xref: /openbmc/linux/drivers/gpio/gpio-bcm-kona.c (revision f3539c12)
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.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 	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 	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 	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 	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 	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 ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
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 	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) == GPIOF_DIR_IN)
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 	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 	spin_lock_irqsave(&kona_gpio->lock, flags);
172 
173 	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
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 	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 	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 	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 	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 	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 	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 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
307 
308 	return 0;
309 }
310 
311 static struct gpio_chip template_chip = {
312 	.label = "bcm-kona-gpio",
313 	.owner = THIS_MODULE,
314 	.request = bcm_kona_gpio_request,
315 	.free = bcm_kona_gpio_free,
316 	.get_direction = bcm_kona_gpio_get_dir,
317 	.direction_input = bcm_kona_gpio_direction_input,
318 	.get = bcm_kona_gpio_get,
319 	.direction_output = bcm_kona_gpio_direction_output,
320 	.set = bcm_kona_gpio_set,
321 	.set_debounce = bcm_kona_gpio_set_debounce,
322 	.to_irq = bcm_kona_gpio_to_irq,
323 	.base = 0,
324 };
325 
326 static void bcm_kona_gpio_irq_ack(struct irq_data *d)
327 {
328 	struct bcm_kona_gpio *kona_gpio;
329 	void __iomem *reg_base;
330 	unsigned gpio = d->hwirq;
331 	int bank_id = GPIO_BANK(gpio);
332 	int bit = GPIO_BIT(gpio);
333 	u32 val;
334 	unsigned long flags;
335 
336 	kona_gpio = irq_data_get_irq_chip_data(d);
337 	reg_base = kona_gpio->reg_base;
338 	spin_lock_irqsave(&kona_gpio->lock, flags);
339 
340 	val = readl(reg_base + GPIO_INT_STATUS(bank_id));
341 	val |= BIT(bit);
342 	writel(val, reg_base + GPIO_INT_STATUS(bank_id));
343 
344 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
345 }
346 
347 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
348 {
349 	struct bcm_kona_gpio *kona_gpio;
350 	void __iomem *reg_base;
351 	unsigned gpio = d->hwirq;
352 	int bank_id = GPIO_BANK(gpio);
353 	int bit = GPIO_BIT(gpio);
354 	u32 val;
355 	unsigned long flags;
356 
357 	kona_gpio = irq_data_get_irq_chip_data(d);
358 	reg_base = kona_gpio->reg_base;
359 	spin_lock_irqsave(&kona_gpio->lock, flags);
360 
361 	val = readl(reg_base + GPIO_INT_MASK(bank_id));
362 	val |= BIT(bit);
363 	writel(val, reg_base + GPIO_INT_MASK(bank_id));
364 
365 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
366 }
367 
368 static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
369 {
370 	struct bcm_kona_gpio *kona_gpio;
371 	void __iomem *reg_base;
372 	unsigned gpio = d->hwirq;
373 	int bank_id = GPIO_BANK(gpio);
374 	int bit = GPIO_BIT(gpio);
375 	u32 val;
376 	unsigned long flags;
377 
378 	kona_gpio = irq_data_get_irq_chip_data(d);
379 	reg_base = kona_gpio->reg_base;
380 	spin_lock_irqsave(&kona_gpio->lock, flags);
381 
382 	val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
383 	val |= BIT(bit);
384 	writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
385 
386 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
387 }
388 
389 static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
390 {
391 	struct bcm_kona_gpio *kona_gpio;
392 	void __iomem *reg_base;
393 	unsigned gpio = d->hwirq;
394 	u32 lvl_type;
395 	u32 val;
396 	unsigned long flags;
397 
398 	kona_gpio = irq_data_get_irq_chip_data(d);
399 	reg_base = kona_gpio->reg_base;
400 	switch (type & IRQ_TYPE_SENSE_MASK) {
401 	case IRQ_TYPE_EDGE_RISING:
402 		lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
403 		break;
404 
405 	case IRQ_TYPE_EDGE_FALLING:
406 		lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
407 		break;
408 
409 	case IRQ_TYPE_EDGE_BOTH:
410 		lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
411 		break;
412 
413 	case IRQ_TYPE_LEVEL_HIGH:
414 	case IRQ_TYPE_LEVEL_LOW:
415 		/* BCM GPIO doesn't support level triggering */
416 	default:
417 		dev_err(kona_gpio->gpio_chip.parent,
418 			"Invalid BCM GPIO irq type 0x%x\n", type);
419 		return -EINVAL;
420 	}
421 
422 	spin_lock_irqsave(&kona_gpio->lock, flags);
423 
424 	val = readl(reg_base + GPIO_CONTROL(gpio));
425 	val &= ~GPIO_GPCTR0_ITR_MASK;
426 	val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
427 	writel(val, reg_base + GPIO_CONTROL(gpio));
428 
429 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
430 
431 	return 0;
432 }
433 
434 static void bcm_kona_gpio_irq_handler(struct irq_desc *desc)
435 {
436 	void __iomem *reg_base;
437 	int bit, bank_id;
438 	unsigned long sta;
439 	struct bcm_kona_gpio_bank *bank = irq_desc_get_handler_data(desc);
440 	struct irq_chip *chip = irq_desc_get_chip(desc);
441 
442 	chained_irq_enter(chip, desc);
443 
444 	/*
445 	 * For bank interrupts, we can't use chip_data to store the kona_gpio
446 	 * pointer, since GIC needs it for its own purposes. Therefore, we get
447 	 * our pointer from the bank structure.
448 	 */
449 	reg_base = bank->kona_gpio->reg_base;
450 	bank_id = bank->id;
451 
452 	while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
453 		    (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
454 		for_each_set_bit(bit, &sta, 32) {
455 			int hwirq = GPIO_PER_BANK * bank_id + bit;
456 			int child_irq =
457 				irq_find_mapping(bank->kona_gpio->irq_domain,
458 						 hwirq);
459 			/*
460 			 * Clear interrupt before handler is called so we don't
461 			 * miss any interrupt occurred during executing them.
462 			 */
463 			writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
464 			       BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
465 			/* Invoke interrupt handler */
466 			generic_handle_irq(child_irq);
467 		}
468 	}
469 
470 	chained_irq_exit(chip, desc);
471 }
472 
473 static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
474 {
475 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
476 
477 	if (gpiochip_lock_as_irq(&kona_gpio->gpio_chip, d->hwirq)) {
478 		dev_err(kona_gpio->gpio_chip.parent,
479 			"unable to lock HW IRQ %lu for IRQ\n",
480 			d->hwirq);
481 		return -EINVAL;
482 	}
483 	return 0;
484 }
485 
486 static void bcm_kona_gpio_irq_relres(struct irq_data *d)
487 {
488 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
489 
490 	gpiochip_unlock_as_irq(&kona_gpio->gpio_chip, d->hwirq);
491 }
492 
493 static struct irq_chip bcm_gpio_irq_chip = {
494 	.name = "bcm-kona-gpio",
495 	.irq_ack = bcm_kona_gpio_irq_ack,
496 	.irq_mask = bcm_kona_gpio_irq_mask,
497 	.irq_unmask = bcm_kona_gpio_irq_unmask,
498 	.irq_set_type = bcm_kona_gpio_irq_set_type,
499 	.irq_request_resources = bcm_kona_gpio_irq_reqres,
500 	.irq_release_resources = bcm_kona_gpio_irq_relres,
501 };
502 
503 static struct of_device_id const bcm_kona_gpio_of_match[] = {
504 	{ .compatible = "brcm,kona-gpio" },
505 	{}
506 };
507 
508 /*
509  * This lock class tells lockdep that GPIO irqs are in a different
510  * category than their parents, so it won't report false recursion.
511  */
512 static struct lock_class_key gpio_lock_class;
513 
514 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
515 				 irq_hw_number_t hwirq)
516 {
517 	int ret;
518 
519 	ret = irq_set_chip_data(irq, d->host_data);
520 	if (ret < 0)
521 		return ret;
522 	irq_set_lockdep_class(irq, &gpio_lock_class);
523 	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
524 	irq_set_noprobe(irq);
525 
526 	return 0;
527 }
528 
529 static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
530 {
531 	irq_set_chip_and_handler(irq, NULL, NULL);
532 	irq_set_chip_data(irq, NULL);
533 }
534 
535 static const struct irq_domain_ops bcm_kona_irq_ops = {
536 	.map = bcm_kona_gpio_irq_map,
537 	.unmap = bcm_kona_gpio_irq_unmap,
538 	.xlate = irq_domain_xlate_twocell,
539 };
540 
541 static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
542 {
543 	void __iomem *reg_base;
544 	int i;
545 
546 	reg_base = kona_gpio->reg_base;
547 	/* disable interrupts and clear status */
548 	for (i = 0; i < kona_gpio->num_bank; i++) {
549 		/* Unlock the entire bank first */
550 		bcm_kona_gpio_write_lock_regs(reg_base, i, UNLOCK_CODE);
551 		writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
552 		writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
553 		/* Now re-lock the bank */
554 		bcm_kona_gpio_write_lock_regs(reg_base, i, LOCK_CODE);
555 	}
556 }
557 
558 static int bcm_kona_gpio_probe(struct platform_device *pdev)
559 {
560 	struct device *dev = &pdev->dev;
561 	const struct of_device_id *match;
562 	struct resource *res;
563 	struct bcm_kona_gpio_bank *bank;
564 	struct bcm_kona_gpio *kona_gpio;
565 	struct gpio_chip *chip;
566 	int ret;
567 	int i;
568 
569 	match = of_match_device(bcm_kona_gpio_of_match, dev);
570 	if (!match) {
571 		dev_err(dev, "Failed to find gpio controller\n");
572 		return -ENODEV;
573 	}
574 
575 	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
576 	if (!kona_gpio)
577 		return -ENOMEM;
578 
579 	kona_gpio->gpio_chip = template_chip;
580 	chip = &kona_gpio->gpio_chip;
581 	kona_gpio->num_bank = of_irq_count(dev->of_node);
582 	if (kona_gpio->num_bank == 0) {
583 		dev_err(dev, "Couldn't determine # GPIO banks\n");
584 		return -ENOENT;
585 	}
586 	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
587 		dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
588 			GPIO_MAX_BANK_NUM);
589 		return -ENXIO;
590 	}
591 	kona_gpio->banks = devm_kzalloc(dev,
592 					kona_gpio->num_bank *
593 					sizeof(*kona_gpio->banks), GFP_KERNEL);
594 	if (!kona_gpio->banks)
595 		return -ENOMEM;
596 
597 	kona_gpio->pdev = pdev;
598 	platform_set_drvdata(pdev, kona_gpio);
599 	chip->of_node = dev->of_node;
600 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
601 
602 	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
603 						      chip->ngpio,
604 						      &bcm_kona_irq_ops,
605 						      kona_gpio);
606 	if (!kona_gpio->irq_domain) {
607 		dev_err(dev, "Couldn't allocate IRQ domain\n");
608 		return -ENXIO;
609 	}
610 
611 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
612 	kona_gpio->reg_base = devm_ioremap_resource(dev, res);
613 	if (IS_ERR(kona_gpio->reg_base)) {
614 		ret = -ENXIO;
615 		goto err_irq_domain;
616 	}
617 
618 	for (i = 0; i < kona_gpio->num_bank; i++) {
619 		bank = &kona_gpio->banks[i];
620 		bank->id = i;
621 		bank->irq = platform_get_irq(pdev, i);
622 		bank->kona_gpio = kona_gpio;
623 		if (bank->irq < 0) {
624 			dev_err(dev, "Couldn't get IRQ for bank %d", i);
625 			ret = -ENOENT;
626 			goto err_irq_domain;
627 		}
628 	}
629 
630 	dev_info(&pdev->dev, "Setting up Kona GPIO\n");
631 
632 	bcm_kona_gpio_reset(kona_gpio);
633 
634 	ret = devm_gpiochip_add_data(dev, chip, kona_gpio);
635 	if (ret < 0) {
636 		dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
637 		goto err_irq_domain;
638 	}
639 	for (i = 0; i < kona_gpio->num_bank; i++) {
640 		bank = &kona_gpio->banks[i];
641 		irq_set_chained_handler_and_data(bank->irq,
642 						 bcm_kona_gpio_irq_handler,
643 						 bank);
644 	}
645 
646 	spin_lock_init(&kona_gpio->lock);
647 
648 	return 0;
649 
650 err_irq_domain:
651 	irq_domain_remove(kona_gpio->irq_domain);
652 
653 	return ret;
654 }
655 
656 static struct platform_driver bcm_kona_gpio_driver = {
657 	.driver = {
658 			.name = "bcm-kona-gpio",
659 			.of_match_table = bcm_kona_gpio_of_match,
660 	},
661 	.probe = bcm_kona_gpio_probe,
662 };
663 builtin_platform_driver(bcm_kona_gpio_driver);
664