xref: /linux/drivers/gpio/gpio-dwapb.c (revision 509d3f45847627f4c5cdce004c3ec79262b5239c)
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/gpio/generic.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/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/property.h>
21 #include <linux/reset.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 
25 #include "gpiolib-acpi.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_DRIVER_NAME	"gpio-dwapb"
48 #define DWAPB_MAX_PORTS		4
49 #define DWAPB_MAX_GPIOS		32
50 
51 #define GPIO_EXT_PORT_STRIDE	0x04 /* register stride 32 bits */
52 #define GPIO_SWPORT_DR_STRIDE	0x0c /* register stride 3*32 bits */
53 #define GPIO_SWPORT_DDR_STRIDE	0x0c /* register stride 3*32 bits */
54 
55 #define GPIO_REG_OFFSET_V1	0
56 #define GPIO_REG_OFFSET_V2	1
57 #define GPIO_REG_OFFSET_MASK	BIT(0)
58 
59 #define GPIO_INTMASK_V2		0x44
60 #define GPIO_INTTYPE_LEVEL_V2	0x34
61 #define GPIO_INT_POLARITY_V2	0x38
62 #define GPIO_INTSTATUS_V2	0x3c
63 #define GPIO_PORTA_EOI_V2	0x40
64 
65 #define DWAPB_NR_CLOCKS		2
66 
67 struct dwapb_gpio;
68 
69 struct dwapb_port_property {
70 	struct fwnode_handle *fwnode;
71 	unsigned int idx;
72 	unsigned int ngpio;
73 	unsigned int gpio_base;
74 	int irq[DWAPB_MAX_GPIOS];
75 };
76 
77 struct dwapb_platform_data {
78 	struct dwapb_port_property *properties;
79 	unsigned int nports;
80 };
81 
82 /* Store GPIO context across system-wide suspend/resume transitions */
83 struct dwapb_context {
84 	u32 data;
85 	u32 dir;
86 	u32 ext;
87 	u32 int_en;
88 	u32 int_mask;
89 	u32 int_type;
90 	u32 int_pol;
91 	u32 int_deb;
92 	u32 wake_en;
93 };
94 
95 struct dwapb_gpio_port_irqchip {
96 	unsigned int		nr_irqs;
97 	unsigned int		irq[DWAPB_MAX_GPIOS];
98 };
99 
100 struct dwapb_gpio_port {
101 	struct gpio_generic_chip chip;
102 	struct dwapb_gpio_port_irqchip *pirq;
103 	struct dwapb_gpio	*gpio;
104 	struct dwapb_context	*ctx;
105 	unsigned int		idx;
106 };
107 
108 static inline struct dwapb_gpio *to_dwapb_gpio(struct gpio_chip *gc)
109 {
110 	return container_of(to_gpio_generic_chip(gc),
111 			    struct dwapb_gpio_port, chip)->gpio;
112 }
113 
114 struct dwapb_gpio {
115 	struct	device		*dev;
116 	void __iomem		*regs;
117 	struct dwapb_gpio_port	*ports;
118 	unsigned int		nr_ports;
119 	unsigned int		flags;
120 	struct reset_control	*rst;
121 	struct clk_bulk_data	clks[DWAPB_NR_CLOCKS];
122 };
123 
124 static inline u32 gpio_reg_v2_convert(unsigned int offset)
125 {
126 	switch (offset) {
127 	case GPIO_INTMASK:
128 		return GPIO_INTMASK_V2;
129 	case GPIO_INTTYPE_LEVEL:
130 		return GPIO_INTTYPE_LEVEL_V2;
131 	case GPIO_INT_POLARITY:
132 		return GPIO_INT_POLARITY_V2;
133 	case GPIO_INTSTATUS:
134 		return GPIO_INTSTATUS_V2;
135 	case GPIO_PORTA_EOI:
136 		return GPIO_PORTA_EOI_V2;
137 	}
138 
139 	return offset;
140 }
141 
142 static inline u32 gpio_reg_convert(struct dwapb_gpio *gpio, unsigned int offset)
143 {
144 	if ((gpio->flags & GPIO_REG_OFFSET_MASK) == GPIO_REG_OFFSET_V2)
145 		return gpio_reg_v2_convert(offset);
146 
147 	return offset;
148 }
149 
150 static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
151 {
152 	struct gpio_generic_chip *chip = &gpio->ports[0].chip;
153 	void __iomem *reg_base = gpio->regs;
154 
155 	return gpio_generic_read_reg(chip, reg_base + gpio_reg_convert(gpio, offset));
156 }
157 
158 static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
159 			       u32 val)
160 {
161 	struct gpio_generic_chip *chip = &gpio->ports[0].chip;
162 	void __iomem *reg_base = gpio->regs;
163 
164 	gpio_generic_write_reg(chip, reg_base + gpio_reg_convert(gpio, offset), val);
165 }
166 
167 static struct dwapb_gpio_port *dwapb_offs_to_port(struct dwapb_gpio *gpio, unsigned int offs)
168 {
169 	struct dwapb_gpio_port *port;
170 	int i;
171 
172 	for (i = 0; i < gpio->nr_ports; i++) {
173 		port = &gpio->ports[i];
174 		if (port->idx == offs / DWAPB_MAX_GPIOS)
175 			return port;
176 	}
177 
178 	return NULL;
179 }
180 
181 static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
182 {
183 	struct dwapb_gpio_port *port = dwapb_offs_to_port(gpio, offs);
184 	struct gpio_chip *gc;
185 	u32 pol;
186 	int val;
187 
188 	if (!port)
189 		return;
190 	gc = &port->chip.gc;
191 
192 	pol = dwapb_read(gpio, GPIO_INT_POLARITY);
193 	/* Just read the current value right out of the data register */
194 	val = gc->get(gc, offs % DWAPB_MAX_GPIOS);
195 	if (val)
196 		pol &= ~BIT(offs);
197 	else
198 		pol |= BIT(offs);
199 
200 	dwapb_write(gpio, GPIO_INT_POLARITY, pol);
201 }
202 
203 static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
204 {
205 	struct gpio_generic_chip *gen_gc = &gpio->ports[0].chip;
206 	unsigned long irq_status;
207 	irq_hw_number_t hwirq;
208 
209 	irq_status = dwapb_read(gpio, GPIO_INTSTATUS);
210 	for_each_set_bit(hwirq, &irq_status, DWAPB_MAX_GPIOS) {
211 		int gpio_irq = irq_find_mapping(gen_gc->gc.irq.domain, hwirq);
212 		u32 irq_type = irq_get_trigger_type(gpio_irq);
213 
214 		generic_handle_irq(gpio_irq);
215 
216 		if ((irq_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH)
217 			dwapb_toggle_trigger(gpio, hwirq);
218 	}
219 
220 	return irq_status;
221 }
222 
223 static void dwapb_irq_handler(struct irq_desc *desc)
224 {
225 	struct dwapb_gpio *gpio = irq_desc_get_handler_data(desc);
226 	struct irq_chip *chip = irq_desc_get_chip(desc);
227 
228 	chained_irq_enter(chip, desc);
229 	dwapb_do_irq(gpio);
230 	chained_irq_exit(chip, desc);
231 }
232 
233 static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id)
234 {
235 	return IRQ_RETVAL(dwapb_do_irq(dev_id));
236 }
237 
238 static void dwapb_irq_ack(struct irq_data *d)
239 {
240 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
241 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
242 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
243 	u32 val = BIT(irqd_to_hwirq(d));
244 
245 	guard(gpio_generic_lock_irqsave)(gen_gc);
246 
247 	dwapb_write(gpio, GPIO_PORTA_EOI, val);
248 }
249 
250 static void dwapb_irq_mask(struct irq_data *d)
251 {
252 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
253 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
254 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
255 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
256 	u32 val;
257 
258 	scoped_guard(gpio_generic_lock_irqsave, gen_gc) {
259 		val = dwapb_read(gpio, GPIO_INTMASK) | BIT(hwirq);
260 		dwapb_write(gpio, GPIO_INTMASK, val);
261 	}
262 
263 	gpiochip_disable_irq(gc, hwirq);
264 }
265 
266 static void dwapb_irq_unmask(struct irq_data *d)
267 {
268 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
269 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
270 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
271 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
272 	u32 val;
273 
274 	gpiochip_enable_irq(gc, hwirq);
275 
276 	guard(gpio_generic_lock_irqsave)(gen_gc);
277 
278 	val = dwapb_read(gpio, GPIO_INTMASK) & ~BIT(hwirq);
279 	dwapb_write(gpio, GPIO_INTMASK, val);
280 }
281 
282 static void dwapb_irq_enable(struct irq_data *d)
283 {
284 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
285 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
286 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
287 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
288 	u32 val;
289 
290 	guard(gpio_generic_lock_irqsave)(gen_gc);
291 
292 	val = dwapb_read(gpio, GPIO_INTEN) | BIT(hwirq);
293 	dwapb_write(gpio, GPIO_INTEN, val);
294 	val = dwapb_read(gpio, GPIO_INTMASK) & ~BIT(hwirq);
295 	dwapb_write(gpio, GPIO_INTMASK, val);
296 }
297 
298 static void dwapb_irq_disable(struct irq_data *d)
299 {
300 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
301 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
302 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
303 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
304 	u32 val;
305 
306 	guard(gpio_generic_lock_irqsave)(gen_gc);
307 
308 	val = dwapb_read(gpio, GPIO_INTMASK) | BIT(hwirq);
309 	dwapb_write(gpio, GPIO_INTMASK, val);
310 	val = dwapb_read(gpio, GPIO_INTEN) & ~BIT(hwirq);
311 	dwapb_write(gpio, GPIO_INTEN, val);
312 }
313 
314 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
315 {
316 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
317 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
318 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
319 	irq_hw_number_t bit = irqd_to_hwirq(d);
320 	unsigned long level, polarity;
321 
322 	guard(gpio_generic_lock_irqsave)(gen_gc);
323 
324 	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
325 	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
326 
327 	switch (type) {
328 	case IRQ_TYPE_EDGE_BOTH:
329 		level |= BIT(bit);
330 		dwapb_toggle_trigger(gpio, bit);
331 		break;
332 	case IRQ_TYPE_EDGE_RISING:
333 		level |= BIT(bit);
334 		polarity |= BIT(bit);
335 		break;
336 	case IRQ_TYPE_EDGE_FALLING:
337 		level |= BIT(bit);
338 		polarity &= ~BIT(bit);
339 		break;
340 	case IRQ_TYPE_LEVEL_HIGH:
341 		level &= ~BIT(bit);
342 		polarity |= BIT(bit);
343 		break;
344 	case IRQ_TYPE_LEVEL_LOW:
345 		level &= ~BIT(bit);
346 		polarity &= ~BIT(bit);
347 		break;
348 	}
349 
350 	if (type & IRQ_TYPE_LEVEL_MASK)
351 		irq_set_handler_locked(d, handle_level_irq);
352 	else if (type & IRQ_TYPE_EDGE_BOTH)
353 		irq_set_handler_locked(d, handle_edge_irq);
354 
355 	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
356 	if (type != IRQ_TYPE_EDGE_BOTH)
357 		dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
358 
359 	return 0;
360 }
361 
362 static int dwapb_irq_set_wake(struct irq_data *d, unsigned int enable)
363 {
364 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
365 	struct dwapb_gpio *gpio = to_dwapb_gpio(gc);
366 	struct dwapb_context *ctx = gpio->ports[0].ctx;
367 	irq_hw_number_t bit = irqd_to_hwirq(d);
368 
369 	if (enable)
370 		ctx->wake_en |= BIT(bit);
371 	else
372 		ctx->wake_en &= ~BIT(bit);
373 
374 	return 0;
375 }
376 
377 static const struct irq_chip dwapb_irq_chip = {
378 	.name		= DWAPB_DRIVER_NAME,
379 	.irq_ack	= dwapb_irq_ack,
380 	.irq_mask	= dwapb_irq_mask,
381 	.irq_unmask	= dwapb_irq_unmask,
382 	.irq_set_type	= dwapb_irq_set_type,
383 	.irq_enable	= dwapb_irq_enable,
384 	.irq_disable	= dwapb_irq_disable,
385 	.irq_set_wake	= pm_sleep_ptr(dwapb_irq_set_wake),
386 	.flags		= IRQCHIP_IMMUTABLE,
387 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
388 };
389 
390 static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
391 				   unsigned offset, unsigned debounce)
392 {
393 	struct dwapb_gpio_port *port = gpiochip_get_data(gc);
394 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
395 	struct dwapb_gpio *gpio = port->gpio;
396 	unsigned long val_deb;
397 	unsigned long mask = BIT(offset);
398 
399 	guard(gpio_generic_lock_irqsave)(gen_gc);
400 
401 	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
402 	if (debounce)
403 		val_deb |= mask;
404 	else
405 		val_deb &= ~mask;
406 	dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb);
407 
408 	return 0;
409 }
410 
411 static int dwapb_gpio_set_config(struct gpio_chip *gc, unsigned offset,
412 				 unsigned long config)
413 {
414 	u32 debounce;
415 
416 	if (pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE) {
417 		debounce = pinconf_to_config_argument(config);
418 		return dwapb_gpio_set_debounce(gc, offset, debounce);
419 	}
420 
421 	return gpiochip_generic_config(gc, offset, config);
422 }
423 
424 static int dwapb_convert_irqs(struct dwapb_gpio_port_irqchip *pirq,
425 			      struct dwapb_port_property *pp)
426 {
427 	int i;
428 
429 	/* Group all available IRQs into an array of parental IRQs. */
430 	for (i = 0; i < pp->ngpio; ++i) {
431 		if (!pp->irq[i])
432 			continue;
433 
434 		pirq->irq[pirq->nr_irqs++] = pp->irq[i];
435 	}
436 
437 	return pirq->nr_irqs ? 0 : -ENOENT;
438 }
439 
440 static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
441 				 struct dwapb_gpio_port *port,
442 				 struct dwapb_port_property *pp)
443 {
444 	struct dwapb_gpio_port_irqchip *pirq;
445 	struct gpio_chip *gc = &port->chip.gc;
446 	struct gpio_irq_chip *girq;
447 	int err;
448 
449 	pirq = devm_kzalloc(gpio->dev, sizeof(*pirq), GFP_KERNEL);
450 	if (!pirq)
451 		return;
452 
453 	if (dwapb_convert_irqs(pirq, pp)) {
454 		dev_warn(gpio->dev, "no IRQ for port%d\n", pp->idx);
455 		goto err_kfree_pirq;
456 	}
457 
458 	girq = &gc->irq;
459 	girq->handler = handle_bad_irq;
460 	girq->default_type = IRQ_TYPE_NONE;
461 
462 	port->pirq = pirq;
463 
464 	/*
465 	 * Intel ACPI-based platforms mostly have the DesignWare APB GPIO
466 	 * IRQ lane shared between several devices. In that case the parental
467 	 * IRQ has to be handled in the shared way so to be properly delivered
468 	 * to all the connected devices.
469 	 */
470 	if (has_acpi_companion(gpio->dev)) {
471 		girq->num_parents = 0;
472 		girq->parents = NULL;
473 		girq->parent_handler = NULL;
474 
475 		err = devm_request_irq(gpio->dev, pp->irq[0],
476 				       dwapb_irq_handler_mfd,
477 				       IRQF_SHARED, DWAPB_DRIVER_NAME, gpio);
478 		if (err) {
479 			dev_err(gpio->dev, "error requesting IRQ\n");
480 			goto err_kfree_pirq;
481 		}
482 	} else {
483 		girq->num_parents = pirq->nr_irqs;
484 		girq->parents = pirq->irq;
485 		girq->parent_handler_data = gpio;
486 		girq->parent_handler = dwapb_irq_handler;
487 	}
488 
489 	gpio_irq_chip_set_chip(girq, &dwapb_irq_chip);
490 
491 	return;
492 
493 err_kfree_pirq:
494 	devm_kfree(gpio->dev, pirq);
495 }
496 
497 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
498 			       struct dwapb_port_property *pp,
499 			       unsigned int offs)
500 {
501 	struct gpio_generic_chip_config config;
502 	struct dwapb_gpio_port *port;
503 	void __iomem *dat, *set, *dirout;
504 	int err;
505 
506 	port = &gpio->ports[offs];
507 	port->gpio = gpio;
508 	port->idx = pp->idx;
509 
510 #ifdef CONFIG_PM_SLEEP
511 	port->ctx = devm_kzalloc(gpio->dev, sizeof(*port->ctx), GFP_KERNEL);
512 	if (!port->ctx)
513 		return -ENOMEM;
514 #endif
515 
516 	dat = gpio->regs + GPIO_EXT_PORTA + pp->idx * GPIO_EXT_PORT_STRIDE;
517 	set = gpio->regs + GPIO_SWPORTA_DR + pp->idx * GPIO_SWPORT_DR_STRIDE;
518 	dirout = gpio->regs + GPIO_SWPORTA_DDR + pp->idx * GPIO_SWPORT_DDR_STRIDE;
519 
520 	config = (struct gpio_generic_chip_config) {
521 		.dev = gpio->dev,
522 		.sz = 4,
523 		.dat = dat,
524 		.set = set,
525 		.dirout = dirout,
526 	};
527 
528 	/* This registers 32 GPIO lines per port */
529 	err = gpio_generic_chip_init(&port->chip, &config);
530 	if (err) {
531 		dev_err(gpio->dev, "failed to init gpio chip for port%d\n",
532 			port->idx);
533 		return err;
534 	}
535 
536 	port->chip.gc.fwnode = pp->fwnode;
537 	port->chip.gc.ngpio = pp->ngpio;
538 	port->chip.gc.base = pp->gpio_base;
539 	port->chip.gc.request = gpiochip_generic_request;
540 	port->chip.gc.free = gpiochip_generic_free;
541 
542 	/* Only port A support debounce */
543 	if (pp->idx == 0)
544 		port->chip.gc.set_config = dwapb_gpio_set_config;
545 	else
546 		port->chip.gc.set_config = gpiochip_generic_config;
547 
548 	/* Only port A can provide interrupts in all configurations of the IP */
549 	if (pp->idx == 0)
550 		dwapb_configure_irqs(gpio, port, pp);
551 
552 	err = devm_gpiochip_add_data(gpio->dev, &port->chip.gc, port);
553 	if (err) {
554 		dev_err(gpio->dev, "failed to register gpiochip for port%d\n",
555 			port->idx);
556 		return err;
557 	}
558 
559 	return 0;
560 }
561 
562 static void dwapb_get_irq(struct device *dev, struct fwnode_handle *fwnode,
563 			  struct dwapb_port_property *pp)
564 {
565 	int irq, j;
566 
567 	for (j = 0; j < pp->ngpio; j++) {
568 		if (has_acpi_companion(dev))
569 			irq = platform_get_irq_optional(to_platform_device(dev), j);
570 		else
571 			irq = fwnode_irq_get(fwnode, j);
572 		if (irq > 0)
573 			pp->irq[j] = irq;
574 	}
575 }
576 
577 static struct dwapb_platform_data *dwapb_gpio_get_pdata(struct device *dev)
578 {
579 	struct dwapb_platform_data *pdata;
580 	struct dwapb_port_property *pp;
581 	int nports;
582 	int i;
583 
584 	nports = device_get_child_node_count(dev);
585 	if (nports == 0)
586 		return ERR_PTR(-ENODEV);
587 
588 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
589 	if (!pdata)
590 		return ERR_PTR(-ENOMEM);
591 
592 	pdata->properties = devm_kcalloc(dev, nports, sizeof(*pp), GFP_KERNEL);
593 	if (!pdata->properties)
594 		return ERR_PTR(-ENOMEM);
595 
596 	pdata->nports = nports;
597 
598 	i = 0;
599 	device_for_each_child_node_scoped(dev, fwnode)  {
600 		pp = &pdata->properties[i++];
601 		pp->fwnode = fwnode;
602 
603 		if (fwnode_property_read_u32(fwnode, "reg", &pp->idx) ||
604 		    pp->idx >= DWAPB_MAX_PORTS) {
605 			dev_err(dev,
606 				"missing/invalid port index for port%d\n", i);
607 			return ERR_PTR(-EINVAL);
608 		}
609 
610 		if (fwnode_property_read_u32(fwnode, "ngpios", &pp->ngpio) &&
611 		    fwnode_property_read_u32(fwnode, "snps,nr-gpios", &pp->ngpio)) {
612 			dev_info(dev,
613 				 "failed to get number of gpios for port%d\n",
614 				 i);
615 			pp->ngpio = DWAPB_MAX_GPIOS;
616 		}
617 
618 		pp->gpio_base	= -1;
619 
620 		/* For internal use only, new platforms mustn't exercise this */
621 		if (is_software_node(fwnode))
622 			fwnode_property_read_u32(fwnode, "gpio-base", &pp->gpio_base);
623 
624 		/*
625 		 * Only port A can provide interrupts in all configurations of
626 		 * the IP.
627 		 */
628 		if (pp->idx == 0)
629 			dwapb_get_irq(dev, fwnode, pp);
630 	}
631 
632 	return pdata;
633 }
634 
635 static void dwapb_assert_reset(void *data)
636 {
637 	struct dwapb_gpio *gpio = data;
638 
639 	reset_control_assert(gpio->rst);
640 }
641 
642 static int dwapb_get_reset(struct dwapb_gpio *gpio)
643 {
644 	int err;
645 
646 	gpio->rst = devm_reset_control_get_optional_shared(gpio->dev, NULL);
647 	if (IS_ERR(gpio->rst))
648 		return dev_err_probe(gpio->dev, PTR_ERR(gpio->rst),
649 				     "Cannot get reset descriptor\n");
650 
651 	err = reset_control_deassert(gpio->rst);
652 	if (err) {
653 		dev_err(gpio->dev, "Cannot deassert reset lane\n");
654 		return err;
655 	}
656 
657 	return devm_add_action_or_reset(gpio->dev, dwapb_assert_reset, gpio);
658 }
659 
660 static void dwapb_disable_clks(void *data)
661 {
662 	struct dwapb_gpio *gpio = data;
663 
664 	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
665 }
666 
667 static int dwapb_get_clks(struct dwapb_gpio *gpio)
668 {
669 	int err;
670 
671 	/* Optional bus and debounce clocks */
672 	gpio->clks[0].id = "bus";
673 	gpio->clks[1].id = "db";
674 	err = devm_clk_bulk_get_optional(gpio->dev, DWAPB_NR_CLOCKS,
675 					 gpio->clks);
676 	if (err)
677 		return dev_err_probe(gpio->dev, err,
678 				     "Cannot get APB/Debounce clocks\n");
679 
680 	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
681 	if (err) {
682 		dev_err(gpio->dev, "Cannot enable APB/Debounce clocks\n");
683 		return err;
684 	}
685 
686 	return devm_add_action_or_reset(gpio->dev, dwapb_disable_clks, gpio);
687 }
688 
689 static const struct of_device_id dwapb_of_match[] = {
690 	{ .compatible = "snps,dw-apb-gpio", .data = (void *)GPIO_REG_OFFSET_V1},
691 	{ .compatible = "apm,xgene-gpio-v2", .data = (void *)GPIO_REG_OFFSET_V2},
692 	{ /* Sentinel */ }
693 };
694 MODULE_DEVICE_TABLE(of, dwapb_of_match);
695 
696 static const struct acpi_device_id dwapb_acpi_match[] = {
697 	{"HISI0181", GPIO_REG_OFFSET_V1},
698 	{"APMC0D07", GPIO_REG_OFFSET_V1},
699 	{"APMC0D81", GPIO_REG_OFFSET_V2},
700 	{"FUJI200A", GPIO_REG_OFFSET_V1},
701 	{ }
702 };
703 MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
704 
705 static int dwapb_gpio_probe(struct platform_device *pdev)
706 {
707 	unsigned int i;
708 	struct dwapb_gpio *gpio;
709 	int err;
710 	struct dwapb_platform_data *pdata;
711 	struct device *dev = &pdev->dev;
712 
713 	pdata = dwapb_gpio_get_pdata(dev);
714 	if (IS_ERR(pdata))
715 		return PTR_ERR(pdata);
716 
717 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
718 	if (!gpio)
719 		return -ENOMEM;
720 
721 	gpio->dev = &pdev->dev;
722 	gpio->nr_ports = pdata->nports;
723 
724 	err = dwapb_get_reset(gpio);
725 	if (err)
726 		return err;
727 
728 	gpio->ports = devm_kcalloc(&pdev->dev, gpio->nr_ports,
729 				   sizeof(*gpio->ports), GFP_KERNEL);
730 	if (!gpio->ports)
731 		return -ENOMEM;
732 
733 	gpio->regs = devm_platform_ioremap_resource(pdev, 0);
734 	if (IS_ERR(gpio->regs))
735 		return PTR_ERR(gpio->regs);
736 
737 	err = dwapb_get_clks(gpio);
738 	if (err)
739 		return err;
740 
741 	gpio->flags = (uintptr_t)device_get_match_data(dev);
742 
743 	for (i = 0; i < gpio->nr_ports; i++) {
744 		err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
745 		if (err)
746 			return err;
747 	}
748 
749 	platform_set_drvdata(pdev, gpio);
750 
751 	return 0;
752 }
753 
754 static int dwapb_gpio_suspend(struct device *dev)
755 {
756 	struct dwapb_gpio *gpio = dev_get_drvdata(dev);
757 	struct gpio_generic_chip *gen_gc = &gpio->ports[0].chip;
758 	int i;
759 
760 	scoped_guard(gpio_generic_lock_irqsave, gen_gc) {
761 		for (i = 0; i < gpio->nr_ports; i++) {
762 			unsigned int offset;
763 			unsigned int idx = gpio->ports[i].idx;
764 			struct dwapb_context *ctx = gpio->ports[i].ctx;
765 
766 			offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_STRIDE;
767 			ctx->dir = dwapb_read(gpio, offset);
768 
769 			offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_STRIDE;
770 			ctx->data = dwapb_read(gpio, offset);
771 
772 			offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_STRIDE;
773 			ctx->ext = dwapb_read(gpio, offset);
774 
775 			/* Only port A can provide interrupts */
776 			if (idx == 0) {
777 				ctx->int_mask = dwapb_read(gpio, GPIO_INTMASK);
778 				ctx->int_en = dwapb_read(gpio, GPIO_INTEN);
779 				ctx->int_pol = dwapb_read(gpio, GPIO_INT_POLARITY);
780 				ctx->int_type = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
781 				ctx->int_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
782 
783 				/* Mask out interrupts */
784 				dwapb_write(gpio, GPIO_INTMASK, ~ctx->wake_en);
785 			}
786 		}
787 	}
788 
789 	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
790 
791 	return 0;
792 }
793 
794 static int dwapb_gpio_resume(struct device *dev)
795 {
796 	struct dwapb_gpio *gpio = dev_get_drvdata(dev);
797 	struct gpio_chip *gc = &gpio->ports[0].chip.gc;
798 	struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc);
799 	int i, err;
800 
801 	err = clk_bulk_prepare_enable(DWAPB_NR_CLOCKS, gpio->clks);
802 	if (err) {
803 		dev_err(gpio->dev, "Cannot reenable APB/Debounce clocks\n");
804 		return err;
805 	}
806 
807 	guard(gpio_generic_lock_irqsave)(gen_gc);
808 
809 	for (i = 0; i < gpio->nr_ports; i++) {
810 		unsigned int offset;
811 		unsigned int idx = gpio->ports[i].idx;
812 		struct dwapb_context *ctx = gpio->ports[i].ctx;
813 
814 		offset = GPIO_SWPORTA_DR + idx * GPIO_SWPORT_DR_STRIDE;
815 		dwapb_write(gpio, offset, ctx->data);
816 
817 		offset = GPIO_SWPORTA_DDR + idx * GPIO_SWPORT_DDR_STRIDE;
818 		dwapb_write(gpio, offset, ctx->dir);
819 
820 		offset = GPIO_EXT_PORTA + idx * GPIO_EXT_PORT_STRIDE;
821 		dwapb_write(gpio, offset, ctx->ext);
822 
823 		/* Only port A can provide interrupts */
824 		if (idx == 0) {
825 			dwapb_write(gpio, GPIO_INTTYPE_LEVEL, ctx->int_type);
826 			dwapb_write(gpio, GPIO_INT_POLARITY, ctx->int_pol);
827 			dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ctx->int_deb);
828 			dwapb_write(gpio, GPIO_INTEN, ctx->int_en);
829 			dwapb_write(gpio, GPIO_INTMASK, ctx->int_mask);
830 
831 			/* Clear out spurious interrupts */
832 			dwapb_write(gpio, GPIO_PORTA_EOI, 0xffffffff);
833 		}
834 	}
835 
836 	return 0;
837 }
838 
839 static DEFINE_SIMPLE_DEV_PM_OPS(dwapb_gpio_pm_ops,
840 				dwapb_gpio_suspend, dwapb_gpio_resume);
841 
842 static struct platform_driver dwapb_gpio_driver = {
843 	.driver		= {
844 		.name	= DWAPB_DRIVER_NAME,
845 		.pm	= pm_sleep_ptr(&dwapb_gpio_pm_ops),
846 		.of_match_table = dwapb_of_match,
847 		.acpi_match_table = dwapb_acpi_match,
848 	},
849 	.probe		= dwapb_gpio_probe,
850 };
851 
852 module_platform_driver(dwapb_gpio_driver);
853 
854 MODULE_LICENSE("GPL");
855 MODULE_AUTHOR("Jamie Iles");
856 MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
857 MODULE_ALIAS("platform:" DWAPB_DRIVER_NAME);
858