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 */
58struct 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
68enum base_type {
69	REG,
70	IO_CTRL
71};
72
73/*
74 * Mapping from PINCONF pins to GPIO pins is 1-to-1
75 */
76static 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 */
91static 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 */
115static 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
124static 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
152static 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 */
171static 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
185static 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
197static 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
209static 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
261static 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
271static 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
284static 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
299static 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
312static 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
324static 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
331static 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 */
340static const char *nsp_get_group_name(struct pinctrl_dev *pctldev,
341				      unsigned selector)
342{
343	return "gpio_grp";
344}
345
346static 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
353static 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
363static 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
378static 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
389static 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
418static 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
445static int nsp_pin_config_group_get(struct pinctrl_dev *pctldev,
446				    unsigned selector,
447			     unsigned long *config)
448{
449	return 0;
450}
451
452static 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
459static 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
504static 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
555out:
556	return ret;
557}
558
559static 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 */
575static 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
607static const struct of_device_id nsp_gpio_of_match[] = {
608	{.compatible = "brcm,nsp-gpio-a",},
609	{}
610};
611
612static 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
700static 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
708static int __init nsp_gpio_init(void)
709{
710	return platform_driver_register(&nsp_gpio_driver);
711}
712arch_initcall_sync(nsp_gpio_init);
713