xref: /openbmc/linux/drivers/gpio/gpio-dwapb.c (revision 8684014d)
1 /*
2  * Copyright (c) 2011 Jamie Iles
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * All enquiries to support@picochip.com
9  */
10 #include <linux/basic_mmio_gpio.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/irq.h>
17 #include <linux/irqdomain.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/platform_device.h>
23 #include <linux/spinlock.h>
24 #include <linux/platform_data/gpio-dwapb.h>
25 #include <linux/slab.h>
26 
27 #define GPIO_SWPORTA_DR		0x00
28 #define GPIO_SWPORTA_DDR	0x04
29 #define GPIO_SWPORTB_DR		0x0c
30 #define GPIO_SWPORTB_DDR	0x10
31 #define GPIO_SWPORTC_DR		0x18
32 #define GPIO_SWPORTC_DDR	0x1c
33 #define GPIO_SWPORTD_DR		0x24
34 #define GPIO_SWPORTD_DDR	0x28
35 #define GPIO_INTEN		0x30
36 #define GPIO_INTMASK		0x34
37 #define GPIO_INTTYPE_LEVEL	0x38
38 #define GPIO_INT_POLARITY	0x3c
39 #define GPIO_INTSTATUS		0x40
40 #define GPIO_PORTA_DEBOUNCE	0x48
41 #define GPIO_PORTA_EOI		0x4c
42 #define GPIO_EXT_PORTA		0x50
43 #define GPIO_EXT_PORTB		0x54
44 #define GPIO_EXT_PORTC		0x58
45 #define GPIO_EXT_PORTD		0x5c
46 
47 #define DWAPB_MAX_PORTS		4
48 #define GPIO_EXT_PORT_SIZE	(GPIO_EXT_PORTB - GPIO_EXT_PORTA)
49 #define GPIO_SWPORT_DR_SIZE	(GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
50 #define GPIO_SWPORT_DDR_SIZE	(GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)
51 
52 struct dwapb_gpio;
53 
54 #ifdef CONFIG_PM_SLEEP
55 /* Store GPIO context across system-wide suspend/resume transitions */
56 struct dwapb_context {
57 	u32 data;
58 	u32 dir;
59 	u32 ext;
60 	u32 int_en;
61 	u32 int_mask;
62 	u32 int_type;
63 	u32 int_pol;
64 	u32 int_deb;
65 };
66 #endif
67 
68 struct dwapb_gpio_port {
69 	struct bgpio_chip	bgc;
70 	bool			is_registered;
71 	struct dwapb_gpio	*gpio;
72 #ifdef CONFIG_PM_SLEEP
73 	struct dwapb_context	*ctx;
74 #endif
75 	unsigned int		idx;
76 };
77 
78 struct dwapb_gpio {
79 	struct	device		*dev;
80 	void __iomem		*regs;
81 	struct dwapb_gpio_port	*ports;
82 	unsigned int		nr_ports;
83 	struct irq_domain	*domain;
84 };
85 
86 static inline struct dwapb_gpio_port *
87 to_dwapb_gpio_port(struct bgpio_chip *bgc)
88 {
89 	return container_of(bgc, struct dwapb_gpio_port, bgc);
90 }
91 
92 static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
93 {
94 	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
95 	void __iomem *reg_base	= gpio->regs;
96 
97 	return bgc->read_reg(reg_base + offset);
98 }
99 
100 static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
101 			       u32 val)
102 {
103 	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
104 	void __iomem *reg_base	= gpio->regs;
105 
106 	bgc->write_reg(reg_base + offset, val);
107 }
108 
109 static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
110 {
111 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
112 	struct dwapb_gpio_port *port = to_dwapb_gpio_port(bgc);
113 	struct dwapb_gpio *gpio = port->gpio;
114 
115 	return irq_find_mapping(gpio->domain, offset);
116 }
117 
118 static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
119 {
120 	u32 v = dwapb_read(gpio, GPIO_INT_POLARITY);
121 
122 	if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs))
123 		v &= ~BIT(offs);
124 	else
125 		v |= BIT(offs);
126 
127 	dwapb_write(gpio, GPIO_INT_POLARITY, v);
128 }
129 
130 static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
131 {
132 	u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);
133 	u32 ret = irq_status;
134 
135 	while (irq_status) {
136 		int hwirq = fls(irq_status) - 1;
137 		int gpio_irq = irq_find_mapping(gpio->domain, hwirq);
138 
139 		generic_handle_irq(gpio_irq);
140 		irq_status &= ~BIT(hwirq);
141 
142 		if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
143 			== IRQ_TYPE_EDGE_BOTH)
144 			dwapb_toggle_trigger(gpio, hwirq);
145 	}
146 
147 	return ret;
148 }
149 
150 static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
151 {
152 	struct dwapb_gpio *gpio = irq_get_handler_data(irq);
153 	struct irq_chip *chip = irq_desc_get_chip(desc);
154 
155 	dwapb_do_irq(gpio);
156 
157 	if (chip->irq_eoi)
158 		chip->irq_eoi(irq_desc_get_irq_data(desc));
159 }
160 
161 static void dwapb_irq_enable(struct irq_data *d)
162 {
163 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
164 	struct dwapb_gpio *gpio = igc->private;
165 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
166 	unsigned long flags;
167 	u32 val;
168 
169 	spin_lock_irqsave(&bgc->lock, flags);
170 	val = dwapb_read(gpio, GPIO_INTEN);
171 	val |= BIT(d->hwirq);
172 	dwapb_write(gpio, GPIO_INTEN, val);
173 	spin_unlock_irqrestore(&bgc->lock, flags);
174 }
175 
176 static void dwapb_irq_disable(struct irq_data *d)
177 {
178 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
179 	struct dwapb_gpio *gpio = igc->private;
180 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
181 	unsigned long flags;
182 	u32 val;
183 
184 	spin_lock_irqsave(&bgc->lock, flags);
185 	val = dwapb_read(gpio, GPIO_INTEN);
186 	val &= ~BIT(d->hwirq);
187 	dwapb_write(gpio, GPIO_INTEN, val);
188 	spin_unlock_irqrestore(&bgc->lock, flags);
189 }
190 
191 static int dwapb_irq_reqres(struct irq_data *d)
192 {
193 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
194 	struct dwapb_gpio *gpio = igc->private;
195 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
196 
197 	if (gpiochip_lock_as_irq(&bgc->gc, irqd_to_hwirq(d))) {
198 		dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
199 			irqd_to_hwirq(d));
200 		return -EINVAL;
201 	}
202 	return 0;
203 }
204 
205 static void dwapb_irq_relres(struct irq_data *d)
206 {
207 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
208 	struct dwapb_gpio *gpio = igc->private;
209 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
210 
211 	gpiochip_unlock_as_irq(&bgc->gc, irqd_to_hwirq(d));
212 }
213 
214 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
215 {
216 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
217 	struct dwapb_gpio *gpio = igc->private;
218 	struct bgpio_chip *bgc = &gpio->ports[0].bgc;
219 	int bit = d->hwirq;
220 	unsigned long level, polarity, flags;
221 
222 	if (type & ~(IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING |
223 		     IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
224 		return -EINVAL;
225 
226 	spin_lock_irqsave(&bgc->lock, flags);
227 	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
228 	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
229 
230 	switch (type) {
231 	case IRQ_TYPE_EDGE_BOTH:
232 		level |= BIT(bit);
233 		dwapb_toggle_trigger(gpio, bit);
234 		break;
235 	case IRQ_TYPE_EDGE_RISING:
236 		level |= BIT(bit);
237 		polarity |= BIT(bit);
238 		break;
239 	case IRQ_TYPE_EDGE_FALLING:
240 		level |= BIT(bit);
241 		polarity &= ~BIT(bit);
242 		break;
243 	case IRQ_TYPE_LEVEL_HIGH:
244 		level &= ~BIT(bit);
245 		polarity |= BIT(bit);
246 		break;
247 	case IRQ_TYPE_LEVEL_LOW:
248 		level &= ~BIT(bit);
249 		polarity &= ~BIT(bit);
250 		break;
251 	}
252 
253 	irq_setup_alt_chip(d, type);
254 
255 	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
256 	dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
257 	spin_unlock_irqrestore(&bgc->lock, flags);
258 
259 	return 0;
260 }
261 
262 static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
263 				   unsigned offset, unsigned debounce)
264 {
265 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
266 	struct dwapb_gpio_port *port = to_dwapb_gpio_port(bgc);
267 	struct dwapb_gpio *gpio = port->gpio;
268 	unsigned long flags, val_deb;
269 	unsigned long mask = bgc->pin2mask(bgc, offset);
270 
271 	spin_lock_irqsave(&bgc->lock, flags);
272 
273 	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
274 	if (debounce)
275 		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb | mask);
276 	else
277 		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb & ~mask);
278 
279 	spin_unlock_irqrestore(&bgc->lock, flags);
280 
281 	return 0;
282 }
283 
284 static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
285 {
286 	u32 worked;
287 	struct dwapb_gpio *gpio = dev_id;
288 
289 	worked = dwapb_do_irq(gpio);
290 
291 	return worked ? IRQ_HANDLED : IRQ_NONE;
292 }
293 
294 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
295 				 struct dwapb_gpio_port *port,
296 				 struct dwapb_port_property *pp)
297 {
298 	struct gpio_chip *gc = &port->bgc.gc;
299 	struct device_node *node = pp->node;
300 	struct irq_chip_generic	*irq_gc = NULL;
301 	unsigned int hwirq, ngpio = gc->ngpio;
302 	struct irq_chip_type *ct;
303 	int err, i;
304 
305 	gpio->domain = irq_domain_add_linear(node, ngpio,
306 					     &irq_generic_chip_ops, gpio);
307 	if (!gpio->domain)
308 		return;
309 
310 	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 2,
311 					     "gpio-dwapb", handle_level_irq,
312 					     IRQ_NOREQUEST, 0,
313 					     IRQ_GC_INIT_NESTED_LOCK);
314 	if (err) {
315 		dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n");
316 		irq_domain_remove(gpio->domain);
317 		gpio->domain = NULL;
318 		return;
319 	}
320 
321 	irq_gc = irq_get_domain_generic_chip(gpio->domain, 0);
322 	if (!irq_gc) {
323 		irq_domain_remove(gpio->domain);
324 		gpio->domain = NULL;
325 		return;
326 	}
327 
328 	irq_gc->reg_base = gpio->regs;
329 	irq_gc->private = gpio;
330 
331 	for (i = 0; i < 2; i++) {
332 		ct = &irq_gc->chip_types[i];
333 		ct->chip.irq_ack = irq_gc_ack_set_bit;
334 		ct->chip.irq_mask = irq_gc_mask_set_bit;
335 		ct->chip.irq_unmask = irq_gc_mask_clr_bit;
336 		ct->chip.irq_set_type = dwapb_irq_set_type;
337 		ct->chip.irq_enable = dwapb_irq_enable;
338 		ct->chip.irq_disable = dwapb_irq_disable;
339 		ct->chip.irq_request_resources = dwapb_irq_reqres;
340 		ct->chip.irq_release_resources = dwapb_irq_relres;
341 		ct->regs.ack = GPIO_PORTA_EOI;
342 		ct->regs.mask = GPIO_INTMASK;
343 		ct->type = IRQ_TYPE_LEVEL_MASK;
344 	}
345 
346 	irq_gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
347 	irq_gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
348 	irq_gc->chip_types[1].handler = handle_edge_irq;
349 
350 	if (!pp->irq_shared) {
351 		irq_set_chained_handler(pp->irq, dwapb_irq_handler);
352 		irq_set_handler_data(pp->irq, gpio);
353 	} else {
354 		/*
355 		 * Request a shared IRQ since where MFD would have devices
356 		 * using the same irq pin
357 		 */
358 		err = devm_request_irq(gpio->dev, pp->irq,
359 				       dwapb_irq_handler_mfd,
360 				       IRQF_SHARED, "gpio-dwapb-mfd", gpio);
361 		if (err) {
362 			dev_err(gpio->dev, "error requesting IRQ\n");
363 			irq_domain_remove(gpio->domain);
364 			gpio->domain = NULL;
365 			return;
366 		}
367 	}
368 
369 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
370 		irq_create_mapping(gpio->domain, hwirq);
371 
372 	port->bgc.gc.to_irq = dwapb_gpio_to_irq;
373 }
374 
375 static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
376 {
377 	struct dwapb_gpio_port *port = &gpio->ports[0];
378 	struct gpio_chip *gc = &port->bgc.gc;
379 	unsigned int ngpio = gc->ngpio;
380 	irq_hw_number_t hwirq;
381 
382 	if (!gpio->domain)
383 		return;
384 
385 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
386 		irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq));
387 
388 	irq_domain_remove(gpio->domain);
389 	gpio->domain = NULL;
390 }
391 
392 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
393 			       struct dwapb_port_property *pp,
394 			       unsigned int offs)
395 {
396 	struct dwapb_gpio_port *port;
397 	void __iomem *dat, *set, *dirout;
398 	int err;
399 
400 	port = &gpio->ports[offs];
401 	port->gpio = gpio;
402 	port->idx = pp->idx;
403 
404 #ifdef CONFIG_PM_SLEEP
405 	port->ctx = devm_kzalloc(gpio->dev, sizeof(*port->ctx), GFP_KERNEL);
406 	if (!port->ctx)
407 		return -ENOMEM;
408 #endif
409 
410 	dat = gpio->regs + GPIO_EXT_PORTA + (pp->idx * GPIO_EXT_PORT_SIZE);
411 	set = gpio->regs + GPIO_SWPORTA_DR + (pp->idx * GPIO_SWPORT_DR_SIZE);
412 	dirout = gpio->regs + GPIO_SWPORTA_DDR +
413 		(pp->idx * GPIO_SWPORT_DDR_SIZE);
414 
415 	err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout,
416 			 NULL, false);
417 	if (err) {
418 		dev_err(gpio->dev, "failed to init gpio chip for %s\n",
419 			pp->name);
420 		return err;
421 	}
422 
423 #ifdef CONFIG_OF_GPIO
424 	port->bgc.gc.of_node = pp->node;
425 #endif
426 	port->bgc.gc.ngpio = pp->ngpio;
427 	port->bgc.gc.base = pp->gpio_base;
428 
429 	/* Only port A support debounce */
430 	if (pp->idx == 0)
431 		port->bgc.gc.set_debounce = dwapb_gpio_set_debounce;
432 
433 	if (pp->irq)
434 		dwapb_configure_irqs(gpio, port, pp);
435 
436 	err = gpiochip_add(&port->bgc.gc);
437 	if (err)
438 		dev_err(gpio->dev, "failed to register gpiochip for %s\n",
439 			pp->name);
440 	else
441 		port->is_registered = true;
442 
443 	return err;
444 }
445 
446 static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
447 {
448 	unsigned int m;
449 
450 	for (m = 0; m < gpio->nr_ports; ++m)
451 		if (gpio->ports[m].is_registered)
452 			gpiochip_remove(&gpio->ports[m].bgc.gc);
453 }
454 
455 static struct dwapb_platform_data *
456 dwapb_gpio_get_pdata_of(struct device *dev)
457 {
458 	struct device_node *node, *port_np;
459 	struct dwapb_platform_data *pdata;
460 	struct dwapb_port_property *pp;
461 	int nports;
462 	int i;
463 
464 	node = dev->of_node;
465 	if (!IS_ENABLED(CONFIG_OF_GPIO) || !node)
466 		return ERR_PTR(-ENODEV);
467 
468 	nports = of_get_child_count(node);
469 	if (nports == 0)
470 		return ERR_PTR(-ENODEV);
471 
472 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
473 	if (!pdata)
474 		return ERR_PTR(-ENOMEM);
475 
476 	pdata->properties = kcalloc(nports, sizeof(*pp), GFP_KERNEL);
477 	if (!pdata->properties) {
478 		kfree(pdata);
479 		return ERR_PTR(-ENOMEM);
480 	}
481 
482 	pdata->nports = nports;
483 
484 	i = 0;
485 	for_each_child_of_node(node, port_np) {
486 		pp = &pdata->properties[i++];
487 		pp->node = port_np;
488 
489 		if (of_property_read_u32(port_np, "reg", &pp->idx) ||
490 		    pp->idx >= DWAPB_MAX_PORTS) {
491 			dev_err(dev, "missing/invalid port index for %s\n",
492 				port_np->full_name);
493 			kfree(pdata->properties);
494 			kfree(pdata);
495 			return ERR_PTR(-EINVAL);
496 		}
497 
498 		if (of_property_read_u32(port_np, "snps,nr-gpios",
499 					 &pp->ngpio)) {
500 			dev_info(dev, "failed to get number of gpios for %s\n",
501 				 port_np->full_name);
502 			pp->ngpio = 32;
503 		}
504 
505 		/*
506 		 * Only port A can provide interrupts in all configurations of
507 		 * the IP.
508 		 */
509 		if (pp->idx == 0 &&
510 		    of_property_read_bool(port_np, "interrupt-controller")) {
511 			pp->irq = irq_of_parse_and_map(port_np, 0);
512 			if (!pp->irq) {
513 				dev_warn(dev, "no irq for bank %s\n",
514 					 port_np->full_name);
515 			}
516 		}
517 
518 		pp->irq_shared	= false;
519 		pp->gpio_base	= -1;
520 		pp->name	= port_np->full_name;
521 	}
522 
523 	return pdata;
524 }
525 
526 static inline void dwapb_free_pdata_of(struct dwapb_platform_data *pdata)
527 {
528 	if (!IS_ENABLED(CONFIG_OF_GPIO) || !pdata)
529 		return;
530 
531 	kfree(pdata->properties);
532 	kfree(pdata);
533 }
534 
535 static int dwapb_gpio_probe(struct platform_device *pdev)
536 {
537 	unsigned int i;
538 	struct resource *res;
539 	struct dwapb_gpio *gpio;
540 	int err;
541 	struct device *dev = &pdev->dev;
542 	struct dwapb_platform_data *pdata = dev_get_platdata(dev);
543 	bool is_pdata_alloc = !pdata;
544 
545 	if (is_pdata_alloc) {
546 		pdata = dwapb_gpio_get_pdata_of(dev);
547 		if (IS_ERR(pdata))
548 			return PTR_ERR(pdata);
549 	}
550 
551 	if (!pdata->nports) {
552 		err = -ENODEV;
553 		goto out_err;
554 	}
555 
556 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
557 	if (!gpio) {
558 		err = -ENOMEM;
559 		goto out_err;
560 	}
561 	gpio->dev = &pdev->dev;
562 	gpio->nr_ports = pdata->nports;
563 
564 	gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
565 				   sizeof(*gpio->ports), GFP_KERNEL);
566 	if (!gpio->ports) {
567 		err = -ENOMEM;
568 		goto out_err;
569 	}
570 
571 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
572 	gpio->regs = devm_ioremap_resource(&pdev->dev, res);
573 	if (IS_ERR(gpio->regs)) {
574 		err = PTR_ERR(gpio->regs);
575 		goto out_err;
576 	}
577 
578 	for (i = 0; i < gpio->nr_ports; i++) {
579 		err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
580 		if (err)
581 			goto out_unregister;
582 	}
583 	platform_set_drvdata(pdev, gpio);
584 
585 	goto out_err;
586 
587 out_unregister:
588 	dwapb_gpio_unregister(gpio);
589 	dwapb_irq_teardown(gpio);
590 
591 out_err:
592 	if (is_pdata_alloc)
593 		dwapb_free_pdata_of(pdata);
594 
595 	return err;
596 }
597 
598 static int dwapb_gpio_remove(struct platform_device *pdev)
599 {
600 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
601 
602 	dwapb_gpio_unregister(gpio);
603 	dwapb_irq_teardown(gpio);
604 
605 	return 0;
606 }
607 
608 static const struct of_device_id dwapb_of_match[] = {
609 	{ .compatible = "snps,dw-apb-gpio" },
610 	{ /* Sentinel */ }
611 };
612 MODULE_DEVICE_TABLE(of, dwapb_of_match);
613 
614 #ifdef CONFIG_PM_SLEEP
615 static int dwapb_gpio_suspend(struct device *dev)
616 {
617 	struct platform_device *pdev = to_platform_device(dev);
618 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
619 	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
620 	unsigned long flags;
621 	int i;
622 
623 	spin_lock_irqsave(&bgc->lock, flags);
624 	for (i = 0; i < gpio->nr_ports; i++) {
625 		unsigned int offset;
626 		unsigned int idx = gpio->ports[i].idx;
627 		struct dwapb_context *ctx = gpio->ports[i].ctx;
628 
629 		BUG_ON(!ctx);
630 
631 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_SIZE;
632 		ctx->dir = dwapb_read(gpio, offset);
633 
634 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_SIZE;
635 		ctx->data = dwapb_read(gpio, offset);
636 
637 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_SIZE;
638 		ctx->ext = dwapb_read(gpio, offset);
639 
640 		/* Only port A can provide interrupts */
641 		if (idx == 0) {
642 			ctx->int_mask	= dwapb_read(gpio, GPIO_INTMASK);
643 			ctx->int_en	= dwapb_read(gpio, GPIO_INTEN);
644 			ctx->int_pol	= dwapb_read(gpio, GPIO_INT_POLARITY);
645 			ctx->int_type	= dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
646 			ctx->int_deb	= dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
647 
648 			/* Mask out interrupts */
649 			dwapb_write(gpio, GPIO_INTMASK, 0xffffffff);
650 		}
651 	}
652 	spin_unlock_irqrestore(&bgc->lock, flags);
653 
654 	return 0;
655 }
656 
657 static int dwapb_gpio_resume(struct device *dev)
658 {
659 	struct platform_device *pdev = to_platform_device(dev);
660 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
661 	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
662 	unsigned long flags;
663 	int i;
664 
665 	spin_lock_irqsave(&bgc->lock, flags);
666 	for (i = 0; i < gpio->nr_ports; i++) {
667 		unsigned int offset;
668 		unsigned int idx = gpio->ports[i].idx;
669 		struct dwapb_context *ctx = gpio->ports[i].ctx;
670 
671 		BUG_ON(!ctx);
672 
673 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_SIZE;
674 		dwapb_write(gpio, offset, ctx->data);
675 
676 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_SIZE;
677 		dwapb_write(gpio, offset, ctx->dir);
678 
679 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_SIZE;
680 		dwapb_write(gpio, offset, ctx->ext);
681 
682 		/* Only port A can provide interrupts */
683 		if (idx == 0) {
684 			dwapb_write(gpio, GPIO_INTTYPE_LEVEL, ctx->int_type);
685 			dwapb_write(gpio, GPIO_INT_POLARITY, ctx->int_pol);
686 			dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ctx->int_deb);
687 			dwapb_write(gpio, GPIO_INTEN, ctx->int_en);
688 			dwapb_write(gpio, GPIO_INTMASK, ctx->int_mask);
689 
690 			/* Clear out spurious interrupts */
691 			dwapb_write(gpio, GPIO_PORTA_EOI, 0xffffffff);
692 		}
693 	}
694 	spin_unlock_irqrestore(&bgc->lock, flags);
695 
696 	return 0;
697 }
698 #endif
699 
700 static SIMPLE_DEV_PM_OPS(dwapb_gpio_pm_ops, dwapb_gpio_suspend,
701 			 dwapb_gpio_resume);
702 
703 static struct platform_driver dwapb_gpio_driver = {
704 	.driver		= {
705 		.name	= "gpio-dwapb",
706 		.pm	= &dwapb_gpio_pm_ops,
707 		.of_match_table = of_match_ptr(dwapb_of_match),
708 	},
709 	.probe		= dwapb_gpio_probe,
710 	.remove		= dwapb_gpio_remove,
711 };
712 
713 module_platform_driver(dwapb_gpio_driver);
714 
715 MODULE_LICENSE("GPL");
716 MODULE_AUTHOR("Jamie Iles");
717 MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
718