1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2014-2017 Broadcom
3 
4 /*
5  * This file contains the Broadcom Northstar Plus (NSP) GPIO driver that
6  * supports the chipCommonA GPIO controller. Basic PINCONF such as bias,
7  * pull up/down, slew and drive strength are also supported in this driver.
8  *
9  * Pins from the chipCommonA  GPIO can be individually muxed to GPIO function,
10  * through the interaction with the NSP IOMUX controller.
11  */
12 
13 #include <linux/gpio/driver.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/kernel.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/of_irq.h>
21 #include <linux/pinctrl/pinconf.h>
22 #include <linux/pinctrl/pinconf-generic.h>
23 #include <linux/pinctrl/pinctrl.h>
24 #include <linux/slab.h>
25 
26 #include "../pinctrl-utils.h"
27 
28 #define NSP_CHIP_A_INT_STATUS		0x00
29 #define NSP_CHIP_A_INT_MASK		0x04
30 #define NSP_GPIO_DATA_IN		0x40
31 #define NSP_GPIO_DATA_OUT		0x44
32 #define NSP_GPIO_OUT_EN			0x48
33 #define NSP_GPIO_INT_POLARITY		0x50
34 #define NSP_GPIO_INT_MASK		0x54
35 #define NSP_GPIO_EVENT			0x58
36 #define NSP_GPIO_EVENT_INT_MASK		0x5c
37 #define NSP_GPIO_EVENT_INT_POLARITY	0x64
38 #define NSP_CHIP_A_GPIO_INT_BIT		0x01
39 
40 /* I/O parameters offset for chipcommon A GPIO */
41 #define NSP_GPIO_DRV_CTRL		0x00
42 #define NSP_GPIO_HYSTERESIS_EN		0x10
43 #define NSP_GPIO_SLEW_RATE_EN		0x14
44 #define NSP_PULL_UP_EN			0x18
45 #define NSP_PULL_DOWN_EN		0x1c
46 #define GPIO_DRV_STRENGTH_BITS		0x03
47 
48 /*
49  * nsp GPIO core
50  *
51  * @dev: pointer to device
52  * @base: I/O register base for nsp GPIO controller
53  * @io_ctrl: I/O register base for PINCONF support outside the GPIO block
54  * @gc: GPIO chip
55  * @pctl: pointer to pinctrl_dev
56  * @pctldesc: pinctrl descriptor
57  * @lock: lock to protect access to I/O registers
58  */
59 struct nsp_gpio {
60 	struct device *dev;
61 	void __iomem *base;
62 	void __iomem *io_ctrl;
63 	struct irq_chip irqchip;
64 	struct gpio_chip gc;
65 	struct pinctrl_dev *pctl;
66 	struct pinctrl_desc pctldesc;
67 	raw_spinlock_t lock;
68 };
69 
70 enum base_type {
71 	REG,
72 	IO_CTRL
73 };
74 
75 /*
76  * Mapping from PINCONF pins to GPIO pins is 1-to-1
77  */
78 static inline unsigned nsp_pin_to_gpio(unsigned pin)
79 {
80 	return pin;
81 }
82 
83 /*
84  *  nsp_set_bit - set or clear one bit (corresponding to the GPIO pin) in a
85  *  nsp GPIO register
86  *
87  *  @nsp_gpio: nsp GPIO device
88  *  @base_type: reg base to modify
89  *  @reg: register offset
90  *  @gpio: GPIO pin
91  *  @set: set or clear
92  */
93 static inline void nsp_set_bit(struct nsp_gpio *chip, enum base_type address,
94 			       unsigned int reg, unsigned gpio, bool set)
95 {
96 	u32 val;
97 	void __iomem *base_address;
98 
99 	if (address == IO_CTRL)
100 		base_address = chip->io_ctrl;
101 	else
102 		base_address = chip->base;
103 
104 	val = readl(base_address + reg);
105 	if (set)
106 		val |= BIT(gpio);
107 	else
108 		val &= ~BIT(gpio);
109 
110 	writel(val, base_address + reg);
111 }
112 
113 /*
114  *  nsp_get_bit - get one bit (corresponding to the GPIO pin) in a
115  *  nsp GPIO register
116  */
117 static inline bool nsp_get_bit(struct nsp_gpio *chip, enum base_type address,
118 			       unsigned int reg, unsigned gpio)
119 {
120 	if (address == IO_CTRL)
121 		return !!(readl(chip->io_ctrl + reg) & BIT(gpio));
122 	else
123 		return !!(readl(chip->base + reg) & BIT(gpio));
124 }
125 
126 static irqreturn_t nsp_gpio_irq_handler(int irq, void *data)
127 {
128 	struct gpio_chip *gc = (struct gpio_chip *)data;
129 	struct nsp_gpio *chip = gpiochip_get_data(gc);
130 	int bit;
131 	unsigned long int_bits = 0;
132 	u32 int_status;
133 
134 	/* go through the entire GPIOs and handle all interrupts */
135 	int_status = readl(chip->base + NSP_CHIP_A_INT_STATUS);
136 	if (int_status & NSP_CHIP_A_GPIO_INT_BIT) {
137 		unsigned int event, level;
138 
139 		/* Get level and edge interrupts */
140 		event = readl(chip->base + NSP_GPIO_EVENT_INT_MASK) &
141 			      readl(chip->base + NSP_GPIO_EVENT);
142 		level = readl(chip->base + NSP_GPIO_DATA_IN) ^
143 			      readl(chip->base + NSP_GPIO_INT_POLARITY);
144 		level &= readl(chip->base + NSP_GPIO_INT_MASK);
145 		int_bits = level | event;
146 
147 		for_each_set_bit(bit, &int_bits, gc->ngpio)
148 			generic_handle_domain_irq(gc->irq.domain, bit);
149 	}
150 
151 	return  int_bits ? IRQ_HANDLED : IRQ_NONE;
152 }
153 
154 static void nsp_gpio_irq_ack(struct irq_data *d)
155 {
156 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
157 	struct nsp_gpio *chip = gpiochip_get_data(gc);
158 	unsigned gpio = d->hwirq;
159 	u32 val = BIT(gpio);
160 	u32 trigger_type;
161 
162 	trigger_type = irq_get_trigger_type(d->irq);
163 	if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
164 		writel(val, chip->base + NSP_GPIO_EVENT);
165 }
166 
167 /*
168  *  nsp_gpio_irq_set_mask - mask/unmask a GPIO interrupt
169  *
170  *  @d: IRQ chip data
171  *  @unmask: mask/unmask GPIO interrupt
172  */
173 static void nsp_gpio_irq_set_mask(struct irq_data *d, bool unmask)
174 {
175 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
176 	struct nsp_gpio *chip = gpiochip_get_data(gc);
177 	unsigned gpio = d->hwirq;
178 	u32 trigger_type;
179 
180 	trigger_type = irq_get_trigger_type(d->irq);
181 	if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
182 		nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_MASK, gpio, unmask);
183 	else
184 		nsp_set_bit(chip, REG, NSP_GPIO_INT_MASK, gpio, unmask);
185 }
186 
187 static void nsp_gpio_irq_mask(struct irq_data *d)
188 {
189 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
190 	struct nsp_gpio *chip = gpiochip_get_data(gc);
191 	unsigned long flags;
192 
193 	raw_spin_lock_irqsave(&chip->lock, flags);
194 	nsp_gpio_irq_set_mask(d, false);
195 	raw_spin_unlock_irqrestore(&chip->lock, flags);
196 }
197 
198 static void nsp_gpio_irq_unmask(struct irq_data *d)
199 {
200 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
201 	struct nsp_gpio *chip = gpiochip_get_data(gc);
202 	unsigned long flags;
203 
204 	raw_spin_lock_irqsave(&chip->lock, flags);
205 	nsp_gpio_irq_set_mask(d, true);
206 	raw_spin_unlock_irqrestore(&chip->lock, flags);
207 }
208 
209 static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
210 {
211 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
212 	struct nsp_gpio *chip = gpiochip_get_data(gc);
213 	unsigned gpio = d->hwirq;
214 	bool level_low;
215 	bool falling;
216 	unsigned long flags;
217 
218 	raw_spin_lock_irqsave(&chip->lock, flags);
219 	falling = nsp_get_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio);
220 	level_low = nsp_get_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio);
221 
222 	switch (type & IRQ_TYPE_SENSE_MASK) {
223 	case IRQ_TYPE_EDGE_RISING:
224 		falling = false;
225 		break;
226 
227 	case IRQ_TYPE_EDGE_FALLING:
228 		falling = true;
229 		break;
230 
231 	case IRQ_TYPE_LEVEL_HIGH:
232 		level_low = false;
233 		break;
234 
235 	case IRQ_TYPE_LEVEL_LOW:
236 		level_low = true;
237 		break;
238 
239 	default:
240 		dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
241 			type);
242 		raw_spin_unlock_irqrestore(&chip->lock, flags);
243 		return -EINVAL;
244 	}
245 
246 	nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio, falling);
247 	nsp_set_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio, level_low);
248 
249 	if (type & IRQ_TYPE_EDGE_BOTH)
250 		irq_set_handler_locked(d, handle_edge_irq);
251 	else
252 		irq_set_handler_locked(d, handle_level_irq);
253 
254 	raw_spin_unlock_irqrestore(&chip->lock, flags);
255 
256 	dev_dbg(chip->dev, "gpio:%u level_low:%s falling:%s\n", gpio,
257 		level_low ? "true" : "false", falling ? "true" : "false");
258 	return 0;
259 }
260 
261 static int nsp_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
262 {
263 	struct nsp_gpio *chip = gpiochip_get_data(gc);
264 	unsigned long flags;
265 
266 	raw_spin_lock_irqsave(&chip->lock, flags);
267 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, false);
268 	raw_spin_unlock_irqrestore(&chip->lock, flags);
269 
270 	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
271 	return 0;
272 }
273 
274 static int nsp_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
275 				     int val)
276 {
277 	struct nsp_gpio *chip = gpiochip_get_data(gc);
278 	unsigned long flags;
279 
280 	raw_spin_lock_irqsave(&chip->lock, flags);
281 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, true);
282 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
283 	raw_spin_unlock_irqrestore(&chip->lock, flags);
284 
285 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
286 	return 0;
287 }
288 
289 static int nsp_gpio_get_direction(struct gpio_chip *gc, unsigned gpio)
290 {
291 	struct nsp_gpio *chip = gpiochip_get_data(gc);
292 	unsigned long flags;
293 	int val;
294 
295 	raw_spin_lock_irqsave(&chip->lock, flags);
296 	val = nsp_get_bit(chip, REG, NSP_GPIO_OUT_EN, gpio);
297 	raw_spin_unlock_irqrestore(&chip->lock, flags);
298 
299 	return !val;
300 }
301 
302 static void nsp_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
303 {
304 	struct nsp_gpio *chip = gpiochip_get_data(gc);
305 	unsigned long flags;
306 
307 	raw_spin_lock_irqsave(&chip->lock, flags);
308 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
309 	raw_spin_unlock_irqrestore(&chip->lock, flags);
310 
311 	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
312 }
313 
314 static int nsp_gpio_get(struct gpio_chip *gc, unsigned gpio)
315 {
316 	struct nsp_gpio *chip = gpiochip_get_data(gc);
317 
318 	return !!(readl(chip->base + NSP_GPIO_DATA_IN) & BIT(gpio));
319 }
320 
321 static int nsp_get_groups_count(struct pinctrl_dev *pctldev)
322 {
323 	return 1;
324 }
325 
326 /*
327  * Only one group: "gpio_grp", since this local pinctrl device only performs
328  * GPIO specific PINCONF configurations
329  */
330 static const char *nsp_get_group_name(struct pinctrl_dev *pctldev,
331 				      unsigned selector)
332 {
333 	return "gpio_grp";
334 }
335 
336 static const struct pinctrl_ops nsp_pctrl_ops = {
337 	.get_groups_count = nsp_get_groups_count,
338 	.get_group_name = nsp_get_group_name,
339 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
340 	.dt_free_map = pinctrl_utils_free_map,
341 };
342 
343 static int nsp_gpio_set_slew(struct nsp_gpio *chip, unsigned gpio, u32 slew)
344 {
345 	if (slew)
346 		nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, true);
347 	else
348 		nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, false);
349 
350 	return 0;
351 }
352 
353 static int nsp_gpio_set_pull(struct nsp_gpio *chip, unsigned gpio,
354 			     bool pull_up, bool pull_down)
355 {
356 	unsigned long flags;
357 
358 	raw_spin_lock_irqsave(&chip->lock, flags);
359 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio, pull_down);
360 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio, pull_up);
361 	raw_spin_unlock_irqrestore(&chip->lock, flags);
362 
363 	dev_dbg(chip->dev, "gpio:%u set pullup:%d pulldown: %d\n",
364 		gpio, pull_up, pull_down);
365 	return 0;
366 }
367 
368 static void nsp_gpio_get_pull(struct nsp_gpio *chip, unsigned gpio,
369 			      bool *pull_up, bool *pull_down)
370 {
371 	unsigned long flags;
372 
373 	raw_spin_lock_irqsave(&chip->lock, flags);
374 	*pull_up = nsp_get_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio);
375 	*pull_down = nsp_get_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio);
376 	raw_spin_unlock_irqrestore(&chip->lock, flags);
377 }
378 
379 static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
380 				 u32 strength)
381 {
382 	u32 offset, shift, i;
383 	u32 val;
384 	unsigned long flags;
385 
386 	/* make sure drive strength is supported */
387 	if (strength < 2 || strength > 16 || (strength % 2))
388 		return -ENOTSUPP;
389 
390 	shift = gpio;
391 	offset = NSP_GPIO_DRV_CTRL;
392 	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
393 		strength);
394 	raw_spin_lock_irqsave(&chip->lock, flags);
395 	strength = (strength / 2) - 1;
396 	for (i = GPIO_DRV_STRENGTH_BITS; i > 0; i--) {
397 		val = readl(chip->io_ctrl + offset);
398 		val &= ~BIT(shift);
399 		val |= ((strength >> (i-1)) & 0x1) << shift;
400 		writel(val, chip->io_ctrl + offset);
401 		offset += 4;
402 	}
403 	raw_spin_unlock_irqrestore(&chip->lock, flags);
404 
405 	return 0;
406 }
407 
408 static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio,
409 				 u16 *strength)
410 {
411 	unsigned int offset, shift;
412 	u32 val;
413 	unsigned long flags;
414 	int i;
415 
416 	offset = NSP_GPIO_DRV_CTRL;
417 	shift = gpio;
418 
419 	raw_spin_lock_irqsave(&chip->lock, flags);
420 	*strength = 0;
421 	for (i = (GPIO_DRV_STRENGTH_BITS - 1); i >= 0; i--) {
422 		val = readl(chip->io_ctrl + offset) & BIT(shift);
423 		val >>= shift;
424 		*strength += (val << i);
425 		offset += 4;
426 	}
427 
428 	/* convert to mA */
429 	*strength = (*strength + 1) * 2;
430 	raw_spin_unlock_irqrestore(&chip->lock, flags);
431 
432 	return 0;
433 }
434 
435 static int nsp_pin_config_group_get(struct pinctrl_dev *pctldev,
436 				    unsigned selector,
437 			     unsigned long *config)
438 {
439 	return 0;
440 }
441 
442 static int nsp_pin_config_group_set(struct pinctrl_dev *pctldev,
443 				    unsigned selector,
444 			     unsigned long *configs, unsigned num_configs)
445 {
446 	return 0;
447 }
448 
449 static int nsp_pin_config_get(struct pinctrl_dev *pctldev, unsigned pin,
450 			      unsigned long *config)
451 {
452 	struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
453 	enum pin_config_param param = pinconf_to_config_param(*config);
454 	unsigned int gpio;
455 	u16 arg = 0;
456 	bool pull_up, pull_down;
457 	int ret;
458 
459 	gpio = nsp_pin_to_gpio(pin);
460 	switch (param) {
461 	case PIN_CONFIG_BIAS_DISABLE:
462 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
463 		if ((pull_up == false) && (pull_down == false))
464 			return 0;
465 		else
466 			return -EINVAL;
467 
468 	case PIN_CONFIG_BIAS_PULL_UP:
469 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
470 		if (pull_up)
471 			return 0;
472 		else
473 			return -EINVAL;
474 
475 	case PIN_CONFIG_BIAS_PULL_DOWN:
476 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
477 		if (pull_down)
478 			return 0;
479 		else
480 			return -EINVAL;
481 
482 	case PIN_CONFIG_DRIVE_STRENGTH:
483 		ret = nsp_gpio_get_strength(chip, gpio, &arg);
484 		if (ret)
485 			return ret;
486 		*config = pinconf_to_config_packed(param, arg);
487 		return 0;
488 
489 	default:
490 		return -ENOTSUPP;
491 	}
492 }
493 
494 static int nsp_pin_config_set(struct pinctrl_dev *pctldev, unsigned pin,
495 			      unsigned long *configs, unsigned num_configs)
496 {
497 	struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
498 	enum pin_config_param param;
499 	u32 arg;
500 	unsigned int i, gpio;
501 	int ret = -ENOTSUPP;
502 
503 	gpio = nsp_pin_to_gpio(pin);
504 	for (i = 0; i < num_configs; i++) {
505 		param = pinconf_to_config_param(configs[i]);
506 		arg = pinconf_to_config_argument(configs[i]);
507 
508 		switch (param) {
509 		case PIN_CONFIG_BIAS_DISABLE:
510 			ret = nsp_gpio_set_pull(chip, gpio, false, false);
511 			if (ret < 0)
512 				goto out;
513 			break;
514 
515 		case PIN_CONFIG_BIAS_PULL_UP:
516 			ret = nsp_gpio_set_pull(chip, gpio, true, false);
517 			if (ret < 0)
518 				goto out;
519 			break;
520 
521 		case PIN_CONFIG_BIAS_PULL_DOWN:
522 			ret = nsp_gpio_set_pull(chip, gpio, false, true);
523 			if (ret < 0)
524 				goto out;
525 			break;
526 
527 		case PIN_CONFIG_DRIVE_STRENGTH:
528 			ret = nsp_gpio_set_strength(chip, gpio, arg);
529 			if (ret < 0)
530 				goto out;
531 			break;
532 
533 		case PIN_CONFIG_SLEW_RATE:
534 			ret = nsp_gpio_set_slew(chip, gpio, arg);
535 			if (ret < 0)
536 				goto out;
537 			break;
538 
539 		default:
540 			dev_err(chip->dev, "invalid configuration\n");
541 			return -ENOTSUPP;
542 		}
543 	}
544 
545 out:
546 	return ret;
547 }
548 
549 static const struct pinconf_ops nsp_pconf_ops = {
550 	.is_generic = true,
551 	.pin_config_get = nsp_pin_config_get,
552 	.pin_config_set = nsp_pin_config_set,
553 	.pin_config_group_get = nsp_pin_config_group_get,
554 	.pin_config_group_set = nsp_pin_config_group_set,
555 };
556 
557 /*
558  * NSP GPIO controller supports some PINCONF related configurations such as
559  * pull up, pull down, slew and drive strength, when the pin is configured
560  * to GPIO.
561  *
562  * Here a local pinctrl device is created with simple 1-to-1 pin mapping to the
563  * local GPIO pins
564  */
565 static int nsp_gpio_register_pinconf(struct nsp_gpio *chip)
566 {
567 	struct pinctrl_desc *pctldesc = &chip->pctldesc;
568 	struct pinctrl_pin_desc *pins;
569 	struct gpio_chip *gc = &chip->gc;
570 	int i;
571 
572 	pins = devm_kcalloc(chip->dev, gc->ngpio, sizeof(*pins), GFP_KERNEL);
573 	if (!pins)
574 		return -ENOMEM;
575 	for (i = 0; i < gc->ngpio; i++) {
576 		pins[i].number = i;
577 		pins[i].name = devm_kasprintf(chip->dev, GFP_KERNEL,
578 					      "gpio-%d", i);
579 		if (!pins[i].name)
580 			return -ENOMEM;
581 	}
582 	pctldesc->name = dev_name(chip->dev);
583 	pctldesc->pctlops = &nsp_pctrl_ops;
584 	pctldesc->pins = pins;
585 	pctldesc->npins = gc->ngpio;
586 	pctldesc->confops = &nsp_pconf_ops;
587 
588 	chip->pctl = devm_pinctrl_register(chip->dev, pctldesc, chip);
589 	if (IS_ERR(chip->pctl)) {
590 		dev_err(chip->dev, "unable to register pinctrl device\n");
591 		return PTR_ERR(chip->pctl);
592 	}
593 
594 	return 0;
595 }
596 
597 static const struct of_device_id nsp_gpio_of_match[] = {
598 	{.compatible = "brcm,nsp-gpio-a",},
599 	{}
600 };
601 
602 static int nsp_gpio_probe(struct platform_device *pdev)
603 {
604 	struct device *dev = &pdev->dev;
605 	struct nsp_gpio *chip;
606 	struct gpio_chip *gc;
607 	u32 val;
608 	int irq, ret;
609 
610 	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &val)) {
611 		dev_err(&pdev->dev, "Missing ngpios OF property\n");
612 		return -ENODEV;
613 	}
614 
615 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
616 	if (!chip)
617 		return -ENOMEM;
618 
619 	chip->dev = dev;
620 	platform_set_drvdata(pdev, chip);
621 
622 	chip->base = devm_platform_ioremap_resource(pdev, 0);
623 	if (IS_ERR(chip->base)) {
624 		dev_err(dev, "unable to map I/O memory\n");
625 		return PTR_ERR(chip->base);
626 	}
627 
628 	chip->io_ctrl = devm_platform_ioremap_resource(pdev, 1);
629 	if (IS_ERR(chip->io_ctrl)) {
630 		dev_err(dev, "unable to map I/O memory\n");
631 		return PTR_ERR(chip->io_ctrl);
632 	}
633 
634 	raw_spin_lock_init(&chip->lock);
635 	gc = &chip->gc;
636 	gc->base = -1;
637 	gc->can_sleep = false;
638 	gc->ngpio = val;
639 	gc->label = dev_name(dev);
640 	gc->parent = dev;
641 	gc->request = gpiochip_generic_request;
642 	gc->free = gpiochip_generic_free;
643 	gc->direction_input = nsp_gpio_direction_input;
644 	gc->direction_output = nsp_gpio_direction_output;
645 	gc->get_direction = nsp_gpio_get_direction;
646 	gc->set = nsp_gpio_set;
647 	gc->get = nsp_gpio_get;
648 
649 	/* optional GPIO interrupt support */
650 	irq = platform_get_irq(pdev, 0);
651 	if (irq > 0) {
652 		struct gpio_irq_chip *girq;
653 		struct irq_chip *irqc;
654 
655 		irqc = &chip->irqchip;
656 		irqc->name = "gpio-a";
657 		irqc->irq_ack = nsp_gpio_irq_ack;
658 		irqc->irq_mask = nsp_gpio_irq_mask;
659 		irqc->irq_unmask = nsp_gpio_irq_unmask;
660 		irqc->irq_set_type = nsp_gpio_irq_set_type;
661 
662 		val = readl(chip->base + NSP_CHIP_A_INT_MASK);
663 		val = val | NSP_CHIP_A_GPIO_INT_BIT;
664 		writel(val, (chip->base + NSP_CHIP_A_INT_MASK));
665 
666 		/* Install ISR for this GPIO controller. */
667 		ret = devm_request_irq(dev, irq, nsp_gpio_irq_handler,
668 				       IRQF_SHARED, "gpio-a", &chip->gc);
669 		if (ret) {
670 			dev_err(&pdev->dev, "Unable to request IRQ%d: %d\n",
671 				irq, ret);
672 			return ret;
673 		}
674 
675 		girq = &chip->gc.irq;
676 		girq->chip = irqc;
677 		/* This will let us handle the parent IRQ in the driver */
678 		girq->parent_handler = NULL;
679 		girq->num_parents = 0;
680 		girq->parents = NULL;
681 		girq->default_type = IRQ_TYPE_NONE;
682 		girq->handler = handle_bad_irq;
683 	}
684 
685 	ret = devm_gpiochip_add_data(dev, gc, chip);
686 	if (ret < 0) {
687 		dev_err(dev, "unable to add GPIO chip\n");
688 		return ret;
689 	}
690 
691 	ret = nsp_gpio_register_pinconf(chip);
692 	if (ret) {
693 		dev_err(dev, "unable to register pinconf\n");
694 		return ret;
695 	}
696 
697 	return 0;
698 }
699 
700 static struct platform_driver nsp_gpio_driver = {
701 	.driver = {
702 		.name = "nsp-gpio-a",
703 		.of_match_table = nsp_gpio_of_match,
704 	},
705 	.probe = nsp_gpio_probe,
706 };
707 
708 static int __init nsp_gpio_init(void)
709 {
710 	return platform_driver_register(&nsp_gpio_driver);
711 }
712 arch_initcall_sync(nsp_gpio_init);
713