xref: /linux/drivers/gpio/gpio-bcm-kona.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 /*
2  * Broadcom Kona GPIO Driver
3  *
4  * Author: Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>
5  * Copyright (C) 2012-2014 Broadcom Corporation
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation version 2.
10  *
11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12  * kind, whether express or implied; without even the implied warranty
13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/bitops.h>
18 #include <linux/err.h>
19 #include <linux/io.h>
20 #include <linux/gpio/driver.h>
21 #include <linux/of_device.h>
22 #include <linux/of_irq.h>
23 #include <linux/init.h>
24 #include <linux/irqdomain.h>
25 #include <linux/irqchip/chained_irq.h>
26 
27 #define BCM_GPIO_PASSWD				0x00a5a501
28 #define GPIO_PER_BANK				32
29 #define GPIO_MAX_BANK_NUM			8
30 
31 #define GPIO_BANK(gpio)				((gpio) >> 5)
32 #define GPIO_BIT(gpio)				((gpio) & (GPIO_PER_BANK - 1))
33 
34 /* There is a GPIO control register for each GPIO */
35 #define GPIO_CONTROL(gpio)			(0x00000100 + ((gpio) << 2))
36 
37 /* The remaining registers are per GPIO bank */
38 #define GPIO_OUT_STATUS(bank)			(0x00000000 + ((bank) << 2))
39 #define GPIO_IN_STATUS(bank)			(0x00000020 + ((bank) << 2))
40 #define GPIO_OUT_SET(bank)			(0x00000040 + ((bank) << 2))
41 #define GPIO_OUT_CLEAR(bank)			(0x00000060 + ((bank) << 2))
42 #define GPIO_INT_STATUS(bank)			(0x00000080 + ((bank) << 2))
43 #define GPIO_INT_MASK(bank)			(0x000000a0 + ((bank) << 2))
44 #define GPIO_INT_MSKCLR(bank)			(0x000000c0 + ((bank) << 2))
45 #define GPIO_PWD_STATUS(bank)			(0x00000500 + ((bank) << 2))
46 
47 #define GPIO_GPPWR_OFFSET			0x00000520
48 
49 #define GPIO_GPCTR0_DBR_SHIFT			5
50 #define GPIO_GPCTR0_DBR_MASK			0x000001e0
51 
52 #define GPIO_GPCTR0_ITR_SHIFT			3
53 #define GPIO_GPCTR0_ITR_MASK			0x00000018
54 #define GPIO_GPCTR0_ITR_CMD_RISING_EDGE		0x00000001
55 #define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE	0x00000002
56 #define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE		0x00000003
57 
58 #define GPIO_GPCTR0_IOTR_MASK			0x00000001
59 #define GPIO_GPCTR0_IOTR_CMD_0UTPUT		0x00000000
60 #define GPIO_GPCTR0_IOTR_CMD_INPUT		0x00000001
61 
62 #define GPIO_GPCTR0_DB_ENABLE_MASK		0x00000100
63 
64 #define LOCK_CODE				0xffffffff
65 #define UNLOCK_CODE				0x00000000
66 
67 struct bcm_kona_gpio {
68 	void __iomem *reg_base;
69 	int num_bank;
70 	raw_spinlock_t lock;
71 	struct gpio_chip gpio_chip;
72 	struct irq_domain *irq_domain;
73 	struct bcm_kona_gpio_bank *banks;
74 	struct platform_device *pdev;
75 };
76 
77 struct bcm_kona_gpio_bank {
78 	int id;
79 	int irq;
80 	/* Used in the interrupt handler */
81 	struct bcm_kona_gpio *kona_gpio;
82 };
83 
84 static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
85 						int bank_id, u32 lockcode)
86 {
87 	writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
88 	writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
89 }
90 
91 static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
92 					unsigned gpio)
93 {
94 	u32 val;
95 	unsigned long flags;
96 	int bank_id = GPIO_BANK(gpio);
97 
98 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
99 
100 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
101 	val |= BIT(gpio);
102 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
103 
104 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
105 }
106 
107 static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
108 					unsigned gpio)
109 {
110 	u32 val;
111 	unsigned long flags;
112 	int bank_id = GPIO_BANK(gpio);
113 
114 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
115 
116 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
117 	val &= ~BIT(gpio);
118 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
119 
120 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
121 }
122 
123 static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
124 {
125 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
126 	void __iomem *reg_base = kona_gpio->reg_base;
127 	u32 val;
128 
129 	val = readl(reg_base + GPIO_CONTROL(gpio)) & GPIO_GPCTR0_IOTR_MASK;
130 	return !!val;
131 }
132 
133 static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
134 {
135 	struct bcm_kona_gpio *kona_gpio;
136 	void __iomem *reg_base;
137 	int bank_id = GPIO_BANK(gpio);
138 	int bit = GPIO_BIT(gpio);
139 	u32 val, reg_offset;
140 	unsigned long flags;
141 
142 	kona_gpio = gpiochip_get_data(chip);
143 	reg_base = kona_gpio->reg_base;
144 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
145 
146 	/* this function only applies to output pin */
147 	if (bcm_kona_gpio_get_dir(chip, gpio) == 1)
148 		goto out;
149 
150 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
151 
152 	val = readl(reg_base + reg_offset);
153 	val |= BIT(bit);
154 	writel(val, reg_base + reg_offset);
155 
156 out:
157 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
158 }
159 
160 static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
161 {
162 	struct bcm_kona_gpio *kona_gpio;
163 	void __iomem *reg_base;
164 	int bank_id = GPIO_BANK(gpio);
165 	int bit = GPIO_BIT(gpio);
166 	u32 val, reg_offset;
167 	unsigned long flags;
168 
169 	kona_gpio = gpiochip_get_data(chip);
170 	reg_base = kona_gpio->reg_base;
171 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
172 
173 	if (bcm_kona_gpio_get_dir(chip, gpio) == 1)
174 		reg_offset = GPIO_IN_STATUS(bank_id);
175 	else
176 		reg_offset = GPIO_OUT_STATUS(bank_id);
177 
178 	/* read the GPIO bank status */
179 	val = readl(reg_base + reg_offset);
180 
181 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
182 
183 	/* return the specified bit status */
184 	return !!(val & BIT(bit));
185 }
186 
187 static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
188 {
189 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
190 
191 	bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
192 	return 0;
193 }
194 
195 static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
196 {
197 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
198 
199 	bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
200 }
201 
202 static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
203 {
204 	struct bcm_kona_gpio *kona_gpio;
205 	void __iomem *reg_base;
206 	u32 val;
207 	unsigned long flags;
208 
209 	kona_gpio = gpiochip_get_data(chip);
210 	reg_base = kona_gpio->reg_base;
211 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
212 
213 	val = readl(reg_base + GPIO_CONTROL(gpio));
214 	val &= ~GPIO_GPCTR0_IOTR_MASK;
215 	val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
216 	writel(val, reg_base + GPIO_CONTROL(gpio));
217 
218 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
219 
220 	return 0;
221 }
222 
223 static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
224 					  unsigned gpio, int value)
225 {
226 	struct bcm_kona_gpio *kona_gpio;
227 	void __iomem *reg_base;
228 	int bank_id = GPIO_BANK(gpio);
229 	int bit = GPIO_BIT(gpio);
230 	u32 val, reg_offset;
231 	unsigned long flags;
232 
233 	kona_gpio = gpiochip_get_data(chip);
234 	reg_base = kona_gpio->reg_base;
235 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
236 
237 	val = readl(reg_base + GPIO_CONTROL(gpio));
238 	val &= ~GPIO_GPCTR0_IOTR_MASK;
239 	val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
240 	writel(val, reg_base + GPIO_CONTROL(gpio));
241 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
242 
243 	val = readl(reg_base + reg_offset);
244 	val |= BIT(bit);
245 	writel(val, reg_base + reg_offset);
246 
247 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
248 
249 	return 0;
250 }
251 
252 static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
253 {
254 	struct bcm_kona_gpio *kona_gpio;
255 
256 	kona_gpio = gpiochip_get_data(chip);
257 	if (gpio >= kona_gpio->gpio_chip.ngpio)
258 		return -ENXIO;
259 	return irq_create_mapping(kona_gpio->irq_domain, gpio);
260 }
261 
262 static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
263 				      unsigned debounce)
264 {
265 	struct bcm_kona_gpio *kona_gpio;
266 	void __iomem *reg_base;
267 	u32 val, res;
268 	unsigned long flags;
269 
270 	kona_gpio = gpiochip_get_data(chip);
271 	reg_base = kona_gpio->reg_base;
272 	/* debounce must be 1-128ms (or 0) */
273 	if ((debounce > 0 && debounce < 1000) || debounce > 128000) {
274 		dev_err(chip->parent, "Debounce value %u not in range\n",
275 			debounce);
276 		return -EINVAL;
277 	}
278 
279 	/* calculate debounce bit value */
280 	if (debounce != 0) {
281 		/* Convert to ms */
282 		debounce /= 1000;
283 		/* find the MSB */
284 		res = fls(debounce) - 1;
285 		/* Check if MSB-1 is set (round up or down) */
286 		if (res > 0 && (debounce & BIT(res - 1)))
287 			res++;
288 	}
289 
290 	/* spin lock for read-modify-write of the GPIO register */
291 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
292 
293 	val = readl(reg_base + GPIO_CONTROL(gpio));
294 	val &= ~GPIO_GPCTR0_DBR_MASK;
295 
296 	if (debounce == 0) {
297 		/* disable debounce */
298 		val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
299 	} else {
300 		val |= GPIO_GPCTR0_DB_ENABLE_MASK |
301 		    (res << GPIO_GPCTR0_DBR_SHIFT);
302 	}
303 
304 	writel(val, reg_base + GPIO_CONTROL(gpio));
305 
306 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
307 
308 	return 0;
309 }
310 
311 static int bcm_kona_gpio_set_config(struct gpio_chip *chip, unsigned gpio,
312 				    unsigned long config)
313 {
314 	u32 debounce;
315 
316 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
317 		return -ENOTSUPP;
318 
319 	debounce = pinconf_to_config_argument(config);
320 	return bcm_kona_gpio_set_debounce(chip, gpio, debounce);
321 }
322 
323 static const struct gpio_chip template_chip = {
324 	.label = "bcm-kona-gpio",
325 	.owner = THIS_MODULE,
326 	.request = bcm_kona_gpio_request,
327 	.free = bcm_kona_gpio_free,
328 	.get_direction = bcm_kona_gpio_get_dir,
329 	.direction_input = bcm_kona_gpio_direction_input,
330 	.get = bcm_kona_gpio_get,
331 	.direction_output = bcm_kona_gpio_direction_output,
332 	.set = bcm_kona_gpio_set,
333 	.set_config = bcm_kona_gpio_set_config,
334 	.to_irq = bcm_kona_gpio_to_irq,
335 	.base = 0,
336 };
337 
338 static void bcm_kona_gpio_irq_ack(struct irq_data *d)
339 {
340 	struct bcm_kona_gpio *kona_gpio;
341 	void __iomem *reg_base;
342 	unsigned gpio = d->hwirq;
343 	int bank_id = GPIO_BANK(gpio);
344 	int bit = GPIO_BIT(gpio);
345 	u32 val;
346 	unsigned long flags;
347 
348 	kona_gpio = irq_data_get_irq_chip_data(d);
349 	reg_base = kona_gpio->reg_base;
350 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
351 
352 	val = readl(reg_base + GPIO_INT_STATUS(bank_id));
353 	val |= BIT(bit);
354 	writel(val, reg_base + GPIO_INT_STATUS(bank_id));
355 
356 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
357 }
358 
359 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
360 {
361 	struct bcm_kona_gpio *kona_gpio;
362 	void __iomem *reg_base;
363 	unsigned gpio = d->hwirq;
364 	int bank_id = GPIO_BANK(gpio);
365 	int bit = GPIO_BIT(gpio);
366 	u32 val;
367 	unsigned long flags;
368 
369 	kona_gpio = irq_data_get_irq_chip_data(d);
370 	reg_base = kona_gpio->reg_base;
371 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
372 
373 	val = readl(reg_base + GPIO_INT_MASK(bank_id));
374 	val |= BIT(bit);
375 	writel(val, reg_base + GPIO_INT_MASK(bank_id));
376 	gpiochip_disable_irq(&kona_gpio->gpio_chip, gpio);
377 
378 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
379 }
380 
381 static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
382 {
383 	struct bcm_kona_gpio *kona_gpio;
384 	void __iomem *reg_base;
385 	unsigned gpio = d->hwirq;
386 	int bank_id = GPIO_BANK(gpio);
387 	int bit = GPIO_BIT(gpio);
388 	u32 val;
389 	unsigned long flags;
390 
391 	kona_gpio = irq_data_get_irq_chip_data(d);
392 	reg_base = kona_gpio->reg_base;
393 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
394 
395 	val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
396 	val |= BIT(bit);
397 	writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
398 	gpiochip_enable_irq(&kona_gpio->gpio_chip, gpio);
399 
400 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
401 }
402 
403 static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
404 {
405 	struct bcm_kona_gpio *kona_gpio;
406 	void __iomem *reg_base;
407 	unsigned gpio = d->hwirq;
408 	u32 lvl_type;
409 	u32 val;
410 	unsigned long flags;
411 
412 	kona_gpio = irq_data_get_irq_chip_data(d);
413 	reg_base = kona_gpio->reg_base;
414 	switch (type & IRQ_TYPE_SENSE_MASK) {
415 	case IRQ_TYPE_EDGE_RISING:
416 		lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
417 		break;
418 
419 	case IRQ_TYPE_EDGE_FALLING:
420 		lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
421 		break;
422 
423 	case IRQ_TYPE_EDGE_BOTH:
424 		lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
425 		break;
426 
427 	case IRQ_TYPE_LEVEL_HIGH:
428 	case IRQ_TYPE_LEVEL_LOW:
429 		/* BCM GPIO doesn't support level triggering */
430 	default:
431 		dev_err(kona_gpio->gpio_chip.parent,
432 			"Invalid BCM GPIO irq type 0x%x\n", type);
433 		return -EINVAL;
434 	}
435 
436 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
437 
438 	val = readl(reg_base + GPIO_CONTROL(gpio));
439 	val &= ~GPIO_GPCTR0_ITR_MASK;
440 	val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
441 	writel(val, reg_base + GPIO_CONTROL(gpio));
442 
443 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
444 
445 	return 0;
446 }
447 
448 static void bcm_kona_gpio_irq_handler(struct irq_desc *desc)
449 {
450 	void __iomem *reg_base;
451 	int bit, bank_id;
452 	unsigned long sta;
453 	struct bcm_kona_gpio_bank *bank = irq_desc_get_handler_data(desc);
454 	struct irq_chip *chip = irq_desc_get_chip(desc);
455 
456 	chained_irq_enter(chip, desc);
457 
458 	/*
459 	 * For bank interrupts, we can't use chip_data to store the kona_gpio
460 	 * pointer, since GIC needs it for its own purposes. Therefore, we get
461 	 * our pointer from the bank structure.
462 	 */
463 	reg_base = bank->kona_gpio->reg_base;
464 	bank_id = bank->id;
465 
466 	while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
467 		    (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
468 		for_each_set_bit(bit, &sta, 32) {
469 			int hwirq = GPIO_PER_BANK * bank_id + bit;
470 			int child_irq =
471 				irq_find_mapping(bank->kona_gpio->irq_domain,
472 						 hwirq);
473 			/*
474 			 * Clear interrupt before handler is called so we don't
475 			 * miss any interrupt occurred during executing them.
476 			 */
477 			writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
478 			       BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
479 			/* Invoke interrupt handler */
480 			generic_handle_irq(child_irq);
481 		}
482 	}
483 
484 	chained_irq_exit(chip, desc);
485 }
486 
487 static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
488 {
489 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
490 
491 	return gpiochip_reqres_irq(&kona_gpio->gpio_chip, d->hwirq);
492 }
493 
494 static void bcm_kona_gpio_irq_relres(struct irq_data *d)
495 {
496 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
497 
498 	gpiochip_relres_irq(&kona_gpio->gpio_chip, d->hwirq);
499 }
500 
501 static struct irq_chip bcm_gpio_irq_chip = {
502 	.name = "bcm-kona-gpio",
503 	.irq_ack = bcm_kona_gpio_irq_ack,
504 	.irq_mask = bcm_kona_gpio_irq_mask,
505 	.irq_unmask = bcm_kona_gpio_irq_unmask,
506 	.irq_set_type = bcm_kona_gpio_irq_set_type,
507 	.irq_request_resources = bcm_kona_gpio_irq_reqres,
508 	.irq_release_resources = bcm_kona_gpio_irq_relres,
509 };
510 
511 static struct of_device_id const bcm_kona_gpio_of_match[] = {
512 	{ .compatible = "brcm,kona-gpio" },
513 	{}
514 };
515 
516 /*
517  * This lock class tells lockdep that GPIO irqs are in a different
518  * category than their parents, so it won't report false recursion.
519  */
520 static struct lock_class_key gpio_lock_class;
521 static struct lock_class_key gpio_request_class;
522 
523 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
524 				 irq_hw_number_t hwirq)
525 {
526 	int ret;
527 
528 	ret = irq_set_chip_data(irq, d->host_data);
529 	if (ret < 0)
530 		return ret;
531 	irq_set_lockdep_class(irq, &gpio_lock_class, &gpio_request_class);
532 	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
533 	irq_set_noprobe(irq);
534 
535 	return 0;
536 }
537 
538 static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
539 {
540 	irq_set_chip_and_handler(irq, NULL, NULL);
541 	irq_set_chip_data(irq, NULL);
542 }
543 
544 static const struct irq_domain_ops bcm_kona_irq_ops = {
545 	.map = bcm_kona_gpio_irq_map,
546 	.unmap = bcm_kona_gpio_irq_unmap,
547 	.xlate = irq_domain_xlate_twocell,
548 };
549 
550 static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
551 {
552 	void __iomem *reg_base;
553 	int i;
554 
555 	reg_base = kona_gpio->reg_base;
556 	/* disable interrupts and clear status */
557 	for (i = 0; i < kona_gpio->num_bank; i++) {
558 		/* Unlock the entire bank first */
559 		bcm_kona_gpio_write_lock_regs(reg_base, i, UNLOCK_CODE);
560 		writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
561 		writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
562 		/* Now re-lock the bank */
563 		bcm_kona_gpio_write_lock_regs(reg_base, i, LOCK_CODE);
564 	}
565 }
566 
567 static int bcm_kona_gpio_probe(struct platform_device *pdev)
568 {
569 	struct device *dev = &pdev->dev;
570 	const struct of_device_id *match;
571 	struct bcm_kona_gpio_bank *bank;
572 	struct bcm_kona_gpio *kona_gpio;
573 	struct gpio_chip *chip;
574 	int ret;
575 	int i;
576 
577 	match = of_match_device(bcm_kona_gpio_of_match, dev);
578 	if (!match) {
579 		dev_err(dev, "Failed to find gpio controller\n");
580 		return -ENODEV;
581 	}
582 
583 	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
584 	if (!kona_gpio)
585 		return -ENOMEM;
586 
587 	kona_gpio->gpio_chip = template_chip;
588 	chip = &kona_gpio->gpio_chip;
589 	kona_gpio->num_bank = of_irq_count(dev->of_node);
590 	if (kona_gpio->num_bank == 0) {
591 		dev_err(dev, "Couldn't determine # GPIO banks\n");
592 		return -ENOENT;
593 	}
594 	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
595 		dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
596 			GPIO_MAX_BANK_NUM);
597 		return -ENXIO;
598 	}
599 	kona_gpio->banks = devm_kcalloc(dev,
600 					kona_gpio->num_bank,
601 					sizeof(*kona_gpio->banks),
602 					GFP_KERNEL);
603 	if (!kona_gpio->banks)
604 		return -ENOMEM;
605 
606 	kona_gpio->pdev = pdev;
607 	platform_set_drvdata(pdev, kona_gpio);
608 	chip->of_node = dev->of_node;
609 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
610 
611 	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
612 						      chip->ngpio,
613 						      &bcm_kona_irq_ops,
614 						      kona_gpio);
615 	if (!kona_gpio->irq_domain) {
616 		dev_err(dev, "Couldn't allocate IRQ domain\n");
617 		return -ENXIO;
618 	}
619 
620 	kona_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
621 	if (IS_ERR(kona_gpio->reg_base)) {
622 		ret = -ENXIO;
623 		goto err_irq_domain;
624 	}
625 
626 	for (i = 0; i < kona_gpio->num_bank; i++) {
627 		bank = &kona_gpio->banks[i];
628 		bank->id = i;
629 		bank->irq = platform_get_irq(pdev, i);
630 		bank->kona_gpio = kona_gpio;
631 		if (bank->irq < 0) {
632 			dev_err(dev, "Couldn't get IRQ for bank %d", i);
633 			ret = -ENOENT;
634 			goto err_irq_domain;
635 		}
636 	}
637 
638 	dev_info(&pdev->dev, "Setting up Kona GPIO\n");
639 
640 	bcm_kona_gpio_reset(kona_gpio);
641 
642 	ret = devm_gpiochip_add_data(dev, chip, kona_gpio);
643 	if (ret < 0) {
644 		dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
645 		goto err_irq_domain;
646 	}
647 	for (i = 0; i < kona_gpio->num_bank; i++) {
648 		bank = &kona_gpio->banks[i];
649 		irq_set_chained_handler_and_data(bank->irq,
650 						 bcm_kona_gpio_irq_handler,
651 						 bank);
652 	}
653 
654 	raw_spin_lock_init(&kona_gpio->lock);
655 
656 	return 0;
657 
658 err_irq_domain:
659 	irq_domain_remove(kona_gpio->irq_domain);
660 
661 	return ret;
662 }
663 
664 static struct platform_driver bcm_kona_gpio_driver = {
665 	.driver = {
666 			.name = "bcm-kona-gpio",
667 			.of_match_table = bcm_kona_gpio_of_match,
668 	},
669 	.probe = bcm_kona_gpio_probe,
670 };
671 builtin_platform_driver(bcm_kona_gpio_driver);
672