1 /* MCP23S08 SPI/I2C GPIO driver */
2 
3 #include <linux/kernel.h>
4 #include <linux/device.h>
5 #include <linux/mutex.h>
6 #include <linux/module.h>
7 #include <linux/gpio.h>
8 #include <linux/i2c.h>
9 #include <linux/spi/spi.h>
10 #include <linux/spi/mcp23s08.h>
11 #include <linux/slab.h>
12 #include <asm/byteorder.h>
13 #include <linux/interrupt.h>
14 #include <linux/of_device.h>
15 #include <linux/regmap.h>
16 #include <linux/pinctrl/pinctrl.h>
17 #include <linux/pinctrl/pinconf.h>
18 #include <linux/pinctrl/pinconf-generic.h>
19 
20 /*
21  * MCP types supported by driver
22  */
23 #define MCP_TYPE_S08	0
24 #define MCP_TYPE_S17	1
25 #define MCP_TYPE_008	2
26 #define MCP_TYPE_017	3
27 #define MCP_TYPE_S18    4
28 #define MCP_TYPE_018    5
29 
30 #define MCP_MAX_DEV_PER_CS	8
31 
32 /* Registers are all 8 bits wide.
33  *
34  * The mcp23s17 has twice as many bits, and can be configured to work
35  * with either 16 bit registers or with two adjacent 8 bit banks.
36  */
37 #define MCP_IODIR	0x00		/* init/reset:  all ones */
38 #define MCP_IPOL	0x01
39 #define MCP_GPINTEN	0x02
40 #define MCP_DEFVAL	0x03
41 #define MCP_INTCON	0x04
42 #define MCP_IOCON	0x05
43 #	define IOCON_MIRROR	(1 << 6)
44 #	define IOCON_SEQOP	(1 << 5)
45 #	define IOCON_HAEN	(1 << 3)
46 #	define IOCON_ODR	(1 << 2)
47 #	define IOCON_INTPOL	(1 << 1)
48 #	define IOCON_INTCC	(1)
49 #define MCP_GPPU	0x06
50 #define MCP_INTF	0x07
51 #define MCP_INTCAP	0x08
52 #define MCP_GPIO	0x09
53 #define MCP_OLAT	0x0a
54 
55 struct mcp23s08;
56 
57 struct mcp23s08 {
58 	u8			addr;
59 	bool			irq_active_high;
60 	bool			reg_shift;
61 
62 	u16			irq_rise;
63 	u16			irq_fall;
64 	int			irq;
65 	bool			irq_controller;
66 	int			cached_gpio;
67 	/* lock protects regmap access with bypass/cache flags */
68 	struct mutex		lock;
69 
70 	struct gpio_chip	chip;
71 
72 	struct regmap		*regmap;
73 	struct device		*dev;
74 
75 	struct pinctrl_dev	*pctldev;
76 	struct pinctrl_desc	pinctrl_desc;
77 };
78 
79 static const struct reg_default mcp23x08_defaults[] = {
80 	{.reg = MCP_IODIR,		.def = 0xff},
81 	{.reg = MCP_IPOL,		.def = 0x00},
82 	{.reg = MCP_GPINTEN,		.def = 0x00},
83 	{.reg = MCP_DEFVAL,		.def = 0x00},
84 	{.reg = MCP_INTCON,		.def = 0x00},
85 	{.reg = MCP_IOCON,		.def = 0x00},
86 	{.reg = MCP_GPPU,		.def = 0x00},
87 	{.reg = MCP_OLAT,		.def = 0x00},
88 };
89 
90 static const struct regmap_range mcp23x08_volatile_range = {
91 	.range_min = MCP_INTF,
92 	.range_max = MCP_GPIO,
93 };
94 
95 static const struct regmap_access_table mcp23x08_volatile_table = {
96 	.yes_ranges = &mcp23x08_volatile_range,
97 	.n_yes_ranges = 1,
98 };
99 
100 static const struct regmap_range mcp23x08_precious_range = {
101 	.range_min = MCP_GPIO,
102 	.range_max = MCP_GPIO,
103 };
104 
105 static const struct regmap_access_table mcp23x08_precious_table = {
106 	.yes_ranges = &mcp23x08_precious_range,
107 	.n_yes_ranges = 1,
108 };
109 
110 static const struct regmap_config mcp23x08_regmap = {
111 	.reg_bits = 8,
112 	.val_bits = 8,
113 
114 	.reg_stride = 1,
115 	.volatile_table = &mcp23x08_volatile_table,
116 	.precious_table = &mcp23x08_precious_table,
117 	.reg_defaults = mcp23x08_defaults,
118 	.num_reg_defaults = ARRAY_SIZE(mcp23x08_defaults),
119 	.cache_type = REGCACHE_FLAT,
120 	.max_register = MCP_OLAT,
121 };
122 
123 static const struct reg_default mcp23x16_defaults[] = {
124 	{.reg = MCP_IODIR << 1,		.def = 0xffff},
125 	{.reg = MCP_IPOL << 1,		.def = 0x0000},
126 	{.reg = MCP_GPINTEN << 1,	.def = 0x0000},
127 	{.reg = MCP_DEFVAL << 1,	.def = 0x0000},
128 	{.reg = MCP_INTCON << 1,	.def = 0x0000},
129 	{.reg = MCP_IOCON << 1,		.def = 0x0000},
130 	{.reg = MCP_GPPU << 1,		.def = 0x0000},
131 	{.reg = MCP_OLAT << 1,		.def = 0x0000},
132 };
133 
134 static const struct regmap_range mcp23x16_volatile_range = {
135 	.range_min = MCP_INTF << 1,
136 	.range_max = MCP_GPIO << 1,
137 };
138 
139 static const struct regmap_access_table mcp23x16_volatile_table = {
140 	.yes_ranges = &mcp23x16_volatile_range,
141 	.n_yes_ranges = 1,
142 };
143 
144 static const struct regmap_range mcp23x16_precious_range = {
145 	.range_min = MCP_GPIO << 1,
146 	.range_max = MCP_GPIO << 1,
147 };
148 
149 static const struct regmap_access_table mcp23x16_precious_table = {
150 	.yes_ranges = &mcp23x16_precious_range,
151 	.n_yes_ranges = 1,
152 };
153 
154 static const struct regmap_config mcp23x17_regmap = {
155 	.reg_bits = 8,
156 	.val_bits = 16,
157 
158 	.reg_stride = 2,
159 	.max_register = MCP_OLAT << 1,
160 	.volatile_table = &mcp23x16_volatile_table,
161 	.precious_table = &mcp23x16_precious_table,
162 	.reg_defaults = mcp23x16_defaults,
163 	.num_reg_defaults = ARRAY_SIZE(mcp23x16_defaults),
164 	.cache_type = REGCACHE_FLAT,
165 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
166 };
167 
168 static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
169 {
170 	return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
171 }
172 
173 static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
174 {
175 	return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
176 }
177 
178 static int mcp_set_mask(struct mcp23s08 *mcp, unsigned int reg,
179 		       unsigned int mask, bool enabled)
180 {
181 	u16 val  = enabled ? 0xffff : 0x0000;
182 	return regmap_update_bits(mcp->regmap, reg << mcp->reg_shift,
183 				  mask, val);
184 }
185 
186 static int mcp_set_bit(struct mcp23s08 *mcp, unsigned int reg,
187 		       unsigned int pin, bool enabled)
188 {
189 	u16 mask = BIT(pin);
190 	return mcp_set_mask(mcp, reg, mask, enabled);
191 }
192 
193 static const struct pinctrl_pin_desc mcp23x08_pins[] = {
194 	PINCTRL_PIN(0, "gpio0"),
195 	PINCTRL_PIN(1, "gpio1"),
196 	PINCTRL_PIN(2, "gpio2"),
197 	PINCTRL_PIN(3, "gpio3"),
198 	PINCTRL_PIN(4, "gpio4"),
199 	PINCTRL_PIN(5, "gpio5"),
200 	PINCTRL_PIN(6, "gpio6"),
201 	PINCTRL_PIN(7, "gpio7"),
202 };
203 
204 static const struct pinctrl_pin_desc mcp23x17_pins[] = {
205 	PINCTRL_PIN(0, "gpio0"),
206 	PINCTRL_PIN(1, "gpio1"),
207 	PINCTRL_PIN(2, "gpio2"),
208 	PINCTRL_PIN(3, "gpio3"),
209 	PINCTRL_PIN(4, "gpio4"),
210 	PINCTRL_PIN(5, "gpio5"),
211 	PINCTRL_PIN(6, "gpio6"),
212 	PINCTRL_PIN(7, "gpio7"),
213 	PINCTRL_PIN(8, "gpio8"),
214 	PINCTRL_PIN(9, "gpio9"),
215 	PINCTRL_PIN(10, "gpio10"),
216 	PINCTRL_PIN(11, "gpio11"),
217 	PINCTRL_PIN(12, "gpio12"),
218 	PINCTRL_PIN(13, "gpio13"),
219 	PINCTRL_PIN(14, "gpio14"),
220 	PINCTRL_PIN(15, "gpio15"),
221 };
222 
223 static int mcp_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
224 {
225 	return 0;
226 }
227 
228 static const char *mcp_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
229 						unsigned int group)
230 {
231 	return NULL;
232 }
233 
234 static int mcp_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
235 					unsigned int group,
236 					const unsigned int **pins,
237 					unsigned int *num_pins)
238 {
239 	return -ENOTSUPP;
240 }
241 
242 static const struct pinctrl_ops mcp_pinctrl_ops = {
243 	.get_groups_count = mcp_pinctrl_get_groups_count,
244 	.get_group_name = mcp_pinctrl_get_group_name,
245 	.get_group_pins = mcp_pinctrl_get_group_pins,
246 #ifdef CONFIG_OF
247 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
248 	.dt_free_map = pinconf_generic_dt_free_map,
249 #endif
250 };
251 
252 static int mcp_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
253 			      unsigned long *config)
254 {
255 	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
256 	enum pin_config_param param = pinconf_to_config_param(*config);
257 	unsigned int data, status;
258 	int ret;
259 
260 	switch (param) {
261 	case PIN_CONFIG_BIAS_PULL_UP:
262 		ret = mcp_read(mcp, MCP_GPPU, &data);
263 		if (ret < 0)
264 			return ret;
265 		status = (data & BIT(pin)) ? 1 : 0;
266 		break;
267 	default:
268 		dev_err(mcp->dev, "Invalid config param %04x\n", param);
269 		return -ENOTSUPP;
270 	}
271 
272 	*config = 0;
273 
274 	return status ? 0 : -EINVAL;
275 }
276 
277 static int mcp_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
278 			      unsigned long *configs, unsigned int num_configs)
279 {
280 	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
281 	enum pin_config_param param;
282 	u32 arg;
283 	int ret = 0;
284 	int i;
285 
286 	for (i = 0; i < num_configs; i++) {
287 		param = pinconf_to_config_param(configs[i]);
288 		arg = pinconf_to_config_argument(configs[i]);
289 
290 		switch (param) {
291 		case PIN_CONFIG_BIAS_PULL_UP:
292 			ret = mcp_set_bit(mcp, MCP_GPPU, pin, arg);
293 			break;
294 		default:
295 			dev_err(mcp->dev, "Invalid config param %04x\n", param);
296 			return -ENOTSUPP;
297 		}
298 	}
299 
300 	return ret;
301 }
302 
303 static const struct pinconf_ops mcp_pinconf_ops = {
304 	.pin_config_get = mcp_pinconf_get,
305 	.pin_config_set = mcp_pinconf_set,
306 	.is_generic = true,
307 };
308 
309 /*----------------------------------------------------------------------*/
310 
311 #ifdef CONFIG_SPI_MASTER
312 
313 static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
314 {
315 	struct mcp23s08 *mcp = context;
316 	struct spi_device *spi = to_spi_device(mcp->dev);
317 	struct spi_message m;
318 	struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
319 				     { .tx_buf = data, .len = count, }, };
320 
321 	spi_message_init(&m);
322 	spi_message_add_tail(&t[0], &m);
323 	spi_message_add_tail(&t[1], &m);
324 
325 	return spi_sync(spi, &m);
326 }
327 
328 static int mcp23sxx_spi_gather_write(void *context,
329 				const void *reg, size_t reg_size,
330 				const void *val, size_t val_size)
331 {
332 	struct mcp23s08 *mcp = context;
333 	struct spi_device *spi = to_spi_device(mcp->dev);
334 	struct spi_message m;
335 	struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, },
336 				     { .tx_buf = reg, .len = reg_size, },
337 				     { .tx_buf = val, .len = val_size, }, };
338 
339 	spi_message_init(&m);
340 	spi_message_add_tail(&t[0], &m);
341 	spi_message_add_tail(&t[1], &m);
342 	spi_message_add_tail(&t[2], &m);
343 
344 	return spi_sync(spi, &m);
345 }
346 
347 static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
348 				void *val, size_t val_size)
349 {
350 	struct mcp23s08 *mcp = context;
351 	struct spi_device *spi = to_spi_device(mcp->dev);
352 	u8 tx[2];
353 
354 	if (reg_size != 1)
355 		return -EINVAL;
356 
357 	tx[0] = mcp->addr | 0x01;
358 	tx[1] = *((u8 *) reg);
359 
360 	return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
361 }
362 
363 static const struct regmap_bus mcp23sxx_spi_regmap = {
364 	.write = mcp23sxx_spi_write,
365 	.gather_write = mcp23sxx_spi_gather_write,
366 	.read = mcp23sxx_spi_read,
367 };
368 
369 #endif /* CONFIG_SPI_MASTER */
370 
371 /*----------------------------------------------------------------------*/
372 
373 /* A given spi_device can represent up to eight mcp23sxx chips
374  * sharing the same chipselect but using different addresses
375  * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
376  * Driver data holds all the per-chip data.
377  */
378 struct mcp23s08_driver_data {
379 	unsigned		ngpio;
380 	struct mcp23s08		*mcp[8];
381 	struct mcp23s08		chip[];
382 };
383 
384 
385 static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
386 {
387 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
388 	int status;
389 
390 	mutex_lock(&mcp->lock);
391 	status = mcp_set_bit(mcp, MCP_IODIR, offset, true);
392 	mutex_unlock(&mcp->lock);
393 
394 	return status;
395 }
396 
397 static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
398 {
399 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
400 	int status, ret;
401 
402 	mutex_lock(&mcp->lock);
403 
404 	/* REVISIT reading this clears any IRQ ... */
405 	ret = mcp_read(mcp, MCP_GPIO, &status);
406 	if (ret < 0)
407 		status = 0;
408 	else {
409 		mcp->cached_gpio = status;
410 		status = !!(status & (1 << offset));
411 	}
412 
413 	mutex_unlock(&mcp->lock);
414 	return status;
415 }
416 
417 static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, bool value)
418 {
419 	return mcp_set_mask(mcp, MCP_OLAT, mask, value);
420 }
421 
422 static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
423 {
424 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
425 	unsigned mask = BIT(offset);
426 
427 	mutex_lock(&mcp->lock);
428 	__mcp23s08_set(mcp, mask, !!value);
429 	mutex_unlock(&mcp->lock);
430 }
431 
432 static int
433 mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
434 {
435 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
436 	unsigned mask = BIT(offset);
437 	int status;
438 
439 	mutex_lock(&mcp->lock);
440 	status = __mcp23s08_set(mcp, mask, value);
441 	if (status == 0) {
442 		status = mcp_set_mask(mcp, MCP_IODIR, mask, false);
443 	}
444 	mutex_unlock(&mcp->lock);
445 	return status;
446 }
447 
448 /*----------------------------------------------------------------------*/
449 static irqreturn_t mcp23s08_irq(int irq, void *data)
450 {
451 	struct mcp23s08 *mcp = data;
452 	int intcap, intcon, intf, i, gpio, gpio_orig, intcap_mask, defval;
453 	unsigned int child_irq;
454 	bool intf_set, intcap_changed, gpio_bit_changed,
455 		defval_changed, gpio_set;
456 
457 	mutex_lock(&mcp->lock);
458 	if (mcp_read(mcp, MCP_INTF, &intf) < 0) {
459 		mutex_unlock(&mcp->lock);
460 		return IRQ_HANDLED;
461 	}
462 
463 	if (mcp_read(mcp, MCP_INTCAP, &intcap) < 0) {
464 		mutex_unlock(&mcp->lock);
465 		return IRQ_HANDLED;
466 	}
467 
468 	if (mcp_read(mcp, MCP_INTCON, &intcon) < 0) {
469 		mutex_unlock(&mcp->lock);
470 		return IRQ_HANDLED;
471 	}
472 
473 	if (mcp_read(mcp, MCP_DEFVAL, &defval) < 0) {
474 		mutex_unlock(&mcp->lock);
475 		return IRQ_HANDLED;
476 	}
477 
478 	/* This clears the interrupt(configurable on S18) */
479 	if (mcp_read(mcp, MCP_GPIO, &gpio) < 0) {
480 		mutex_unlock(&mcp->lock);
481 		return IRQ_HANDLED;
482 	}
483 	gpio_orig = mcp->cached_gpio;
484 	mcp->cached_gpio = gpio;
485 	mutex_unlock(&mcp->lock);
486 
487 	if (intf == 0) {
488 		/* There is no interrupt pending */
489 		return IRQ_HANDLED;
490 	}
491 
492 	dev_dbg(mcp->chip.parent,
493 		"intcap 0x%04X intf 0x%04X gpio_orig 0x%04X gpio 0x%04X\n",
494 		intcap, intf, gpio_orig, gpio);
495 
496 	for (i = 0; i < mcp->chip.ngpio; i++) {
497 		/* We must check all of the inputs on the chip,
498 		 * otherwise we may not notice a change on >=2 pins.
499 		 *
500 		 * On at least the mcp23s17, INTCAP is only updated
501 		 * one byte at a time(INTCAPA and INTCAPB are
502 		 * not written to at the same time - only on a per-bank
503 		 * basis).
504 		 *
505 		 * INTF only contains the single bit that caused the
506 		 * interrupt per-bank.  On the mcp23s17, there is
507 		 * INTFA and INTFB.  If two pins are changed on the A
508 		 * side at the same time, INTF will only have one bit
509 		 * set.  If one pin on the A side and one pin on the B
510 		 * side are changed at the same time, INTF will have
511 		 * two bits set.  Thus, INTF can't be the only check
512 		 * to see if the input has changed.
513 		 */
514 
515 		intf_set = intf & BIT(i);
516 		if (i < 8 && intf_set)
517 			intcap_mask = 0x00FF;
518 		else if (i >= 8 && intf_set)
519 			intcap_mask = 0xFF00;
520 		else
521 			intcap_mask = 0x00;
522 
523 		intcap_changed = (intcap_mask &
524 			(intcap & BIT(i))) !=
525 			(intcap_mask & (BIT(i) & gpio_orig));
526 		gpio_set = BIT(i) & gpio;
527 		gpio_bit_changed = (BIT(i) & gpio_orig) !=
528 			(BIT(i) & gpio);
529 		defval_changed = (BIT(i) & intcon) &&
530 			((BIT(i) & gpio) !=
531 			(BIT(i) & defval));
532 
533 		if (((gpio_bit_changed || intcap_changed) &&
534 			(BIT(i) & mcp->irq_rise) && gpio_set) ||
535 		    ((gpio_bit_changed || intcap_changed) &&
536 			(BIT(i) & mcp->irq_fall) && !gpio_set) ||
537 		    defval_changed) {
538 			child_irq = irq_find_mapping(mcp->chip.irq.domain, i);
539 			handle_nested_irq(child_irq);
540 		}
541 	}
542 
543 	return IRQ_HANDLED;
544 }
545 
546 static void mcp23s08_irq_mask(struct irq_data *data)
547 {
548 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
549 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
550 	unsigned int pos = data->hwirq;
551 
552 	mcp_set_bit(mcp, MCP_GPINTEN, pos, false);
553 }
554 
555 static void mcp23s08_irq_unmask(struct irq_data *data)
556 {
557 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
558 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
559 	unsigned int pos = data->hwirq;
560 
561 	mcp_set_bit(mcp, MCP_GPINTEN, pos, true);
562 }
563 
564 static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type)
565 {
566 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
567 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
568 	unsigned int pos = data->hwirq;
569 	int status = 0;
570 
571 	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
572 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
573 		mcp->irq_rise |= BIT(pos);
574 		mcp->irq_fall |= BIT(pos);
575 	} else if (type & IRQ_TYPE_EDGE_RISING) {
576 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
577 		mcp->irq_rise |= BIT(pos);
578 		mcp->irq_fall &= ~BIT(pos);
579 	} else if (type & IRQ_TYPE_EDGE_FALLING) {
580 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
581 		mcp->irq_rise &= ~BIT(pos);
582 		mcp->irq_fall |= BIT(pos);
583 	} else if (type & IRQ_TYPE_LEVEL_HIGH) {
584 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
585 		mcp_set_bit(mcp, MCP_DEFVAL, pos, false);
586 	} else if (type & IRQ_TYPE_LEVEL_LOW) {
587 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
588 		mcp_set_bit(mcp, MCP_DEFVAL, pos, true);
589 	} else
590 		return -EINVAL;
591 
592 	return status;
593 }
594 
595 static void mcp23s08_irq_bus_lock(struct irq_data *data)
596 {
597 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
598 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
599 
600 	mutex_lock(&mcp->lock);
601 	regcache_cache_only(mcp->regmap, true);
602 }
603 
604 static void mcp23s08_irq_bus_unlock(struct irq_data *data)
605 {
606 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
607 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
608 
609 	regcache_cache_only(mcp->regmap, false);
610 	regcache_sync(mcp->regmap);
611 
612 	mutex_unlock(&mcp->lock);
613 }
614 
615 static struct irq_chip mcp23s08_irq_chip = {
616 	.name = "gpio-mcp23xxx",
617 	.irq_mask = mcp23s08_irq_mask,
618 	.irq_unmask = mcp23s08_irq_unmask,
619 	.irq_set_type = mcp23s08_irq_set_type,
620 	.irq_bus_lock = mcp23s08_irq_bus_lock,
621 	.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock,
622 };
623 
624 static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
625 {
626 	struct gpio_chip *chip = &mcp->chip;
627 	int err;
628 	unsigned long irqflags = IRQF_ONESHOT | IRQF_SHARED;
629 
630 	if (mcp->irq_active_high)
631 		irqflags |= IRQF_TRIGGER_HIGH;
632 	else
633 		irqflags |= IRQF_TRIGGER_LOW;
634 
635 	err = devm_request_threaded_irq(chip->parent, mcp->irq, NULL,
636 					mcp23s08_irq,
637 					irqflags, dev_name(chip->parent), mcp);
638 	if (err != 0) {
639 		dev_err(chip->parent, "unable to request IRQ#%d: %d\n",
640 			mcp->irq, err);
641 		return err;
642 	}
643 
644 	err =  gpiochip_irqchip_add_nested(chip,
645 					   &mcp23s08_irq_chip,
646 					   0,
647 					   handle_simple_irq,
648 					   IRQ_TYPE_NONE);
649 	if (err) {
650 		dev_err(chip->parent,
651 			"could not connect irqchip to gpiochip: %d\n", err);
652 		return err;
653 	}
654 
655 	gpiochip_set_nested_irqchip(chip,
656 				    &mcp23s08_irq_chip,
657 				    mcp->irq);
658 
659 	return 0;
660 }
661 
662 /*----------------------------------------------------------------------*/
663 
664 #ifdef CONFIG_DEBUG_FS
665 
666 #include <linux/seq_file.h>
667 
668 /*
669  * This compares the chip's registers with the register
670  * cache and corrects any incorrectly set register. This
671  * can be used to fix state for MCP23xxx, that temporary
672  * lost its power supply.
673  */
674 #define MCP23S08_CONFIG_REGS 8
675 static int __check_mcp23s08_reg_cache(struct mcp23s08 *mcp)
676 {
677 	int cached[MCP23S08_CONFIG_REGS];
678 	int err = 0, i;
679 
680 	/* read cached config registers */
681 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
682 		err = mcp_read(mcp, i, &cached[i]);
683 		if (err)
684 			goto out;
685 	}
686 
687 	regcache_cache_bypass(mcp->regmap, true);
688 
689 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
690 		int uncached;
691 		err = mcp_read(mcp, i, &uncached);
692 		if (err)
693 			goto out;
694 
695 		if (uncached != cached[i]) {
696 			dev_err(mcp->dev, "restoring reg 0x%02x from 0x%04x to 0x%04x (power-loss?)\n",
697 				i, uncached, cached[i]);
698 			mcp_write(mcp, i, cached[i]);
699 		}
700 	}
701 
702 out:
703 	if (err)
704 		dev_err(mcp->dev, "read error: reg=%02x, err=%d", i, err);
705 	regcache_cache_bypass(mcp->regmap, false);
706 	return err;
707 }
708 
709 /*
710  * This shows more info than the generic gpio dump code:
711  * pullups, deglitching, open drain drive.
712  */
713 static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
714 {
715 	struct mcp23s08	*mcp;
716 	char		bank;
717 	int		t;
718 	unsigned	mask;
719 	int iodir, gpio, gppu;
720 
721 	mcp = gpiochip_get_data(chip);
722 
723 	/* NOTE: we only handle one bank for now ... */
724 	bank = '0' + ((mcp->addr >> 1) & 0x7);
725 
726 	mutex_lock(&mcp->lock);
727 
728 	t = __check_mcp23s08_reg_cache(mcp);
729 	if (t) {
730 		seq_printf(s, " I/O Error\n");
731 		goto done;
732 	}
733 	t = mcp_read(mcp, MCP_IODIR, &iodir);
734 	if (t) {
735 		seq_printf(s, " I/O Error\n");
736 		goto done;
737 	}
738 	t = mcp_read(mcp, MCP_GPIO, &gpio);
739 	if (t) {
740 		seq_printf(s, " I/O Error\n");
741 		goto done;
742 	}
743 	t = mcp_read(mcp, MCP_GPPU, &gppu);
744 	if (t) {
745 		seq_printf(s, " I/O Error\n");
746 		goto done;
747 	}
748 
749 	for (t = 0, mask = BIT(0); t < chip->ngpio; t++, mask <<= 1) {
750 		const char *label;
751 
752 		label = gpiochip_is_requested(chip, t);
753 		if (!label)
754 			continue;
755 
756 		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
757 			chip->base + t, bank, t, label,
758 			(iodir & mask) ? "in " : "out",
759 			(gpio & mask) ? "hi" : "lo",
760 			(gppu & mask) ? "up" : "  ");
761 		/* NOTE:  ignoring the irq-related registers */
762 		seq_puts(s, "\n");
763 	}
764 done:
765 	mutex_unlock(&mcp->lock);
766 }
767 
768 #else
769 #define mcp23s08_dbg_show	NULL
770 #endif
771 
772 /*----------------------------------------------------------------------*/
773 
774 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
775 			      void *data, unsigned addr, unsigned type,
776 			      unsigned int base, int cs)
777 {
778 	int status, ret;
779 	bool mirror = false;
780 
781 	mutex_init(&mcp->lock);
782 
783 	mcp->dev = dev;
784 	mcp->addr = addr;
785 	mcp->irq_active_high = false;
786 
787 	mcp->chip.direction_input = mcp23s08_direction_input;
788 	mcp->chip.get = mcp23s08_get;
789 	mcp->chip.direction_output = mcp23s08_direction_output;
790 	mcp->chip.set = mcp23s08_set;
791 	mcp->chip.dbg_show = mcp23s08_dbg_show;
792 #ifdef CONFIG_OF_GPIO
793 	mcp->chip.of_gpio_n_cells = 2;
794 	mcp->chip.of_node = dev->of_node;
795 #endif
796 
797 	switch (type) {
798 #ifdef CONFIG_SPI_MASTER
799 	case MCP_TYPE_S08:
800 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
801 					       &mcp23x08_regmap);
802 		mcp->reg_shift = 0;
803 		mcp->chip.ngpio = 8;
804 		mcp->chip.label = "mcp23s08";
805 		break;
806 
807 	case MCP_TYPE_S17:
808 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
809 					       &mcp23x17_regmap);
810 		mcp->reg_shift = 1;
811 		mcp->chip.ngpio = 16;
812 		mcp->chip.label = "mcp23s17";
813 		break;
814 
815 	case MCP_TYPE_S18:
816 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
817 					       &mcp23x17_regmap);
818 		mcp->reg_shift = 1;
819 		mcp->chip.ngpio = 16;
820 		mcp->chip.label = "mcp23s18";
821 		break;
822 #endif /* CONFIG_SPI_MASTER */
823 
824 #if IS_ENABLED(CONFIG_I2C)
825 	case MCP_TYPE_008:
826 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x08_regmap);
827 		mcp->reg_shift = 0;
828 		mcp->chip.ngpio = 8;
829 		mcp->chip.label = "mcp23008";
830 		break;
831 
832 	case MCP_TYPE_017:
833 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x17_regmap);
834 		mcp->reg_shift = 1;
835 		mcp->chip.ngpio = 16;
836 		mcp->chip.label = "mcp23017";
837 		break;
838 
839 	case MCP_TYPE_018:
840 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x17_regmap);
841 		mcp->reg_shift = 1;
842 		mcp->chip.ngpio = 16;
843 		mcp->chip.label = "mcp23018";
844 		break;
845 #endif /* CONFIG_I2C */
846 
847 	default:
848 		dev_err(dev, "invalid device type (%d)\n", type);
849 		return -EINVAL;
850 	}
851 
852 	if (IS_ERR(mcp->regmap))
853 		return PTR_ERR(mcp->regmap);
854 
855 	mcp->chip.base = base;
856 	mcp->chip.can_sleep = true;
857 	mcp->chip.parent = dev;
858 	mcp->chip.owner = THIS_MODULE;
859 
860 	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
861 	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
862 	 */
863 
864 	ret = mcp_read(mcp, MCP_IOCON, &status);
865 	if (ret < 0)
866 		goto fail;
867 
868 	mcp->irq_controller =
869 		device_property_read_bool(dev, "interrupt-controller");
870 	if (mcp->irq && mcp->irq_controller) {
871 		mcp->irq_active_high =
872 			device_property_read_bool(dev,
873 					      "microchip,irq-active-high");
874 
875 		mirror = device_property_read_bool(dev, "microchip,irq-mirror");
876 	}
877 
878 	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror ||
879 	     mcp->irq_active_high) {
880 		/* mcp23s17 has IOCON twice, make sure they are in sync */
881 		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
882 		status |= IOCON_HAEN | (IOCON_HAEN << 8);
883 		if (mcp->irq_active_high)
884 			status |= IOCON_INTPOL | (IOCON_INTPOL << 8);
885 		else
886 			status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));
887 
888 		if (mirror)
889 			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);
890 
891 		if (type == MCP_TYPE_S18 || type == MCP_TYPE_018)
892 			status |= IOCON_INTCC | (IOCON_INTCC << 8);
893 
894 		ret = mcp_write(mcp, MCP_IOCON, status);
895 		if (ret < 0)
896 			goto fail;
897 	}
898 
899 	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
900 	if (ret < 0)
901 		goto fail;
902 
903 	if (mcp->irq && mcp->irq_controller) {
904 		ret = mcp23s08_irq_setup(mcp);
905 		if (ret)
906 			goto fail;
907 	}
908 
909 	mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
910 	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
911 	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
912 	mcp->pinctrl_desc.npins = mcp->chip.ngpio;
913 	if (mcp->pinctrl_desc.npins == 8)
914 		mcp->pinctrl_desc.pins = mcp23x08_pins;
915 	else if (mcp->pinctrl_desc.npins == 16)
916 		mcp->pinctrl_desc.pins = mcp23x17_pins;
917 	mcp->pinctrl_desc.owner = THIS_MODULE;
918 
919 	mcp->pctldev = devm_pinctrl_register(dev, &mcp->pinctrl_desc, mcp);
920 	if (IS_ERR(mcp->pctldev)) {
921 		ret = PTR_ERR(mcp->pctldev);
922 		goto fail;
923 	}
924 
925 fail:
926 	if (ret < 0)
927 		dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);
928 	return ret;
929 }
930 
931 /*----------------------------------------------------------------------*/
932 
933 #ifdef CONFIG_OF
934 #ifdef CONFIG_SPI_MASTER
935 static const struct of_device_id mcp23s08_spi_of_match[] = {
936 	{
937 		.compatible = "microchip,mcp23s08",
938 		.data = (void *) MCP_TYPE_S08,
939 	},
940 	{
941 		.compatible = "microchip,mcp23s17",
942 		.data = (void *) MCP_TYPE_S17,
943 	},
944 	{
945 		.compatible = "microchip,mcp23s18",
946 		.data = (void *) MCP_TYPE_S18,
947 	},
948 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
949 	{
950 		.compatible = "mcp,mcp23s08",
951 		.data = (void *) MCP_TYPE_S08,
952 	},
953 	{
954 		.compatible = "mcp,mcp23s17",
955 		.data = (void *) MCP_TYPE_S17,
956 	},
957 	{ },
958 };
959 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
960 #endif
961 
962 #if IS_ENABLED(CONFIG_I2C)
963 static const struct of_device_id mcp23s08_i2c_of_match[] = {
964 	{
965 		.compatible = "microchip,mcp23008",
966 		.data = (void *) MCP_TYPE_008,
967 	},
968 	{
969 		.compatible = "microchip,mcp23017",
970 		.data = (void *) MCP_TYPE_017,
971 	},
972 	{
973 		.compatible = "microchip,mcp23018",
974 		.data = (void *) MCP_TYPE_018,
975 	},
976 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
977 	{
978 		.compatible = "mcp,mcp23008",
979 		.data = (void *) MCP_TYPE_008,
980 	},
981 	{
982 		.compatible = "mcp,mcp23017",
983 		.data = (void *) MCP_TYPE_017,
984 	},
985 	{ },
986 };
987 MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
988 #endif
989 #endif /* CONFIG_OF */
990 
991 
992 #if IS_ENABLED(CONFIG_I2C)
993 
994 static int mcp230xx_probe(struct i2c_client *client,
995 				    const struct i2c_device_id *id)
996 {
997 	struct mcp23s08_platform_data *pdata, local_pdata;
998 	struct mcp23s08 *mcp;
999 	int status;
1000 
1001 	pdata = dev_get_platdata(&client->dev);
1002 	if (!pdata) {
1003 		pdata = &local_pdata;
1004 		pdata->base = -1;
1005 	}
1006 
1007 	mcp = devm_kzalloc(&client->dev, sizeof(*mcp), GFP_KERNEL);
1008 	if (!mcp)
1009 		return -ENOMEM;
1010 
1011 	mcp->irq = client->irq;
1012 	status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
1013 				    id->driver_data, pdata->base, 0);
1014 	if (status)
1015 		return status;
1016 
1017 	i2c_set_clientdata(client, mcp);
1018 
1019 	return 0;
1020 }
1021 
1022 static const struct i2c_device_id mcp230xx_id[] = {
1023 	{ "mcp23008", MCP_TYPE_008 },
1024 	{ "mcp23017", MCP_TYPE_017 },
1025 	{ "mcp23018", MCP_TYPE_018 },
1026 	{ },
1027 };
1028 MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
1029 
1030 static struct i2c_driver mcp230xx_driver = {
1031 	.driver = {
1032 		.name	= "mcp230xx",
1033 		.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
1034 	},
1035 	.probe		= mcp230xx_probe,
1036 	.id_table	= mcp230xx_id,
1037 };
1038 
1039 static int __init mcp23s08_i2c_init(void)
1040 {
1041 	return i2c_add_driver(&mcp230xx_driver);
1042 }
1043 
1044 static void mcp23s08_i2c_exit(void)
1045 {
1046 	i2c_del_driver(&mcp230xx_driver);
1047 }
1048 
1049 #else
1050 
1051 static int __init mcp23s08_i2c_init(void) { return 0; }
1052 static void mcp23s08_i2c_exit(void) { }
1053 
1054 #endif /* CONFIG_I2C */
1055 
1056 /*----------------------------------------------------------------------*/
1057 
1058 #ifdef CONFIG_SPI_MASTER
1059 
1060 static int mcp23s08_probe(struct spi_device *spi)
1061 {
1062 	struct mcp23s08_platform_data	*pdata, local_pdata;
1063 	unsigned			addr;
1064 	int				chips = 0;
1065 	struct mcp23s08_driver_data	*data;
1066 	int				status, type;
1067 	unsigned			ngpio = 0;
1068 	const struct			of_device_id *match;
1069 
1070 	match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
1071 	if (match)
1072 		type = (int)(uintptr_t)match->data;
1073 	else
1074 		type = spi_get_device_id(spi)->driver_data;
1075 
1076 	pdata = dev_get_platdata(&spi->dev);
1077 	if (!pdata) {
1078 		pdata = &local_pdata;
1079 		pdata->base = -1;
1080 
1081 		status = device_property_read_u32(&spi->dev,
1082 			"microchip,spi-present-mask", &pdata->spi_present_mask);
1083 		if (status) {
1084 			status = device_property_read_u32(&spi->dev,
1085 				"mcp,spi-present-mask",
1086 				&pdata->spi_present_mask);
1087 
1088 			if (status) {
1089 				dev_err(&spi->dev, "missing spi-present-mask");
1090 				return -ENODEV;
1091 			}
1092 		}
1093 	}
1094 
1095 	if (!pdata->spi_present_mask || pdata->spi_present_mask > 0xff) {
1096 		dev_err(&spi->dev, "invalid spi-present-mask");
1097 		return -ENODEV;
1098 	}
1099 
1100 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1101 		if (pdata->spi_present_mask & BIT(addr))
1102 			chips++;
1103 	}
1104 
1105 	if (!chips)
1106 		return -ENODEV;
1107 
1108 	data = devm_kzalloc(&spi->dev,
1109 			    sizeof(*data) + chips * sizeof(struct mcp23s08),
1110 			    GFP_KERNEL);
1111 	if (!data)
1112 		return -ENOMEM;
1113 
1114 	spi_set_drvdata(spi, data);
1115 
1116 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1117 		if (!(pdata->spi_present_mask & BIT(addr)))
1118 			continue;
1119 		chips--;
1120 		data->mcp[addr] = &data->chip[chips];
1121 		data->mcp[addr]->irq = spi->irq;
1122 		status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
1123 					    0x40 | (addr << 1), type,
1124 					    pdata->base, addr);
1125 		if (status < 0)
1126 			return status;
1127 
1128 		if (pdata->base != -1)
1129 			pdata->base += data->mcp[addr]->chip.ngpio;
1130 		ngpio += data->mcp[addr]->chip.ngpio;
1131 	}
1132 	data->ngpio = ngpio;
1133 
1134 	return 0;
1135 }
1136 
1137 static const struct spi_device_id mcp23s08_ids[] = {
1138 	{ "mcp23s08", MCP_TYPE_S08 },
1139 	{ "mcp23s17", MCP_TYPE_S17 },
1140 	{ "mcp23s18", MCP_TYPE_S18 },
1141 	{ },
1142 };
1143 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
1144 
1145 static struct spi_driver mcp23s08_driver = {
1146 	.probe		= mcp23s08_probe,
1147 	.id_table	= mcp23s08_ids,
1148 	.driver = {
1149 		.name	= "mcp23s08",
1150 		.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
1151 	},
1152 };
1153 
1154 static int __init mcp23s08_spi_init(void)
1155 {
1156 	return spi_register_driver(&mcp23s08_driver);
1157 }
1158 
1159 static void mcp23s08_spi_exit(void)
1160 {
1161 	spi_unregister_driver(&mcp23s08_driver);
1162 }
1163 
1164 #else
1165 
1166 static int __init mcp23s08_spi_init(void) { return 0; }
1167 static void mcp23s08_spi_exit(void) { }
1168 
1169 #endif /* CONFIG_SPI_MASTER */
1170 
1171 /*----------------------------------------------------------------------*/
1172 
1173 static int __init mcp23s08_init(void)
1174 {
1175 	int ret;
1176 
1177 	ret = mcp23s08_spi_init();
1178 	if (ret)
1179 		goto spi_fail;
1180 
1181 	ret = mcp23s08_i2c_init();
1182 	if (ret)
1183 		goto i2c_fail;
1184 
1185 	return 0;
1186 
1187  i2c_fail:
1188 	mcp23s08_spi_exit();
1189  spi_fail:
1190 	return ret;
1191 }
1192 /* register after spi/i2c postcore initcall and before
1193  * subsys initcalls that may rely on these GPIOs
1194  */
1195 subsys_initcall(mcp23s08_init);
1196 
1197 static void __exit mcp23s08_exit(void)
1198 {
1199 	mcp23s08_spi_exit();
1200 	mcp23s08_i2c_exit();
1201 }
1202 module_exit(mcp23s08_exit);
1203 
1204 MODULE_LICENSE("GPL");
1205