1 /*
2  * Copyright (C) 2014-2017 Broadcom
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 /*
15  * This file contains the Broadcom Northstar Plus (NSP) GPIO driver that
16  * supports the chipCommonA GPIO controller. Basic PINCONF such as bias,
17  * pull up/down, slew and drive strength are also supported in this driver.
18  *
19  * Pins from the chipCommonA  GPIO can be individually muxed to GPIO function,
20  * through the interaction with the NSP IOMUX controller.
21  */
22 
23 #include <linux/gpio/driver.h>
24 #include <linux/interrupt.h>
25 #include <linux/io.h>
26 #include <linux/ioport.h>
27 #include <linux/kernel.h>
28 #include <linux/of_address.h>
29 #include <linux/of_device.h>
30 #include <linux/of_irq.h>
31 #include <linux/pinctrl/pinconf.h>
32 #include <linux/pinctrl/pinconf-generic.h>
33 #include <linux/pinctrl/pinctrl.h>
34 #include <linux/slab.h>
35 
36 #include "../pinctrl-utils.h"
37 
38 #define NSP_CHIP_A_INT_STATUS		0x00
39 #define NSP_CHIP_A_INT_MASK		0x04
40 #define NSP_GPIO_DATA_IN		0x40
41 #define NSP_GPIO_DATA_OUT		0x44
42 #define NSP_GPIO_OUT_EN			0x48
43 #define NSP_GPIO_INT_POLARITY		0x50
44 #define NSP_GPIO_INT_MASK		0x54
45 #define NSP_GPIO_EVENT			0x58
46 #define NSP_GPIO_EVENT_INT_MASK		0x5c
47 #define NSP_GPIO_EVENT_INT_POLARITY	0x64
48 #define NSP_CHIP_A_GPIO_INT_BIT		0x01
49 
50 /* I/O parameters offset for chipcommon A GPIO */
51 #define NSP_GPIO_DRV_CTRL		0x00
52 #define NSP_GPIO_HYSTERESIS_EN		0x10
53 #define NSP_GPIO_SLEW_RATE_EN		0x14
54 #define NSP_PULL_UP_EN			0x18
55 #define NSP_PULL_DOWN_EN		0x1c
56 #define GPIO_DRV_STRENGTH_BITS		0x03
57 
58 /*
59  * nsp GPIO core
60  *
61  * @dev: pointer to device
62  * @base: I/O register base for nsp GPIO controller
63  * @io_ctrl: I/O register base for PINCONF support outside the GPIO block
64  * @gc: GPIO chip
65  * @pctl: pointer to pinctrl_dev
66  * @pctldesc: pinctrl descriptor
67  * @irq_domain: pointer to irq domain
68  * @lock: lock to protect access to I/O registers
69  */
70 struct nsp_gpio {
71 	struct device *dev;
72 	void __iomem *base;
73 	void __iomem *io_ctrl;
74 	struct gpio_chip gc;
75 	struct pinctrl_dev *pctl;
76 	struct pinctrl_desc pctldesc;
77 	struct irq_domain *irq_domain;
78 	raw_spinlock_t lock;
79 };
80 
81 enum base_type {
82 	REG,
83 	IO_CTRL
84 };
85 
86 /*
87  * Mapping from PINCONF pins to GPIO pins is 1-to-1
88  */
89 static inline unsigned nsp_pin_to_gpio(unsigned pin)
90 {
91 	return pin;
92 }
93 
94 /*
95  *  nsp_set_bit - set or clear one bit (corresponding to the GPIO pin) in a
96  *  nsp GPIO register
97  *
98  *  @nsp_gpio: nsp GPIO device
99  *  @base_type: reg base to modify
100  *  @reg: register offset
101  *  @gpio: GPIO pin
102  *  @set: set or clear
103  */
104 static inline void nsp_set_bit(struct nsp_gpio *chip, enum base_type address,
105 			       unsigned int reg, unsigned gpio, bool set)
106 {
107 	u32 val;
108 	void __iomem *base_address;
109 
110 	if (address == IO_CTRL)
111 		base_address = chip->io_ctrl;
112 	else
113 		base_address = chip->base;
114 
115 	val = readl(base_address + reg);
116 	if (set)
117 		val |= BIT(gpio);
118 	else
119 		val &= ~BIT(gpio);
120 
121 	writel(val, base_address + reg);
122 }
123 
124 /*
125  *  nsp_get_bit - get one bit (corresponding to the GPIO pin) in a
126  *  nsp GPIO register
127  */
128 static inline bool nsp_get_bit(struct nsp_gpio *chip, enum base_type address,
129 			       unsigned int reg, unsigned gpio)
130 {
131 	if (address == IO_CTRL)
132 		return !!(readl(chip->io_ctrl + reg) & BIT(gpio));
133 	else
134 		return !!(readl(chip->base + reg) & BIT(gpio));
135 }
136 
137 static irqreturn_t nsp_gpio_irq_handler(int irq, void *data)
138 {
139 	struct nsp_gpio *chip = (struct nsp_gpio *)data;
140 	struct gpio_chip gc = chip->gc;
141 	int bit;
142 	unsigned long int_bits = 0;
143 	u32 int_status;
144 
145 	/* go through the entire GPIOs and handle all interrupts */
146 	int_status = readl(chip->base + NSP_CHIP_A_INT_STATUS);
147 	if (int_status & NSP_CHIP_A_GPIO_INT_BIT) {
148 		unsigned int event, level;
149 
150 		/* Get level and edge interrupts */
151 		event = readl(chip->base + NSP_GPIO_EVENT_INT_MASK) &
152 			      readl(chip->base + NSP_GPIO_EVENT);
153 		level = readl(chip->base + NSP_GPIO_DATA_IN) ^
154 			      readl(chip->base + NSP_GPIO_INT_POLARITY);
155 		level &= readl(chip->base + NSP_GPIO_INT_MASK);
156 		int_bits = level | event;
157 
158 		for_each_set_bit(bit, &int_bits, gc.ngpio) {
159 			/*
160 			 * Clear the interrupt before invoking the
161 			 * handler, so we do not leave any window
162 			 */
163 			writel(BIT(bit), chip->base + NSP_GPIO_EVENT);
164 			generic_handle_irq(
165 				irq_linear_revmap(chip->irq_domain, bit));
166 		}
167 	}
168 
169 	return  int_bits ? IRQ_HANDLED : IRQ_NONE;
170 }
171 
172 static void nsp_gpio_irq_ack(struct irq_data *d)
173 {
174 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
175 	unsigned gpio = d->hwirq;
176 	u32 val = BIT(gpio);
177 	u32 trigger_type;
178 
179 	trigger_type = irq_get_trigger_type(d->irq);
180 	if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
181 		nsp_set_bit(chip, REG, NSP_GPIO_EVENT, gpio, val);
182 }
183 
184 /*
185  *  nsp_gpio_irq_set_mask - mask/unmask a GPIO interrupt
186  *
187  *  @d: IRQ chip data
188  *  @unmask: mask/unmask GPIO interrupt
189  */
190 static void nsp_gpio_irq_set_mask(struct irq_data *d, bool unmask)
191 {
192 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
193 	unsigned gpio = d->hwirq;
194 	u32 trigger_type;
195 
196 	trigger_type = irq_get_trigger_type(d->irq);
197 	if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
198 		nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_MASK, gpio, unmask);
199 	else
200 		nsp_set_bit(chip, REG, NSP_GPIO_INT_MASK, gpio, unmask);
201 }
202 
203 static void nsp_gpio_irq_mask(struct irq_data *d)
204 {
205 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
206 	unsigned long flags;
207 
208 	raw_spin_lock_irqsave(&chip->lock, flags);
209 	nsp_gpio_irq_set_mask(d, false);
210 	raw_spin_unlock_irqrestore(&chip->lock, flags);
211 }
212 
213 static void nsp_gpio_irq_unmask(struct irq_data *d)
214 {
215 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
216 	unsigned long flags;
217 
218 	raw_spin_lock_irqsave(&chip->lock, flags);
219 	nsp_gpio_irq_set_mask(d, true);
220 	raw_spin_unlock_irqrestore(&chip->lock, flags);
221 }
222 
223 static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
224 {
225 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
226 	unsigned gpio = d->hwirq;
227 	bool level_low;
228 	bool falling;
229 	unsigned long flags;
230 
231 	raw_spin_lock_irqsave(&chip->lock, flags);
232 	falling = nsp_get_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio);
233 	level_low = nsp_get_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio);
234 
235 	switch (type & IRQ_TYPE_SENSE_MASK) {
236 	case IRQ_TYPE_EDGE_RISING:
237 		falling = false;
238 		break;
239 
240 	case IRQ_TYPE_EDGE_FALLING:
241 		falling = true;
242 		break;
243 
244 	case IRQ_TYPE_LEVEL_HIGH:
245 		level_low = false;
246 		break;
247 
248 	case IRQ_TYPE_LEVEL_LOW:
249 		level_low = true;
250 		break;
251 
252 	default:
253 		dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
254 			type);
255 		raw_spin_unlock_irqrestore(&chip->lock, flags);
256 		return -EINVAL;
257 	}
258 
259 	nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio, falling);
260 	nsp_set_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio, level_low);
261 	raw_spin_unlock_irqrestore(&chip->lock, flags);
262 
263 	dev_dbg(chip->dev, "gpio:%u level_low:%s falling:%s\n", gpio,
264 		level_low ? "true" : "false", falling ? "true" : "false");
265 	return 0;
266 }
267 
268 static struct irq_chip nsp_gpio_irq_chip = {
269 	.name = "gpio-a",
270 	.irq_enable = nsp_gpio_irq_unmask,
271 	.irq_disable = nsp_gpio_irq_mask,
272 	.irq_ack = nsp_gpio_irq_ack,
273 	.irq_mask = nsp_gpio_irq_mask,
274 	.irq_unmask = nsp_gpio_irq_unmask,
275 	.irq_set_type = nsp_gpio_irq_set_type,
276 };
277 
278 static int nsp_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
279 {
280 	struct nsp_gpio *chip = gpiochip_get_data(gc);
281 	unsigned long flags;
282 
283 	raw_spin_lock_irqsave(&chip->lock, flags);
284 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, false);
285 	raw_spin_unlock_irqrestore(&chip->lock, flags);
286 
287 	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
288 	return 0;
289 }
290 
291 static int nsp_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
292 				     int val)
293 {
294 	struct nsp_gpio *chip = gpiochip_get_data(gc);
295 	unsigned long flags;
296 
297 	raw_spin_lock_irqsave(&chip->lock, flags);
298 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, true);
299 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
300 	raw_spin_unlock_irqrestore(&chip->lock, flags);
301 
302 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
303 	return 0;
304 }
305 
306 static void nsp_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
307 {
308 	struct nsp_gpio *chip = gpiochip_get_data(gc);
309 	unsigned long flags;
310 
311 	raw_spin_lock_irqsave(&chip->lock, flags);
312 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
313 	raw_spin_unlock_irqrestore(&chip->lock, flags);
314 
315 	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
316 }
317 
318 static int nsp_gpio_get(struct gpio_chip *gc, unsigned gpio)
319 {
320 	struct nsp_gpio *chip = gpiochip_get_data(gc);
321 
322 	return !!(readl(chip->base + NSP_GPIO_DATA_IN) & BIT(gpio));
323 }
324 
325 static int nsp_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
326 {
327 	struct nsp_gpio *chip = gpiochip_get_data(gc);
328 
329 	return irq_linear_revmap(chip->irq_domain, offset);
330 }
331 
332 static int nsp_get_groups_count(struct pinctrl_dev *pctldev)
333 {
334 	return 1;
335 }
336 
337 /*
338  * Only one group: "gpio_grp", since this local pinctrl device only performs
339  * GPIO specific PINCONF configurations
340  */
341 static const char *nsp_get_group_name(struct pinctrl_dev *pctldev,
342 				      unsigned selector)
343 {
344 	return "gpio_grp";
345 }
346 
347 static const struct pinctrl_ops nsp_pctrl_ops = {
348 	.get_groups_count = nsp_get_groups_count,
349 	.get_group_name = nsp_get_group_name,
350 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
351 	.dt_free_map = pinctrl_utils_free_map,
352 };
353 
354 static int nsp_gpio_set_slew(struct nsp_gpio *chip, unsigned gpio, u32 slew)
355 {
356 	if (slew)
357 		nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, true);
358 	else
359 		nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, false);
360 
361 	return 0;
362 }
363 
364 static int nsp_gpio_set_pull(struct nsp_gpio *chip, unsigned gpio,
365 			     bool pull_up, bool pull_down)
366 {
367 	unsigned long flags;
368 
369 	raw_spin_lock_irqsave(&chip->lock, flags);
370 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio, pull_down);
371 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio, pull_up);
372 	raw_spin_unlock_irqrestore(&chip->lock, flags);
373 
374 	dev_dbg(chip->dev, "gpio:%u set pullup:%d pulldown: %d\n",
375 		gpio, pull_up, pull_down);
376 	return 0;
377 }
378 
379 static void nsp_gpio_get_pull(struct nsp_gpio *chip, unsigned gpio,
380 			      bool *pull_up, bool *pull_down)
381 {
382 	unsigned long flags;
383 
384 	raw_spin_lock_irqsave(&chip->lock, flags);
385 	*pull_up = nsp_get_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio);
386 	*pull_down = nsp_get_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio);
387 	raw_spin_unlock_irqrestore(&chip->lock, flags);
388 }
389 
390 static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
391 				 u32 strength)
392 {
393 	u32 offset, shift, i;
394 	u32 val;
395 	unsigned long flags;
396 
397 	/* make sure drive strength is supported */
398 	if (strength < 2 || strength > 16 || (strength % 2))
399 		return -ENOTSUPP;
400 
401 	shift = gpio;
402 	offset = NSP_GPIO_DRV_CTRL;
403 	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
404 		strength);
405 	raw_spin_lock_irqsave(&chip->lock, flags);
406 	strength = (strength / 2) - 1;
407 	for (i = GPIO_DRV_STRENGTH_BITS; i > 0; i--) {
408 		val = readl(chip->io_ctrl + offset);
409 		val &= ~BIT(shift);
410 		val |= ((strength >> (i-1)) & 0x1) << shift;
411 		writel(val, chip->io_ctrl + offset);
412 		offset += 4;
413 	}
414 	raw_spin_unlock_irqrestore(&chip->lock, flags);
415 
416 	return 0;
417 }
418 
419 static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio,
420 				 u16 *strength)
421 {
422 	unsigned int offset, shift;
423 	u32 val;
424 	unsigned long flags;
425 	int i;
426 
427 	offset = NSP_GPIO_DRV_CTRL;
428 	shift = gpio;
429 
430 	raw_spin_lock_irqsave(&chip->lock, flags);
431 	*strength = 0;
432 	for (i = (GPIO_DRV_STRENGTH_BITS - 1); i >= 0; i--) {
433 		val = readl(chip->io_ctrl + offset) & BIT(shift);
434 		val >>= shift;
435 		*strength += (val << i);
436 		offset += 4;
437 	}
438 
439 	/* convert to mA */
440 	*strength = (*strength + 1) * 2;
441 	raw_spin_unlock_irqrestore(&chip->lock, flags);
442 
443 	return 0;
444 }
445 
446 static int nsp_pin_config_group_get(struct pinctrl_dev *pctldev,
447 				    unsigned selector,
448 			     unsigned long *config)
449 {
450 	return 0;
451 }
452 
453 static int nsp_pin_config_group_set(struct pinctrl_dev *pctldev,
454 				    unsigned selector,
455 			     unsigned long *configs, unsigned num_configs)
456 {
457 	return 0;
458 }
459 
460 static int nsp_pin_config_get(struct pinctrl_dev *pctldev, unsigned pin,
461 			      unsigned long *config)
462 {
463 	struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
464 	enum pin_config_param param = pinconf_to_config_param(*config);
465 	unsigned int gpio;
466 	u16 arg = 0;
467 	bool pull_up, pull_down;
468 	int ret;
469 
470 	gpio = nsp_pin_to_gpio(pin);
471 	switch (param) {
472 	case PIN_CONFIG_BIAS_DISABLE:
473 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
474 		if ((pull_up == false) && (pull_down == false))
475 			return 0;
476 		else
477 			return -EINVAL;
478 
479 	case PIN_CONFIG_BIAS_PULL_UP:
480 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
481 		if (pull_up)
482 			return 0;
483 		else
484 			return -EINVAL;
485 
486 	case PIN_CONFIG_BIAS_PULL_DOWN:
487 		nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
488 		if (pull_down)
489 			return 0;
490 		else
491 			return -EINVAL;
492 
493 	case PIN_CONFIG_DRIVE_STRENGTH:
494 		ret = nsp_gpio_get_strength(chip, gpio, &arg);
495 		if (ret)
496 			return ret;
497 		*config = pinconf_to_config_packed(param, arg);
498 		return 0;
499 
500 	default:
501 		return -ENOTSUPP;
502 	}
503 }
504 
505 static int nsp_pin_config_set(struct pinctrl_dev *pctldev, unsigned pin,
506 			      unsigned long *configs, unsigned num_configs)
507 {
508 	struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
509 	enum pin_config_param param;
510 	u32 arg;
511 	unsigned int i, gpio;
512 	int ret = -ENOTSUPP;
513 
514 	gpio = nsp_pin_to_gpio(pin);
515 	for (i = 0; i < num_configs; i++) {
516 		param = pinconf_to_config_param(configs[i]);
517 		arg = pinconf_to_config_argument(configs[i]);
518 
519 		switch (param) {
520 		case PIN_CONFIG_BIAS_DISABLE:
521 			ret = nsp_gpio_set_pull(chip, gpio, false, false);
522 			if (ret < 0)
523 				goto out;
524 			break;
525 
526 		case PIN_CONFIG_BIAS_PULL_UP:
527 			ret = nsp_gpio_set_pull(chip, gpio, true, false);
528 			if (ret < 0)
529 				goto out;
530 			break;
531 
532 		case PIN_CONFIG_BIAS_PULL_DOWN:
533 			ret = nsp_gpio_set_pull(chip, gpio, false, true);
534 			if (ret < 0)
535 				goto out;
536 			break;
537 
538 		case PIN_CONFIG_DRIVE_STRENGTH:
539 			ret = nsp_gpio_set_strength(chip, gpio, arg);
540 			if (ret < 0)
541 				goto out;
542 			break;
543 
544 		case PIN_CONFIG_SLEW_RATE:
545 			ret = nsp_gpio_set_slew(chip, gpio, arg);
546 			if (ret < 0)
547 				goto out;
548 			break;
549 
550 		default:
551 			dev_err(chip->dev, "invalid configuration\n");
552 			return -ENOTSUPP;
553 		}
554 	}
555 
556 out:
557 	return ret;
558 }
559 
560 static const struct pinconf_ops nsp_pconf_ops = {
561 	.is_generic = true,
562 	.pin_config_get = nsp_pin_config_get,
563 	.pin_config_set = nsp_pin_config_set,
564 	.pin_config_group_get = nsp_pin_config_group_get,
565 	.pin_config_group_set = nsp_pin_config_group_set,
566 };
567 
568 /*
569  * NSP GPIO controller supports some PINCONF related configurations such as
570  * pull up, pull down, slew and drive strength, when the pin is configured
571  * to GPIO.
572  *
573  * Here a local pinctrl device is created with simple 1-to-1 pin mapping to the
574  * local GPIO pins
575  */
576 static int nsp_gpio_register_pinconf(struct nsp_gpio *chip)
577 {
578 	struct pinctrl_desc *pctldesc = &chip->pctldesc;
579 	struct pinctrl_pin_desc *pins;
580 	struct gpio_chip *gc = &chip->gc;
581 	int i;
582 
583 	pins = devm_kcalloc(chip->dev, gc->ngpio, sizeof(*pins), GFP_KERNEL);
584 	if (!pins)
585 		return -ENOMEM;
586 	for (i = 0; i < gc->ngpio; i++) {
587 		pins[i].number = i;
588 		pins[i].name = devm_kasprintf(chip->dev, GFP_KERNEL,
589 					      "gpio-%d", i);
590 		if (!pins[i].name)
591 			return -ENOMEM;
592 	}
593 	pctldesc->name = dev_name(chip->dev);
594 	pctldesc->pctlops = &nsp_pctrl_ops;
595 	pctldesc->pins = pins;
596 	pctldesc->npins = gc->ngpio;
597 	pctldesc->confops = &nsp_pconf_ops;
598 
599 	chip->pctl = devm_pinctrl_register(chip->dev, pctldesc, chip);
600 	if (IS_ERR(chip->pctl)) {
601 		dev_err(chip->dev, "unable to register pinctrl device\n");
602 		return PTR_ERR(chip->pctl);
603 	}
604 
605 	return 0;
606 }
607 
608 static const struct of_device_id nsp_gpio_of_match[] = {
609 	{.compatible = "brcm,nsp-gpio-a",},
610 	{}
611 };
612 
613 static int nsp_gpio_probe(struct platform_device *pdev)
614 {
615 	struct device *dev = &pdev->dev;
616 	struct resource *res;
617 	struct nsp_gpio *chip;
618 	struct gpio_chip *gc;
619 	u32 val, count;
620 	int irq, ret;
621 
622 	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &val)) {
623 		dev_err(&pdev->dev, "Missing ngpios OF property\n");
624 		return -ENODEV;
625 	}
626 
627 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
628 	if (!chip)
629 		return -ENOMEM;
630 
631 	chip->dev = dev;
632 	platform_set_drvdata(pdev, chip);
633 
634 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
635 	chip->base = devm_ioremap_resource(dev, res);
636 	if (IS_ERR(chip->base)) {
637 		dev_err(dev, "unable to map I/O memory\n");
638 		return PTR_ERR(chip->base);
639 	}
640 
641 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
642 	chip->io_ctrl = devm_ioremap_resource(dev, res);
643 	if (IS_ERR(chip->io_ctrl)) {
644 		dev_err(dev, "unable to map I/O memory\n");
645 		return PTR_ERR(chip->io_ctrl);
646 	}
647 
648 	raw_spin_lock_init(&chip->lock);
649 	gc = &chip->gc;
650 	gc->base = -1;
651 	gc->can_sleep = false;
652 	gc->ngpio = val;
653 	gc->label = dev_name(dev);
654 	gc->parent = dev;
655 	gc->of_node = dev->of_node;
656 	gc->request = gpiochip_generic_request;
657 	gc->free = gpiochip_generic_free;
658 	gc->direction_input = nsp_gpio_direction_input;
659 	gc->direction_output = nsp_gpio_direction_output;
660 	gc->set = nsp_gpio_set;
661 	gc->get = nsp_gpio_get;
662 	gc->to_irq = nsp_gpio_to_irq;
663 
664 	/* optional GPIO interrupt support */
665 	irq = platform_get_irq(pdev, 0);
666 	if (irq > 0) {
667 		/* Create irq domain so that each pin can be assigned an IRQ.*/
668 		chip->irq_domain = irq_domain_add_linear(gc->of_node, gc->ngpio,
669 							 &irq_domain_simple_ops,
670 							 chip);
671 		if (!chip->irq_domain) {
672 			dev_err(&pdev->dev, "Couldn't allocate IRQ domain\n");
673 			return -ENXIO;
674 		}
675 
676 		/* Map each gpio to an IRQ and set the handler for gpiolib. */
677 		for (count = 0; count < gc->ngpio; count++) {
678 			int irq = irq_create_mapping(chip->irq_domain, count);
679 
680 			irq_set_chip_and_handler(irq, &nsp_gpio_irq_chip,
681 						 handle_simple_irq);
682 			irq_set_chip_data(irq, chip);
683 		}
684 
685 		/* Install ISR for this GPIO controller. */
686 		ret = devm_request_irq(&pdev->dev, irq, nsp_gpio_irq_handler,
687 				       IRQF_SHARED, "gpio-a", chip);
688 		if (ret) {
689 			dev_err(&pdev->dev, "Unable to request IRQ%d: %d\n",
690 				irq, ret);
691 			goto err_rm_gpiochip;
692 		}
693 
694 		val = readl(chip->base + NSP_CHIP_A_INT_MASK);
695 		val = val | NSP_CHIP_A_GPIO_INT_BIT;
696 		writel(val, (chip->base + NSP_CHIP_A_INT_MASK));
697 	}
698 
699 	ret = gpiochip_add_data(gc, chip);
700 	if (ret < 0) {
701 		dev_err(dev, "unable to add GPIO chip\n");
702 		return ret;
703 	}
704 
705 	ret = nsp_gpio_register_pinconf(chip);
706 	if (ret) {
707 		dev_err(dev, "unable to register pinconf\n");
708 		goto err_rm_gpiochip;
709 	}
710 
711 	return 0;
712 
713 err_rm_gpiochip:
714 	gpiochip_remove(gc);
715 
716 	return ret;
717 }
718 
719 static struct platform_driver nsp_gpio_driver = {
720 	.driver = {
721 		.name = "nsp-gpio-a",
722 		.of_match_table = nsp_gpio_of_match,
723 	},
724 	.probe = nsp_gpio_probe,
725 };
726 
727 static int __init nsp_gpio_init(void)
728 {
729 	return platform_driver_register(&nsp_gpio_driver);
730 }
731 arch_initcall_sync(nsp_gpio_init);
732