xref: /openbmc/linux/drivers/gpio/gpio-bcm-kona.c (revision 842ed298)
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/init.h>
23 #include <linux/irqdomain.h>
24 #include <linux/irqchip/chained_irq.h>
25 
26 #define BCM_GPIO_PASSWD				0x00a5a501
27 #define GPIO_PER_BANK				32
28 #define GPIO_MAX_BANK_NUM			8
29 
30 #define GPIO_BANK(gpio)				((gpio) >> 5)
31 #define GPIO_BIT(gpio)				((gpio) & (GPIO_PER_BANK - 1))
32 
33 /* There is a GPIO control register for each GPIO */
34 #define GPIO_CONTROL(gpio)			(0x00000100 + ((gpio) << 2))
35 
36 /* The remaining registers are per GPIO bank */
37 #define GPIO_OUT_STATUS(bank)			(0x00000000 + ((bank) << 2))
38 #define GPIO_IN_STATUS(bank)			(0x00000020 + ((bank) << 2))
39 #define GPIO_OUT_SET(bank)			(0x00000040 + ((bank) << 2))
40 #define GPIO_OUT_CLEAR(bank)			(0x00000060 + ((bank) << 2))
41 #define GPIO_INT_STATUS(bank)			(0x00000080 + ((bank) << 2))
42 #define GPIO_INT_MASK(bank)			(0x000000a0 + ((bank) << 2))
43 #define GPIO_INT_MSKCLR(bank)			(0x000000c0 + ((bank) << 2))
44 #define GPIO_PWD_STATUS(bank)			(0x00000500 + ((bank) << 2))
45 
46 #define GPIO_GPPWR_OFFSET			0x00000520
47 
48 #define GPIO_GPCTR0_DBR_SHIFT			5
49 #define GPIO_GPCTR0_DBR_MASK			0x000001e0
50 
51 #define GPIO_GPCTR0_ITR_SHIFT			3
52 #define GPIO_GPCTR0_ITR_MASK			0x00000018
53 #define GPIO_GPCTR0_ITR_CMD_RISING_EDGE		0x00000001
54 #define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE	0x00000002
55 #define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE		0x00000003
56 
57 #define GPIO_GPCTR0_IOTR_MASK			0x00000001
58 #define GPIO_GPCTR0_IOTR_CMD_0UTPUT		0x00000000
59 #define GPIO_GPCTR0_IOTR_CMD_INPUT		0x00000001
60 
61 #define GPIO_GPCTR0_DB_ENABLE_MASK		0x00000100
62 
63 #define LOCK_CODE				0xffffffff
64 #define UNLOCK_CODE				0x00000000
65 
66 struct bcm_kona_gpio {
67 	void __iomem *reg_base;
68 	int num_bank;
69 	raw_spinlock_t lock;
70 	struct gpio_chip gpio_chip;
71 	struct irq_domain *irq_domain;
72 	struct bcm_kona_gpio_bank *banks;
73 	struct platform_device *pdev;
74 };
75 
76 struct bcm_kona_gpio_bank {
77 	int id;
78 	int irq;
79 	/* Used in the interrupt handler */
80 	struct bcm_kona_gpio *kona_gpio;
81 };
82 
83 static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
84 						int bank_id, u32 lockcode)
85 {
86 	writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
87 	writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
88 }
89 
90 static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
91 					unsigned gpio)
92 {
93 	u32 val;
94 	unsigned long flags;
95 	int bank_id = GPIO_BANK(gpio);
96 
97 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
98 
99 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
100 	val |= BIT(gpio);
101 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
102 
103 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
104 }
105 
106 static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
107 					unsigned gpio)
108 {
109 	u32 val;
110 	unsigned long flags;
111 	int bank_id = GPIO_BANK(gpio);
112 
113 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
114 
115 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
116 	val &= ~BIT(gpio);
117 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
118 
119 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
120 }
121 
122 static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
123 {
124 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
125 	void __iomem *reg_base = kona_gpio->reg_base;
126 	u32 val;
127 
128 	val = readl(reg_base + GPIO_CONTROL(gpio)) & GPIO_GPCTR0_IOTR_MASK;
129 	return val ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
130 }
131 
132 static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
133 {
134 	struct bcm_kona_gpio *kona_gpio;
135 	void __iomem *reg_base;
136 	int bank_id = GPIO_BANK(gpio);
137 	int bit = GPIO_BIT(gpio);
138 	u32 val, reg_offset;
139 	unsigned long flags;
140 
141 	kona_gpio = gpiochip_get_data(chip);
142 	reg_base = kona_gpio->reg_base;
143 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
144 
145 	/* this function only applies to output pin */
146 	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIO_LINE_DIRECTION_IN)
147 		goto out;
148 
149 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
150 
151 	val = readl(reg_base + reg_offset);
152 	val |= BIT(bit);
153 	writel(val, reg_base + reg_offset);
154 
155 out:
156 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
157 }
158 
159 static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
160 {
161 	struct bcm_kona_gpio *kona_gpio;
162 	void __iomem *reg_base;
163 	int bank_id = GPIO_BANK(gpio);
164 	int bit = GPIO_BIT(gpio);
165 	u32 val, reg_offset;
166 	unsigned long flags;
167 
168 	kona_gpio = gpiochip_get_data(chip);
169 	reg_base = kona_gpio->reg_base;
170 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
171 
172 	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIO_LINE_DIRECTION_IN)
173 		reg_offset = GPIO_IN_STATUS(bank_id);
174 	else
175 		reg_offset = GPIO_OUT_STATUS(bank_id);
176 
177 	/* read the GPIO bank status */
178 	val = readl(reg_base + reg_offset);
179 
180 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
181 
182 	/* return the specified bit status */
183 	return !!(val & BIT(bit));
184 }
185 
186 static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
187 {
188 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
189 
190 	bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
191 	return 0;
192 }
193 
194 static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
195 {
196 	struct bcm_kona_gpio *kona_gpio = gpiochip_get_data(chip);
197 
198 	bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
199 }
200 
201 static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
202 {
203 	struct bcm_kona_gpio *kona_gpio;
204 	void __iomem *reg_base;
205 	u32 val;
206 	unsigned long flags;
207 
208 	kona_gpio = gpiochip_get_data(chip);
209 	reg_base = kona_gpio->reg_base;
210 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
211 
212 	val = readl(reg_base + GPIO_CONTROL(gpio));
213 	val &= ~GPIO_GPCTR0_IOTR_MASK;
214 	val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
215 	writel(val, reg_base + GPIO_CONTROL(gpio));
216 
217 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
218 
219 	return 0;
220 }
221 
222 static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
223 					  unsigned gpio, int value)
224 {
225 	struct bcm_kona_gpio *kona_gpio;
226 	void __iomem *reg_base;
227 	int bank_id = GPIO_BANK(gpio);
228 	int bit = GPIO_BIT(gpio);
229 	u32 val, reg_offset;
230 	unsigned long flags;
231 
232 	kona_gpio = gpiochip_get_data(chip);
233 	reg_base = kona_gpio->reg_base;
234 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
235 
236 	val = readl(reg_base + GPIO_CONTROL(gpio));
237 	val &= ~GPIO_GPCTR0_IOTR_MASK;
238 	val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
239 	writel(val, reg_base + GPIO_CONTROL(gpio));
240 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
241 
242 	val = readl(reg_base + reg_offset);
243 	val |= BIT(bit);
244 	writel(val, reg_base + reg_offset);
245 
246 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
247 
248 	return 0;
249 }
250 
251 static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
252 {
253 	struct bcm_kona_gpio *kona_gpio;
254 
255 	kona_gpio = gpiochip_get_data(chip);
256 	if (gpio >= kona_gpio->gpio_chip.ngpio)
257 		return -ENXIO;
258 	return irq_create_mapping(kona_gpio->irq_domain, gpio);
259 }
260 
261 static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
262 				      unsigned debounce)
263 {
264 	struct bcm_kona_gpio *kona_gpio;
265 	void __iomem *reg_base;
266 	u32 val, res;
267 	unsigned long flags;
268 
269 	kona_gpio = gpiochip_get_data(chip);
270 	reg_base = kona_gpio->reg_base;
271 	/* debounce must be 1-128ms (or 0) */
272 	if ((debounce > 0 && debounce < 1000) || debounce > 128000) {
273 		dev_err(chip->parent, "Debounce value %u not in range\n",
274 			debounce);
275 		return -EINVAL;
276 	}
277 
278 	/* calculate debounce bit value */
279 	if (debounce != 0) {
280 		/* Convert to ms */
281 		debounce /= 1000;
282 		/* find the MSB */
283 		res = fls(debounce) - 1;
284 		/* Check if MSB-1 is set (round up or down) */
285 		if (res > 0 && (debounce & BIT(res - 1)))
286 			res++;
287 	}
288 
289 	/* spin lock for read-modify-write of the GPIO register */
290 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
291 
292 	val = readl(reg_base + GPIO_CONTROL(gpio));
293 	val &= ~GPIO_GPCTR0_DBR_MASK;
294 
295 	if (debounce == 0) {
296 		/* disable debounce */
297 		val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
298 	} else {
299 		val |= GPIO_GPCTR0_DB_ENABLE_MASK |
300 		    (res << GPIO_GPCTR0_DBR_SHIFT);
301 	}
302 
303 	writel(val, reg_base + GPIO_CONTROL(gpio));
304 
305 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
306 
307 	return 0;
308 }
309 
310 static int bcm_kona_gpio_set_config(struct gpio_chip *chip, unsigned gpio,
311 				    unsigned long config)
312 {
313 	u32 debounce;
314 
315 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
316 		return -ENOTSUPP;
317 
318 	debounce = pinconf_to_config_argument(config);
319 	return bcm_kona_gpio_set_debounce(chip, gpio, debounce);
320 }
321 
322 static const struct gpio_chip template_chip = {
323 	.label = "bcm-kona-gpio",
324 	.owner = THIS_MODULE,
325 	.request = bcm_kona_gpio_request,
326 	.free = bcm_kona_gpio_free,
327 	.get_direction = bcm_kona_gpio_get_dir,
328 	.direction_input = bcm_kona_gpio_direction_input,
329 	.get = bcm_kona_gpio_get,
330 	.direction_output = bcm_kona_gpio_direction_output,
331 	.set = bcm_kona_gpio_set,
332 	.set_config = bcm_kona_gpio_set_config,
333 	.to_irq = bcm_kona_gpio_to_irq,
334 	.base = 0,
335 };
336 
337 static void bcm_kona_gpio_irq_ack(struct irq_data *d)
338 {
339 	struct bcm_kona_gpio *kona_gpio;
340 	void __iomem *reg_base;
341 	unsigned gpio = d->hwirq;
342 	int bank_id = GPIO_BANK(gpio);
343 	int bit = GPIO_BIT(gpio);
344 	u32 val;
345 	unsigned long flags;
346 
347 	kona_gpio = irq_data_get_irq_chip_data(d);
348 	reg_base = kona_gpio->reg_base;
349 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
350 
351 	val = readl(reg_base + GPIO_INT_STATUS(bank_id));
352 	val |= BIT(bit);
353 	writel(val, reg_base + GPIO_INT_STATUS(bank_id));
354 
355 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
356 }
357 
358 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
359 {
360 	struct bcm_kona_gpio *kona_gpio;
361 	void __iomem *reg_base;
362 	unsigned gpio = d->hwirq;
363 	int bank_id = GPIO_BANK(gpio);
364 	int bit = GPIO_BIT(gpio);
365 	u32 val;
366 	unsigned long flags;
367 
368 	kona_gpio = irq_data_get_irq_chip_data(d);
369 	reg_base = kona_gpio->reg_base;
370 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
371 
372 	val = readl(reg_base + GPIO_INT_MASK(bank_id));
373 	val |= BIT(bit);
374 	writel(val, reg_base + GPIO_INT_MASK(bank_id));
375 	gpiochip_disable_irq(&kona_gpio->gpio_chip, gpio);
376 
377 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
378 }
379 
380 static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
381 {
382 	struct bcm_kona_gpio *kona_gpio;
383 	void __iomem *reg_base;
384 	unsigned gpio = d->hwirq;
385 	int bank_id = GPIO_BANK(gpio);
386 	int bit = GPIO_BIT(gpio);
387 	u32 val;
388 	unsigned long flags;
389 
390 	kona_gpio = irq_data_get_irq_chip_data(d);
391 	reg_base = kona_gpio->reg_base;
392 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
393 
394 	val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
395 	val |= BIT(bit);
396 	writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
397 	gpiochip_enable_irq(&kona_gpio->gpio_chip, gpio);
398 
399 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
400 }
401 
402 static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
403 {
404 	struct bcm_kona_gpio *kona_gpio;
405 	void __iomem *reg_base;
406 	unsigned gpio = d->hwirq;
407 	u32 lvl_type;
408 	u32 val;
409 	unsigned long flags;
410 
411 	kona_gpio = irq_data_get_irq_chip_data(d);
412 	reg_base = kona_gpio->reg_base;
413 	switch (type & IRQ_TYPE_SENSE_MASK) {
414 	case IRQ_TYPE_EDGE_RISING:
415 		lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
416 		break;
417 
418 	case IRQ_TYPE_EDGE_FALLING:
419 		lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
420 		break;
421 
422 	case IRQ_TYPE_EDGE_BOTH:
423 		lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
424 		break;
425 
426 	case IRQ_TYPE_LEVEL_HIGH:
427 	case IRQ_TYPE_LEVEL_LOW:
428 		/* BCM GPIO doesn't support level triggering */
429 	default:
430 		dev_err(kona_gpio->gpio_chip.parent,
431 			"Invalid BCM GPIO irq type 0x%x\n", type);
432 		return -EINVAL;
433 	}
434 
435 	raw_spin_lock_irqsave(&kona_gpio->lock, flags);
436 
437 	val = readl(reg_base + GPIO_CONTROL(gpio));
438 	val &= ~GPIO_GPCTR0_ITR_MASK;
439 	val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
440 	writel(val, reg_base + GPIO_CONTROL(gpio));
441 
442 	raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
443 
444 	return 0;
445 }
446 
447 static void bcm_kona_gpio_irq_handler(struct irq_desc *desc)
448 {
449 	void __iomem *reg_base;
450 	int bit, bank_id;
451 	unsigned long sta;
452 	struct bcm_kona_gpio_bank *bank = irq_desc_get_handler_data(desc);
453 	struct irq_chip *chip = irq_desc_get_chip(desc);
454 
455 	chained_irq_enter(chip, desc);
456 
457 	/*
458 	 * For bank interrupts, we can't use chip_data to store the kona_gpio
459 	 * pointer, since GIC needs it for its own purposes. Therefore, we get
460 	 * our pointer from the bank structure.
461 	 */
462 	reg_base = bank->kona_gpio->reg_base;
463 	bank_id = bank->id;
464 
465 	while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
466 		    (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
467 		for_each_set_bit(bit, &sta, 32) {
468 			int hwirq = GPIO_PER_BANK * bank_id + bit;
469 			int child_irq =
470 				irq_find_mapping(bank->kona_gpio->irq_domain,
471 						 hwirq);
472 			/*
473 			 * Clear interrupt before handler is called so we don't
474 			 * miss any interrupt occurred during executing them.
475 			 */
476 			writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
477 			       BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
478 			/* Invoke interrupt handler */
479 			generic_handle_irq(child_irq);
480 		}
481 	}
482 
483 	chained_irq_exit(chip, desc);
484 }
485 
486 static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
487 {
488 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
489 
490 	return gpiochip_reqres_irq(&kona_gpio->gpio_chip, d->hwirq);
491 }
492 
493 static void bcm_kona_gpio_irq_relres(struct irq_data *d)
494 {
495 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
496 
497 	gpiochip_relres_irq(&kona_gpio->gpio_chip, d->hwirq);
498 }
499 
500 static struct irq_chip bcm_gpio_irq_chip = {
501 	.name = "bcm-kona-gpio",
502 	.irq_ack = bcm_kona_gpio_irq_ack,
503 	.irq_mask = bcm_kona_gpio_irq_mask,
504 	.irq_unmask = bcm_kona_gpio_irq_unmask,
505 	.irq_set_type = bcm_kona_gpio_irq_set_type,
506 	.irq_request_resources = bcm_kona_gpio_irq_reqres,
507 	.irq_release_resources = bcm_kona_gpio_irq_relres,
508 };
509 
510 static struct of_device_id const bcm_kona_gpio_of_match[] = {
511 	{ .compatible = "brcm,kona-gpio" },
512 	{}
513 };
514 
515 /*
516  * This lock class tells lockdep that GPIO irqs are in a different
517  * category than their parents, so it won't report false recursion.
518  */
519 static struct lock_class_key gpio_lock_class;
520 static struct lock_class_key gpio_request_class;
521 
522 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
523 				 irq_hw_number_t hwirq)
524 {
525 	int ret;
526 
527 	ret = irq_set_chip_data(irq, d->host_data);
528 	if (ret < 0)
529 		return ret;
530 	irq_set_lockdep_class(irq, &gpio_lock_class, &gpio_request_class);
531 	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
532 	irq_set_noprobe(irq);
533 
534 	return 0;
535 }
536 
537 static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
538 {
539 	irq_set_chip_and_handler(irq, NULL, NULL);
540 	irq_set_chip_data(irq, NULL);
541 }
542 
543 static const struct irq_domain_ops bcm_kona_irq_ops = {
544 	.map = bcm_kona_gpio_irq_map,
545 	.unmap = bcm_kona_gpio_irq_unmap,
546 	.xlate = irq_domain_xlate_twocell,
547 };
548 
549 static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
550 {
551 	void __iomem *reg_base;
552 	int i;
553 
554 	reg_base = kona_gpio->reg_base;
555 	/* disable interrupts and clear status */
556 	for (i = 0; i < kona_gpio->num_bank; i++) {
557 		/* Unlock the entire bank first */
558 		bcm_kona_gpio_write_lock_regs(reg_base, i, UNLOCK_CODE);
559 		writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
560 		writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
561 		/* Now re-lock the bank */
562 		bcm_kona_gpio_write_lock_regs(reg_base, i, LOCK_CODE);
563 	}
564 }
565 
566 static int bcm_kona_gpio_probe(struct platform_device *pdev)
567 {
568 	struct device *dev = &pdev->dev;
569 	const struct of_device_id *match;
570 	struct bcm_kona_gpio_bank *bank;
571 	struct bcm_kona_gpio *kona_gpio;
572 	struct gpio_chip *chip;
573 	int ret;
574 	int i;
575 
576 	match = of_match_device(bcm_kona_gpio_of_match, dev);
577 	if (!match) {
578 		dev_err(dev, "Failed to find gpio controller\n");
579 		return -ENODEV;
580 	}
581 
582 	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
583 	if (!kona_gpio)
584 		return -ENOMEM;
585 
586 	kona_gpio->gpio_chip = template_chip;
587 	chip = &kona_gpio->gpio_chip;
588 	ret = platform_irq_count(pdev);
589 	if (!ret) {
590 		dev_err(dev, "Couldn't determine # GPIO banks\n");
591 		return -ENOENT;
592 	} else if (ret < 0) {
593 		return dev_err_probe(dev, ret, "Couldn't determine GPIO banks\n");
594 	}
595 	kona_gpio->num_bank = ret;
596 
597 	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
598 		dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
599 			GPIO_MAX_BANK_NUM);
600 		return -ENXIO;
601 	}
602 	kona_gpio->banks = devm_kcalloc(dev,
603 					kona_gpio->num_bank,
604 					sizeof(*kona_gpio->banks),
605 					GFP_KERNEL);
606 	if (!kona_gpio->banks)
607 		return -ENOMEM;
608 
609 	kona_gpio->pdev = pdev;
610 	platform_set_drvdata(pdev, kona_gpio);
611 	chip->of_node = dev->of_node;
612 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
613 
614 	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
615 						      chip->ngpio,
616 						      &bcm_kona_irq_ops,
617 						      kona_gpio);
618 	if (!kona_gpio->irq_domain) {
619 		dev_err(dev, "Couldn't allocate IRQ domain\n");
620 		return -ENXIO;
621 	}
622 
623 	kona_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
624 	if (IS_ERR(kona_gpio->reg_base)) {
625 		ret = PTR_ERR(kona_gpio->reg_base);
626 		goto err_irq_domain;
627 	}
628 
629 	for (i = 0; i < kona_gpio->num_bank; i++) {
630 		bank = &kona_gpio->banks[i];
631 		bank->id = i;
632 		bank->irq = platform_get_irq(pdev, i);
633 		bank->kona_gpio = kona_gpio;
634 		if (bank->irq < 0) {
635 			dev_err(dev, "Couldn't get IRQ for bank %d", i);
636 			ret = -ENOENT;
637 			goto err_irq_domain;
638 		}
639 	}
640 
641 	dev_info(&pdev->dev, "Setting up Kona GPIO\n");
642 
643 	bcm_kona_gpio_reset(kona_gpio);
644 
645 	ret = devm_gpiochip_add_data(dev, chip, kona_gpio);
646 	if (ret < 0) {
647 		dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
648 		goto err_irq_domain;
649 	}
650 	for (i = 0; i < kona_gpio->num_bank; i++) {
651 		bank = &kona_gpio->banks[i];
652 		irq_set_chained_handler_and_data(bank->irq,
653 						 bcm_kona_gpio_irq_handler,
654 						 bank);
655 	}
656 
657 	raw_spin_lock_init(&kona_gpio->lock);
658 
659 	return 0;
660 
661 err_irq_domain:
662 	irq_domain_remove(kona_gpio->irq_domain);
663 
664 	return ret;
665 }
666 
667 static struct platform_driver bcm_kona_gpio_driver = {
668 	.driver = {
669 			.name = "bcm-kona-gpio",
670 			.of_match_table = bcm_kona_gpio_of_match,
671 	},
672 	.probe = bcm_kona_gpio_probe,
673 };
674 builtin_platform_driver(bcm_kona_gpio_driver);
675