xref: /openbmc/linux/drivers/gpio/gpio-mvebu.c (revision 609e478b)
1 /*
2  * GPIO driver for Marvell SoCs
3  *
4  * Copyright (C) 2012 Marvell
5  *
6  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
7  * Andrew Lunn <andrew@lunn.ch>
8  * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2.  This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  *
14  * This driver is a fairly straightforward GPIO driver for the
15  * complete family of Marvell EBU SoC platforms (Orion, Dove,
16  * Kirkwood, Discovery, Armada 370/XP). The only complexity of this
17  * driver is the different register layout that exists between the
18  * non-SMP platforms (Orion, Dove, Kirkwood, Armada 370) and the SMP
19  * platforms (MV78200 from the Discovery family and the Armada
20  * XP). Therefore, this driver handles three variants of the GPIO
21  * block:
22  * - the basic variant, called "orion-gpio", with the simplest
23  *   register set. Used on Orion, Dove, Kirkwoord, Armada 370 and
24  *   non-SMP Discovery systems
25  * - the mv78200 variant for MV78200 Discovery systems. This variant
26  *   turns the edge mask and level mask registers into CPU0 edge
27  *   mask/level mask registers, and adds CPU1 edge mask/level mask
28  *   registers.
29  * - the armadaxp variant for Armada XP systems. This variant keeps
30  *   the normal cause/edge mask/level mask registers when the global
31  *   interrupts are used, but adds per-CPU cause/edge mask/level mask
32  *   registers n a separate memory area for the per-CPU GPIO
33  *   interrupts.
34  */
35 
36 #include <linux/err.h>
37 #include <linux/module.h>
38 #include <linux/gpio.h>
39 #include <linux/irq.h>
40 #include <linux/slab.h>
41 #include <linux/irqdomain.h>
42 #include <linux/io.h>
43 #include <linux/of_irq.h>
44 #include <linux/of_device.h>
45 #include <linux/clk.h>
46 #include <linux/pinctrl/consumer.h>
47 #include <linux/irqchip/chained_irq.h>
48 
49 /*
50  * GPIO unit register offsets.
51  */
52 #define GPIO_OUT_OFF		0x0000
53 #define GPIO_IO_CONF_OFF	0x0004
54 #define GPIO_BLINK_EN_OFF	0x0008
55 #define GPIO_IN_POL_OFF		0x000c
56 #define GPIO_DATA_IN_OFF	0x0010
57 #define GPIO_EDGE_CAUSE_OFF	0x0014
58 #define GPIO_EDGE_MASK_OFF	0x0018
59 #define GPIO_LEVEL_MASK_OFF	0x001c
60 
61 /* The MV78200 has per-CPU registers for edge mask and level mask */
62 #define GPIO_EDGE_MASK_MV78200_OFF(cpu)   ((cpu) ? 0x30 : 0x18)
63 #define GPIO_LEVEL_MASK_MV78200_OFF(cpu)  ((cpu) ? 0x34 : 0x1C)
64 
65 /* The Armada XP has per-CPU registers for interrupt cause, interrupt
66  * mask and interrupt level mask. Those are relative to the
67  * percpu_membase. */
68 #define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
69 #define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu)  (0x10 + (cpu) * 0x4)
70 #define GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu) (0x20 + (cpu) * 0x4)
71 
72 #define MVEBU_GPIO_SOC_VARIANT_ORION    0x1
73 #define MVEBU_GPIO_SOC_VARIANT_MV78200  0x2
74 #define MVEBU_GPIO_SOC_VARIANT_ARMADAXP 0x3
75 
76 #define MVEBU_MAX_GPIO_PER_BANK         32
77 
78 struct mvebu_gpio_chip {
79 	struct gpio_chip   chip;
80 	spinlock_t	   lock;
81 	void __iomem	  *membase;
82 	void __iomem	  *percpu_membase;
83 	int		   irqbase;
84 	struct irq_domain *domain;
85 	int                soc_variant;
86 };
87 
88 /*
89  * Functions returning addresses of individual registers for a given
90  * GPIO controller.
91  */
92 static inline void __iomem *mvebu_gpioreg_out(struct mvebu_gpio_chip *mvchip)
93 {
94 	return mvchip->membase + GPIO_OUT_OFF;
95 }
96 
97 static inline void __iomem *mvebu_gpioreg_blink(struct mvebu_gpio_chip *mvchip)
98 {
99 	return mvchip->membase + GPIO_BLINK_EN_OFF;
100 }
101 
102 static inline void __iomem *mvebu_gpioreg_io_conf(struct mvebu_gpio_chip *mvchip)
103 {
104 	return mvchip->membase + GPIO_IO_CONF_OFF;
105 }
106 
107 static inline void __iomem *mvebu_gpioreg_in_pol(struct mvebu_gpio_chip *mvchip)
108 {
109 	return mvchip->membase + GPIO_IN_POL_OFF;
110 }
111 
112 static inline void __iomem *mvebu_gpioreg_data_in(struct mvebu_gpio_chip *mvchip)
113 {
114 	return mvchip->membase + GPIO_DATA_IN_OFF;
115 }
116 
117 static inline void __iomem *mvebu_gpioreg_edge_cause(struct mvebu_gpio_chip *mvchip)
118 {
119 	int cpu;
120 
121 	switch (mvchip->soc_variant) {
122 	case MVEBU_GPIO_SOC_VARIANT_ORION:
123 	case MVEBU_GPIO_SOC_VARIANT_MV78200:
124 		return mvchip->membase + GPIO_EDGE_CAUSE_OFF;
125 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
126 		cpu = smp_processor_id();
127 		return mvchip->percpu_membase + GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu);
128 	default:
129 		BUG();
130 	}
131 }
132 
133 static inline void __iomem *mvebu_gpioreg_edge_mask(struct mvebu_gpio_chip *mvchip)
134 {
135 	int cpu;
136 
137 	switch (mvchip->soc_variant) {
138 	case MVEBU_GPIO_SOC_VARIANT_ORION:
139 		return mvchip->membase + GPIO_EDGE_MASK_OFF;
140 	case MVEBU_GPIO_SOC_VARIANT_MV78200:
141 		cpu = smp_processor_id();
142 		return mvchip->membase + GPIO_EDGE_MASK_MV78200_OFF(cpu);
143 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
144 		cpu = smp_processor_id();
145 		return mvchip->percpu_membase + GPIO_EDGE_MASK_ARMADAXP_OFF(cpu);
146 	default:
147 		BUG();
148 	}
149 }
150 
151 static void __iomem *mvebu_gpioreg_level_mask(struct mvebu_gpio_chip *mvchip)
152 {
153 	int cpu;
154 
155 	switch (mvchip->soc_variant) {
156 	case MVEBU_GPIO_SOC_VARIANT_ORION:
157 		return mvchip->membase + GPIO_LEVEL_MASK_OFF;
158 	case MVEBU_GPIO_SOC_VARIANT_MV78200:
159 		cpu = smp_processor_id();
160 		return mvchip->membase + GPIO_LEVEL_MASK_MV78200_OFF(cpu);
161 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
162 		cpu = smp_processor_id();
163 		return mvchip->percpu_membase + GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu);
164 	default:
165 		BUG();
166 	}
167 }
168 
169 /*
170  * Functions implementing the gpio_chip methods
171  */
172 
173 static int mvebu_gpio_request(struct gpio_chip *chip, unsigned pin)
174 {
175 	return pinctrl_request_gpio(chip->base + pin);
176 }
177 
178 static void mvebu_gpio_free(struct gpio_chip *chip, unsigned pin)
179 {
180 	pinctrl_free_gpio(chip->base + pin);
181 }
182 
183 static void mvebu_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
184 {
185 	struct mvebu_gpio_chip *mvchip =
186 		container_of(chip, struct mvebu_gpio_chip, chip);
187 	unsigned long flags;
188 	u32 u;
189 
190 	spin_lock_irqsave(&mvchip->lock, flags);
191 	u = readl_relaxed(mvebu_gpioreg_out(mvchip));
192 	if (value)
193 		u |= 1 << pin;
194 	else
195 		u &= ~(1 << pin);
196 	writel_relaxed(u, mvebu_gpioreg_out(mvchip));
197 	spin_unlock_irqrestore(&mvchip->lock, flags);
198 }
199 
200 static int mvebu_gpio_get(struct gpio_chip *chip, unsigned pin)
201 {
202 	struct mvebu_gpio_chip *mvchip =
203 		container_of(chip, struct mvebu_gpio_chip, chip);
204 	u32 u;
205 
206 	if (readl_relaxed(mvebu_gpioreg_io_conf(mvchip)) & (1 << pin)) {
207 		u = readl_relaxed(mvebu_gpioreg_data_in(mvchip)) ^
208 			readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
209 	} else {
210 		u = readl_relaxed(mvebu_gpioreg_out(mvchip));
211 	}
212 
213 	return (u >> pin) & 1;
214 }
215 
216 static void mvebu_gpio_blink(struct gpio_chip *chip, unsigned pin, int value)
217 {
218 	struct mvebu_gpio_chip *mvchip =
219 		container_of(chip, struct mvebu_gpio_chip, chip);
220 	unsigned long flags;
221 	u32 u;
222 
223 	spin_lock_irqsave(&mvchip->lock, flags);
224 	u = readl_relaxed(mvebu_gpioreg_blink(mvchip));
225 	if (value)
226 		u |= 1 << pin;
227 	else
228 		u &= ~(1 << pin);
229 	writel_relaxed(u, mvebu_gpioreg_blink(mvchip));
230 	spin_unlock_irqrestore(&mvchip->lock, flags);
231 }
232 
233 static int mvebu_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
234 {
235 	struct mvebu_gpio_chip *mvchip =
236 		container_of(chip, struct mvebu_gpio_chip, chip);
237 	unsigned long flags;
238 	int ret;
239 	u32 u;
240 
241 	/* Check with the pinctrl driver whether this pin is usable as
242 	 * an input GPIO */
243 	ret = pinctrl_gpio_direction_input(chip->base + pin);
244 	if (ret)
245 		return ret;
246 
247 	spin_lock_irqsave(&mvchip->lock, flags);
248 	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
249 	u |= 1 << pin;
250 	writel_relaxed(u, mvebu_gpioreg_io_conf(mvchip));
251 	spin_unlock_irqrestore(&mvchip->lock, flags);
252 
253 	return 0;
254 }
255 
256 static int mvebu_gpio_direction_output(struct gpio_chip *chip, unsigned pin,
257 				       int value)
258 {
259 	struct mvebu_gpio_chip *mvchip =
260 		container_of(chip, struct mvebu_gpio_chip, chip);
261 	unsigned long flags;
262 	int ret;
263 	u32 u;
264 
265 	/* Check with the pinctrl driver whether this pin is usable as
266 	 * an output GPIO */
267 	ret = pinctrl_gpio_direction_output(chip->base + pin);
268 	if (ret)
269 		return ret;
270 
271 	mvebu_gpio_blink(chip, pin, 0);
272 	mvebu_gpio_set(chip, pin, value);
273 
274 	spin_lock_irqsave(&mvchip->lock, flags);
275 	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
276 	u &= ~(1 << pin);
277 	writel_relaxed(u, mvebu_gpioreg_io_conf(mvchip));
278 	spin_unlock_irqrestore(&mvchip->lock, flags);
279 
280 	return 0;
281 }
282 
283 static int mvebu_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
284 {
285 	struct mvebu_gpio_chip *mvchip =
286 		container_of(chip, struct mvebu_gpio_chip, chip);
287 	return irq_create_mapping(mvchip->domain, pin);
288 }
289 
290 /*
291  * Functions implementing the irq_chip methods
292  */
293 static void mvebu_gpio_irq_ack(struct irq_data *d)
294 {
295 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
296 	struct mvebu_gpio_chip *mvchip = gc->private;
297 	u32 mask = ~(1 << (d->irq - gc->irq_base));
298 
299 	irq_gc_lock(gc);
300 	writel_relaxed(mask, mvebu_gpioreg_edge_cause(mvchip));
301 	irq_gc_unlock(gc);
302 }
303 
304 static void mvebu_gpio_edge_irq_mask(struct irq_data *d)
305 {
306 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
307 	struct mvebu_gpio_chip *mvchip = gc->private;
308 	u32 mask = 1 << (d->irq - gc->irq_base);
309 
310 	irq_gc_lock(gc);
311 	gc->mask_cache &= ~mask;
312 	writel_relaxed(gc->mask_cache, mvebu_gpioreg_edge_mask(mvchip));
313 	irq_gc_unlock(gc);
314 }
315 
316 static void mvebu_gpio_edge_irq_unmask(struct irq_data *d)
317 {
318 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
319 	struct mvebu_gpio_chip *mvchip = gc->private;
320 	u32 mask = 1 << (d->irq - gc->irq_base);
321 
322 	irq_gc_lock(gc);
323 	gc->mask_cache |= mask;
324 	writel_relaxed(gc->mask_cache, mvebu_gpioreg_edge_mask(mvchip));
325 	irq_gc_unlock(gc);
326 }
327 
328 static void mvebu_gpio_level_irq_mask(struct irq_data *d)
329 {
330 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
331 	struct mvebu_gpio_chip *mvchip = gc->private;
332 	u32 mask = 1 << (d->irq - gc->irq_base);
333 
334 	irq_gc_lock(gc);
335 	gc->mask_cache &= ~mask;
336 	writel_relaxed(gc->mask_cache, mvebu_gpioreg_level_mask(mvchip));
337 	irq_gc_unlock(gc);
338 }
339 
340 static void mvebu_gpio_level_irq_unmask(struct irq_data *d)
341 {
342 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
343 	struct mvebu_gpio_chip *mvchip = gc->private;
344 	u32 mask = 1 << (d->irq - gc->irq_base);
345 
346 	irq_gc_lock(gc);
347 	gc->mask_cache |= mask;
348 	writel_relaxed(gc->mask_cache, mvebu_gpioreg_level_mask(mvchip));
349 	irq_gc_unlock(gc);
350 }
351 
352 /*****************************************************************************
353  * MVEBU GPIO IRQ
354  *
355  * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
356  * value of the line or the opposite value.
357  *
358  * Level IRQ handlers: DATA_IN is used directly as cause register.
359  *                     Interrupt are masked by LEVEL_MASK registers.
360  * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
361  *                     Interrupt are masked by EDGE_MASK registers.
362  * Both-edge handlers: Similar to regular Edge handlers, but also swaps
363  *                     the polarity to catch the next line transaction.
364  *                     This is a race condition that might not perfectly
365  *                     work on some use cases.
366  *
367  * Every eight GPIO lines are grouped (OR'ed) before going up to main
368  * cause register.
369  *
370  *                    EDGE  cause    mask
371  *        data-in   /--------| |-----| |----\
372  *     -----| |-----                         ---- to main cause reg
373  *           X      \----------------| |----/
374  *        polarity    LEVEL          mask
375  *
376  ****************************************************************************/
377 
378 static int mvebu_gpio_irq_set_type(struct irq_data *d, unsigned int type)
379 {
380 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
381 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
382 	struct mvebu_gpio_chip *mvchip = gc->private;
383 	int pin;
384 	u32 u;
385 
386 	pin = d->hwirq;
387 
388 	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip)) & (1 << pin);
389 	if (!u) {
390 		return -EINVAL;
391 	}
392 
393 	type &= IRQ_TYPE_SENSE_MASK;
394 	if (type == IRQ_TYPE_NONE)
395 		return -EINVAL;
396 
397 	/* Check if we need to change chip and handler */
398 	if (!(ct->type & type))
399 		if (irq_setup_alt_chip(d, type))
400 			return -EINVAL;
401 
402 	/*
403 	 * Configure interrupt polarity.
404 	 */
405 	switch (type) {
406 	case IRQ_TYPE_EDGE_RISING:
407 	case IRQ_TYPE_LEVEL_HIGH:
408 		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
409 		u &= ~(1 << pin);
410 		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
411 		break;
412 	case IRQ_TYPE_EDGE_FALLING:
413 	case IRQ_TYPE_LEVEL_LOW:
414 		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
415 		u |= 1 << pin;
416 		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
417 		break;
418 	case IRQ_TYPE_EDGE_BOTH: {
419 		u32 v;
420 
421 		v = readl_relaxed(mvebu_gpioreg_in_pol(mvchip)) ^
422 			readl_relaxed(mvebu_gpioreg_data_in(mvchip));
423 
424 		/*
425 		 * set initial polarity based on current input level
426 		 */
427 		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
428 		if (v & (1 << pin))
429 			u |= 1 << pin;		/* falling */
430 		else
431 			u &= ~(1 << pin);	/* rising */
432 		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
433 		break;
434 	}
435 	}
436 	return 0;
437 }
438 
439 static void mvebu_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
440 {
441 	struct mvebu_gpio_chip *mvchip = irq_get_handler_data(irq);
442 	struct irq_chip *chip = irq_desc_get_chip(desc);
443 	u32 cause, type;
444 	int i;
445 
446 	if (mvchip == NULL)
447 		return;
448 
449 	chained_irq_enter(chip, desc);
450 
451 	cause = readl_relaxed(mvebu_gpioreg_data_in(mvchip)) &
452 		readl_relaxed(mvebu_gpioreg_level_mask(mvchip));
453 	cause |= readl_relaxed(mvebu_gpioreg_edge_cause(mvchip)) &
454 		readl_relaxed(mvebu_gpioreg_edge_mask(mvchip));
455 
456 	for (i = 0; i < mvchip->chip.ngpio; i++) {
457 		int irq;
458 
459 		irq = mvchip->irqbase + i;
460 
461 		if (!(cause & (1 << i)))
462 			continue;
463 
464 		type = irq_get_trigger_type(irq);
465 		if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
466 			/* Swap polarity (race with GPIO line) */
467 			u32 polarity;
468 
469 			polarity = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
470 			polarity ^= 1 << i;
471 			writel_relaxed(polarity, mvebu_gpioreg_in_pol(mvchip));
472 		}
473 
474 		generic_handle_irq(irq);
475 	}
476 
477 	chained_irq_exit(chip, desc);
478 }
479 
480 #ifdef CONFIG_DEBUG_FS
481 #include <linux/seq_file.h>
482 
483 static void mvebu_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
484 {
485 	struct mvebu_gpio_chip *mvchip =
486 		container_of(chip, struct mvebu_gpio_chip, chip);
487 	u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
488 	int i;
489 
490 	out	= readl_relaxed(mvebu_gpioreg_out(mvchip));
491 	io_conf	= readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
492 	blink	= readl_relaxed(mvebu_gpioreg_blink(mvchip));
493 	in_pol	= readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
494 	data_in	= readl_relaxed(mvebu_gpioreg_data_in(mvchip));
495 	cause	= readl_relaxed(mvebu_gpioreg_edge_cause(mvchip));
496 	edg_msk	= readl_relaxed(mvebu_gpioreg_edge_mask(mvchip));
497 	lvl_msk	= readl_relaxed(mvebu_gpioreg_level_mask(mvchip));
498 
499 	for (i = 0; i < chip->ngpio; i++) {
500 		const char *label;
501 		u32 msk;
502 		bool is_out;
503 
504 		label = gpiochip_is_requested(chip, i);
505 		if (!label)
506 			continue;
507 
508 		msk = 1 << i;
509 		is_out = !(io_conf & msk);
510 
511 		seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
512 
513 		if (is_out) {
514 			seq_printf(s, " out %s %s\n",
515 				   out & msk ? "hi" : "lo",
516 				   blink & msk ? "(blink )" : "");
517 			continue;
518 		}
519 
520 		seq_printf(s, " in  %s (act %s) - IRQ",
521 			   (data_in ^ in_pol) & msk  ? "hi" : "lo",
522 			   in_pol & msk ? "lo" : "hi");
523 		if (!((edg_msk | lvl_msk) & msk)) {
524 			seq_printf(s, " disabled\n");
525 			continue;
526 		}
527 		if (edg_msk & msk)
528 			seq_printf(s, " edge ");
529 		if (lvl_msk & msk)
530 			seq_printf(s, " level");
531 		seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear  ");
532 	}
533 }
534 #else
535 #define mvebu_gpio_dbg_show NULL
536 #endif
537 
538 static const struct of_device_id mvebu_gpio_of_match[] = {
539 	{
540 		.compatible = "marvell,orion-gpio",
541 		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
542 	},
543 	{
544 		.compatible = "marvell,mv78200-gpio",
545 		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_MV78200,
546 	},
547 	{
548 		.compatible = "marvell,armadaxp-gpio",
549 		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
550 	},
551 	{
552 		/* sentinel */
553 	},
554 };
555 MODULE_DEVICE_TABLE(of, mvebu_gpio_of_match);
556 
557 static int mvebu_gpio_probe(struct platform_device *pdev)
558 {
559 	struct mvebu_gpio_chip *mvchip;
560 	const struct of_device_id *match;
561 	struct device_node *np = pdev->dev.of_node;
562 	struct resource *res;
563 	struct irq_chip_generic *gc;
564 	struct irq_chip_type *ct;
565 	struct clk *clk;
566 	unsigned int ngpios;
567 	int soc_variant;
568 	int i, cpu, id;
569 
570 	match = of_match_device(mvebu_gpio_of_match, &pdev->dev);
571 	if (match)
572 		soc_variant = (int) match->data;
573 	else
574 		soc_variant = MVEBU_GPIO_SOC_VARIANT_ORION;
575 
576 	mvchip = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_gpio_chip), GFP_KERNEL);
577 	if (!mvchip)
578 		return -ENOMEM;
579 
580 	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
581 		dev_err(&pdev->dev, "Missing ngpios OF property\n");
582 		return -ENODEV;
583 	}
584 
585 	id = of_alias_get_id(pdev->dev.of_node, "gpio");
586 	if (id < 0) {
587 		dev_err(&pdev->dev, "Couldn't get OF id\n");
588 		return id;
589 	}
590 
591 	clk = devm_clk_get(&pdev->dev, NULL);
592 	/* Not all SoCs require a clock.*/
593 	if (!IS_ERR(clk))
594 		clk_prepare_enable(clk);
595 
596 	mvchip->soc_variant = soc_variant;
597 	mvchip->chip.label = dev_name(&pdev->dev);
598 	mvchip->chip.dev = &pdev->dev;
599 	mvchip->chip.request = mvebu_gpio_request;
600 	mvchip->chip.free = mvebu_gpio_free;
601 	mvchip->chip.direction_input = mvebu_gpio_direction_input;
602 	mvchip->chip.get = mvebu_gpio_get;
603 	mvchip->chip.direction_output = mvebu_gpio_direction_output;
604 	mvchip->chip.set = mvebu_gpio_set;
605 	mvchip->chip.to_irq = mvebu_gpio_to_irq;
606 	mvchip->chip.base = id * MVEBU_MAX_GPIO_PER_BANK;
607 	mvchip->chip.ngpio = ngpios;
608 	mvchip->chip.can_sleep = false;
609 	mvchip->chip.of_node = np;
610 	mvchip->chip.dbg_show = mvebu_gpio_dbg_show;
611 
612 	spin_lock_init(&mvchip->lock);
613 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
614 	mvchip->membase = devm_ioremap_resource(&pdev->dev, res);
615 	if (IS_ERR(mvchip->membase))
616 		return PTR_ERR(mvchip->membase);
617 
618 	/* The Armada XP has a second range of registers for the
619 	 * per-CPU registers */
620 	if (soc_variant == MVEBU_GPIO_SOC_VARIANT_ARMADAXP) {
621 		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
622 		mvchip->percpu_membase = devm_ioremap_resource(&pdev->dev,
623 							       res);
624 		if (IS_ERR(mvchip->percpu_membase))
625 			return PTR_ERR(mvchip->percpu_membase);
626 	}
627 
628 	/*
629 	 * Mask and clear GPIO interrupts.
630 	 */
631 	switch (soc_variant) {
632 	case MVEBU_GPIO_SOC_VARIANT_ORION:
633 		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
634 		writel_relaxed(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
635 		writel_relaxed(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
636 		break;
637 	case MVEBU_GPIO_SOC_VARIANT_MV78200:
638 		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
639 		for (cpu = 0; cpu < 2; cpu++) {
640 			writel_relaxed(0, mvchip->membase +
641 				       GPIO_EDGE_MASK_MV78200_OFF(cpu));
642 			writel_relaxed(0, mvchip->membase +
643 				       GPIO_LEVEL_MASK_MV78200_OFF(cpu));
644 		}
645 		break;
646 	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
647 		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
648 		writel_relaxed(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
649 		writel_relaxed(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
650 		for (cpu = 0; cpu < 4; cpu++) {
651 			writel_relaxed(0, mvchip->percpu_membase +
652 				       GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu));
653 			writel_relaxed(0, mvchip->percpu_membase +
654 				       GPIO_EDGE_MASK_ARMADAXP_OFF(cpu));
655 			writel_relaxed(0, mvchip->percpu_membase +
656 				       GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu));
657 		}
658 		break;
659 	default:
660 		BUG();
661 	}
662 
663 	gpiochip_add(&mvchip->chip);
664 
665 	/* Some gpio controllers do not provide irq support */
666 	if (!of_irq_count(np))
667 		return 0;
668 
669 	/* Setup the interrupt handlers. Each chip can have up to 4
670 	 * interrupt handlers, with each handler dealing with 8 GPIO
671 	 * pins. */
672 	for (i = 0; i < 4; i++) {
673 		int irq;
674 		irq = platform_get_irq(pdev, i);
675 		if (irq < 0)
676 			continue;
677 		irq_set_handler_data(irq, mvchip);
678 		irq_set_chained_handler(irq, mvebu_gpio_irq_handler);
679 	}
680 
681 	mvchip->irqbase = irq_alloc_descs(-1, 0, ngpios, -1);
682 	if (mvchip->irqbase < 0) {
683 		dev_err(&pdev->dev, "no irqs\n");
684 		return mvchip->irqbase;
685 	}
686 
687 	gc = irq_alloc_generic_chip("mvebu_gpio_irq", 2, mvchip->irqbase,
688 				    mvchip->membase, handle_level_irq);
689 	if (!gc) {
690 		dev_err(&pdev->dev, "Cannot allocate generic irq_chip\n");
691 		return -ENOMEM;
692 	}
693 
694 	gc->private = mvchip;
695 	ct = &gc->chip_types[0];
696 	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
697 	ct->chip.irq_mask = mvebu_gpio_level_irq_mask;
698 	ct->chip.irq_unmask = mvebu_gpio_level_irq_unmask;
699 	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
700 	ct->chip.name = mvchip->chip.label;
701 
702 	ct = &gc->chip_types[1];
703 	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
704 	ct->chip.irq_ack = mvebu_gpio_irq_ack;
705 	ct->chip.irq_mask = mvebu_gpio_edge_irq_mask;
706 	ct->chip.irq_unmask = mvebu_gpio_edge_irq_unmask;
707 	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
708 	ct->handler = handle_edge_irq;
709 	ct->chip.name = mvchip->chip.label;
710 
711 	irq_setup_generic_chip(gc, IRQ_MSK(ngpios), 0,
712 			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
713 
714 	/* Setup irq domain on top of the generic chip. */
715 	mvchip->domain = irq_domain_add_simple(np, mvchip->chip.ngpio,
716 					       mvchip->irqbase,
717 					       &irq_domain_simple_ops,
718 					       mvchip);
719 	if (!mvchip->domain) {
720 		dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).\n",
721 			mvchip->chip.label);
722 		irq_remove_generic_chip(gc, IRQ_MSK(ngpios), IRQ_NOREQUEST,
723 					IRQ_LEVEL | IRQ_NOPROBE);
724 		kfree(gc);
725 		return -ENODEV;
726 	}
727 
728 	return 0;
729 }
730 
731 static struct platform_driver mvebu_gpio_driver = {
732 	.driver		= {
733 		.name	        = "mvebu-gpio",
734 		.owner	        = THIS_MODULE,
735 		.of_match_table = mvebu_gpio_of_match,
736 	},
737 	.probe		= mvebu_gpio_probe,
738 };
739 module_platform_driver(mvebu_gpio_driver);
740