xref: /openbmc/linux/drivers/gpio/gpio-dwapb.c (revision 8730046c)
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/acpi.h>
11 #include <linux/gpio/driver.h>
12 /* FIXME: for gpio_get_value(), replace this with direct register read */
13 #include <linux/gpio.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/ioport.h>
19 #include <linux/irq.h>
20 #include <linux/irqdomain.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25 #include <linux/platform_device.h>
26 #include <linux/property.h>
27 #include <linux/spinlock.h>
28 #include <linux/platform_data/gpio-dwapb.h>
29 #include <linux/slab.h>
30 
31 #include "gpiolib.h"
32 
33 #define GPIO_SWPORTA_DR		0x00
34 #define GPIO_SWPORTA_DDR	0x04
35 #define GPIO_SWPORTB_DR		0x0c
36 #define GPIO_SWPORTB_DDR	0x10
37 #define GPIO_SWPORTC_DR		0x18
38 #define GPIO_SWPORTC_DDR	0x1c
39 #define GPIO_SWPORTD_DR		0x24
40 #define GPIO_SWPORTD_DDR	0x28
41 #define GPIO_INTEN		0x30
42 #define GPIO_INTMASK		0x34
43 #define GPIO_INTTYPE_LEVEL	0x38
44 #define GPIO_INT_POLARITY	0x3c
45 #define GPIO_INTSTATUS		0x40
46 #define GPIO_PORTA_DEBOUNCE	0x48
47 #define GPIO_PORTA_EOI		0x4c
48 #define GPIO_EXT_PORTA		0x50
49 #define GPIO_EXT_PORTB		0x54
50 #define GPIO_EXT_PORTC		0x58
51 #define GPIO_EXT_PORTD		0x5c
52 
53 #define DWAPB_MAX_PORTS		4
54 #define GPIO_EXT_PORT_SIZE	(GPIO_EXT_PORTB - GPIO_EXT_PORTA)
55 #define GPIO_SWPORT_DR_SIZE	(GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
56 #define GPIO_SWPORT_DDR_SIZE	(GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)
57 
58 struct dwapb_gpio;
59 
60 #ifdef CONFIG_PM_SLEEP
61 /* Store GPIO context across system-wide suspend/resume transitions */
62 struct dwapb_context {
63 	u32 data;
64 	u32 dir;
65 	u32 ext;
66 	u32 int_en;
67 	u32 int_mask;
68 	u32 int_type;
69 	u32 int_pol;
70 	u32 int_deb;
71 };
72 #endif
73 
74 struct dwapb_gpio_port {
75 	struct gpio_chip	gc;
76 	bool			is_registered;
77 	struct dwapb_gpio	*gpio;
78 #ifdef CONFIG_PM_SLEEP
79 	struct dwapb_context	*ctx;
80 #endif
81 	unsigned int		idx;
82 };
83 
84 struct dwapb_gpio {
85 	struct	device		*dev;
86 	void __iomem		*regs;
87 	struct dwapb_gpio_port	*ports;
88 	unsigned int		nr_ports;
89 	struct irq_domain	*domain;
90 };
91 
92 static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
93 {
94 	struct gpio_chip *gc	= &gpio->ports[0].gc;
95 	void __iomem *reg_base	= gpio->regs;
96 
97 	return gc->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 gpio_chip *gc	= &gpio->ports[0].gc;
104 	void __iomem *reg_base	= gpio->regs;
105 
106 	gc->write_reg(reg_base + offset, val);
107 }
108 
109 static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
110 {
111 	struct dwapb_gpio_port *port = gpiochip_get_data(gc);
112 	struct dwapb_gpio *gpio = port->gpio;
113 
114 	return irq_find_mapping(gpio->domain, offset);
115 }
116 
117 static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
118 {
119 	u32 v = dwapb_read(gpio, GPIO_INT_POLARITY);
120 
121 	if (gpio_get_value(gpio->ports[0].gc.base + offs))
122 		v &= ~BIT(offs);
123 	else
124 		v |= BIT(offs);
125 
126 	dwapb_write(gpio, GPIO_INT_POLARITY, v);
127 }
128 
129 static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
130 {
131 	u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);
132 	u32 ret = irq_status;
133 
134 	while (irq_status) {
135 		int hwirq = fls(irq_status) - 1;
136 		int gpio_irq = irq_find_mapping(gpio->domain, hwirq);
137 
138 		generic_handle_irq(gpio_irq);
139 		irq_status &= ~BIT(hwirq);
140 
141 		if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
142 			== IRQ_TYPE_EDGE_BOTH)
143 			dwapb_toggle_trigger(gpio, hwirq);
144 	}
145 
146 	return ret;
147 }
148 
149 static void dwapb_irq_handler(struct irq_desc *desc)
150 {
151 	struct dwapb_gpio *gpio = irq_desc_get_handler_data(desc);
152 	struct irq_chip *chip = irq_desc_get_chip(desc);
153 
154 	dwapb_do_irq(gpio);
155 
156 	if (chip->irq_eoi)
157 		chip->irq_eoi(irq_desc_get_irq_data(desc));
158 }
159 
160 static void dwapb_irq_enable(struct irq_data *d)
161 {
162 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
163 	struct dwapb_gpio *gpio = igc->private;
164 	struct gpio_chip *gc = &gpio->ports[0].gc;
165 	unsigned long flags;
166 	u32 val;
167 
168 	spin_lock_irqsave(&gc->bgpio_lock, flags);
169 	val = dwapb_read(gpio, GPIO_INTEN);
170 	val |= BIT(d->hwirq);
171 	dwapb_write(gpio, GPIO_INTEN, val);
172 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
173 }
174 
175 static void dwapb_irq_disable(struct irq_data *d)
176 {
177 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
178 	struct dwapb_gpio *gpio = igc->private;
179 	struct gpio_chip *gc = &gpio->ports[0].gc;
180 	unsigned long flags;
181 	u32 val;
182 
183 	spin_lock_irqsave(&gc->bgpio_lock, flags);
184 	val = dwapb_read(gpio, GPIO_INTEN);
185 	val &= ~BIT(d->hwirq);
186 	dwapb_write(gpio, GPIO_INTEN, val);
187 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
188 }
189 
190 static int dwapb_irq_reqres(struct irq_data *d)
191 {
192 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
193 	struct dwapb_gpio *gpio = igc->private;
194 	struct gpio_chip *gc = &gpio->ports[0].gc;
195 
196 	if (gpiochip_lock_as_irq(gc, irqd_to_hwirq(d))) {
197 		dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
198 			irqd_to_hwirq(d));
199 		return -EINVAL;
200 	}
201 	return 0;
202 }
203 
204 static void dwapb_irq_relres(struct irq_data *d)
205 {
206 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
207 	struct dwapb_gpio *gpio = igc->private;
208 	struct gpio_chip *gc = &gpio->ports[0].gc;
209 
210 	gpiochip_unlock_as_irq(gc, irqd_to_hwirq(d));
211 }
212 
213 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
214 {
215 	struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
216 	struct dwapb_gpio *gpio = igc->private;
217 	struct gpio_chip *gc = &gpio->ports[0].gc;
218 	int bit = d->hwirq;
219 	unsigned long level, polarity, flags;
220 
221 	if (type & ~(IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING |
222 		     IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
223 		return -EINVAL;
224 
225 	spin_lock_irqsave(&gc->bgpio_lock, flags);
226 	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
227 	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
228 
229 	switch (type) {
230 	case IRQ_TYPE_EDGE_BOTH:
231 		level |= BIT(bit);
232 		dwapb_toggle_trigger(gpio, bit);
233 		break;
234 	case IRQ_TYPE_EDGE_RISING:
235 		level |= BIT(bit);
236 		polarity |= BIT(bit);
237 		break;
238 	case IRQ_TYPE_EDGE_FALLING:
239 		level |= BIT(bit);
240 		polarity &= ~BIT(bit);
241 		break;
242 	case IRQ_TYPE_LEVEL_HIGH:
243 		level &= ~BIT(bit);
244 		polarity |= BIT(bit);
245 		break;
246 	case IRQ_TYPE_LEVEL_LOW:
247 		level &= ~BIT(bit);
248 		polarity &= ~BIT(bit);
249 		break;
250 	}
251 
252 	irq_setup_alt_chip(d, type);
253 
254 	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
255 	dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
256 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
257 
258 	return 0;
259 }
260 
261 static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
262 				   unsigned offset, unsigned debounce)
263 {
264 	struct dwapb_gpio_port *port = gpiochip_get_data(gc);
265 	struct dwapb_gpio *gpio = port->gpio;
266 	unsigned long flags, val_deb;
267 	unsigned long mask = gc->pin2mask(gc, offset);
268 
269 	spin_lock_irqsave(&gc->bgpio_lock, flags);
270 
271 	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
272 	if (debounce)
273 		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb | mask);
274 	else
275 		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb & ~mask);
276 
277 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
278 
279 	return 0;
280 }
281 
282 static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
283 {
284 	u32 worked;
285 	struct dwapb_gpio *gpio = dev_id;
286 
287 	worked = dwapb_do_irq(gpio);
288 
289 	return worked ? IRQ_HANDLED : IRQ_NONE;
290 }
291 
292 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
293 				 struct dwapb_gpio_port *port,
294 				 struct dwapb_port_property *pp)
295 {
296 	struct gpio_chip *gc = &port->gc;
297 	struct fwnode_handle  *fwnode = pp->fwnode;
298 	struct irq_chip_generic	*irq_gc = NULL;
299 	unsigned int hwirq, ngpio = gc->ngpio;
300 	struct irq_chip_type *ct;
301 	int err, i;
302 
303 	gpio->domain = irq_domain_create_linear(fwnode, ngpio,
304 						 &irq_generic_chip_ops, gpio);
305 	if (!gpio->domain)
306 		return;
307 
308 	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 2,
309 					     "gpio-dwapb", handle_level_irq,
310 					     IRQ_NOREQUEST, 0,
311 					     IRQ_GC_INIT_NESTED_LOCK);
312 	if (err) {
313 		dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n");
314 		irq_domain_remove(gpio->domain);
315 		gpio->domain = NULL;
316 		return;
317 	}
318 
319 	irq_gc = irq_get_domain_generic_chip(gpio->domain, 0);
320 	if (!irq_gc) {
321 		irq_domain_remove(gpio->domain);
322 		gpio->domain = NULL;
323 		return;
324 	}
325 
326 	irq_gc->reg_base = gpio->regs;
327 	irq_gc->private = gpio;
328 
329 	for (i = 0; i < 2; i++) {
330 		ct = &irq_gc->chip_types[i];
331 		ct->chip.irq_ack = irq_gc_ack_set_bit;
332 		ct->chip.irq_mask = irq_gc_mask_set_bit;
333 		ct->chip.irq_unmask = irq_gc_mask_clr_bit;
334 		ct->chip.irq_set_type = dwapb_irq_set_type;
335 		ct->chip.irq_enable = dwapb_irq_enable;
336 		ct->chip.irq_disable = dwapb_irq_disable;
337 		ct->chip.irq_request_resources = dwapb_irq_reqres;
338 		ct->chip.irq_release_resources = dwapb_irq_relres;
339 		ct->regs.ack = GPIO_PORTA_EOI;
340 		ct->regs.mask = GPIO_INTMASK;
341 		ct->type = IRQ_TYPE_LEVEL_MASK;
342 	}
343 
344 	irq_gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
345 	irq_gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
346 	irq_gc->chip_types[1].handler = handle_edge_irq;
347 
348 	if (!pp->irq_shared) {
349 		irq_set_chained_handler_and_data(pp->irq, dwapb_irq_handler,
350 						 gpio);
351 	} else {
352 		/*
353 		 * Request a shared IRQ since where MFD would have devices
354 		 * using the same irq pin
355 		 */
356 		err = devm_request_irq(gpio->dev, pp->irq,
357 				       dwapb_irq_handler_mfd,
358 				       IRQF_SHARED, "gpio-dwapb-mfd", gpio);
359 		if (err) {
360 			dev_err(gpio->dev, "error requesting IRQ\n");
361 			irq_domain_remove(gpio->domain);
362 			gpio->domain = NULL;
363 			return;
364 		}
365 	}
366 
367 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
368 		irq_create_mapping(gpio->domain, hwirq);
369 
370 	port->gc.to_irq = dwapb_gpio_to_irq;
371 }
372 
373 static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
374 {
375 	struct dwapb_gpio_port *port = &gpio->ports[0];
376 	struct gpio_chip *gc = &port->gc;
377 	unsigned int ngpio = gc->ngpio;
378 	irq_hw_number_t hwirq;
379 
380 	if (!gpio->domain)
381 		return;
382 
383 	for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
384 		irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq));
385 
386 	irq_domain_remove(gpio->domain);
387 	gpio->domain = NULL;
388 }
389 
390 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
391 			       struct dwapb_port_property *pp,
392 			       unsigned int offs)
393 {
394 	struct dwapb_gpio_port *port;
395 	void __iomem *dat, *set, *dirout;
396 	int err;
397 
398 	port = &gpio->ports[offs];
399 	port->gpio = gpio;
400 	port->idx = pp->idx;
401 
402 #ifdef CONFIG_PM_SLEEP
403 	port->ctx = devm_kzalloc(gpio->dev, sizeof(*port->ctx), GFP_KERNEL);
404 	if (!port->ctx)
405 		return -ENOMEM;
406 #endif
407 
408 	dat = gpio->regs + GPIO_EXT_PORTA + (pp->idx * GPIO_EXT_PORT_SIZE);
409 	set = gpio->regs + GPIO_SWPORTA_DR + (pp->idx * GPIO_SWPORT_DR_SIZE);
410 	dirout = gpio->regs + GPIO_SWPORTA_DDR +
411 		(pp->idx * GPIO_SWPORT_DDR_SIZE);
412 
413 	err = bgpio_init(&port->gc, gpio->dev, 4, dat, set, NULL, dirout,
414 			 NULL, false);
415 	if (err) {
416 		dev_err(gpio->dev, "failed to init gpio chip for port%d\n",
417 			port->idx);
418 		return err;
419 	}
420 
421 #ifdef CONFIG_OF_GPIO
422 	port->gc.of_node = to_of_node(pp->fwnode);
423 #endif
424 	port->gc.ngpio = pp->ngpio;
425 	port->gc.base = pp->gpio_base;
426 
427 	/* Only port A support debounce */
428 	if (pp->idx == 0)
429 		port->gc.set_debounce = dwapb_gpio_set_debounce;
430 
431 	if (pp->irq)
432 		dwapb_configure_irqs(gpio, port, pp);
433 
434 	err = gpiochip_add_data(&port->gc, port);
435 	if (err)
436 		dev_err(gpio->dev, "failed to register gpiochip for port%d\n",
437 			port->idx);
438 	else
439 		port->is_registered = true;
440 
441 	/* Add GPIO-signaled ACPI event support */
442 	if (pp->irq)
443 		acpi_gpiochip_request_interrupts(&port->gc);
444 
445 	return err;
446 }
447 
448 static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
449 {
450 	unsigned int m;
451 
452 	for (m = 0; m < gpio->nr_ports; ++m)
453 		if (gpio->ports[m].is_registered)
454 			gpiochip_remove(&gpio->ports[m].gc);
455 }
456 
457 static struct dwapb_platform_data *
458 dwapb_gpio_get_pdata(struct device *dev)
459 {
460 	struct fwnode_handle *fwnode;
461 	struct dwapb_platform_data *pdata;
462 	struct dwapb_port_property *pp;
463 	int nports;
464 	int i;
465 
466 	nports = device_get_child_node_count(dev);
467 	if (nports == 0)
468 		return ERR_PTR(-ENODEV);
469 
470 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
471 	if (!pdata)
472 		return ERR_PTR(-ENOMEM);
473 
474 	pdata->properties = devm_kcalloc(dev, nports, sizeof(*pp), GFP_KERNEL);
475 	if (!pdata->properties)
476 		return ERR_PTR(-ENOMEM);
477 
478 	pdata->nports = nports;
479 
480 	i = 0;
481 	device_for_each_child_node(dev, fwnode)  {
482 		pp = &pdata->properties[i++];
483 		pp->fwnode = fwnode;
484 
485 		if (fwnode_property_read_u32(fwnode, "reg", &pp->idx) ||
486 		    pp->idx >= DWAPB_MAX_PORTS) {
487 			dev_err(dev,
488 				"missing/invalid port index for port%d\n", i);
489 			fwnode_handle_put(fwnode);
490 			return ERR_PTR(-EINVAL);
491 		}
492 
493 		if (fwnode_property_read_u32(fwnode, "snps,nr-gpios",
494 					 &pp->ngpio)) {
495 			dev_info(dev,
496 				 "failed to get number of gpios for port%d\n",
497 				 i);
498 			pp->ngpio = 32;
499 		}
500 
501 		/*
502 		 * Only port A can provide interrupts in all configurations of
503 		 * the IP.
504 		 */
505 		if (dev->of_node && pp->idx == 0 &&
506 			fwnode_property_read_bool(fwnode,
507 						  "interrupt-controller")) {
508 			pp->irq = irq_of_parse_and_map(to_of_node(fwnode), 0);
509 			if (!pp->irq)
510 				dev_warn(dev, "no irq for port%d\n", pp->idx);
511 		}
512 
513 		if (has_acpi_companion(dev) && pp->idx == 0)
514 			pp->irq = platform_get_irq(to_platform_device(dev), 0);
515 
516 		pp->irq_shared	= false;
517 		pp->gpio_base	= -1;
518 	}
519 
520 	return pdata;
521 }
522 
523 static int dwapb_gpio_probe(struct platform_device *pdev)
524 {
525 	unsigned int i;
526 	struct resource *res;
527 	struct dwapb_gpio *gpio;
528 	int err;
529 	struct device *dev = &pdev->dev;
530 	struct dwapb_platform_data *pdata = dev_get_platdata(dev);
531 
532 	if (!pdata) {
533 		pdata = dwapb_gpio_get_pdata(dev);
534 		if (IS_ERR(pdata))
535 			return PTR_ERR(pdata);
536 	}
537 
538 	if (!pdata->nports)
539 		return -ENODEV;
540 
541 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
542 	if (!gpio)
543 		return -ENOMEM;
544 
545 	gpio->dev = &pdev->dev;
546 	gpio->nr_ports = pdata->nports;
547 
548 	gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
549 				   sizeof(*gpio->ports), GFP_KERNEL);
550 	if (!gpio->ports)
551 		return -ENOMEM;
552 
553 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
554 	gpio->regs = devm_ioremap_resource(&pdev->dev, res);
555 	if (IS_ERR(gpio->regs))
556 		return PTR_ERR(gpio->regs);
557 
558 	for (i = 0; i < gpio->nr_ports; i++) {
559 		err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
560 		if (err)
561 			goto out_unregister;
562 	}
563 	platform_set_drvdata(pdev, gpio);
564 
565 	return 0;
566 
567 out_unregister:
568 	dwapb_gpio_unregister(gpio);
569 	dwapb_irq_teardown(gpio);
570 
571 	return err;
572 }
573 
574 static int dwapb_gpio_remove(struct platform_device *pdev)
575 {
576 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
577 
578 	dwapb_gpio_unregister(gpio);
579 	dwapb_irq_teardown(gpio);
580 
581 	return 0;
582 }
583 
584 static const struct of_device_id dwapb_of_match[] = {
585 	{ .compatible = "snps,dw-apb-gpio" },
586 	{ /* Sentinel */ }
587 };
588 MODULE_DEVICE_TABLE(of, dwapb_of_match);
589 
590 static const struct acpi_device_id dwapb_acpi_match[] = {
591 	{"HISI0181", 0},
592 	{"APMC0D07", 0},
593 	{ }
594 };
595 MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
596 
597 #ifdef CONFIG_PM_SLEEP
598 static int dwapb_gpio_suspend(struct device *dev)
599 {
600 	struct platform_device *pdev = to_platform_device(dev);
601 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
602 	struct gpio_chip *gc	= &gpio->ports[0].gc;
603 	unsigned long flags;
604 	int i;
605 
606 	spin_lock_irqsave(&gc->bgpio_lock, flags);
607 	for (i = 0; i < gpio->nr_ports; i++) {
608 		unsigned int offset;
609 		unsigned int idx = gpio->ports[i].idx;
610 		struct dwapb_context *ctx = gpio->ports[i].ctx;
611 
612 		BUG_ON(!ctx);
613 
614 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_SIZE;
615 		ctx->dir = dwapb_read(gpio, offset);
616 
617 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_SIZE;
618 		ctx->data = dwapb_read(gpio, offset);
619 
620 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_SIZE;
621 		ctx->ext = dwapb_read(gpio, offset);
622 
623 		/* Only port A can provide interrupts */
624 		if (idx == 0) {
625 			ctx->int_mask	= dwapb_read(gpio, GPIO_INTMASK);
626 			ctx->int_en	= dwapb_read(gpio, GPIO_INTEN);
627 			ctx->int_pol	= dwapb_read(gpio, GPIO_INT_POLARITY);
628 			ctx->int_type	= dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
629 			ctx->int_deb	= dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
630 
631 			/* Mask out interrupts */
632 			dwapb_write(gpio, GPIO_INTMASK, 0xffffffff);
633 		}
634 	}
635 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
636 
637 	return 0;
638 }
639 
640 static int dwapb_gpio_resume(struct device *dev)
641 {
642 	struct platform_device *pdev = to_platform_device(dev);
643 	struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
644 	struct gpio_chip *gc	= &gpio->ports[0].gc;
645 	unsigned long flags;
646 	int i;
647 
648 	spin_lock_irqsave(&gc->bgpio_lock, flags);
649 	for (i = 0; i < gpio->nr_ports; i++) {
650 		unsigned int offset;
651 		unsigned int idx = gpio->ports[i].idx;
652 		struct dwapb_context *ctx = gpio->ports[i].ctx;
653 
654 		BUG_ON(!ctx);
655 
656 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_SIZE;
657 		dwapb_write(gpio, offset, ctx->data);
658 
659 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_SIZE;
660 		dwapb_write(gpio, offset, ctx->dir);
661 
662 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_SIZE;
663 		dwapb_write(gpio, offset, ctx->ext);
664 
665 		/* Only port A can provide interrupts */
666 		if (idx == 0) {
667 			dwapb_write(gpio, GPIO_INTTYPE_LEVEL, ctx->int_type);
668 			dwapb_write(gpio, GPIO_INT_POLARITY, ctx->int_pol);
669 			dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ctx->int_deb);
670 			dwapb_write(gpio, GPIO_INTEN, ctx->int_en);
671 			dwapb_write(gpio, GPIO_INTMASK, ctx->int_mask);
672 
673 			/* Clear out spurious interrupts */
674 			dwapb_write(gpio, GPIO_PORTA_EOI, 0xffffffff);
675 		}
676 	}
677 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
678 
679 	return 0;
680 }
681 #endif
682 
683 static SIMPLE_DEV_PM_OPS(dwapb_gpio_pm_ops, dwapb_gpio_suspend,
684 			 dwapb_gpio_resume);
685 
686 static struct platform_driver dwapb_gpio_driver = {
687 	.driver		= {
688 		.name	= "gpio-dwapb",
689 		.pm	= &dwapb_gpio_pm_ops,
690 		.of_match_table = of_match_ptr(dwapb_of_match),
691 		.acpi_match_table = ACPI_PTR(dwapb_acpi_match),
692 	},
693 	.probe		= dwapb_gpio_probe,
694 	.remove		= dwapb_gpio_remove,
695 };
696 
697 module_platform_driver(dwapb_gpio_driver);
698 
699 MODULE_LICENSE("GPL");
700 MODULE_AUTHOR("Jamie Iles");
701 MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
702