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