xref: /linux/drivers/pinctrl/pinctrl-mcp23s08.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
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 
29 #define MCP_MAX_DEV_PER_CS	8
30 
31 /* Registers are all 8 bits wide.
32  *
33  * The mcp23s17 has twice as many bits, and can be configured to work
34  * with either 16 bit registers or with two adjacent 8 bit banks.
35  */
36 #define MCP_IODIR	0x00		/* init/reset:  all ones */
37 #define MCP_IPOL	0x01
38 #define MCP_GPINTEN	0x02
39 #define MCP_DEFVAL	0x03
40 #define MCP_INTCON	0x04
41 #define MCP_IOCON	0x05
42 #	define IOCON_MIRROR	(1 << 6)
43 #	define IOCON_SEQOP	(1 << 5)
44 #	define IOCON_HAEN	(1 << 3)
45 #	define IOCON_ODR	(1 << 2)
46 #	define IOCON_INTPOL	(1 << 1)
47 #	define IOCON_INTCC	(1)
48 #define MCP_GPPU	0x06
49 #define MCP_INTF	0x07
50 #define MCP_INTCAP	0x08
51 #define MCP_GPIO	0x09
52 #define MCP_OLAT	0x0a
53 
54 struct mcp23s08;
55 
56 struct mcp23s08 {
57 	u8			addr;
58 	bool			irq_active_high;
59 	bool			reg_shift;
60 
61 	u16			irq_rise;
62 	u16			irq_fall;
63 	int			irq;
64 	bool			irq_controller;
65 	int			cached_gpio;
66 	/* lock protects regmap access with bypass/cache flags */
67 	struct mutex		lock;
68 
69 	struct gpio_chip	chip;
70 
71 	struct regmap		*regmap;
72 	struct device		*dev;
73 
74 	struct pinctrl_dev	*pctldev;
75 	struct pinctrl_desc	pinctrl_desc;
76 };
77 
78 static const struct reg_default mcp23x08_defaults[] = {
79 	{.reg = MCP_IODIR,		.def = 0xff},
80 	{.reg = MCP_IPOL,		.def = 0x00},
81 	{.reg = MCP_GPINTEN,		.def = 0x00},
82 	{.reg = MCP_DEFVAL,		.def = 0x00},
83 	{.reg = MCP_INTCON,		.def = 0x00},
84 	{.reg = MCP_IOCON,		.def = 0x00},
85 	{.reg = MCP_GPPU,		.def = 0x00},
86 	{.reg = MCP_OLAT,		.def = 0x00},
87 };
88 
89 static const struct regmap_range mcp23x08_volatile_range = {
90 	.range_min = MCP_INTF,
91 	.range_max = MCP_GPIO,
92 };
93 
94 static const struct regmap_access_table mcp23x08_volatile_table = {
95 	.yes_ranges = &mcp23x08_volatile_range,
96 	.n_yes_ranges = 1,
97 };
98 
99 static const struct regmap_range mcp23x08_precious_range = {
100 	.range_min = MCP_GPIO,
101 	.range_max = MCP_GPIO,
102 };
103 
104 static const struct regmap_access_table mcp23x08_precious_table = {
105 	.yes_ranges = &mcp23x08_precious_range,
106 	.n_yes_ranges = 1,
107 };
108 
109 static const struct regmap_config mcp23x08_regmap = {
110 	.reg_bits = 8,
111 	.val_bits = 8,
112 
113 	.reg_stride = 1,
114 	.volatile_table = &mcp23x08_volatile_table,
115 	.precious_table = &mcp23x08_precious_table,
116 	.reg_defaults = mcp23x08_defaults,
117 	.num_reg_defaults = ARRAY_SIZE(mcp23x08_defaults),
118 	.cache_type = REGCACHE_FLAT,
119 	.max_register = MCP_OLAT,
120 };
121 
122 static const struct reg_default mcp23x16_defaults[] = {
123 	{.reg = MCP_IODIR << 1,		.def = 0xffff},
124 	{.reg = MCP_IPOL << 1,		.def = 0x0000},
125 	{.reg = MCP_GPINTEN << 1,	.def = 0x0000},
126 	{.reg = MCP_DEFVAL << 1,	.def = 0x0000},
127 	{.reg = MCP_INTCON << 1,	.def = 0x0000},
128 	{.reg = MCP_IOCON << 1,		.def = 0x0000},
129 	{.reg = MCP_GPPU << 1,		.def = 0x0000},
130 	{.reg = MCP_OLAT << 1,		.def = 0x0000},
131 };
132 
133 static const struct regmap_range mcp23x16_volatile_range = {
134 	.range_min = MCP_INTF << 1,
135 	.range_max = MCP_GPIO << 1,
136 };
137 
138 static const struct regmap_access_table mcp23x16_volatile_table = {
139 	.yes_ranges = &mcp23x16_volatile_range,
140 	.n_yes_ranges = 1,
141 };
142 
143 static const struct regmap_range mcp23x16_precious_range = {
144 	.range_min = MCP_GPIO << 1,
145 	.range_max = MCP_GPIO << 1,
146 };
147 
148 static const struct regmap_access_table mcp23x16_precious_table = {
149 	.yes_ranges = &mcp23x16_precious_range,
150 	.n_yes_ranges = 1,
151 };
152 
153 static const struct regmap_config mcp23x17_regmap = {
154 	.reg_bits = 8,
155 	.val_bits = 16,
156 
157 	.reg_stride = 2,
158 	.max_register = MCP_OLAT << 1,
159 	.volatile_table = &mcp23x16_volatile_table,
160 	.precious_table = &mcp23x16_precious_table,
161 	.reg_defaults = mcp23x16_defaults,
162 	.num_reg_defaults = ARRAY_SIZE(mcp23x16_defaults),
163 	.cache_type = REGCACHE_FLAT,
164 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
165 };
166 
167 static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
168 {
169 	return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
170 }
171 
172 static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
173 {
174 	return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
175 }
176 
177 static int mcp_set_mask(struct mcp23s08 *mcp, unsigned int reg,
178 		       unsigned int mask, bool enabled)
179 {
180 	u16 val  = enabled ? 0xffff : 0x0000;
181 	return regmap_update_bits(mcp->regmap, reg << mcp->reg_shift,
182 				  mask, val);
183 }
184 
185 static int mcp_set_bit(struct mcp23s08 *mcp, unsigned int reg,
186 		       unsigned int pin, bool enabled)
187 {
188 	u16 mask = BIT(pin);
189 	return mcp_set_mask(mcp, reg, mask, enabled);
190 }
191 
192 static const struct pinctrl_pin_desc mcp23x08_pins[] = {
193 	PINCTRL_PIN(0, "gpio0"),
194 	PINCTRL_PIN(1, "gpio1"),
195 	PINCTRL_PIN(2, "gpio2"),
196 	PINCTRL_PIN(3, "gpio3"),
197 	PINCTRL_PIN(4, "gpio4"),
198 	PINCTRL_PIN(5, "gpio5"),
199 	PINCTRL_PIN(6, "gpio6"),
200 	PINCTRL_PIN(7, "gpio7"),
201 };
202 
203 static const struct pinctrl_pin_desc mcp23x17_pins[] = {
204 	PINCTRL_PIN(0, "gpio0"),
205 	PINCTRL_PIN(1, "gpio1"),
206 	PINCTRL_PIN(2, "gpio2"),
207 	PINCTRL_PIN(3, "gpio3"),
208 	PINCTRL_PIN(4, "gpio4"),
209 	PINCTRL_PIN(5, "gpio5"),
210 	PINCTRL_PIN(6, "gpio6"),
211 	PINCTRL_PIN(7, "gpio7"),
212 	PINCTRL_PIN(8, "gpio8"),
213 	PINCTRL_PIN(9, "gpio9"),
214 	PINCTRL_PIN(10, "gpio10"),
215 	PINCTRL_PIN(11, "gpio11"),
216 	PINCTRL_PIN(12, "gpio12"),
217 	PINCTRL_PIN(13, "gpio13"),
218 	PINCTRL_PIN(14, "gpio14"),
219 	PINCTRL_PIN(15, "gpio15"),
220 };
221 
222 static int mcp_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
223 {
224 	return 0;
225 }
226 
227 static const char *mcp_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
228 						unsigned int group)
229 {
230 	return NULL;
231 }
232 
233 static int mcp_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
234 					unsigned int group,
235 					const unsigned int **pins,
236 					unsigned int *num_pins)
237 {
238 	return -ENOTSUPP;
239 }
240 
241 static const struct pinctrl_ops mcp_pinctrl_ops = {
242 	.get_groups_count = mcp_pinctrl_get_groups_count,
243 	.get_group_name = mcp_pinctrl_get_group_name,
244 	.get_group_pins = mcp_pinctrl_get_group_pins,
245 #ifdef CONFIG_OF
246 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
247 	.dt_free_map = pinconf_generic_dt_free_map,
248 #endif
249 };
250 
251 static int mcp_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
252 			      unsigned long *config)
253 {
254 	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
255 	enum pin_config_param param = pinconf_to_config_param(*config);
256 	unsigned int data, status;
257 	int ret;
258 
259 	switch (param) {
260 	case PIN_CONFIG_BIAS_PULL_UP:
261 		ret = mcp_read(mcp, MCP_GPPU, &data);
262 		if (ret < 0)
263 			return ret;
264 		status = (data & BIT(pin)) ? 1 : 0;
265 		break;
266 	default:
267 		dev_err(mcp->dev, "Invalid config param %04x\n", param);
268 		return -ENOTSUPP;
269 	}
270 
271 	*config = 0;
272 
273 	return status ? 0 : -EINVAL;
274 }
275 
276 static int mcp_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
277 			      unsigned long *configs, unsigned int num_configs)
278 {
279 	struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
280 	enum pin_config_param param;
281 	u32 arg, mask;
282 	u16 val;
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 			val = arg ? 0xFFFF : 0x0000;
293 			mask = BIT(pin);
294 			ret = mcp_set_bit(mcp, MCP_GPPU, pin, arg);
295 			break;
296 		default:
297 			dev_err(mcp->dev, "Invalid config param %04x\n", param);
298 			return -ENOTSUPP;
299 		}
300 	}
301 
302 	return ret;
303 }
304 
305 static const struct pinconf_ops mcp_pinconf_ops = {
306 	.pin_config_get = mcp_pinconf_get,
307 	.pin_config_set = mcp_pinconf_set,
308 	.is_generic = true,
309 };
310 
311 /*----------------------------------------------------------------------*/
312 
313 #ifdef CONFIG_SPI_MASTER
314 
315 static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
316 {
317 	struct mcp23s08 *mcp = context;
318 	struct spi_device *spi = to_spi_device(mcp->dev);
319 	struct spi_message m;
320 	struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
321 				     { .tx_buf = data, .len = count, }, };
322 
323 	spi_message_init(&m);
324 	spi_message_add_tail(&t[0], &m);
325 	spi_message_add_tail(&t[1], &m);
326 
327 	return spi_sync(spi, &m);
328 }
329 
330 static int mcp23sxx_spi_gather_write(void *context,
331 				const void *reg, size_t reg_size,
332 				const void *val, size_t val_size)
333 {
334 	struct mcp23s08 *mcp = context;
335 	struct spi_device *spi = to_spi_device(mcp->dev);
336 	struct spi_message m;
337 	struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, },
338 				     { .tx_buf = reg, .len = reg_size, },
339 				     { .tx_buf = val, .len = val_size, }, };
340 
341 	spi_message_init(&m);
342 	spi_message_add_tail(&t[0], &m);
343 	spi_message_add_tail(&t[1], &m);
344 	spi_message_add_tail(&t[2], &m);
345 
346 	return spi_sync(spi, &m);
347 }
348 
349 static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
350 				void *val, size_t val_size)
351 {
352 	struct mcp23s08 *mcp = context;
353 	struct spi_device *spi = to_spi_device(mcp->dev);
354 	u8 tx[2];
355 
356 	if (reg_size != 1)
357 		return -EINVAL;
358 
359 	tx[0] = mcp->addr | 0x01;
360 	tx[1] = *((u8 *) reg);
361 
362 	return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
363 }
364 
365 static const struct regmap_bus mcp23sxx_spi_regmap = {
366 	.write = mcp23sxx_spi_write,
367 	.gather_write = mcp23sxx_spi_gather_write,
368 	.read = mcp23sxx_spi_read,
369 };
370 
371 #endif /* CONFIG_SPI_MASTER */
372 
373 /*----------------------------------------------------------------------*/
374 
375 /* A given spi_device can represent up to eight mcp23sxx chips
376  * sharing the same chipselect but using different addresses
377  * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
378  * Driver data holds all the per-chip data.
379  */
380 struct mcp23s08_driver_data {
381 	unsigned		ngpio;
382 	struct mcp23s08		*mcp[8];
383 	struct mcp23s08		chip[];
384 };
385 
386 
387 static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
388 {
389 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
390 	int status;
391 
392 	mutex_lock(&mcp->lock);
393 	status = mcp_set_bit(mcp, MCP_IODIR, offset, true);
394 	mutex_unlock(&mcp->lock);
395 
396 	return status;
397 }
398 
399 static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
400 {
401 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
402 	int status, ret;
403 
404 	mutex_lock(&mcp->lock);
405 
406 	/* REVISIT reading this clears any IRQ ... */
407 	ret = mcp_read(mcp, MCP_GPIO, &status);
408 	if (ret < 0)
409 		status = 0;
410 	else
411 		status = !!(status & (1 << offset));
412 
413 	mcp->cached_gpio = status;
414 
415 	mutex_unlock(&mcp->lock);
416 	return status;
417 }
418 
419 static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, bool value)
420 {
421 	return mcp_set_mask(mcp, MCP_OLAT, mask, value);
422 }
423 
424 static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
425 {
426 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
427 	unsigned mask = BIT(offset);
428 
429 	mutex_lock(&mcp->lock);
430 	__mcp23s08_set(mcp, mask, !!value);
431 	mutex_unlock(&mcp->lock);
432 }
433 
434 static int
435 mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
436 {
437 	struct mcp23s08	*mcp = gpiochip_get_data(chip);
438 	unsigned mask = BIT(offset);
439 	int status;
440 
441 	mutex_lock(&mcp->lock);
442 	status = __mcp23s08_set(mcp, mask, value);
443 	if (status == 0) {
444 		status = mcp_set_mask(mcp, MCP_IODIR, mask, false);
445 	}
446 	mutex_unlock(&mcp->lock);
447 	return status;
448 }
449 
450 /*----------------------------------------------------------------------*/
451 static irqreturn_t mcp23s08_irq(int irq, void *data)
452 {
453 	struct mcp23s08 *mcp = data;
454 	int intcap, intcon, intf, i, gpio, gpio_orig, intcap_mask, defval;
455 	unsigned int child_irq;
456 	bool intf_set, intcap_changed, gpio_bit_changed,
457 		defval_changed, gpio_set;
458 
459 	mutex_lock(&mcp->lock);
460 	if (mcp_read(mcp, MCP_INTF, &intf) < 0) {
461 		mutex_unlock(&mcp->lock);
462 		return IRQ_HANDLED;
463 	}
464 
465 	if (mcp_read(mcp, MCP_INTCAP, &intcap) < 0) {
466 		mutex_unlock(&mcp->lock);
467 		return IRQ_HANDLED;
468 	}
469 
470 	if (mcp_read(mcp, MCP_INTCON, &intcon) < 0) {
471 		mutex_unlock(&mcp->lock);
472 		return IRQ_HANDLED;
473 	}
474 
475 	if (mcp_read(mcp, MCP_DEFVAL, &defval) < 0) {
476 		mutex_unlock(&mcp->lock);
477 		return IRQ_HANDLED;
478 	}
479 
480 	/* This clears the interrupt(configurable on S18) */
481 	if (mcp_read(mcp, MCP_GPIO, &gpio) < 0) {
482 		mutex_unlock(&mcp->lock);
483 		return IRQ_HANDLED;
484 	}
485 	gpio_orig = mcp->cached_gpio;
486 	mcp->cached_gpio = gpio;
487 	mutex_unlock(&mcp->lock);
488 
489 	if (intf == 0) {
490 		/* There is no interrupt pending */
491 		return IRQ_HANDLED;
492 	}
493 
494 	dev_dbg(mcp->chip.parent,
495 		"intcap 0x%04X intf 0x%04X gpio_orig 0x%04X gpio 0x%04X\n",
496 		intcap, intf, gpio_orig, gpio);
497 
498 	for (i = 0; i < mcp->chip.ngpio; i++) {
499 		/* We must check all of the inputs on the chip,
500 		 * otherwise we may not notice a change on >=2 pins.
501 		 *
502 		 * On at least the mcp23s17, INTCAP is only updated
503 		 * one byte at a time(INTCAPA and INTCAPB are
504 		 * not written to at the same time - only on a per-bank
505 		 * basis).
506 		 *
507 		 * INTF only contains the single bit that caused the
508 		 * interrupt per-bank.  On the mcp23s17, there is
509 		 * INTFA and INTFB.  If two pins are changed on the A
510 		 * side at the same time, INTF will only have one bit
511 		 * set.  If one pin on the A side and one pin on the B
512 		 * side are changed at the same time, INTF will have
513 		 * two bits set.  Thus, INTF can't be the only check
514 		 * to see if the input has changed.
515 		 */
516 
517 		intf_set = intf & BIT(i);
518 		if (i < 8 && intf_set)
519 			intcap_mask = 0x00FF;
520 		else if (i >= 8 && intf_set)
521 			intcap_mask = 0xFF00;
522 		else
523 			intcap_mask = 0x00;
524 
525 		intcap_changed = (intcap_mask &
526 			(intcap & BIT(i))) !=
527 			(intcap_mask & (BIT(i) & gpio_orig));
528 		gpio_set = BIT(i) & gpio;
529 		gpio_bit_changed = (BIT(i) & gpio_orig) !=
530 			(BIT(i) & gpio);
531 		defval_changed = (BIT(i) & intcon) &&
532 			((BIT(i) & gpio) !=
533 			(BIT(i) & defval));
534 
535 		if (((gpio_bit_changed || intcap_changed) &&
536 			(BIT(i) & mcp->irq_rise) && gpio_set) ||
537 		    ((gpio_bit_changed || intcap_changed) &&
538 			(BIT(i) & mcp->irq_fall) && !gpio_set) ||
539 		    defval_changed) {
540 			child_irq = irq_find_mapping(mcp->chip.irqdomain, i);
541 			handle_nested_irq(child_irq);
542 		}
543 	}
544 
545 	return IRQ_HANDLED;
546 }
547 
548 static void mcp23s08_irq_mask(struct irq_data *data)
549 {
550 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
551 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
552 	unsigned int pos = data->hwirq;
553 
554 	mcp_set_bit(mcp, MCP_GPINTEN, pos, false);
555 }
556 
557 static void mcp23s08_irq_unmask(struct irq_data *data)
558 {
559 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
560 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
561 	unsigned int pos = data->hwirq;
562 
563 	mcp_set_bit(mcp, MCP_GPINTEN, pos, true);
564 }
565 
566 static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type)
567 {
568 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
569 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
570 	unsigned int pos = data->hwirq;
571 	int status = 0;
572 
573 	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
574 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
575 		mcp->irq_rise |= BIT(pos);
576 		mcp->irq_fall |= BIT(pos);
577 	} else if (type & IRQ_TYPE_EDGE_RISING) {
578 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
579 		mcp->irq_rise |= BIT(pos);
580 		mcp->irq_fall &= ~BIT(pos);
581 	} else if (type & IRQ_TYPE_EDGE_FALLING) {
582 		mcp_set_bit(mcp, MCP_INTCON, pos, false);
583 		mcp->irq_rise &= ~BIT(pos);
584 		mcp->irq_fall |= BIT(pos);
585 	} else if (type & IRQ_TYPE_LEVEL_HIGH) {
586 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
587 		mcp_set_bit(mcp, MCP_DEFVAL, pos, false);
588 	} else if (type & IRQ_TYPE_LEVEL_LOW) {
589 		mcp_set_bit(mcp, MCP_INTCON, pos, true);
590 		mcp_set_bit(mcp, MCP_DEFVAL, pos, true);
591 	} else
592 		return -EINVAL;
593 
594 	return status;
595 }
596 
597 static void mcp23s08_irq_bus_lock(struct irq_data *data)
598 {
599 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
600 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
601 
602 	mutex_lock(&mcp->lock);
603 	regcache_cache_only(mcp->regmap, true);
604 }
605 
606 static void mcp23s08_irq_bus_unlock(struct irq_data *data)
607 {
608 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
609 	struct mcp23s08 *mcp = gpiochip_get_data(gc);
610 
611 	regcache_cache_only(mcp->regmap, false);
612 	regcache_sync(mcp->regmap);
613 
614 	mutex_unlock(&mcp->lock);
615 }
616 
617 static struct irq_chip mcp23s08_irq_chip = {
618 	.name = "gpio-mcp23xxx",
619 	.irq_mask = mcp23s08_irq_mask,
620 	.irq_unmask = mcp23s08_irq_unmask,
621 	.irq_set_type = mcp23s08_irq_set_type,
622 	.irq_bus_lock = mcp23s08_irq_bus_lock,
623 	.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock,
624 };
625 
626 static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
627 {
628 	struct gpio_chip *chip = &mcp->chip;
629 	int err;
630 	unsigned long irqflags = IRQF_ONESHOT | IRQF_SHARED;
631 
632 	if (mcp->irq_active_high)
633 		irqflags |= IRQF_TRIGGER_HIGH;
634 	else
635 		irqflags |= IRQF_TRIGGER_LOW;
636 
637 	err = devm_request_threaded_irq(chip->parent, mcp->irq, NULL,
638 					mcp23s08_irq,
639 					irqflags, dev_name(chip->parent), mcp);
640 	if (err != 0) {
641 		dev_err(chip->parent, "unable to request IRQ#%d: %d\n",
642 			mcp->irq, err);
643 		return err;
644 	}
645 
646 	err =  gpiochip_irqchip_add_nested(chip,
647 					   &mcp23s08_irq_chip,
648 					   0,
649 					   handle_simple_irq,
650 					   IRQ_TYPE_NONE);
651 	if (err) {
652 		dev_err(chip->parent,
653 			"could not connect irqchip to gpiochip: %d\n", err);
654 		return err;
655 	}
656 
657 	gpiochip_set_nested_irqchip(chip,
658 				    &mcp23s08_irq_chip,
659 				    mcp->irq);
660 
661 	return 0;
662 }
663 
664 /*----------------------------------------------------------------------*/
665 
666 #ifdef CONFIG_DEBUG_FS
667 
668 #include <linux/seq_file.h>
669 
670 /*
671  * This compares the chip's registers with the register
672  * cache and corrects any incorrectly set register. This
673  * can be used to fix state for MCP23xxx, that temporary
674  * lost its power supply.
675  */
676 #define MCP23S08_CONFIG_REGS 8
677 static int __check_mcp23s08_reg_cache(struct mcp23s08 *mcp)
678 {
679 	int cached[MCP23S08_CONFIG_REGS];
680 	int err = 0, i;
681 
682 	/* read cached config registers */
683 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
684 		err = mcp_read(mcp, i, &cached[i]);
685 		if (err)
686 			goto out;
687 	}
688 
689 	regcache_cache_bypass(mcp->regmap, true);
690 
691 	for (i = 0; i < MCP23S08_CONFIG_REGS; i++) {
692 		int uncached;
693 		err = mcp_read(mcp, i, &uncached);
694 		if (err)
695 			goto out;
696 
697 		if (uncached != cached[i]) {
698 			dev_err(mcp->dev, "restoring reg 0x%02x from 0x%04x to 0x%04x (power-loss?)\n",
699 				i, uncached, cached[i]);
700 			mcp_write(mcp, i, cached[i]);
701 		}
702 	}
703 
704 out:
705 	if (err)
706 		dev_err(mcp->dev, "read error: reg=%02x, err=%d", i, err);
707 	regcache_cache_bypass(mcp->regmap, false);
708 	return err;
709 }
710 
711 /*
712  * This shows more info than the generic gpio dump code:
713  * pullups, deglitching, open drain drive.
714  */
715 static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
716 {
717 	struct mcp23s08	*mcp;
718 	char		bank;
719 	int		t;
720 	unsigned	mask;
721 	int iodir, gpio, gppu;
722 
723 	mcp = gpiochip_get_data(chip);
724 
725 	/* NOTE: we only handle one bank for now ... */
726 	bank = '0' + ((mcp->addr >> 1) & 0x7);
727 
728 	mutex_lock(&mcp->lock);
729 
730 	t = __check_mcp23s08_reg_cache(mcp);
731 	if (t) {
732 		seq_printf(s, " I/O Error\n");
733 		goto done;
734 	}
735 	t = mcp_read(mcp, MCP_IODIR, &iodir);
736 	if (t) {
737 		seq_printf(s, " I/O Error\n");
738 		goto done;
739 	}
740 	t = mcp_read(mcp, MCP_GPIO, &gpio);
741 	if (t) {
742 		seq_printf(s, " I/O Error\n");
743 		goto done;
744 	}
745 	t = mcp_read(mcp, MCP_GPPU, &gppu);
746 	if (t) {
747 		seq_printf(s, " I/O Error\n");
748 		goto done;
749 	}
750 
751 	for (t = 0, mask = BIT(0); t < chip->ngpio; t++, mask <<= 1) {
752 		const char *label;
753 
754 		label = gpiochip_is_requested(chip, t);
755 		if (!label)
756 			continue;
757 
758 		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
759 			chip->base + t, bank, t, label,
760 			(iodir & mask) ? "in " : "out",
761 			(gpio & mask) ? "hi" : "lo",
762 			(gppu & mask) ? "up" : "  ");
763 		/* NOTE:  ignoring the irq-related registers */
764 		seq_puts(s, "\n");
765 	}
766 done:
767 	mutex_unlock(&mcp->lock);
768 }
769 
770 #else
771 #define mcp23s08_dbg_show	NULL
772 #endif
773 
774 /*----------------------------------------------------------------------*/
775 
776 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
777 			      void *data, unsigned addr, unsigned type,
778 			      unsigned int base, int cs)
779 {
780 	int status, ret;
781 	bool mirror = false;
782 
783 	mutex_init(&mcp->lock);
784 
785 	mcp->dev = dev;
786 	mcp->addr = addr;
787 	mcp->irq_active_high = false;
788 
789 	mcp->chip.direction_input = mcp23s08_direction_input;
790 	mcp->chip.get = mcp23s08_get;
791 	mcp->chip.direction_output = mcp23s08_direction_output;
792 	mcp->chip.set = mcp23s08_set;
793 	mcp->chip.dbg_show = mcp23s08_dbg_show;
794 #ifdef CONFIG_OF_GPIO
795 	mcp->chip.of_gpio_n_cells = 2;
796 	mcp->chip.of_node = dev->of_node;
797 #endif
798 
799 	switch (type) {
800 #ifdef CONFIG_SPI_MASTER
801 	case MCP_TYPE_S08:
802 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
803 					       &mcp23x08_regmap);
804 		mcp->reg_shift = 0;
805 		mcp->chip.ngpio = 8;
806 		mcp->chip.label = "mcp23s08";
807 		break;
808 
809 	case MCP_TYPE_S17:
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 = "mcp23s17";
815 		break;
816 
817 	case MCP_TYPE_S18:
818 		mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp,
819 					       &mcp23x17_regmap);
820 		mcp->reg_shift = 1;
821 		mcp->chip.ngpio = 16;
822 		mcp->chip.label = "mcp23s18";
823 		break;
824 #endif /* CONFIG_SPI_MASTER */
825 
826 #if IS_ENABLED(CONFIG_I2C)
827 	case MCP_TYPE_008:
828 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x08_regmap);
829 		mcp->reg_shift = 0;
830 		mcp->chip.ngpio = 8;
831 		mcp->chip.label = "mcp23008";
832 		break;
833 
834 	case MCP_TYPE_017:
835 		mcp->regmap = devm_regmap_init_i2c(data, &mcp23x17_regmap);
836 		mcp->reg_shift = 1;
837 		mcp->chip.ngpio = 16;
838 		mcp->chip.label = "mcp23017";
839 		break;
840 #endif /* CONFIG_I2C */
841 
842 	default:
843 		dev_err(dev, "invalid device type (%d)\n", type);
844 		return -EINVAL;
845 	}
846 
847 	if (IS_ERR(mcp->regmap))
848 		return PTR_ERR(mcp->regmap);
849 
850 	mcp->chip.base = base;
851 	mcp->chip.can_sleep = true;
852 	mcp->chip.parent = dev;
853 	mcp->chip.owner = THIS_MODULE;
854 
855 	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
856 	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
857 	 */
858 
859 	ret = mcp_read(mcp, MCP_IOCON, &status);
860 	if (ret < 0)
861 		goto fail;
862 
863 	mcp->irq_controller =
864 		device_property_read_bool(dev, "interrupt-controller");
865 	if (mcp->irq && mcp->irq_controller) {
866 		mcp->irq_active_high =
867 			device_property_read_bool(dev,
868 					      "microchip,irq-active-high");
869 
870 		mirror = device_property_read_bool(dev, "microchip,irq-mirror");
871 	}
872 
873 	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror ||
874 	     mcp->irq_active_high) {
875 		/* mcp23s17 has IOCON twice, make sure they are in sync */
876 		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
877 		status |= IOCON_HAEN | (IOCON_HAEN << 8);
878 		if (mcp->irq_active_high)
879 			status |= IOCON_INTPOL | (IOCON_INTPOL << 8);
880 		else
881 			status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));
882 
883 		if (mirror)
884 			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);
885 
886 		if (type == MCP_TYPE_S18)
887 			status |= IOCON_INTCC | (IOCON_INTCC << 8);
888 
889 		ret = mcp_write(mcp, MCP_IOCON, status);
890 		if (ret < 0)
891 			goto fail;
892 	}
893 
894 	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
895 	if (ret < 0)
896 		goto fail;
897 
898 	if (mcp->irq && mcp->irq_controller) {
899 		ret = mcp23s08_irq_setup(mcp);
900 		if (ret)
901 			goto fail;
902 	}
903 
904 	mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
905 	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
906 	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
907 	mcp->pinctrl_desc.npins = mcp->chip.ngpio;
908 	if (mcp->pinctrl_desc.npins == 8)
909 		mcp->pinctrl_desc.pins = mcp23x08_pins;
910 	else if (mcp->pinctrl_desc.npins == 16)
911 		mcp->pinctrl_desc.pins = mcp23x17_pins;
912 	mcp->pinctrl_desc.owner = THIS_MODULE;
913 
914 	mcp->pctldev = devm_pinctrl_register(dev, &mcp->pinctrl_desc, mcp);
915 	if (IS_ERR(mcp->pctldev)) {
916 		ret = PTR_ERR(mcp->pctldev);
917 		goto fail;
918 	}
919 
920 fail:
921 	if (ret < 0)
922 		dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);
923 	return ret;
924 }
925 
926 /*----------------------------------------------------------------------*/
927 
928 #ifdef CONFIG_OF
929 #ifdef CONFIG_SPI_MASTER
930 static const struct of_device_id mcp23s08_spi_of_match[] = {
931 	{
932 		.compatible = "microchip,mcp23s08",
933 		.data = (void *) MCP_TYPE_S08,
934 	},
935 	{
936 		.compatible = "microchip,mcp23s17",
937 		.data = (void *) MCP_TYPE_S17,
938 	},
939 	{
940 		.compatible = "microchip,mcp23s18",
941 		.data = (void *) MCP_TYPE_S18,
942 	},
943 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
944 	{
945 		.compatible = "mcp,mcp23s08",
946 		.data = (void *) MCP_TYPE_S08,
947 	},
948 	{
949 		.compatible = "mcp,mcp23s17",
950 		.data = (void *) MCP_TYPE_S17,
951 	},
952 	{ },
953 };
954 MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
955 #endif
956 
957 #if IS_ENABLED(CONFIG_I2C)
958 static const struct of_device_id mcp23s08_i2c_of_match[] = {
959 	{
960 		.compatible = "microchip,mcp23008",
961 		.data = (void *) MCP_TYPE_008,
962 	},
963 	{
964 		.compatible = "microchip,mcp23017",
965 		.data = (void *) MCP_TYPE_017,
966 	},
967 /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
968 	{
969 		.compatible = "mcp,mcp23008",
970 		.data = (void *) MCP_TYPE_008,
971 	},
972 	{
973 		.compatible = "mcp,mcp23017",
974 		.data = (void *) MCP_TYPE_017,
975 	},
976 	{ },
977 };
978 MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
979 #endif
980 #endif /* CONFIG_OF */
981 
982 
983 #if IS_ENABLED(CONFIG_I2C)
984 
985 static int mcp230xx_probe(struct i2c_client *client,
986 				    const struct i2c_device_id *id)
987 {
988 	struct mcp23s08_platform_data *pdata, local_pdata;
989 	struct mcp23s08 *mcp;
990 	int status;
991 
992 	pdata = dev_get_platdata(&client->dev);
993 	if (!pdata) {
994 		pdata = &local_pdata;
995 		pdata->base = -1;
996 	}
997 
998 	mcp = devm_kzalloc(&client->dev, sizeof(*mcp), GFP_KERNEL);
999 	if (!mcp)
1000 		return -ENOMEM;
1001 
1002 	mcp->irq = client->irq;
1003 	status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
1004 				    id->driver_data, pdata->base, 0);
1005 	if (status)
1006 		return status;
1007 
1008 	i2c_set_clientdata(client, mcp);
1009 
1010 	return 0;
1011 }
1012 
1013 static const struct i2c_device_id mcp230xx_id[] = {
1014 	{ "mcp23008", MCP_TYPE_008 },
1015 	{ "mcp23017", MCP_TYPE_017 },
1016 	{ },
1017 };
1018 MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
1019 
1020 static struct i2c_driver mcp230xx_driver = {
1021 	.driver = {
1022 		.name	= "mcp230xx",
1023 		.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
1024 	},
1025 	.probe		= mcp230xx_probe,
1026 	.id_table	= mcp230xx_id,
1027 };
1028 
1029 static int __init mcp23s08_i2c_init(void)
1030 {
1031 	return i2c_add_driver(&mcp230xx_driver);
1032 }
1033 
1034 static void mcp23s08_i2c_exit(void)
1035 {
1036 	i2c_del_driver(&mcp230xx_driver);
1037 }
1038 
1039 #else
1040 
1041 static int __init mcp23s08_i2c_init(void) { return 0; }
1042 static void mcp23s08_i2c_exit(void) { }
1043 
1044 #endif /* CONFIG_I2C */
1045 
1046 /*----------------------------------------------------------------------*/
1047 
1048 #ifdef CONFIG_SPI_MASTER
1049 
1050 static int mcp23s08_probe(struct spi_device *spi)
1051 {
1052 	struct mcp23s08_platform_data	*pdata, local_pdata;
1053 	unsigned			addr;
1054 	int				chips = 0;
1055 	struct mcp23s08_driver_data	*data;
1056 	int				status, type;
1057 	unsigned			ngpio = 0;
1058 	const struct			of_device_id *match;
1059 
1060 	match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
1061 	if (match)
1062 		type = (int)(uintptr_t)match->data;
1063 	else
1064 		type = spi_get_device_id(spi)->driver_data;
1065 
1066 	pdata = dev_get_platdata(&spi->dev);
1067 	if (!pdata) {
1068 		pdata = &local_pdata;
1069 		pdata->base = -1;
1070 
1071 		status = device_property_read_u32(&spi->dev,
1072 			"microchip,spi-present-mask", &pdata->spi_present_mask);
1073 		if (status) {
1074 			status = device_property_read_u32(&spi->dev,
1075 				"mcp,spi-present-mask",
1076 				&pdata->spi_present_mask);
1077 
1078 			if (status) {
1079 				dev_err(&spi->dev, "missing spi-present-mask");
1080 				return -ENODEV;
1081 			}
1082 		}
1083 	}
1084 
1085 	if (!pdata->spi_present_mask || pdata->spi_present_mask > 0xff) {
1086 		dev_err(&spi->dev, "invalid spi-present-mask");
1087 		return -ENODEV;
1088 	}
1089 
1090 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1091 		if (pdata->spi_present_mask & BIT(addr))
1092 			chips++;
1093 	}
1094 
1095 	if (!chips)
1096 		return -ENODEV;
1097 
1098 	data = devm_kzalloc(&spi->dev,
1099 			    sizeof(*data) + chips * sizeof(struct mcp23s08),
1100 			    GFP_KERNEL);
1101 	if (!data)
1102 		return -ENOMEM;
1103 
1104 	spi_set_drvdata(spi, data);
1105 
1106 	for (addr = 0; addr < MCP_MAX_DEV_PER_CS; addr++) {
1107 		if (!(pdata->spi_present_mask & BIT(addr)))
1108 			continue;
1109 		chips--;
1110 		data->mcp[addr] = &data->chip[chips];
1111 		data->mcp[addr]->irq = spi->irq;
1112 		status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
1113 					    0x40 | (addr << 1), type,
1114 					    pdata->base, addr);
1115 		if (status < 0)
1116 			return status;
1117 
1118 		if (pdata->base != -1)
1119 			pdata->base += data->mcp[addr]->chip.ngpio;
1120 		ngpio += data->mcp[addr]->chip.ngpio;
1121 	}
1122 	data->ngpio = ngpio;
1123 
1124 	return 0;
1125 }
1126 
1127 static const struct spi_device_id mcp23s08_ids[] = {
1128 	{ "mcp23s08", MCP_TYPE_S08 },
1129 	{ "mcp23s17", MCP_TYPE_S17 },
1130 	{ "mcp23s18", MCP_TYPE_S18 },
1131 	{ },
1132 };
1133 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
1134 
1135 static struct spi_driver mcp23s08_driver = {
1136 	.probe		= mcp23s08_probe,
1137 	.id_table	= mcp23s08_ids,
1138 	.driver = {
1139 		.name	= "mcp23s08",
1140 		.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
1141 	},
1142 };
1143 
1144 static int __init mcp23s08_spi_init(void)
1145 {
1146 	return spi_register_driver(&mcp23s08_driver);
1147 }
1148 
1149 static void mcp23s08_spi_exit(void)
1150 {
1151 	spi_unregister_driver(&mcp23s08_driver);
1152 }
1153 
1154 #else
1155 
1156 static int __init mcp23s08_spi_init(void) { return 0; }
1157 static void mcp23s08_spi_exit(void) { }
1158 
1159 #endif /* CONFIG_SPI_MASTER */
1160 
1161 /*----------------------------------------------------------------------*/
1162 
1163 static int __init mcp23s08_init(void)
1164 {
1165 	int ret;
1166 
1167 	ret = mcp23s08_spi_init();
1168 	if (ret)
1169 		goto spi_fail;
1170 
1171 	ret = mcp23s08_i2c_init();
1172 	if (ret)
1173 		goto i2c_fail;
1174 
1175 	return 0;
1176 
1177  i2c_fail:
1178 	mcp23s08_spi_exit();
1179  spi_fail:
1180 	return ret;
1181 }
1182 /* register after spi/i2c postcore initcall and before
1183  * subsys initcalls that may rely on these GPIOs
1184  */
1185 subsys_initcall(mcp23s08_init);
1186 
1187 static void __exit mcp23s08_exit(void)
1188 {
1189 	mcp23s08_spi_exit();
1190 	mcp23s08_i2c_exit();
1191 }
1192 module_exit(mcp23s08_exit);
1193 
1194 MODULE_LICENSE("GPL");
1195