xref: /linux/drivers/gpio/gpio-brcmstb.c (revision 5e2cb28dd7e182dfa641550dfa225913509ad45d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2015-2017 Broadcom
3 
4 #include <linux/bitops.h>
5 #include <linux/gpio/driver.h>
6 #include <linux/of.h>
7 #include <linux/module.h>
8 #include <linux/irqdomain.h>
9 #include <linux/irqchip/chained_irq.h>
10 #include <linux/interrupt.h>
11 #include <linux/platform_device.h>
12 
13 enum gio_reg_index {
14 	GIO_REG_ODEN = 0,
15 	GIO_REG_DATA,
16 	GIO_REG_IODIR,
17 	GIO_REG_EC,
18 	GIO_REG_EI,
19 	GIO_REG_MASK,
20 	GIO_REG_LEVEL,
21 	GIO_REG_STAT,
22 	NUMBER_OF_GIO_REGISTERS
23 };
24 
25 #define GIO_BANK_SIZE           (NUMBER_OF_GIO_REGISTERS * sizeof(u32))
26 #define GIO_BANK_OFF(bank, off)	(((bank) * GIO_BANK_SIZE) + (off * sizeof(u32)))
27 #define GIO_ODEN(bank)          GIO_BANK_OFF(bank, GIO_REG_ODEN)
28 #define GIO_DATA(bank)          GIO_BANK_OFF(bank, GIO_REG_DATA)
29 #define GIO_IODIR(bank)         GIO_BANK_OFF(bank, GIO_REG_IODIR)
30 #define GIO_EC(bank)            GIO_BANK_OFF(bank, GIO_REG_EC)
31 #define GIO_EI(bank)            GIO_BANK_OFF(bank, GIO_REG_EI)
32 #define GIO_MASK(bank)          GIO_BANK_OFF(bank, GIO_REG_MASK)
33 #define GIO_LEVEL(bank)         GIO_BANK_OFF(bank, GIO_REG_LEVEL)
34 #define GIO_STAT(bank)          GIO_BANK_OFF(bank, GIO_REG_STAT)
35 
36 struct brcmstb_gpio_bank {
37 	struct list_head node;
38 	int id;
39 	struct gpio_chip gc;
40 	struct brcmstb_gpio_priv *parent_priv;
41 	u32 width;
42 	u32 wake_active;
43 	u32 saved_regs[GIO_REG_STAT]; /* Don't save and restore GIO_REG_STAT */
44 };
45 
46 struct brcmstb_gpio_priv {
47 	struct list_head bank_list;
48 	void __iomem *reg_base;
49 	struct platform_device *pdev;
50 	struct irq_domain *irq_domain;
51 	struct irq_chip irq_chip;
52 	int parent_irq;
53 	int gpio_base;
54 	int num_gpios;
55 	int parent_wake_irq;
56 };
57 
58 #define MAX_GPIO_PER_BANK       32
59 #define GPIO_BANK(gpio)         ((gpio) >> 5)
60 /* assumes MAX_GPIO_PER_BANK is a multiple of 2 */
61 #define GPIO_BIT(gpio)          ((gpio) & (MAX_GPIO_PER_BANK - 1))
62 
63 static inline struct brcmstb_gpio_priv *
64 brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
65 {
66 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
67 	return bank->parent_priv;
68 }
69 
70 static unsigned long
71 __brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
72 {
73 	void __iomem *reg_base = bank->parent_priv->reg_base;
74 
75 	return bank->gc.read_reg(reg_base + GIO_STAT(bank->id)) &
76 	       bank->gc.read_reg(reg_base + GIO_MASK(bank->id));
77 }
78 
79 static unsigned long
80 brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
81 {
82 	unsigned long status;
83 	unsigned long flags;
84 
85 	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
86 	status = __brcmstb_gpio_get_active_irqs(bank);
87 	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
88 
89 	return status;
90 }
91 
92 static int brcmstb_gpio_hwirq_to_offset(irq_hw_number_t hwirq,
93 					struct brcmstb_gpio_bank *bank)
94 {
95 	return hwirq - (bank->gc.base - bank->parent_priv->gpio_base);
96 }
97 
98 static void brcmstb_gpio_set_imask(struct brcmstb_gpio_bank *bank,
99 		unsigned int hwirq, bool enable)
100 {
101 	struct gpio_chip *gc = &bank->gc;
102 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
103 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(hwirq, bank));
104 	u32 imask;
105 	unsigned long flags;
106 
107 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
108 	imask = gc->read_reg(priv->reg_base + GIO_MASK(bank->id));
109 	if (enable)
110 		imask |= mask;
111 	else
112 		imask &= ~mask;
113 	gc->write_reg(priv->reg_base + GIO_MASK(bank->id), imask);
114 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
115 }
116 
117 static int brcmstb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
118 {
119 	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
120 	/* gc_offset is relative to this gpio_chip; want real offset */
121 	int hwirq = offset + (gc->base - priv->gpio_base);
122 
123 	if (hwirq >= priv->num_gpios)
124 		return -ENXIO;
125 	return irq_create_mapping(priv->irq_domain, hwirq);
126 }
127 
128 /* -------------------- IRQ chip functions -------------------- */
129 
130 static void brcmstb_gpio_irq_mask(struct irq_data *d)
131 {
132 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
133 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
134 
135 	brcmstb_gpio_set_imask(bank, d->hwirq, false);
136 }
137 
138 static void brcmstb_gpio_irq_unmask(struct irq_data *d)
139 {
140 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
141 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
142 
143 	brcmstb_gpio_set_imask(bank, d->hwirq, true);
144 }
145 
146 static void brcmstb_gpio_irq_ack(struct irq_data *d)
147 {
148 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
149 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
150 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
151 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
152 
153 	gc->write_reg(priv->reg_base + GIO_STAT(bank->id), mask);
154 }
155 
156 static int brcmstb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
157 {
158 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
159 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
160 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
161 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
162 	u32 edge_insensitive, iedge_insensitive;
163 	u32 edge_config, iedge_config;
164 	u32 level, ilevel;
165 	unsigned long flags;
166 
167 	switch (type) {
168 	case IRQ_TYPE_LEVEL_LOW:
169 		level = mask;
170 		edge_config = 0;
171 		edge_insensitive = 0;
172 		break;
173 	case IRQ_TYPE_LEVEL_HIGH:
174 		level = mask;
175 		edge_config = mask;
176 		edge_insensitive = 0;
177 		break;
178 	case IRQ_TYPE_EDGE_FALLING:
179 		level = 0;
180 		edge_config = 0;
181 		edge_insensitive = 0;
182 		break;
183 	case IRQ_TYPE_EDGE_RISING:
184 		level = 0;
185 		edge_config = mask;
186 		edge_insensitive = 0;
187 		break;
188 	case IRQ_TYPE_EDGE_BOTH:
189 		level = 0;
190 		edge_config = 0;  /* don't care, but want known value */
191 		edge_insensitive = mask;
192 		break;
193 	default:
194 		return -EINVAL;
195 	}
196 
197 	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
198 
199 	iedge_config = bank->gc.read_reg(priv->reg_base +
200 			GIO_EC(bank->id)) & ~mask;
201 	iedge_insensitive = bank->gc.read_reg(priv->reg_base +
202 			GIO_EI(bank->id)) & ~mask;
203 	ilevel = bank->gc.read_reg(priv->reg_base +
204 			GIO_LEVEL(bank->id)) & ~mask;
205 
206 	bank->gc.write_reg(priv->reg_base + GIO_EC(bank->id),
207 			iedge_config | edge_config);
208 	bank->gc.write_reg(priv->reg_base + GIO_EI(bank->id),
209 			iedge_insensitive | edge_insensitive);
210 	bank->gc.write_reg(priv->reg_base + GIO_LEVEL(bank->id),
211 			ilevel | level);
212 
213 	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
214 	return 0;
215 }
216 
217 static int brcmstb_gpio_priv_set_wake(struct brcmstb_gpio_priv *priv,
218 		unsigned int enable)
219 {
220 	int ret = 0;
221 
222 	if (enable)
223 		ret = enable_irq_wake(priv->parent_wake_irq);
224 	else
225 		ret = disable_irq_wake(priv->parent_wake_irq);
226 	if (ret)
227 		dev_err(&priv->pdev->dev, "failed to %s wake-up interrupt\n",
228 				enable ? "enable" : "disable");
229 	return ret;
230 }
231 
232 static int brcmstb_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
233 {
234 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
235 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
236 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
237 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
238 
239 	/*
240 	 * Do not do anything specific for now, suspend/resume callbacks will
241 	 * configure the interrupt mask appropriately
242 	 */
243 	if (enable)
244 		bank->wake_active |= mask;
245 	else
246 		bank->wake_active &= ~mask;
247 
248 	return brcmstb_gpio_priv_set_wake(priv, enable);
249 }
250 
251 static irqreturn_t brcmstb_gpio_wake_irq_handler(int irq, void *data)
252 {
253 	struct brcmstb_gpio_priv *priv = data;
254 
255 	if (!priv || irq != priv->parent_wake_irq)
256 		return IRQ_NONE;
257 
258 	/* Nothing to do */
259 	return IRQ_HANDLED;
260 }
261 
262 static void brcmstb_gpio_irq_bank_handler(struct brcmstb_gpio_bank *bank)
263 {
264 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
265 	struct irq_domain *domain = priv->irq_domain;
266 	int hwbase = bank->gc.base - priv->gpio_base;
267 	unsigned long status;
268 
269 	while ((status = brcmstb_gpio_get_active_irqs(bank))) {
270 		unsigned int offset;
271 
272 		for_each_set_bit(offset, &status, 32) {
273 			if (offset >= bank->width)
274 				dev_warn(&priv->pdev->dev,
275 					 "IRQ for invalid GPIO (bank=%d, offset=%d)\n",
276 					 bank->id, offset);
277 			generic_handle_domain_irq(domain, hwbase + offset);
278 		}
279 	}
280 }
281 
282 /* Each UPG GIO block has one IRQ for all banks */
283 static void brcmstb_gpio_irq_handler(struct irq_desc *desc)
284 {
285 	struct brcmstb_gpio_priv *priv = irq_desc_get_handler_data(desc);
286 	struct irq_chip *chip = irq_desc_get_chip(desc);
287 	struct brcmstb_gpio_bank *bank;
288 
289 	/* Interrupts weren't properly cleared during probe */
290 	BUG_ON(!priv || !chip);
291 
292 	chained_irq_enter(chip, desc);
293 	list_for_each_entry(bank, &priv->bank_list, node)
294 		brcmstb_gpio_irq_bank_handler(bank);
295 	chained_irq_exit(chip, desc);
296 }
297 
298 static struct brcmstb_gpio_bank *brcmstb_gpio_hwirq_to_bank(
299 		struct brcmstb_gpio_priv *priv, irq_hw_number_t hwirq)
300 {
301 	struct brcmstb_gpio_bank *bank;
302 	int i = 0;
303 
304 	/* banks are in descending order */
305 	list_for_each_entry_reverse(bank, &priv->bank_list, node) {
306 		i += bank->gc.ngpio;
307 		if (hwirq < i)
308 			return bank;
309 	}
310 	return NULL;
311 }
312 
313 /*
314  * This lock class tells lockdep that GPIO irqs are in a different
315  * category than their parents, so it won't report false recursion.
316  */
317 static struct lock_class_key brcmstb_gpio_irq_lock_class;
318 static struct lock_class_key brcmstb_gpio_irq_request_class;
319 
320 
321 static int brcmstb_gpio_irq_map(struct irq_domain *d, unsigned int irq,
322 		irq_hw_number_t hwirq)
323 {
324 	struct brcmstb_gpio_priv *priv = d->host_data;
325 	struct brcmstb_gpio_bank *bank =
326 		brcmstb_gpio_hwirq_to_bank(priv, hwirq);
327 	struct platform_device *pdev = priv->pdev;
328 	int ret;
329 
330 	if (!bank)
331 		return -EINVAL;
332 
333 	dev_dbg(&pdev->dev, "Mapping irq %d for gpio line %d (bank %d)\n",
334 		irq, (int)hwirq, bank->id);
335 	ret = irq_set_chip_data(irq, &bank->gc);
336 	if (ret < 0)
337 		return ret;
338 	irq_set_lockdep_class(irq, &brcmstb_gpio_irq_lock_class,
339 			      &brcmstb_gpio_irq_request_class);
340 	irq_set_chip_and_handler(irq, &priv->irq_chip, handle_level_irq);
341 	irq_set_noprobe(irq);
342 	return 0;
343 }
344 
345 static void brcmstb_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
346 {
347 	irq_set_chip_and_handler(irq, NULL, NULL);
348 	irq_set_chip_data(irq, NULL);
349 }
350 
351 static const struct irq_domain_ops brcmstb_gpio_irq_domain_ops = {
352 	.map = brcmstb_gpio_irq_map,
353 	.unmap = brcmstb_gpio_irq_unmap,
354 	.xlate = irq_domain_xlate_twocell,
355 };
356 
357 /* Make sure that the number of banks matches up between properties */
358 static int brcmstb_gpio_sanity_check_banks(struct device *dev,
359 		struct device_node *np, struct resource *res)
360 {
361 	int res_num_banks = resource_size(res) / GIO_BANK_SIZE;
362 	int num_banks =
363 		of_property_count_u32_elems(np, "brcm,gpio-bank-widths");
364 
365 	if (res_num_banks != num_banks) {
366 		dev_err(dev, "Mismatch in banks: res had %d, bank-widths had %d\n",
367 				res_num_banks, num_banks);
368 		return -EINVAL;
369 	} else {
370 		return 0;
371 	}
372 }
373 
374 static void brcmstb_gpio_remove(struct platform_device *pdev)
375 {
376 	struct brcmstb_gpio_priv *priv = platform_get_drvdata(pdev);
377 	struct brcmstb_gpio_bank *bank;
378 	int offset, virq;
379 
380 	if (priv->parent_irq > 0)
381 		irq_set_chained_handler_and_data(priv->parent_irq, NULL, NULL);
382 
383 	/* Remove all IRQ mappings and delete the domain */
384 	if (priv->irq_domain) {
385 		for (offset = 0; offset < priv->num_gpios; offset++) {
386 			virq = irq_find_mapping(priv->irq_domain, offset);
387 			irq_dispose_mapping(virq);
388 		}
389 		irq_domain_remove(priv->irq_domain);
390 	}
391 
392 	/*
393 	 * You can lose return values below, but we report all errors, and it's
394 	 * more important to actually perform all of the steps.
395 	 */
396 	list_for_each_entry(bank, &priv->bank_list, node)
397 		gpiochip_remove(&bank->gc);
398 }
399 
400 static int brcmstb_gpio_of_xlate(struct gpio_chip *gc,
401 		const struct of_phandle_args *gpiospec, u32 *flags)
402 {
403 	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
404 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
405 	int offset;
406 
407 	if (gc->of_gpio_n_cells != 2) {
408 		WARN_ON(1);
409 		return -EINVAL;
410 	}
411 
412 	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
413 		return -EINVAL;
414 
415 	offset = gpiospec->args[0] - (gc->base - priv->gpio_base);
416 	if (offset >= gc->ngpio || offset < 0)
417 		return -EINVAL;
418 
419 	if (unlikely(offset >= bank->width)) {
420 		dev_warn_ratelimited(&priv->pdev->dev,
421 			"Received request for invalid GPIO offset %d\n",
422 			gpiospec->args[0]);
423 	}
424 
425 	if (flags)
426 		*flags = gpiospec->args[1];
427 
428 	return offset;
429 }
430 
431 /* priv->parent_irq and priv->num_gpios must be set before calling */
432 static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
433 		struct brcmstb_gpio_priv *priv)
434 {
435 	struct device *dev = &pdev->dev;
436 	struct device_node *np = dev->of_node;
437 	int err;
438 
439 	priv->irq_domain =
440 		irq_domain_add_linear(np, priv->num_gpios,
441 				      &brcmstb_gpio_irq_domain_ops,
442 				      priv);
443 	if (!priv->irq_domain) {
444 		dev_err(dev, "Couldn't allocate IRQ domain\n");
445 		return -ENXIO;
446 	}
447 
448 	if (of_property_read_bool(np, "wakeup-source")) {
449 		priv->parent_wake_irq = platform_get_irq(pdev, 1);
450 		if (priv->parent_wake_irq < 0) {
451 			priv->parent_wake_irq = 0;
452 			dev_warn(dev,
453 				"Couldn't get wake IRQ - GPIOs will not be able to wake from sleep");
454 		} else {
455 			/*
456 			 * Set wakeup capability so we can process boot-time
457 			 * "wakeups" (e.g., from S5 cold boot)
458 			 */
459 			device_set_wakeup_capable(dev, true);
460 			device_wakeup_enable(dev);
461 			err = devm_request_irq(dev, priv->parent_wake_irq,
462 					       brcmstb_gpio_wake_irq_handler,
463 					       IRQF_SHARED,
464 					       "brcmstb-gpio-wake", priv);
465 
466 			if (err < 0) {
467 				dev_err(dev, "Couldn't request wake IRQ");
468 				goto out_free_domain;
469 			}
470 		}
471 	}
472 
473 	priv->irq_chip.name = dev_name(dev);
474 	priv->irq_chip.irq_disable = brcmstb_gpio_irq_mask;
475 	priv->irq_chip.irq_mask = brcmstb_gpio_irq_mask;
476 	priv->irq_chip.irq_unmask = brcmstb_gpio_irq_unmask;
477 	priv->irq_chip.irq_ack = brcmstb_gpio_irq_ack;
478 	priv->irq_chip.irq_set_type = brcmstb_gpio_irq_set_type;
479 
480 	if (priv->parent_wake_irq)
481 		priv->irq_chip.irq_set_wake = brcmstb_gpio_irq_set_wake;
482 
483 	irq_set_chained_handler_and_data(priv->parent_irq,
484 					 brcmstb_gpio_irq_handler, priv);
485 	irq_set_status_flags(priv->parent_irq, IRQ_DISABLE_UNLAZY);
486 
487 	return 0;
488 
489 out_free_domain:
490 	irq_domain_remove(priv->irq_domain);
491 
492 	return err;
493 }
494 
495 static void brcmstb_gpio_bank_save(struct brcmstb_gpio_priv *priv,
496 				   struct brcmstb_gpio_bank *bank)
497 {
498 	struct gpio_chip *gc = &bank->gc;
499 	unsigned int i;
500 
501 	for (i = 0; i < GIO_REG_STAT; i++)
502 		bank->saved_regs[i] = gc->read_reg(priv->reg_base +
503 						   GIO_BANK_OFF(bank->id, i));
504 }
505 
506 static void brcmstb_gpio_quiesce(struct device *dev, bool save)
507 {
508 	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
509 	struct brcmstb_gpio_bank *bank;
510 	struct gpio_chip *gc;
511 	u32 imask;
512 
513 	/* disable non-wake interrupt */
514 	if (priv->parent_irq >= 0)
515 		disable_irq(priv->parent_irq);
516 
517 	list_for_each_entry(bank, &priv->bank_list, node) {
518 		gc = &bank->gc;
519 
520 		if (save)
521 			brcmstb_gpio_bank_save(priv, bank);
522 
523 		/* Unmask GPIOs which have been flagged as wake-up sources */
524 		if (priv->parent_wake_irq)
525 			imask = bank->wake_active;
526 		else
527 			imask = 0;
528 		gc->write_reg(priv->reg_base + GIO_MASK(bank->id),
529 			       imask);
530 	}
531 }
532 
533 static void brcmstb_gpio_shutdown(struct platform_device *pdev)
534 {
535 	/* Enable GPIO for S5 cold boot */
536 	brcmstb_gpio_quiesce(&pdev->dev, false);
537 }
538 
539 #ifdef CONFIG_PM_SLEEP
540 static void brcmstb_gpio_bank_restore(struct brcmstb_gpio_priv *priv,
541 				      struct brcmstb_gpio_bank *bank)
542 {
543 	struct gpio_chip *gc = &bank->gc;
544 	unsigned int i;
545 
546 	for (i = 0; i < GIO_REG_STAT; i++)
547 		gc->write_reg(priv->reg_base + GIO_BANK_OFF(bank->id, i),
548 			      bank->saved_regs[i]);
549 }
550 
551 static int brcmstb_gpio_suspend(struct device *dev)
552 {
553 	brcmstb_gpio_quiesce(dev, true);
554 	return 0;
555 }
556 
557 static int brcmstb_gpio_resume(struct device *dev)
558 {
559 	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
560 	struct brcmstb_gpio_bank *bank;
561 	bool need_wakeup_event = false;
562 
563 	list_for_each_entry(bank, &priv->bank_list, node) {
564 		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
565 		brcmstb_gpio_bank_restore(priv, bank);
566 	}
567 
568 	if (priv->parent_wake_irq && need_wakeup_event)
569 		pm_wakeup_event(dev, 0);
570 
571 	/* enable non-wake interrupt */
572 	if (priv->parent_irq >= 0)
573 		enable_irq(priv->parent_irq);
574 
575 	return 0;
576 }
577 
578 #else
579 #define brcmstb_gpio_suspend	NULL
580 #define brcmstb_gpio_resume	NULL
581 #endif /* CONFIG_PM_SLEEP */
582 
583 static const struct dev_pm_ops brcmstb_gpio_pm_ops = {
584 	.suspend_noirq	= brcmstb_gpio_suspend,
585 	.resume_noirq = brcmstb_gpio_resume,
586 };
587 
588 static int brcmstb_gpio_probe(struct platform_device *pdev)
589 {
590 	struct device *dev = &pdev->dev;
591 	struct device_node *np = dev->of_node;
592 	void __iomem *reg_base;
593 	struct brcmstb_gpio_priv *priv;
594 	struct resource *res;
595 	struct property *prop;
596 	const __be32 *p;
597 	u32 bank_width;
598 	int num_banks = 0;
599 	int err;
600 	static int gpio_base;
601 	unsigned long flags = 0;
602 	bool need_wakeup_event = false;
603 
604 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
605 	if (!priv)
606 		return -ENOMEM;
607 	platform_set_drvdata(pdev, priv);
608 	INIT_LIST_HEAD(&priv->bank_list);
609 
610 	reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
611 	if (IS_ERR(reg_base))
612 		return PTR_ERR(reg_base);
613 
614 	priv->gpio_base = gpio_base;
615 	priv->reg_base = reg_base;
616 	priv->pdev = pdev;
617 
618 	if (of_property_read_bool(np, "interrupt-controller")) {
619 		priv->parent_irq = platform_get_irq(pdev, 0);
620 		if (priv->parent_irq <= 0)
621 			return -ENOENT;
622 	} else {
623 		priv->parent_irq = -ENOENT;
624 	}
625 
626 	if (brcmstb_gpio_sanity_check_banks(dev, np, res))
627 		return -EINVAL;
628 
629 	/*
630 	 * MIPS endianness is configured by boot strap, which also reverses all
631 	 * bus endianness (i.e., big-endian CPU + big endian bus ==> native
632 	 * endian I/O).
633 	 *
634 	 * Other architectures (e.g., ARM) either do not support big endian, or
635 	 * else leave I/O in little endian mode.
636 	 */
637 #if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
638 	flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
639 #endif
640 
641 	of_property_for_each_u32(np, "brcm,gpio-bank-widths", prop, p,
642 			bank_width) {
643 		struct brcmstb_gpio_bank *bank;
644 		struct gpio_chip *gc;
645 
646 		/*
647 		 * If bank_width is 0, then there is an empty bank in the
648 		 * register block. Special handling for this case.
649 		 */
650 		if (bank_width == 0) {
651 			dev_dbg(dev, "Width 0 found: Empty bank @ %d\n",
652 				num_banks);
653 			num_banks++;
654 			gpio_base += MAX_GPIO_PER_BANK;
655 			continue;
656 		}
657 
658 		bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
659 		if (!bank) {
660 			err = -ENOMEM;
661 			goto fail;
662 		}
663 
664 		bank->parent_priv = priv;
665 		bank->id = num_banks;
666 		if (bank_width <= 0 || bank_width > MAX_GPIO_PER_BANK) {
667 			dev_err(dev, "Invalid bank width %d\n", bank_width);
668 			err = -EINVAL;
669 			goto fail;
670 		} else {
671 			bank->width = bank_width;
672 		}
673 
674 		/*
675 		 * Regs are 4 bytes wide, have data reg, no set/clear regs,
676 		 * and direction bits have 0 = output and 1 = input
677 		 */
678 		gc = &bank->gc;
679 		err = bgpio_init(gc, dev, 4,
680 				reg_base + GIO_DATA(bank->id),
681 				NULL, NULL, NULL,
682 				reg_base + GIO_IODIR(bank->id), flags);
683 		if (err) {
684 			dev_err(dev, "bgpio_init() failed\n");
685 			goto fail;
686 		}
687 
688 		gc->owner = THIS_MODULE;
689 		gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
690 		if (!gc->label) {
691 			err = -ENOMEM;
692 			goto fail;
693 		}
694 		gc->base = gpio_base;
695 		gc->of_gpio_n_cells = 2;
696 		gc->of_xlate = brcmstb_gpio_of_xlate;
697 		/* not all ngpio lines are valid, will use bank width later */
698 		gc->ngpio = MAX_GPIO_PER_BANK;
699 		gc->offset = bank->id * MAX_GPIO_PER_BANK;
700 		if (priv->parent_irq > 0)
701 			gc->to_irq = brcmstb_gpio_to_irq;
702 
703 		/*
704 		 * Mask all interrupts by default, since wakeup interrupts may
705 		 * be retained from S5 cold boot
706 		 */
707 		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
708 		gc->write_reg(reg_base + GIO_MASK(bank->id), 0);
709 
710 		err = gpiochip_add_data(gc, bank);
711 		if (err) {
712 			dev_err(dev, "Could not add gpiochip for bank %d\n",
713 					bank->id);
714 			goto fail;
715 		}
716 		gpio_base += gc->ngpio;
717 
718 		dev_dbg(dev, "bank=%d, base=%d, ngpio=%d, width=%d\n", bank->id,
719 			gc->base, gc->ngpio, bank->width);
720 
721 		/* Everything looks good, so add bank to list */
722 		list_add(&bank->node, &priv->bank_list);
723 
724 		num_banks++;
725 	}
726 
727 	priv->num_gpios = gpio_base - priv->gpio_base;
728 	if (priv->parent_irq > 0) {
729 		err = brcmstb_gpio_irq_setup(pdev, priv);
730 		if (err)
731 			goto fail;
732 	}
733 
734 	if (priv->parent_wake_irq && need_wakeup_event)
735 		pm_wakeup_event(dev, 0);
736 
737 	return 0;
738 
739 fail:
740 	(void) brcmstb_gpio_remove(pdev);
741 	return err;
742 }
743 
744 static const struct of_device_id brcmstb_gpio_of_match[] = {
745 	{ .compatible = "brcm,brcmstb-gpio" },
746 	{},
747 };
748 
749 MODULE_DEVICE_TABLE(of, brcmstb_gpio_of_match);
750 
751 static struct platform_driver brcmstb_gpio_driver = {
752 	.driver = {
753 		.name = "brcmstb-gpio",
754 		.of_match_table = brcmstb_gpio_of_match,
755 		.pm = &brcmstb_gpio_pm_ops,
756 	},
757 	.probe = brcmstb_gpio_probe,
758 	.remove_new = brcmstb_gpio_remove,
759 	.shutdown = brcmstb_gpio_shutdown,
760 };
761 module_platform_driver(brcmstb_gpio_driver);
762 
763 MODULE_AUTHOR("Gregory Fong");
764 MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");
765 MODULE_LICENSE("GPL v2");
766