcp23s08_init);
716
717static void __exit mcp23s08_exit(void)
718{
719 mcp23s08_spi_exit();
720 mcp23s08_i2c_exit();
721}
722module_exit(mcp23s08_exit);
723
724MODULE_LICENSE("GPL");