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))
459 		goto unlock;
460 
461 	if (mcp_read(mcp, MCP_INTCAP, &intcap))
462 		goto unlock;
463 
464 	if (mcp_read(mcp, MCP_INTCON, &intcon))
465 		goto unlock;
466 
467 	if (mcp_read(mcp, MCP_DEFVAL, &defval))
468 		goto unlock;
469 
470 	/* This clears the interrupt(configurable on S18) */
471 	if (mcp_read(mcp, MCP_GPIO, &gpio))
472 		goto unlock;
473 
474 	gpio_orig = mcp->cached_gpio;
475 	mcp->cached_gpio = gpio;
476 	mutex_unlock(&mcp->lock);
477 
478 	if (intf == 0) {
479 		/* There is no interrupt pending */
480 		return IRQ_HANDLED;
481 	}
482 
483 	dev_dbg(mcp->chip.parent,
484 		"intcap 0x%04X intf 0x%04X gpio_orig 0x%04X gpio 0x%04X\n",
485 		intcap, intf, gpio_orig, gpio);
486 
487 	for (i = 0; i < mcp->chip.ngpio; i++) {
488 		/* We must check all of the inputs on the chip,
489 		 * otherwise we may not notice a change on >=2 pins.
490 		 *
491 		 * On at least the mcp23s17, INTCAP is only updated
492 		 * one byte at a time(INTCAPA and INTCAPB are
493 		 * not written to at the same time - only on a per-bank
494 		 * basis).
495 		 *
496 		 * INTF only contains the single bit that caused the
497 		 * interrupt per-bank.  On the mcp23s17, there is
498 		 * INTFA and INTFB.  If two pins are changed on the A
499 		 * side at the same time, INTF will only have one bit
500 		 * set.  If one pin on the A side and one pin on the B
501 		 * side are changed at the same time, INTF will have
502 		 * two bits set.  Thus, INTF can't be the only check
503 		 * to see if the input has changed.
504 		 */
505 
506 		intf_set = intf & BIT(i);
507 		if (i < 8 && intf_set)
508 			intcap_mask = 0x00FF;
509 		else if (i >= 8 && intf_set)
510 			intcap_mask = 0xFF00;
511 		else
512 			intcap_mask = 0x00;
513 
514 		intcap_changed = (intcap_mask &
515 			(intcap & BIT(i))) !=
516 			(intcap_mask & (BIT(i) & gpio_orig));
517 		gpio_set = BIT(i) & gpio;
518 		gpio_bit_changed = (BIT(i) & gpio_orig) !=
519 			(BIT(i) & gpio);
520 		defval_changed = (BIT(i) & intcon) &&
521 			((BIT(i) & gpio) !=
522 			(BIT(i) & defval));
523 
524 		if (((gpio_bit_changed || intcap_changed) &&
525 			(BIT(i) & mcp->irq_rise) && gpio_set) ||
526 		    ((gpio_bit_changed || intcap_changed) &&
527 			(BIT(i) & mcp->irq_fall) && !gpio_set) ||
528 		    defval_changed) {
529 			child_irq = irq_find_mapping(mcp->chip.irq.domain, i);
530 			handle_nested_irq(child_irq);
531 		}
532 	}
533 
534 	return IRQ_HANDLED;
535 
536 unlock:
537 	mutex_unlock(&mcp->lock);
538 	return IRQ_HANDLED;
539 }
540 
541 static void mcp23s08_irq_mask(struct irq_data *data)
542 {
543 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
544 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
545 	unsigned int pos = data->hwirq;
546 
547 	mcp_set_bit(mcp, MCP_GPINTEN, pos, false);
548 }
549 
550 static void mcp23s08_irq_unmask(struct irq_data *data)
551 {
552 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
553 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
554 	unsigned int pos = data->hwirq;
555 
556 	mcp_set_bit(mcp, MCP_GPINTEN, pos, true);
557 }
558 
559 static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type)
560 {
561 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
562 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
563 	unsigned int pos = data->hwirq;
564 	int status = 0;
565 
566 	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
567 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
568 		mcp->irq_rise |= BIT(pos);
569 		mcp->irq_fall |= BIT(pos);
570 	} else if (type & IRQ_TYPE_EDGE_RISING) {
571 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
572 		mcp->irq_rise |= BIT(pos);
573 		mcp->irq_fall &= ~BIT(pos);
574 	} else if (type & IRQ_TYPE_EDGE_FALLING) {
575 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
576 		mcp->irq_rise &= ~BIT(pos);
577 		mcp->irq_fall |= BIT(pos);
578 	} else if (type & IRQ_TYPE_LEVEL_HIGH) {
579 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
580 		mcp_set_bit(mcp, MCP_DEFVAL, pos, false);
581 	} else if (type & IRQ_TYPE_LEVEL_LOW) {
582 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
583 		mcp_set_bit(mcp, MCP_DEFVAL, pos, true);
584 	} else
585 		return -EINVAL;
586 
587 	return status;
588 }
589 
590 static void mcp23s08_irq_bus_lock(struct irq_data *data)
591 {
592 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
593 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
594 
595 	mutex_lock(&mcp->lock);
596 	regcache_cache_only(mcp->regmap, true);
597 }
598 
599 static void mcp23s08_irq_bus_unlock(struct irq_data *data)
600 {
601 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
602 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
603 
604 	regcache_cache_only(mcp->regmap, false);
605 	regcache_sync(mcp->regmap);
606 
607 	mutex_unlock(&mcp->lock);
608 }
609 
610 static struct irq_chip mcp23s08_irq_chip = {
611 	.name = "gpio-mcp23xxx",
612 	.irq_mask = mcp23s08_irq_mask,
613 	.irq_unmask = mcp23s08_irq_unmask,
614 	.irq_set_type = mcp23s08_irq_set_type,
615 	.irq_bus_lock = mcp23s08_irq_bus_lock,
616 	.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock,
617 };
618 
619 static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
620 {
621 	struct gpio_chip *chip = &mcp->chip;
622 	int err;
623 	unsigned long irqflags = IRQF_ONESHOT | IRQF_SHARED;
624 
625 	if (mcp->irq_active_high)
626 		irqflags |= IRQF_TRIGGER_HIGH;
627 	else
628 		irqflags |= IRQF_TRIGGER_LOW;
629 
630 	err = devm_request_threaded_irq(chip->parent, mcp->irq, NULL,
631 					mcp23s08_irq,
632 					irqflags, dev_name(chip->parent), mcp);
633 	if (err != 0) {
634 		dev_err(chip->parent, "unable to request IRQ#%d: %d\n",
635 			mcp->irq, err);
636 		return err;
637 	}
638 
639 	err =  gpiochip_irqchip_add_nested(chip,
640 					   &mcp23s08_irq_chip,
641 					   0,
642 					   handle_simple_irq,
643 					   IRQ_TYPE_NONE);
644 	if (err) {
645 		dev_err(chip->parent,
646 			"could not connect irqchip to gpiochip: %d\n", err);
647 		return err;
648 	}
649 
650 	gpiochip_set_nested_irqchip(chip,
651 				    &mcp23s08_irq_chip,
652 				    mcp->irq);
653 
654 	return 0;
655 }
656 
657 /*----------------------------------------------------------------------*/
658 
659 #ifdef CONFIG_DEBUG_FS
660 
661 #include <linux/seq_file.h>
662 
663 /*
664  * This compares the chip's registers with the register
665  * cache and corrects any incorrectly set register. This
666  * can be used to fix state for MCP23xxx, that temporary
667  * lost its power supply.
668  */
669 #define MCP23S08_CONFIG_REGS 8
670 static int __check_mcp23s08_reg_cache(struct mcp23s08 *mcp)
671 {
672 	int cached[MCP23S08_CONFIG_REGS];
673 	int err = 0, i;
674 
675 	/* read cached config registers */
676 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
677 		err = mcp_read(mcp, i, &cached[i]);
678 		if (err)
679 			goto out;
680 	}
681 
682 	regcache_cache_bypass(mcp->regmap, true);
683 
684 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
685 		int uncached;
686 		err = mcp_read(mcp, i, &uncached);
687 		if (err)
688 			goto out;
689 
690 		if (uncached != cached[i]) {
691 			dev_err(mcp->dev, "restoring reg 0x%02x from 0x%04x to 0x%04x (power-loss?)\n",
692 				i, uncached, cached[i]);
693 			mcp_write(mcp, i, cached[i]);
694 		}
695 	}
696 
697 out:
698 	if (err)
699 		dev_err(mcp->dev, "read error: reg=%02x, err=%d", i, err);
700 	regcache_cache_bypass(mcp->regmap, false);
701 	return err;
702 }
703 
704 /*
705  * This shows more info than the generic gpio dump code:
706  * pullups, deglitching, open drain drive.
707  */
708 static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
709 {
710 	struct mcp23s08	*mcp;
711 	char		bank;
712 	int		t;
713 	unsigned	mask;
714 	int iodir, gpio, gppu;
715 
716 	mcp = gpiochip_get_data(chip);
717 
718 	/* NOTE: we only handle one bank for now ... */
719 	bank = '0' + ((mcp->addr >> 1) & 0x7);
720 
721 	mutex_lock(&mcp->lock);
722 
723 	t = __check_mcp23s08_reg_cache(mcp);
724 	if (t) {
725 		seq_printf(s, " I/O Error\n");
726 		goto done;
727 	}
728 	t = mcp_read(mcp, MCP_IODIR, &iodir);
729 	if (t) {
730 		seq_printf(s, " I/O Error\n");
731 		goto done;
732 	}
733 	t = mcp_read(mcp, MCP_GPIO, &gpio);
734 	if (t) {
735 		seq_printf(s, " I/O Error\n");
736 		goto done;
737 	}
738 	t = mcp_read(mcp, MCP_GPPU, &gppu);
739 	if (t) {
740 		seq_printf(s, " I/O Error\n");
741 		goto done;
742 	}
743 
744 	for (t = 0, mask = BIT(0); t < chip->ngpio; t++, mask <<= 1) {
745 		const char *label;
746 
747 		label = gpiochip_is_requested(chip, t);
748 		if (!label)
749 			continue;
750 
751 		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s\n",
752 			   chip->base + t, bank, t, label,
753 			   (iodir & mask) ? "in " : "out",
754 			   (gpio & mask) ? "hi" : "lo",
755 			   (gppu & mask) ? "up" : "  ");
756 		/* NOTE:  ignoring the irq-related registers */
757 	}
758 done:
759 	mutex_unlock(&mcp->lock);
760 }
761 
762 #else
763 #define mcp23s08_dbg_show	NULL
764 #endif
765 
766 /*----------------------------------------------------------------------*/
767 
768 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
769 			      void *data, unsigned addr, unsigned type,
770 			      unsigned int base, int cs)
771 {
772 	int status, ret;
773 	bool mirror = false;
774 
775 	mutex_init(&mcp->lock);
776 
777 	mcp->dev = dev;
778 	mcp->addr = addr;
779 	mcp->irq_active_high = false;
780 
781 	mcp->chip.direction_input = mcp23s08_direction_input;
782 	mcp->chip.get = mcp23s08_get;
783 	mcp->chip.direction_output = mcp23s08_direction_output;
784 	mcp->chip.set = mcp23s08_set;
785 	mcp->chip.dbg_show = mcp23s08_dbg_show;
786 #ifdef CONFIG_OF_GPIO
787 	mcp->chip.of_gpio_n_cells = 2;
788 	mcp->chip.of_node = dev->of_node;
789 #endif
790 
791 	switch (type) {
792 #ifdef CONFIG_SPI_MASTER
793 	case MCP_TYPE_S08:
794 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
795 					       &mcp23x08_regmap);
796 		mcp->reg_shift = 0;
797 		mcp->chip.ngpio = 8;
798 		mcp->chip.label = "mcp23s08";
799 		break;
800 
801 	case MCP_TYPE_S17:
802 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
803 					       &mcp23x17_regmap);
804 		mcp->reg_shift = 1;
805 		mcp->chip.ngpio = 16;
806 		mcp->chip.label = "mcp23s17";
807 		break;
808 
809 	case MCP_TYPE_S18:
810 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
811 					       &mcp23x17_regmap);
812 		mcp->reg_shift = 1;
813 		mcp->chip.ngpio = 16;
814 		mcp->chip.label = "mcp23s18";
815 		break;
816 #endif /* CONFIG_SPI_MASTER */
817 
818 #if IS_ENABLED(CONFIG_I2C)
819 	case MCP_TYPE_008:
820 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x08_regmap);
821 		mcp->reg_shift = 0;
822 		mcp->chip.ngpio = 8;
823 		mcp->chip.label = "mcp23008";
824 		break;
825 
826 	case MCP_TYPE_017:
827 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x17_regmap);
828 		mcp->reg_shift = 1;
829 		mcp->chip.ngpio = 16;
830 		mcp->chip.label = "mcp23017";
831 		break;
832 
833 	case MCP_TYPE_018:
834 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x17_regmap);
835 		mcp->reg_shift = 1;
836 		mcp->chip.ngpio = 16;
837 		mcp->chip.label = "mcp23018";
838 		break;
839 #endif /* CONFIG_I2C */
840 
841 	default:
842 		dev_err(dev, "invalid device type (%d)\n", type);
843 		return -EINVAL;
844 	}
845 
846 	if (IS_ERR(mcp->regmap))
847 		return PTR_ERR(mcp->regmap);
848 
849 	mcp->chip.base = base;
850 	mcp->chip.can_sleep = true;
851 	mcp->chip.parent = dev;
852 	mcp->chip.owner = THIS_MODULE;
853 
854 	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
855 	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
856 	 */
857 
858 	ret = mcp_read(mcp, MCP_IOCON, &status);
859 	if (ret < 0)
860 		goto fail;
861 
862 	mcp->irq_controller =
863 		device_property_read_bool(dev, "interrupt-controller");
864 	if (mcp->irq && mcp->irq_controller) {
865 		mcp->irq_active_high =
866 			device_property_read_bool(dev,
867 					      "microchip,irq-active-high");
868 
869 		mirror = device_property_read_bool(dev, "microchip,irq-mirror");
870 	}
871 
872 	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror ||
873 	     mcp->irq_active_high) {
874 		/* mcp23s17 has IOCON twice, make sure they are in sync */
875 		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
876 		status |= IOCON_HAEN | (IOCON_HAEN << 8);
877 		if (mcp->irq_active_high)
878 			status |= IOCON_INTPOL | (IOCON_INTPOL << 8);
879 		else
880 			status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));
881 
882 		if (mirror)
883 			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);
884 
885 		if (type == MCP_TYPE_S18 || type == MCP_TYPE_018)
886 			status |= IOCON_INTCC | (IOCON_INTCC << 8);
887 
888 		ret = mcp_write(mcp, MCP_IOCON, status);
889 		if (ret < 0)
890 			goto fail;
891 	}
892 
893 	if (mcp->irq && mcp->irq_controller) {
894 		ret = mcp23s08_irq_setup(mcp);
895 		if (ret)
896 			goto fail;
897 	}
898 
899 	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
900 	if (ret < 0)
901 		goto fail;
902 
903 	mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
904 	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
905 	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
906 	mcp->pinctrl_desc.npins = mcp->chip.ngpio;
907 	if (mcp->pinctrl_desc.npins == 8)
908 		mcp->pinctrl_desc.pins = mcp23x08_pins;
909 	else if (mcp->pinctrl_desc.npins == 16)
910 		mcp->pinctrl_desc.pins = mcp23x17_pins;
911 	mcp->pinctrl_desc.owner = THIS_MODULE;
912 
913 	mcp->pctldev = devm_pinctrl_register(dev, &mcp->pinctrl_desc, mcp);
914 	if (IS_ERR(mcp->pctldev)) {
915 		ret = PTR_ERR(mcp->pctldev);
916 		goto fail;
917 	}
918 
919 fail:
920 	if (ret < 0)
921 		dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);
922 	return ret;
923 }
924 
925 /*----------------------------------------------------------------------*/
926 
927 #ifdef CONFIG_OF
928 #ifdef CONFIG_SPI_MASTER
929 static const struct of_device_id mcp23s08_spi_of_match[] = {
930 	{
931 		.compatible = "microchip,mcp23s08",
932 		.data = (void *) MCP_TYPE_S08,
933 	},
934 	{
935 		.compatible = "microchip,mcp23s17",
936 		.data = (void *) MCP_TYPE_S17,
937 	},
938 	{
939 		.compatible = "microchip,mcp23s18",
940 		.data = (void *) MCP_TYPE_S18,
941 	},
942 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
943 	{
944 		.compatible = "mcp,mcp23s08",
945 		.data = (void *) MCP_TYPE_S08,
946 	},
947 	{
948 		.compatible = "mcp,mcp23s17",
949 		.data = (void *) MCP_TYPE_S17,
950 	},
951 	{ },
952 };
953 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
954 #endif
955 
956 #if IS_ENABLED(CONFIG_I2C)
957 static const struct of_device_id mcp23s08_i2c_of_match[] = {
958 	{
959 		.compatible = "microchip,mcp23008",
960 		.data = (void *) MCP_TYPE_008,
961 	},
962 	{
963 		.compatible = "microchip,mcp23017",
964 		.data = (void *) MCP_TYPE_017,
965 	},
966 	{
967 		.compatible = "microchip,mcp23018",
968 		.data = (void *) MCP_TYPE_018,
969 	},
970 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
971 	{
972 		.compatible = "mcp,mcp23008",
973 		.data = (void *) MCP_TYPE_008,
974 	},
975 	{
976 		.compatible = "mcp,mcp23017",
977 		.data = (void *) MCP_TYPE_017,
978 	},
979 	{ },
980 };
981 MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
982 #endif
983 #endif /* CONFIG_OF */
984 
985 
986 #if IS_ENABLED(CONFIG_I2C)
987 
988 static int mcp230xx_probe(struct i2c_client *client,
989 				    const struct i2c_device_id *id)
990 {
991 	struct mcp23s08_platform_data *pdata, local_pdata;
992 	struct mcp23s08 *mcp;
993 	int status;
994 
995 	pdata = dev_get_platdata(&client->dev);
996 	if (!pdata) {
997 		pdata = &local_pdata;
998 		pdata->base = -1;
999 	}
1000 
1001 	mcp = devm_kzalloc(&client->dev, sizeof(*mcp), GFP_KERNEL);
1002 	if (!mcp)
1003 		return -ENOMEM;
1004 
1005 	mcp->irq = client->irq;
1006 	status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
1007 				    id->driver_data, pdata->base, 0);
1008 	if (status)
1009 		return status;
1010 
1011 	i2c_set_clientdata(client, mcp);
1012 
1013 	return 0;
1014 }
1015 
1016 static const struct i2c_device_id mcp230xx_id[] = {
1017 	{ "mcp23008", MCP_TYPE_008 },
1018 	{ "mcp23017", MCP_TYPE_017 },
1019 	{ "mcp23018", MCP_TYPE_018 },
1020 	{ },
1021 };
1022 MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
1023 
1024 static struct i2c_driver mcp230xx_driver = {
1025 	.driver = {
1026 		.name	= "mcp230xx",
1027 		.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
1028 	},
1029 	.probe		= mcp230xx_probe,
1030 	.id_table	= mcp230xx_id,
1031 };
1032 
1033 static int __init mcp23s08_i2c_init(void)
1034 {
1035 	return i2c_add_driver(&mcp230xx_driver);
1036 }
1037 
1038 static void mcp23s08_i2c_exit(void)
1039 {
1040 	i2c_del_driver(&mcp230xx_driver);
1041 }
1042 
1043 #else
1044 
1045 static int __init mcp23s08_i2c_init(void) { return 0; }
1046 static void mcp23s08_i2c_exit(void) { }
1047 
1048 #endif /* CONFIG_I2C */
1049 
1050 /*----------------------------------------------------------------------*/
1051 
1052 #ifdef CONFIG_SPI_MASTER
1053 
1054 static int mcp23s08_probe(struct spi_device *spi)
1055 {
1056 	struct mcp23s08_platform_data	*pdata, local_pdata;
1057 	unsigned			addr;
1058 	int				chips = 0;
1059 	struct mcp23s08_driver_data	*data;
1060 	int				status, type;
1061 	unsigned			ngpio = 0;
1062 	const struct			of_device_id *match;
1063 
1064 	match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
1065 	if (match)
1066 		type = (int)(uintptr_t)match->data;
1067 	else
1068 		type = spi_get_device_id(spi)->driver_data;
1069 
1070 	pdata = dev_get_platdata(&spi->dev);
1071 	if (!pdata) {
1072 		pdata = &local_pdata;
1073 		pdata->base = -1;
1074 
1075 		status = device_property_read_u32(&spi->dev,
1076 			"microchip,spi-present-mask", &pdata->spi_present_mask);
1077 		if (status) {
1078 			status = device_property_read_u32(&spi->dev,
1079 				"mcp,spi-present-mask",
1080 				&pdata->spi_present_mask);
1081 
1082 			if (status) {
1083 				dev_err(&spi->dev, "missing spi-present-mask");
1084 				return -ENODEV;
1085 			}
1086 		}
1087 	}
1088 
1089 	if (!pdata->spi_present_mask || pdata->spi_present_mask > 0xff) {
1090 		dev_err(&spi->dev, "invalid spi-present-mask");
1091 		return -ENODEV;
1092 	}
1093 
1094 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1095 		if (pdata->spi_present_mask & BIT(addr))
1096 			chips++;
1097 	}
1098 
1099 	if (!chips)
1100 		return -ENODEV;
1101 
1102 	data = devm_kzalloc(&spi->dev,
1103 			    sizeof(*data) + chips * sizeof(struct mcp23s08),
1104 			    GFP_KERNEL);
1105 	if (!data)
1106 		return -ENOMEM;
1107 
1108 	spi_set_drvdata(spi, data);
1109 
1110 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1111 		if (!(pdata->spi_present_mask & BIT(addr)))
1112 			continue;
1113 		chips--;
1114 		data->mcp[addr] = &data->chip[chips];
1115 		data->mcp[addr]->irq = spi->irq;
1116 		status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
1117 					    0x40 | (addr << 1), type,
1118 					    pdata->base, addr);
1119 		if (status < 0)
1120 			return status;
1121 
1122 		if (pdata->base != -1)
1123 			pdata->base += data->mcp[addr]->chip.ngpio;
1124 		ngpio += data->mcp[addr]->chip.ngpio;
1125 	}
1126 	data->ngpio = ngpio;
1127 
1128 	return 0;
1129 }
1130 
1131 static const struct spi_device_id mcp23s08_ids[] = {
1132 	{ "mcp23s08", MCP_TYPE_S08 },
1133 	{ "mcp23s17", MCP_TYPE_S17 },
1134 	{ "mcp23s18", MCP_TYPE_S18 },
1135 	{ },
1136 };
1137 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
1138 
1139 static struct spi_driver mcp23s08_driver = {
1140 	.probe		= mcp23s08_probe,
1141 	.id_table	= mcp23s08_ids,
1142 	.driver = {
1143 		.name	= "mcp23s08",
1144 		.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
1145 	},
1146 };
1147 
1148 static int __init mcp23s08_spi_init(void)
1149 {
1150 	return spi_register_driver(&mcp23s08_driver);
1151 }
1152 
1153 static void mcp23s08_spi_exit(void)
1154 {
1155 	spi_unregister_driver(&mcp23s08_driver);
1156 }
1157 
1158 #else
1159 
1160 static int __init mcp23s08_spi_init(void) { return 0; }
1161 static void mcp23s08_spi_exit(void) { }
1162 
1163 #endif /* CONFIG_SPI_MASTER */
1164 
1165 /*----------------------------------------------------------------------*/
1166 
1167 static int __init mcp23s08_init(void)
1168 {
1169 	int ret;
1170 
1171 	ret = mcp23s08_spi_init();
1172 	if (ret)
1173 		goto spi_fail;
1174 
1175 	ret = mcp23s08_i2c_init();
1176 	if (ret)
1177 		goto i2c_fail;
1178 
1179 	return 0;
1180 
1181  i2c_fail:
1182 	mcp23s08_spi_exit();
1183  spi_fail:
1184 	return ret;
1185 }
1186 /* register after spi/i2c postcore initcall and before
1187  * subsys initcalls that may rely on these GPIOs
1188  */
1189 subsys_initcall(mcp23s08_init);
1190 
1191 static void __exit mcp23s08_exit(void)
1192 {
1193 	mcp23s08_spi_exit();
1194 	mcp23s08_i2c_exit();
1195 }
1196 module_exit(mcp23s08_exit);
1197 
1198 MODULE_LICENSE("GPL");
1199