xref: /openbmc/linux/drivers/gpio/gpio-dwapb.c (revision 3a35093a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2011 Jamie Iles
4  *
5  * All enquiries to support@picochip.com
6  */
7 #include <linux/acpi.h>
8 #include <linux/clk.h>
9 #include <linux/err.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/ioport.h>
15 #include <linux/irq.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/of_irq.h>
21 #include <linux/platform_device.h>
22 #include <linux/property.h>
23 #include <linux/reset.h>
24 #include <linux/spinlock.h>
25 #include <linux/platform_data/gpio-dwapb.h>
26 #include <linux/slab.h>
27 
28 #include "gpiolib.h"
29 #include "gpiolib-acpi.h"
30 
31 #define GPIO_SWPORTA_DR		0x00
32 #define GPIO_SWPORTA_DDR	0x04
33 #define GPIO_SWPORTB_DR		0x0c
34 #define GPIO_SWPORTB_DDR	0x10
35 #define GPIO_SWPORTC_DR		0x18
36 #define GPIO_SWPORTC_DDR	0x1c
37 #define GPIO_SWPORTD_DR		0x24
38 #define GPIO_SWPORTD_DDR	0x28
39 #define GPIO_INTEN		0x30
40 #define GPIO_INTMASK		0x34
41 #define GPIO_INTTYPE_LEVEL	0x38
42 #define GPIO_INT_POLARITY	0x3c
43 #define GPIO_INTSTATUS		0x40
44 #define GPIO_PORTA_DEBOUNCE	0x48
45 #define GPIO_PORTA_EOI		0x4c
46 #define GPIO_EXT_PORTA		0x50
47 #define GPIO_EXT_PORTB		0x54
48 #define GPIO_EXT_PORTC		0x58
49 #define GPIO_EXT_PORTD		0x5c
50 
51 #define DWAPB_DRIVER_NAME	"gpio-dwapb"
52 #define DWAPB_MAX_PORTS		4
53 
54 #define GPIO_EXT_PORT_STRIDE	0x04 /* register stride 32 bits */
55 #define GPIO_SWPORT_DR_STRIDE	0x0c /* register stride 3*32 bits */
56 #define GPIO_SWPORT_DDR_STRIDE	0x0c /* register stride 3*32 bits */
57 
58 #define GPIO_REG_OFFSET_V2	1
59 
60 #define GPIO_INTMASK_V2		0x44
61 #define GPIO_INTTYPE_LEVEL_V2	0x34
62 #define GPIO_INT_POLARITY_V2	0x38
63 #define GPIO_INTSTATUS_V2	0x3c
64 #define GPIO_PORTA_EOI_V2	0x40
65 
66 #define DWAPB_NR_CLOCKS		2
67 
68 struct dwapb_gpio;
69 
70 #ifdef CONFIG_PM_SLEEP
71 /* Store GPIO context across system-wide suspend/resume transitions */
72 struct dwapb_context {
73 	u32 data;
74 	u32 dir;
75 	u32 ext;
76 	u32 int_en;
77 	u32 int_mask;
78 	u32 int_type;
79 	u32 int_pol;
80 	u32 int_deb;
81 	u32 wake_en;
82 };
83 #endif
84 
85 struct dwapb_gpio_port_irqchip {
86 	struct irq_chip		irqchip;
87 	unsigned int		nr_irqs;
88 	unsigned int		irq[DWAPB_MAX_GPIOS];
89 };
90 
91 struct dwapb_gpio_port {
92 	struct gpio_chip	gc;
93 	struct dwapb_gpio_port_irqchip *pirq;
94 	struct dwapb_gpio	*gpio;
95 #ifdef CONFIG_PM_SLEEP
96 	struct dwapb_context	*ctx;
97 #endif
98 	unsigned int		idx;
99 };
100 #define to_dwapb_gpio(_gc) \
101 	(container_of(_gc, struct dwapb_gpio_port, gc)->gpio)
102 
103 struct dwapb_gpio {
104 	struct	device		*dev;
105 	void __iomem		*regs;
106 	struct dwapb_gpio_port	*ports;
107 	unsigned int		nr_ports;
108 	unsigned int		flags;
109 	struct reset_control	*rst;
110 	struct clk_bulk_data	clks[DWAPB_NR_CLOCKS];
111 };
112 
113 static inline u32 gpio_reg_v2_convert(unsigned int offset)
114 {
115 	switch (offset) {
116 	case GPIO_INTMASK:
117 		return GPIO_INTMASK_V2;
118 	case GPIO_INTTYPE_LEVEL:
119 		return GPIO_INTTYPE_LEVEL_V2;
120 	case GPIO_INT_POLARITY:
121 		return GPIO_INT_POLARITY_V2;
122 	case GPIO_INTSTATUS:
123 		return GPIO_INTSTATUS_V2;
124 	case GPIO_PORTA_EOI:
125 		return GPIO_PORTA_EOI_V2;
126 	}
127 
128 	return offset;
129 }
130 
131 static inline u32 gpio_reg_convert(struct dwapb_gpio *gpio, unsigned int offset)
132 {
133 	if (gpio->flags & GPIO_REG_OFFSET_V2)
134 		return gpio_reg_v2_convert(offset);
135 
136 	return offset;
137 }
138 
139 static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
140 {
141 	struct gpio_chip *gc	= &gpio->ports[0].gc;
142 	void __iomem *reg_base	= gpio->regs;
143 
144 	return gc->read_reg(reg_base + gpio_reg_convert(gpio, offset));
145 }
146 
147 static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
148 			       u32 val)
149 {
150 	struct gpio_chip *gc	= &gpio->ports[0].gc;
151 	void __iomem *reg_base	= gpio->regs;
152 
153 	gc->write_reg(reg_base + gpio_reg_convert(gpio, offset), val);
154 }
155 
156 static struct dwapb_gpio_port *dwapb_offs_to_port(struct dwapb_gpio *gpio, unsigned int offs)
157 {
158 	struct dwapb_gpio_port *port;
159 	int i;
160 
161 	for (i = 0; i < gpio->nr_ports; i++) {
162 		port = &gpio->ports[i];
163 		if (port->idx == offs / DWAPB_MAX_GPIOS)
164 			return port;
165 	}
166 
167 	return NULL;
168 }
169 
170 static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
171 {
172 	struct dwapb_gpio_port *port = dwapb_offs_to_port(gpio, offs);
173 	struct gpio_chip *gc;
174 	u32 pol;
175 	int val;
176 
177 	if (!port)
178 		return;
179 	gc = &port->gc;
180 
181 	pol = dwapb_read(gpio, GPIO_INT_POLARITY);
182 	/* Just read the current value right out of the data register */
183 	val = gc->get(gc, offs % DWAPB_MAX_GPIOS);
184 	if (val)
185 		pol &= ~BIT(offs);
186 	else
187 		pol |= BIT(offs);
188 
189 	dwapb_write(gpio, GPIO_INT_POLARITY, pol);
190 }
191 
192 static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
193 {
194 	struct gpio_chip *gc = &gpio->ports[0].gc;
195 	unsigned long irq_status;
196 	irq_hw_number_t hwirq;
197 
198 	irq_status = dwapb_read(gpio, GPIO_INTSTATUS);
199 	for_each_set_bit(hwirq, &irq_status, DWAPB_MAX_GPIOS) {
200 		int gpio_irq = irq_find_mapping(gc->irq.domain, hwirq);
201 		u32 irq_type = irq_get_trigger_type(gpio_irq);
202 
203 		generic_handle_irq(gpio_irq);
204 
205 		if ((irq_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH)
206 			dwapb_toggle_trigger(gpio, hwirq);
207 	}
208 
209 	return irq_status;
210 }
211 
212 static void dwapb_irq_handler(struct irq_desc *desc)
213 {
214 	struct dwapb_gpio *gpio = irq_desc_get_handler_data(desc);
215 	struct irq_chip *chip = irq_desc_get_chip(desc);
216 
217 	chained_irq_enter(chip, desc);
218 	dwapb_do_irq(gpio);
219 	chained_irq_exit(chip, desc);
220 }
221 
222 static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
223 {
224 	return IRQ_RETVAL(dwapb_do_irq(dev_id));
225 }
226 
227 static void dwapb_irq_ack(struct irq_data *d)
228 {
229 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
230 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
231 	u32 val = BIT(irqd_to_hwirq(d));
232 	unsigned long flags;
233 
234 	spin_lock_irqsave(&gc->bgpio_lock, flags);
235 	dwapb_write(gpio, GPIO_PORTA_EOI, val);
236 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
237 }
238 
239 static void dwapb_irq_mask(struct irq_data *d)
240 {
241 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
242 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
243 	unsigned long flags;
244 	u32 val;
245 
246 	spin_lock_irqsave(&gc->bgpio_lock, flags);
247 	val = dwapb_read(gpio, GPIO_INTMASK) | BIT(irqd_to_hwirq(d));
248 	dwapb_write(gpio, GPIO_INTMASK, val);
249 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
250 }
251 
252 static void dwapb_irq_unmask(struct irq_data *d)
253 {
254 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
255 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
256 	unsigned long flags;
257 	u32 val;
258 
259 	spin_lock_irqsave(&gc->bgpio_lock, flags);
260 	val = dwapb_read(gpio, GPIO_INTMASK) & ~BIT(irqd_to_hwirq(d));
261 	dwapb_write(gpio, GPIO_INTMASK, val);
262 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
263 }
264 
265 static void dwapb_irq_enable(struct irq_data *d)
266 {
267 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
268 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
269 	unsigned long flags;
270 	u32 val;
271 
272 	spin_lock_irqsave(&gc->bgpio_lock, flags);
273 	val = dwapb_read(gpio, GPIO_INTEN);
274 	val |= BIT(irqd_to_hwirq(d));
275 	dwapb_write(gpio, GPIO_INTEN, val);
276 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
277 }
278 
279 static void dwapb_irq_disable(struct irq_data *d)
280 {
281 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
282 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
283 	unsigned long flags;
284 	u32 val;
285 
286 	spin_lock_irqsave(&gc->bgpio_lock, flags);
287 	val = dwapb_read(gpio, GPIO_INTEN);
288 	val &= ~BIT(irqd_to_hwirq(d));
289 	dwapb_write(gpio, GPIO_INTEN, val);
290 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
291 }
292 
293 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
294 {
295 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
296 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
297 	irq_hw_number_t bit = irqd_to_hwirq(d);
298 	unsigned long level, polarity, flags;
299 
300 	if (type & ~IRQ_TYPE_SENSE_MASK)
301 		return -EINVAL;
302 
303 	spin_lock_irqsave(&gc->bgpio_lock, flags);
304 	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
305 	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
306 
307 	switch (type) {
308 	case IRQ_TYPE_EDGE_BOTH:
309 		level |= BIT(bit);
310 		dwapb_toggle_trigger(gpio, bit);
311 		break;
312 	case IRQ_TYPE_EDGE_RISING:
313 		level |= BIT(bit);
314 		polarity |= BIT(bit);
315 		break;
316 	case IRQ_TYPE_EDGE_FALLING:
317 		level |= BIT(bit);
318 		polarity &= ~BIT(bit);
319 		break;
320 	case IRQ_TYPE_LEVEL_HIGH:
321 		level &= ~BIT(bit);
322 		polarity |= BIT(bit);
323 		break;
324 	case IRQ_TYPE_LEVEL_LOW:
325 		level &= ~BIT(bit);
326 		polarity &= ~BIT(bit);
327 		break;
328 	}
329 
330 	if (type & IRQ_TYPE_LEVEL_MASK)
331 		irq_set_handler_locked(d, handle_level_irq);
332 	else if (type & IRQ_TYPE_EDGE_BOTH)
333 		irq_set_handler_locked(d, handle_edge_irq);
334 
335 	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
336 	if (type != IRQ_TYPE_EDGE_BOTH)
337 		dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
338 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
339 
340 	return 0;
341 }
342 
343 #ifdef CONFIG_PM_SLEEP
344 static int dwapb_irq_set_wake(struct irq_data *d, unsigned int enable)
345 {
346 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
347 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
348 	struct dwapb_context *ctx = gpio->ports[0].ctx;
349 	irq_hw_number_t bit = irqd_to_hwirq(d);
350 
351 	if (enable)
352 		ctx->wake_en |= BIT(bit);
353 	else
354 		ctx->wake_en &= ~BIT(bit);
355 
356 	return 0;
357 }
358 #endif
359 
360 static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
361 				   unsigned offset, unsigned debounce)
362 {
363 	struct dwapb_gpio_port *port = gpiochip_get_data(gc);
364 	struct dwapb_gpio *gpio = port->gpio;
365 	unsigned long flags, val_deb;
366 	unsigned long mask = BIT(offset);
367 
368 	spin_lock_irqsave(&gc->bgpio_lock, flags);
369 
370 	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
371 	if (debounce)
372 		val_deb |= mask;
373 	else
374 		val_deb &= ~mask;
375 	dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb);
376 
377 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
378 
379 	return 0;
380 }
381 
382 static int dwapb_gpio_set_config(struct gpio_chip *gc, unsigned offset,
383 				 unsigned long config)
384 {
385 	u32 debounce;
386 
387 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
388 		return -ENOTSUPP;
389 
390 	debounce = pinconf_to_config_argument(config);
391 	return dwapb_gpio_set_debounce(gc, offset, debounce);
392 }
393 
394 static int dwapb_convert_irqs(struct dwapb_gpio_port_irqchip *pirq,
395 			      struct dwapb_port_property *pp)
396 {
397 	int i;
398 
399 	/* Group all available IRQs into an array of parental IRQs. */
400 	for (i = 0; i < pp->ngpio; ++i) {
401 		if (!pp->irq[i])
402 			continue;
403 
404 		pirq->irq[pirq->nr_irqs++] = pp->irq[i];
405 	}
406 
407 	return pirq->nr_irqs ? 0 : -ENOENT;
408 }
409 
410 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
411 				 struct dwapb_gpio_port *port,
412 				 struct dwapb_port_property *pp)
413 {
414 	struct dwapb_gpio_port_irqchip *pirq;
415 	struct gpio_chip *gc = &port->gc;
416 	struct gpio_irq_chip *girq;
417 	int err;
418 
419 	pirq = devm_kzalloc(gpio->dev, sizeof(*pirq), GFP_KERNEL);
420 	if (!pirq)
421 		return;
422 
423 	if (dwapb_convert_irqs(pirq, pp)) {
424 		dev_warn(gpio->dev, "no IRQ for port%d\n", pp->idx);
425 		goto err_kfree_pirq;
426 	}
427 
428 	girq = &gc->irq;
429 	girq->handler = handle_bad_irq;
430 	girq->default_type = IRQ_TYPE_NONE;
431 
432 	port->pirq = pirq;
433 	pirq->irqchip.name = DWAPB_DRIVER_NAME;
434 	pirq->irqchip.irq_ack = dwapb_irq_ack;
435 	pirq->irqchip.irq_mask = dwapb_irq_mask;
436 	pirq->irqchip.irq_unmask = dwapb_irq_unmask;
437 	pirq->irqchip.irq_set_type = dwapb_irq_set_type;
438 	pirq->irqchip.irq_enable = dwapb_irq_enable;
439 	pirq->irqchip.irq_disable = dwapb_irq_disable;
440 #ifdef CONFIG_PM_SLEEP
441 	pirq->irqchip.irq_set_wake = dwapb_irq_set_wake;
442 #endif
443 
444 	if (!pp->irq_shared) {
445 		girq->num_parents = pirq->nr_irqs;
446 		girq->parents = pirq->irq;
447 		girq->parent_handler_data = gpio;
448 		girq->parent_handler = dwapb_irq_handler;
449 	} else {
450 		/* This will let us handle the parent IRQ in the driver */
451 		girq->num_parents = 0;
452 		girq->parents = NULL;
453 		girq->parent_handler = NULL;
454 
455 		/*
456 		 * Request a shared IRQ since where MFD would have devices
457 		 * using the same irq pin
458 		 */
459 		err = devm_request_irq(gpio->dev, pp->irq[0],
460 				       dwapb_irq_handler_mfd,
461 				       IRQF_SHARED, DWAPB_DRIVER_NAME, gpio);
462 		if (err) {
463 			dev_err(gpio->dev, "error requesting IRQ\n");
464 			goto err_kfree_pirq;
465 		}
466 	}
467 
468 	girq->chip = &pirq->irqchip;
469 
470 	return;
471 
472 err_kfree_pirq:
473 	devm_kfree(gpio->dev, pirq);
474 }
475 
476 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
477 			       struct dwapb_port_property *pp,
478 			       unsigned int offs)
479 {
480 	struct dwapb_gpio_port *port;
481 	void __iomem *dat, *set, *dirout;
482 	int err;
483 
484 	port = &gpio->ports[offs];
485 	port->gpio = gpio;
486 	port->idx = pp->idx;
487 
488 #ifdef CONFIG_PM_SLEEP
489 	port->ctx = devm_kzalloc(gpio->dev, sizeof(*port->ctx), GFP_KERNEL);
490 	if (!port->ctx)
491 		return -ENOMEM;
492 #endif
493 
494 	dat = gpio->regs + GPIO_EXT_PORTA + pp->idx * GPIO_EXT_PORT_STRIDE;
495 	set = gpio->regs + GPIO_SWPORTA_DR + pp->idx * GPIO_SWPORT_DR_STRIDE;
496 	dirout = gpio->regs + GPIO_SWPORTA_DDR + pp->idx * GPIO_SWPORT_DDR_STRIDE;
497 
498 	/* This registers 32 GPIO lines per port */
499 	err = bgpio_init(&port->gc, gpio->dev, 4, dat, set, NULL, dirout,
500 			 NULL, 0);
501 	if (err) {
502 		dev_err(gpio->dev, "failed to init gpio chip for port%d\n",
503 			port->idx);
504 		return err;
505 	}
506 
507 #ifdef CONFIG_OF_GPIO
508 	port->gc.of_node = to_of_node(pp->fwnode);
509 #endif
510 	port->gc.ngpio = pp->ngpio;
511 	port->gc.base = pp->gpio_base;
512 
513 	/* Only port A support debounce */
514 	if (pp->idx == 0)
515 		port->gc.set_config = dwapb_gpio_set_config;
516 
517 	/* Only port A can provide interrupts in all configurations of the IP */
518 	if (pp->idx == 0)
519 		dwapb_configure_irqs(gpio, port, pp);
520 
521 	err = devm_gpiochip_add_data(gpio->dev, &port->gc, port);
522 	if (err) {
523 		dev_err(gpio->dev, "failed to register gpiochip for port%d\n",
524 			port->idx);
525 		return err;
526 	}
527 
528 	return 0;
529 }
530 
531 static void dwapb_get_irq(struct device *dev, struct fwnode_handle *fwnode,
532 			  struct dwapb_port_property *pp)
533 {
534 	struct device_node *np = NULL;
535 	int irq = -ENXIO, j;
536 
537 	if (fwnode_property_read_bool(fwnode, "interrupt-controller"))
538 		np = to_of_node(fwnode);
539 
540 	for (j = 0; j < pp->ngpio; j++) {
541 		if (np)
542 			irq = of_irq_get(np, j);
543 		else if (has_acpi_companion(dev))
544 			irq = platform_get_irq_optional(to_platform_device(dev), j);
545 		if (irq > 0)
546 			pp->irq[j] = irq;
547 	}
548 }
549 
550 static struct dwapb_platform_data *dwapb_gpio_get_pdata(struct device *dev)
551 {
552 	struct fwnode_handle *fwnode;
553 	struct dwapb_platform_data *pdata;
554 	struct dwapb_port_property *pp;
555 	int nports;
556 	int i;
557 
558 	nports = device_get_child_node_count(dev);
559 	if (nports == 0)
560 		return ERR_PTR(-ENODEV);
561 
562 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
563 	if (!pdata)
564 		return ERR_PTR(-ENOMEM);
565 
566 	pdata->properties = devm_kcalloc(dev, nports, sizeof(*pp), GFP_KERNEL);
567 	if (!pdata->properties)
568 		return ERR_PTR(-ENOMEM);
569 
570 	pdata->nports = nports;
571 
572 	i = 0;
573 	device_for_each_child_node(dev, fwnode)  {
574 		pp = &pdata->properties[i++];
575 		pp->fwnode = fwnode;
576 
577 		if (fwnode_property_read_u32(fwnode, "reg", &pp->idx) ||
578 		    pp->idx >= DWAPB_MAX_PORTS) {
579 			dev_err(dev,
580 				"missing/invalid port index for port%d\n", i);
581 			fwnode_handle_put(fwnode);
582 			return ERR_PTR(-EINVAL);
583 		}
584 
585 		if (fwnode_property_read_u32(fwnode, "ngpios", &pp->ngpio) &&
586 		    fwnode_property_read_u32(fwnode, "snps,nr-gpios", &pp->ngpio)) {
587 			dev_info(dev,
588 				 "failed to get number of gpios for port%d\n",
589 				 i);
590 			pp->ngpio = DWAPB_MAX_GPIOS;
591 		}
592 
593 		pp->irq_shared	= false;
594 		pp->gpio_base	= -1;
595 
596 		/*
597 		 * Only port A can provide interrupts in all configurations of
598 		 * the IP.
599 		 */
600 		if (pp->idx == 0)
601 			dwapb_get_irq(dev, fwnode, pp);
602 	}
603 
604 	return pdata;
605 }
606 
607 static void dwapb_assert_reset(void *data)
608 {
609 	struct dwapb_gpio *gpio = data;
610 
611 	reset_control_assert(gpio->rst);
612 }
613 
614 static int dwapb_get_reset(struct dwapb_gpio *gpio)
615 {
616 	int err;
617 
618 	gpio->rst = devm_reset_control_get_optional_shared(gpio->dev, NULL);
619 	if (IS_ERR(gpio->rst))
620 		return dev_err_probe(gpio->dev, PTR_ERR(gpio->rst),
621 				     "Cannot get reset descriptor\n");
622 
623 	err = reset_control_deassert(gpio->rst);
624 	if (err) {
625 		dev_err(gpio->dev, "Cannot deassert reset lane\n");
626 		return err;
627 	}
628 
629 	return devm_add_action_or_reset(gpio->dev, dwapb_assert_reset, gpio);
630 }
631 
632 static void dwapb_disable_clks(void *data)
633 {
634 	struct dwapb_gpio *gpio = data;
635 
636 	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
637 }
638 
639 static int dwapb_get_clks(struct dwapb_gpio *gpio)
640 {
641 	int err;
642 
643 	/* Optional bus and debounce clocks */
644 	gpio->clks[0].id = "bus";
645 	gpio->clks[1].id = "db";
646 	err = devm_clk_bulk_get_optional(gpio->dev, DWAPB_NR_CLOCKS,
647 					 gpio->clks);
648 	if (err) {
649 		dev_err(gpio->dev, "Cannot get APB/Debounce clocks\n");
650 		return err;
651 	}
652 
653 	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
654 	if (err) {
655 		dev_err(gpio->dev, "Cannot enable APB/Debounce clocks\n");
656 		return err;
657 	}
658 
659 	return devm_add_action_or_reset(gpio->dev, dwapb_disable_clks, gpio);
660 }
661 
662 static const struct of_device_id dwapb_of_match[] = {
663 	{ .compatible = "snps,dw-apb-gpio", .data = (void *)0},
664 	{ .compatible = "apm,xgene-gpio-v2", .data = (void *)GPIO_REG_OFFSET_V2},
665 	{ /* Sentinel */ }
666 };
667 MODULE_DEVICE_TABLE(of, dwapb_of_match);
668 
669 static const struct acpi_device_id dwapb_acpi_match[] = {
670 	{"HISI0181", 0},
671 	{"APMC0D07", 0},
672 	{"APMC0D81", GPIO_REG_OFFSET_V2},
673 	{ }
674 };
675 MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
676 
677 static int dwapb_gpio_probe(struct platform_device *pdev)
678 {
679 	unsigned int i;
680 	struct dwapb_gpio *gpio;
681 	int err;
682 	struct device *dev = &pdev->dev;
683 	struct dwapb_platform_data *pdata = dev_get_platdata(dev);
684 
685 	if (!pdata) {
686 		pdata = dwapb_gpio_get_pdata(dev);
687 		if (IS_ERR(pdata))
688 			return PTR_ERR(pdata);
689 	}
690 
691 	if (!pdata->nports)
692 		return -ENODEV;
693 
694 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
695 	if (!gpio)
696 		return -ENOMEM;
697 
698 	gpio->dev = &pdev->dev;
699 	gpio->nr_ports = pdata->nports;
700 
701 	err = dwapb_get_reset(gpio);
702 	if (err)
703 		return err;
704 
705 	gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
706 				   sizeof(*gpio->ports), GFP_KERNEL);
707 	if (!gpio->ports)
708 		return -ENOMEM;
709 
710 	gpio->regs = devm_platform_ioremap_resource(pdev, 0);
711 	if (IS_ERR(gpio->regs))
712 		return PTR_ERR(gpio->regs);
713 
714 	err = dwapb_get_clks(gpio);
715 	if (err)
716 		return err;
717 
718 	gpio->flags = (uintptr_t)device_get_match_data(dev);
719 
720 	for (i = 0; i < gpio->nr_ports; i++) {
721 		err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
722 		if (err)
723 			return err;
724 	}
725 
726 	platform_set_drvdata(pdev, gpio);
727 
728 	return 0;
729 }
730 
731 #ifdef CONFIG_PM_SLEEP
732 static int dwapb_gpio_suspend(struct device *dev)
733 {
734 	struct dwapb_gpio *gpio = dev_get_drvdata(dev);
735 	struct gpio_chip *gc	= &gpio->ports[0].gc;
736 	unsigned long flags;
737 	int i;
738 
739 	spin_lock_irqsave(&gc->bgpio_lock, flags);
740 	for (i = 0; i < gpio->nr_ports; i++) {
741 		unsigned int offset;
742 		unsigned int idx = gpio->ports[i].idx;
743 		struct dwapb_context *ctx = gpio->ports[i].ctx;
744 
745 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_STRIDE;
746 		ctx->dir = dwapb_read(gpio, offset);
747 
748 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_STRIDE;
749 		ctx->data = dwapb_read(gpio, offset);
750 
751 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_STRIDE;
752 		ctx->ext = dwapb_read(gpio, offset);
753 
754 		/* Only port A can provide interrupts */
755 		if (idx == 0) {
756 			ctx->int_mask	= dwapb_read(gpio, GPIO_INTMASK);
757 			ctx->int_en	= dwapb_read(gpio, GPIO_INTEN);
758 			ctx->int_pol	= dwapb_read(gpio, GPIO_INT_POLARITY);
759 			ctx->int_type	= dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
760 			ctx->int_deb	= dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
761 
762 			/* Mask out interrupts */
763 			dwapb_write(gpio, GPIO_INTMASK, ~ctx->wake_en);
764 		}
765 	}
766 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
767 
768 	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
769 
770 	return 0;
771 }
772 
773 static int dwapb_gpio_resume(struct device *dev)
774 {
775 	struct dwapb_gpio *gpio = dev_get_drvdata(dev);
776 	struct gpio_chip *gc	= &gpio->ports[0].gc;
777 	unsigned long flags;
778 	int i, err;
779 
780 	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
781 	if (err) {
782 		dev_err(gpio->dev, "Cannot reenable APB/Debounce clocks\n");
783 		return err;
784 	}
785 
786 	spin_lock_irqsave(&gc->bgpio_lock, flags);
787 	for (i = 0; i < gpio->nr_ports; i++) {
788 		unsigned int offset;
789 		unsigned int idx = gpio->ports[i].idx;
790 		struct dwapb_context *ctx = gpio->ports[i].ctx;
791 
792 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_STRIDE;
793 		dwapb_write(gpio, offset, ctx->data);
794 
795 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_STRIDE;
796 		dwapb_write(gpio, offset, ctx->dir);
797 
798 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_STRIDE;
799 		dwapb_write(gpio, offset, ctx->ext);
800 
801 		/* Only port A can provide interrupts */
802 		if (idx == 0) {
803 			dwapb_write(gpio, GPIO_INTTYPE_LEVEL, ctx->int_type);
804 			dwapb_write(gpio, GPIO_INT_POLARITY, ctx->int_pol);
805 			dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ctx->int_deb);
806 			dwapb_write(gpio, GPIO_INTEN, ctx->int_en);
807 			dwapb_write(gpio, GPIO_INTMASK, ctx->int_mask);
808 
809 			/* Clear out spurious interrupts */
810 			dwapb_write(gpio, GPIO_PORTA_EOI, 0xffffffff);
811 		}
812 	}
813 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
814 
815 	return 0;
816 }
817 #endif
818 
819 static SIMPLE_DEV_PM_OPS(dwapb_gpio_pm_ops, dwapb_gpio_suspend,
820 			 dwapb_gpio_resume);
821 
822 static struct platform_driver dwapb_gpio_driver = {
823 	.driver		= {
824 		.name	= DWAPB_DRIVER_NAME,
825 		.pm	= &dwapb_gpio_pm_ops,
826 		.of_match_table = dwapb_of_match,
827 		.acpi_match_table = dwapb_acpi_match,
828 	},
829 	.probe		= dwapb_gpio_probe,
830 };
831 
832 module_platform_driver(dwapb_gpio_driver);
833 
834 MODULE_LICENSE("GPL");
835 MODULE_AUTHOR("Jamie Iles");
836 MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
837 MODULE_ALIAS("platform:" DWAPB_DRIVER_NAME);
838