xref: /linux/drivers/gpio/gpio-brcmstb.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 num_gpios;
54 	int parent_wake_irq;
55 };
56 
57 #define MAX_GPIO_PER_BANK       32
58 #define GPIO_BANK(gpio)         ((gpio) >> 5)
59 /* assumes MAX_GPIO_PER_BANK is a multiple of 2 */
60 #define GPIO_BIT(gpio)          ((gpio) & (MAX_GPIO_PER_BANK - 1))
61 
62 static inline struct brcmstb_gpio_priv *
63 brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
64 {
65 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
66 	return bank->parent_priv;
67 }
68 
69 static unsigned long
70 __brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
71 {
72 	void __iomem *reg_base = bank->parent_priv->reg_base;
73 
74 	return bank->gc.read_reg(reg_base + GIO_STAT(bank->id)) &
75 	       bank->gc.read_reg(reg_base + GIO_MASK(bank->id));
76 }
77 
78 static unsigned long
79 brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
80 {
81 	unsigned long status;
82 	unsigned long flags;
83 
84 	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
85 	status = __brcmstb_gpio_get_active_irqs(bank);
86 	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
87 
88 	return status;
89 }
90 
91 static int brcmstb_gpio_hwirq_to_offset(irq_hw_number_t hwirq,
92 					struct brcmstb_gpio_bank *bank)
93 {
94 	return hwirq - bank->gc.offset;
95 }
96 
97 static void brcmstb_gpio_set_imask(struct brcmstb_gpio_bank *bank,
98 		unsigned int hwirq, bool enable)
99 {
100 	struct gpio_chip *gc = &bank->gc;
101 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
102 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(hwirq, bank));
103 	u32 imask;
104 	unsigned long flags;
105 
106 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
107 	imask = gc->read_reg(priv->reg_base + GIO_MASK(bank->id));
108 	if (enable)
109 		imask |= mask;
110 	else
111 		imask &= ~mask;
112 	gc->write_reg(priv->reg_base + GIO_MASK(bank->id), imask);
113 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
114 }
115 
116 static int brcmstb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
117 {
118 	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
119 	/* gc_offset is relative to this gpio_chip; want real offset */
120 	int hwirq = offset + gc->offset;
121 
122 	if (hwirq >= priv->num_gpios)
123 		return -ENXIO;
124 	return irq_create_mapping(priv->irq_domain, hwirq);
125 }
126 
127 /* -------------------- IRQ chip functions -------------------- */
128 
129 static void brcmstb_gpio_irq_mask(struct irq_data *d)
130 {
131 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
132 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
133 
134 	brcmstb_gpio_set_imask(bank, d->hwirq, false);
135 }
136 
137 static void brcmstb_gpio_irq_unmask(struct irq_data *d)
138 {
139 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
140 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
141 
142 	brcmstb_gpio_set_imask(bank, d->hwirq, true);
143 }
144 
145 static void brcmstb_gpio_irq_ack(struct irq_data *d)
146 {
147 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
148 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
149 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
150 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
151 
152 	gc->write_reg(priv->reg_base + GIO_STAT(bank->id), mask);
153 }
154 
155 static int brcmstb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
156 {
157 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
158 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
159 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
160 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
161 	u32 edge_insensitive, iedge_insensitive;
162 	u32 edge_config, iedge_config;
163 	u32 level, ilevel;
164 	unsigned long flags;
165 
166 	switch (type) {
167 	case IRQ_TYPE_LEVEL_LOW:
168 		level = mask;
169 		edge_config = 0;
170 		edge_insensitive = 0;
171 		break;
172 	case IRQ_TYPE_LEVEL_HIGH:
173 		level = mask;
174 		edge_config = mask;
175 		edge_insensitive = 0;
176 		break;
177 	case IRQ_TYPE_EDGE_FALLING:
178 		level = 0;
179 		edge_config = 0;
180 		edge_insensitive = 0;
181 		break;
182 	case IRQ_TYPE_EDGE_RISING:
183 		level = 0;
184 		edge_config = mask;
185 		edge_insensitive = 0;
186 		break;
187 	case IRQ_TYPE_EDGE_BOTH:
188 		level = 0;
189 		edge_config = 0;  /* don't care, but want known value */
190 		edge_insensitive = mask;
191 		break;
192 	default:
193 		return -EINVAL;
194 	}
195 
196 	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
197 
198 	iedge_config = bank->gc.read_reg(priv->reg_base +
199 			GIO_EC(bank->id)) & ~mask;
200 	iedge_insensitive = bank->gc.read_reg(priv->reg_base +
201 			GIO_EI(bank->id)) & ~mask;
202 	ilevel = bank->gc.read_reg(priv->reg_base +
203 			GIO_LEVEL(bank->id)) & ~mask;
204 
205 	bank->gc.write_reg(priv->reg_base + GIO_EC(bank->id),
206 			iedge_config | edge_config);
207 	bank->gc.write_reg(priv->reg_base + GIO_EI(bank->id),
208 			iedge_insensitive | edge_insensitive);
209 	bank->gc.write_reg(priv->reg_base + GIO_LEVEL(bank->id),
210 			ilevel | level);
211 
212 	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
213 	return 0;
214 }
215 
216 static int brcmstb_gpio_priv_set_wake(struct brcmstb_gpio_priv *priv,
217 		unsigned int enable)
218 {
219 	int ret = 0;
220 
221 	if (enable)
222 		ret = enable_irq_wake(priv->parent_wake_irq);
223 	else
224 		ret = disable_irq_wake(priv->parent_wake_irq);
225 	if (ret)
226 		dev_err(&priv->pdev->dev, "failed to %s wake-up interrupt\n",
227 				enable ? "enable" : "disable");
228 	return ret;
229 }
230 
231 static int brcmstb_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
232 {
233 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
234 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
235 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
236 	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
237 
238 	/*
239 	 * Do not do anything specific for now, suspend/resume callbacks will
240 	 * configure the interrupt mask appropriately
241 	 */
242 	if (enable)
243 		bank->wake_active |= mask;
244 	else
245 		bank->wake_active &= ~mask;
246 
247 	return brcmstb_gpio_priv_set_wake(priv, enable);
248 }
249 
250 static irqreturn_t brcmstb_gpio_wake_irq_handler(int irq, void *data)
251 {
252 	struct brcmstb_gpio_priv *priv = data;
253 
254 	if (!priv || irq != priv->parent_wake_irq)
255 		return IRQ_NONE;
256 
257 	/* Nothing to do */
258 	return IRQ_HANDLED;
259 }
260 
261 static void brcmstb_gpio_irq_bank_handler(struct brcmstb_gpio_bank *bank)
262 {
263 	struct brcmstb_gpio_priv *priv = bank->parent_priv;
264 	struct irq_domain *domain = priv->irq_domain;
265 	int hwbase = bank->gc.offset;
266 	unsigned long status;
267 
268 	while ((status = brcmstb_gpio_get_active_irqs(bank))) {
269 		unsigned int offset;
270 
271 		for_each_set_bit(offset, &status, 32) {
272 			if (offset >= bank->width)
273 				dev_warn(&priv->pdev->dev,
274 					 "IRQ for invalid GPIO (bank=%d, offset=%d)\n",
275 					 bank->id, offset);
276 			generic_handle_domain_irq(domain, hwbase + offset);
277 		}
278 	}
279 }
280 
281 /* Each UPG GIO block has one IRQ for all banks */
282 static void brcmstb_gpio_irq_handler(struct irq_desc *desc)
283 {
284 	struct brcmstb_gpio_priv *priv = irq_desc_get_handler_data(desc);
285 	struct irq_chip *chip = irq_desc_get_chip(desc);
286 	struct brcmstb_gpio_bank *bank;
287 
288 	/* Interrupts weren't properly cleared during probe */
289 	BUG_ON(!priv || !chip);
290 
291 	chained_irq_enter(chip, desc);
292 	list_for_each_entry(bank, &priv->bank_list, node)
293 		brcmstb_gpio_irq_bank_handler(bank);
294 	chained_irq_exit(chip, desc);
295 }
296 
297 static struct brcmstb_gpio_bank *brcmstb_gpio_hwirq_to_bank(
298 		struct brcmstb_gpio_priv *priv, irq_hw_number_t hwirq)
299 {
300 	struct brcmstb_gpio_bank *bank;
301 	int i = 0;
302 
303 	/* banks are in descending order */
304 	list_for_each_entry_reverse(bank, &priv->bank_list, node) {
305 		i += bank->gc.ngpio;
306 		if (hwirq < i)
307 			return bank;
308 	}
309 	return NULL;
310 }
311 
312 /*
313  * This lock class tells lockdep that GPIO irqs are in a different
314  * category than their parents, so it won't report false recursion.
315  */
316 static struct lock_class_key brcmstb_gpio_irq_lock_class;
317 static struct lock_class_key brcmstb_gpio_irq_request_class;
318 
319 
320 static int brcmstb_gpio_irq_map(struct irq_domain *d, unsigned int irq,
321 		irq_hw_number_t hwirq)
322 {
323 	struct brcmstb_gpio_priv *priv = d->host_data;
324 	struct brcmstb_gpio_bank *bank =
325 		brcmstb_gpio_hwirq_to_bank(priv, hwirq);
326 	struct platform_device *pdev = priv->pdev;
327 	int ret;
328 
329 	if (!bank)
330 		return -EINVAL;
331 
332 	dev_dbg(&pdev->dev, "Mapping irq %d for gpio line %d (bank %d)\n",
333 		irq, (int)hwirq, bank->id);
334 	ret = irq_set_chip_data(irq, &bank->gc);
335 	if (ret < 0)
336 		return ret;
337 	irq_set_lockdep_class(irq, &brcmstb_gpio_irq_lock_class,
338 			      &brcmstb_gpio_irq_request_class);
339 	irq_set_chip_and_handler(irq, &priv->irq_chip, handle_level_irq);
340 	irq_set_noprobe(irq);
341 	return 0;
342 }
343 
344 static void brcmstb_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
345 {
346 	irq_set_chip_and_handler(irq, NULL, NULL);
347 	irq_set_chip_data(irq, NULL);
348 }
349 
350 static const struct irq_domain_ops brcmstb_gpio_irq_domain_ops = {
351 	.map = brcmstb_gpio_irq_map,
352 	.unmap = brcmstb_gpio_irq_unmap,
353 	.xlate = irq_domain_xlate_twocell,
354 };
355 
356 /* Make sure that the number of banks matches up between properties */
357 static int brcmstb_gpio_sanity_check_banks(struct device *dev,
358 		struct device_node *np, struct resource *res)
359 {
360 	int res_num_banks = resource_size(res) / GIO_BANK_SIZE;
361 	int num_banks =
362 		of_property_count_u32_elems(np, "brcm,gpio-bank-widths");
363 
364 	if (res_num_banks != num_banks) {
365 		dev_err(dev, "Mismatch in banks: res had %d, bank-widths had %d\n",
366 				res_num_banks, num_banks);
367 		return -EINVAL;
368 	} else {
369 		return 0;
370 	}
371 }
372 
373 static void brcmstb_gpio_remove(struct platform_device *pdev)
374 {
375 	struct brcmstb_gpio_priv *priv = platform_get_drvdata(pdev);
376 	struct brcmstb_gpio_bank *bank;
377 	int offset, virq;
378 
379 	if (priv->parent_irq > 0)
380 		irq_set_chained_handler_and_data(priv->parent_irq, NULL, NULL);
381 
382 	/* Remove all IRQ mappings and delete the domain */
383 	if (priv->irq_domain) {
384 		for (offset = 0; offset < priv->num_gpios; offset++) {
385 			virq = irq_find_mapping(priv->irq_domain, offset);
386 			irq_dispose_mapping(virq);
387 		}
388 		irq_domain_remove(priv->irq_domain);
389 	}
390 
391 	/*
392 	 * You can lose return values below, but we report all errors, and it's
393 	 * more important to actually perform all of the steps.
394 	 */
395 	list_for_each_entry(bank, &priv->bank_list, node)
396 		gpiochip_remove(&bank->gc);
397 }
398 
399 static int brcmstb_gpio_of_xlate(struct gpio_chip *gc,
400 		const struct of_phandle_args *gpiospec, u32 *flags)
401 {
402 	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
403 	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
404 	int offset;
405 
406 	if (gc->of_gpio_n_cells != 2) {
407 		WARN_ON(1);
408 		return -EINVAL;
409 	}
410 
411 	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
412 		return -EINVAL;
413 
414 	offset = gpiospec->args[0] - bank->gc.offset;
415 	if (offset >= gc->ngpio || offset < 0)
416 		return -EINVAL;
417 
418 	if (unlikely(offset >= bank->width)) {
419 		dev_warn_ratelimited(&priv->pdev->dev,
420 			"Received request for invalid GPIO offset %d\n",
421 			gpiospec->args[0]);
422 	}
423 
424 	if (flags)
425 		*flags = gpiospec->args[1];
426 
427 	return offset;
428 }
429 
430 /* priv->parent_irq and priv->num_gpios must be set before calling */
431 static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
432 		struct brcmstb_gpio_priv *priv)
433 {
434 	struct device *dev = &pdev->dev;
435 	struct device_node *np = dev->of_node;
436 	int err;
437 
438 	priv->irq_domain =
439 		irq_domain_add_linear(np, priv->num_gpios,
440 				      &brcmstb_gpio_irq_domain_ops,
441 				      priv);
442 	if (!priv->irq_domain) {
443 		dev_err(dev, "Couldn't allocate IRQ domain\n");
444 		return -ENXIO;
445 	}
446 
447 	if (of_property_read_bool(np, "wakeup-source")) {
448 		priv->parent_wake_irq = platform_get_irq(pdev, 1);
449 		if (priv->parent_wake_irq < 0) {
450 			priv->parent_wake_irq = 0;
451 			dev_warn(dev,
452 				"Couldn't get wake IRQ - GPIOs will not be able to wake from sleep");
453 		} else {
454 			/*
455 			 * Set wakeup capability so we can process boot-time
456 			 * "wakeups" (e.g., from S5 cold boot)
457 			 */
458 			device_set_wakeup_capable(dev, true);
459 			device_wakeup_enable(dev);
460 			err = devm_request_irq(dev, priv->parent_wake_irq,
461 					       brcmstb_gpio_wake_irq_handler,
462 					       IRQF_SHARED,
463 					       "brcmstb-gpio-wake", priv);
464 
465 			if (err < 0) {
466 				dev_err(dev, "Couldn't request wake IRQ");
467 				goto out_free_domain;
468 			}
469 		}
470 	}
471 
472 	priv->irq_chip.name = dev_name(dev);
473 	priv->irq_chip.irq_disable = brcmstb_gpio_irq_mask;
474 	priv->irq_chip.irq_mask = brcmstb_gpio_irq_mask;
475 	priv->irq_chip.irq_unmask = brcmstb_gpio_irq_unmask;
476 	priv->irq_chip.irq_ack = brcmstb_gpio_irq_ack;
477 	priv->irq_chip.irq_set_type = brcmstb_gpio_irq_set_type;
478 
479 	if (priv->parent_wake_irq)
480 		priv->irq_chip.irq_set_wake = brcmstb_gpio_irq_set_wake;
481 
482 	irq_set_chained_handler_and_data(priv->parent_irq,
483 					 brcmstb_gpio_irq_handler, priv);
484 	irq_set_status_flags(priv->parent_irq, IRQ_DISABLE_UNLAZY);
485 
486 	return 0;
487 
488 out_free_domain:
489 	irq_domain_remove(priv->irq_domain);
490 
491 	return err;
492 }
493 
494 static void brcmstb_gpio_bank_save(struct brcmstb_gpio_priv *priv,
495 				   struct brcmstb_gpio_bank *bank)
496 {
497 	struct gpio_chip *gc = &bank->gc;
498 	unsigned int i;
499 
500 	for (i = 0; i < GIO_REG_STAT; i++)
501 		bank->saved_regs[i] = gc->read_reg(priv->reg_base +
502 						   GIO_BANK_OFF(bank->id, i));
503 }
504 
505 static void brcmstb_gpio_quiesce(struct device *dev, bool save)
506 {
507 	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
508 	struct brcmstb_gpio_bank *bank;
509 	struct gpio_chip *gc;
510 	u32 imask;
511 
512 	/* disable non-wake interrupt */
513 	if (priv->parent_irq >= 0)
514 		disable_irq(priv->parent_irq);
515 
516 	list_for_each_entry(bank, &priv->bank_list, node) {
517 		gc = &bank->gc;
518 
519 		if (save)
520 			brcmstb_gpio_bank_save(priv, bank);
521 
522 		/* Unmask GPIOs which have been flagged as wake-up sources */
523 		if (priv->parent_wake_irq)
524 			imask = bank->wake_active;
525 		else
526 			imask = 0;
527 		gc->write_reg(priv->reg_base + GIO_MASK(bank->id),
528 			       imask);
529 	}
530 }
531 
532 static void brcmstb_gpio_shutdown(struct platform_device *pdev)
533 {
534 	/* Enable GPIO for S5 cold boot */
535 	brcmstb_gpio_quiesce(&pdev->dev, false);
536 }
537 
538 #ifdef CONFIG_PM_SLEEP
539 static void brcmstb_gpio_bank_restore(struct brcmstb_gpio_priv *priv,
540 				      struct brcmstb_gpio_bank *bank)
541 {
542 	struct gpio_chip *gc = &bank->gc;
543 	unsigned int i;
544 
545 	for (i = 0; i < GIO_REG_STAT; i++)
546 		gc->write_reg(priv->reg_base + GIO_BANK_OFF(bank->id, i),
547 			      bank->saved_regs[i]);
548 }
549 
550 static int brcmstb_gpio_suspend(struct device *dev)
551 {
552 	brcmstb_gpio_quiesce(dev, true);
553 	return 0;
554 }
555 
556 static int brcmstb_gpio_resume(struct device *dev)
557 {
558 	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
559 	struct brcmstb_gpio_bank *bank;
560 	bool need_wakeup_event = false;
561 
562 	list_for_each_entry(bank, &priv->bank_list, node) {
563 		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
564 		brcmstb_gpio_bank_restore(priv, bank);
565 	}
566 
567 	if (priv->parent_wake_irq && need_wakeup_event)
568 		pm_wakeup_event(dev, 0);
569 
570 	/* enable non-wake interrupt */
571 	if (priv->parent_irq >= 0)
572 		enable_irq(priv->parent_irq);
573 
574 	return 0;
575 }
576 
577 #else
578 #define brcmstb_gpio_suspend	NULL
579 #define brcmstb_gpio_resume	NULL
580 #endif /* CONFIG_PM_SLEEP */
581 
582 static const struct dev_pm_ops brcmstb_gpio_pm_ops = {
583 	.suspend_noirq	= brcmstb_gpio_suspend,
584 	.resume_noirq = brcmstb_gpio_resume,
585 };
586 
587 static int brcmstb_gpio_probe(struct platform_device *pdev)
588 {
589 	struct device *dev = &pdev->dev;
590 	struct device_node *np = dev->of_node;
591 	void __iomem *reg_base;
592 	struct brcmstb_gpio_priv *priv;
593 	struct resource *res;
594 	struct property *prop;
595 	const __be32 *p;
596 	u32 bank_width;
597 	int num_banks = 0;
598 	int num_gpios = 0;
599 	int err;
600 	unsigned long flags = 0;
601 	bool need_wakeup_event = false;
602 
603 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
604 	if (!priv)
605 		return -ENOMEM;
606 	platform_set_drvdata(pdev, priv);
607 	INIT_LIST_HEAD(&priv->bank_list);
608 
609 	reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
610 	if (IS_ERR(reg_base))
611 		return PTR_ERR(reg_base);
612 
613 	priv->reg_base = reg_base;
614 	priv->pdev = pdev;
615 
616 	if (of_property_read_bool(np, "interrupt-controller")) {
617 		priv->parent_irq = platform_get_irq(pdev, 0);
618 		if (priv->parent_irq <= 0)
619 			return -ENOENT;
620 	} else {
621 		priv->parent_irq = -ENOENT;
622 	}
623 
624 	if (brcmstb_gpio_sanity_check_banks(dev, np, res))
625 		return -EINVAL;
626 
627 	/*
628 	 * MIPS endianness is configured by boot strap, which also reverses all
629 	 * bus endianness (i.e., big-endian CPU + big endian bus ==> native
630 	 * endian I/O).
631 	 *
632 	 * Other architectures (e.g., ARM) either do not support big endian, or
633 	 * else leave I/O in little endian mode.
634 	 */
635 #if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
636 	flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
637 #endif
638 
639 	of_property_for_each_u32(np, "brcm,gpio-bank-widths", prop, p,
640 			bank_width) {
641 		struct brcmstb_gpio_bank *bank;
642 		struct gpio_chip *gc;
643 
644 		/*
645 		 * If bank_width is 0, then there is an empty bank in the
646 		 * register block. Special handling for this case.
647 		 */
648 		if (bank_width == 0) {
649 			dev_dbg(dev, "Width 0 found: Empty bank @ %d\n",
650 				num_banks);
651 			num_banks++;
652 			num_gpios += MAX_GPIO_PER_BANK;
653 			continue;
654 		}
655 
656 		bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
657 		if (!bank) {
658 			err = -ENOMEM;
659 			goto fail;
660 		}
661 
662 		bank->parent_priv = priv;
663 		bank->id = num_banks;
664 		if (bank_width <= 0 || bank_width > MAX_GPIO_PER_BANK) {
665 			dev_err(dev, "Invalid bank width %d\n", bank_width);
666 			err = -EINVAL;
667 			goto fail;
668 		} else {
669 			bank->width = bank_width;
670 		}
671 
672 		/*
673 		 * Regs are 4 bytes wide, have data reg, no set/clear regs,
674 		 * and direction bits have 0 = output and 1 = input
675 		 */
676 		gc = &bank->gc;
677 		err = bgpio_init(gc, dev, 4,
678 				reg_base + GIO_DATA(bank->id),
679 				NULL, NULL, NULL,
680 				reg_base + GIO_IODIR(bank->id), flags);
681 		if (err) {
682 			dev_err(dev, "bgpio_init() failed\n");
683 			goto fail;
684 		}
685 
686 		gc->owner = THIS_MODULE;
687 		gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
688 		if (!gc->label) {
689 			err = -ENOMEM;
690 			goto fail;
691 		}
692 		gc->of_gpio_n_cells = 2;
693 		gc->of_xlate = brcmstb_gpio_of_xlate;
694 		/* not all ngpio lines are valid, will use bank width later */
695 		gc->ngpio = MAX_GPIO_PER_BANK;
696 		gc->offset = bank->id * MAX_GPIO_PER_BANK;
697 		gc->request = gpiochip_generic_request;
698 		gc->free = gpiochip_generic_free;
699 		if (priv->parent_irq > 0)
700 			gc->to_irq = brcmstb_gpio_to_irq;
701 
702 		/*
703 		 * Mask all interrupts by default, since wakeup interrupts may
704 		 * be retained from S5 cold boot
705 		 */
706 		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
707 		gc->write_reg(reg_base + GIO_MASK(bank->id), 0);
708 
709 		err = gpiochip_add_data(gc, bank);
710 		if (err) {
711 			dev_err(dev, "Could not add gpiochip for bank %d\n",
712 					bank->id);
713 			goto fail;
714 		}
715 		num_gpios += gc->ngpio;
716 
717 		dev_dbg(dev, "bank=%d, base=%d, ngpio=%d, width=%d\n", bank->id,
718 			gc->base, gc->ngpio, bank->width);
719 
720 		/* Everything looks good, so add bank to list */
721 		list_add(&bank->node, &priv->bank_list);
722 
723 		num_banks++;
724 	}
725 
726 	priv->num_gpios = num_gpios;
727 	if (priv->parent_irq > 0) {
728 		err = brcmstb_gpio_irq_setup(pdev, priv);
729 		if (err)
730 			goto fail;
731 	}
732 
733 	if (priv->parent_wake_irq && need_wakeup_event)
734 		pm_wakeup_event(dev, 0);
735 
736 	return 0;
737 
738 fail:
739 	(void) brcmstb_gpio_remove(pdev);
740 	return err;
741 }
742 
743 static const struct of_device_id brcmstb_gpio_of_match[] = {
744 	{ .compatible = "brcm,brcmstb-gpio" },
745 	{},
746 };
747 
748 MODULE_DEVICE_TABLE(of, brcmstb_gpio_of_match);
749 
750 static struct platform_driver brcmstb_gpio_driver = {
751 	.driver = {
752 		.name = "brcmstb-gpio",
753 		.of_match_table = brcmstb_gpio_of_match,
754 		.pm = &brcmstb_gpio_pm_ops,
755 	},
756 	.probe = brcmstb_gpio_probe,
757 	.remove_new = brcmstb_gpio_remove,
758 	.shutdown = brcmstb_gpio_shutdown,
759 };
760 module_platform_driver(brcmstb_gpio_driver);
761 
762 MODULE_AUTHOR("Gregory Fong");
763 MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");
764 MODULE_LICENSE("GPL v2");
765