xref: /linux/drivers/gpio/gpio-davinci.c (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * TI DaVinci GPIO Support
4  *
5  * Copyright (c) 2006-2007 David Brownell
6  * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
7  */
8 
9 #include <linux/gpio/driver.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/platform_device.h>
21 #include <linux/platform_data/gpio-davinci.h>
22 #include <linux/property.h>
23 #include <linux/irqchip/chained_irq.h>
24 #include <linux/spinlock.h>
25 #include <linux/pm_runtime.h>
26 
27 #define MAX_REGS_BANKS 5
28 #define MAX_INT_PER_BANK 32
29 
30 struct davinci_gpio_regs {
31 	u32	dir;
32 	u32	out_data;
33 	u32	set_data;
34 	u32	clr_data;
35 	u32	in_data;
36 	u32	set_rising;
37 	u32	clr_rising;
38 	u32	set_falling;
39 	u32	clr_falling;
40 	u32	intstat;
41 };
42 
43 typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
44 
45 #define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
46 
47 static void __iomem *gpio_base;
48 static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0};
49 
50 struct davinci_gpio_irq_data {
51 	void __iomem			*regs;
52 	struct davinci_gpio_controller	*chip;
53 	int				bank_num;
54 };
55 
56 struct davinci_gpio_controller {
57 	struct gpio_chip	chip;
58 	struct irq_domain	*irq_domain;
59 	/* Serialize access to GPIO registers */
60 	spinlock_t		lock;
61 	void __iomem		*regs[MAX_REGS_BANKS];
62 	int			gpio_unbanked;
63 	int			irqs[MAX_INT_PER_BANK];
64 	struct davinci_gpio_regs context[MAX_REGS_BANKS];
65 	u32			binten_context;
66 };
67 
68 static inline u32 __gpio_mask(unsigned gpio)
69 {
70 	return 1 << (gpio % 32);
71 }
72 
73 static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d)
74 {
75 	struct davinci_gpio_regs __iomem *g;
76 
77 	g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d);
78 
79 	return g;
80 }
81 
82 static int davinci_gpio_irq_setup(struct platform_device *pdev);
83 
84 /*--------------------------------------------------------------------------*/
85 
86 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */
87 static inline int __davinci_direction(struct gpio_chip *chip,
88 			unsigned offset, bool out, int value)
89 {
90 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
91 	struct davinci_gpio_regs __iomem *g;
92 	unsigned long flags;
93 	u32 temp;
94 	int bank = offset / 32;
95 	u32 mask = __gpio_mask(offset);
96 
97 	g = d->regs[bank];
98 	spin_lock_irqsave(&d->lock, flags);
99 	temp = readl_relaxed(&g->dir);
100 	if (out) {
101 		temp &= ~mask;
102 		writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
103 	} else {
104 		temp |= mask;
105 	}
106 	writel_relaxed(temp, &g->dir);
107 	spin_unlock_irqrestore(&d->lock, flags);
108 
109 	return 0;
110 }
111 
112 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
113 {
114 	return __davinci_direction(chip, offset, false, 0);
115 }
116 
117 static int
118 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
119 {
120 	return __davinci_direction(chip, offset, true, value);
121 }
122 
123 /*
124  * Read the pin's value (works even if it's set up as output);
125  * returns zero/nonzero.
126  *
127  * Note that changes are synched to the GPIO clock, so reading values back
128  * right after you've set them may give old values.
129  */
130 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
131 {
132 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
133 	struct davinci_gpio_regs __iomem *g;
134 	int bank = offset / 32;
135 
136 	g = d->regs[bank];
137 
138 	return !!(__gpio_mask(offset) & readl_relaxed(&g->in_data));
139 }
140 
141 /*
142  * Assuming the pin is muxed as a gpio output, set its output value.
143  */
144 static void
145 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
146 {
147 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
148 	struct davinci_gpio_regs __iomem *g;
149 	int bank = offset / 32;
150 
151 	g = d->regs[bank];
152 
153 	writel_relaxed(__gpio_mask(offset),
154 		       value ? &g->set_data : &g->clr_data);
155 }
156 
157 static struct davinci_gpio_platform_data *
158 davinci_gpio_get_pdata(struct platform_device *pdev)
159 {
160 	struct device_node *dn = pdev->dev.of_node;
161 	struct davinci_gpio_platform_data *pdata;
162 	int ret;
163 	u32 val;
164 
165 	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
166 		return dev_get_platdata(&pdev->dev);
167 
168 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
169 	if (!pdata)
170 		return NULL;
171 
172 	ret = of_property_read_u32(dn, "ti,ngpio", &val);
173 	if (ret)
174 		goto of_err;
175 
176 	pdata->ngpio = val;
177 
178 	ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
179 	if (ret)
180 		goto of_err;
181 
182 	pdata->gpio_unbanked = val;
183 
184 	return pdata;
185 
186 of_err:
187 	dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
188 	return NULL;
189 }
190 
191 static int davinci_gpio_probe(struct platform_device *pdev)
192 {
193 	int bank, i, ret = 0;
194 	unsigned int ngpio, nbank, nirq;
195 	struct davinci_gpio_controller *chips;
196 	struct davinci_gpio_platform_data *pdata;
197 	struct device *dev = &pdev->dev;
198 
199 	pdata = davinci_gpio_get_pdata(pdev);
200 	if (!pdata) {
201 		dev_err(dev, "No platform data found\n");
202 		return -EINVAL;
203 	}
204 
205 	dev->platform_data = pdata;
206 
207 	/*
208 	 * The gpio banks conceptually expose a segmented bitmap,
209 	 * and "ngpio" is one more than the largest zero-based
210 	 * bit index that's valid.
211 	 */
212 	ngpio = pdata->ngpio;
213 	if (ngpio == 0) {
214 		dev_err(dev, "How many GPIOs?\n");
215 		return -EINVAL;
216 	}
217 
218 	/*
219 	 * If there are unbanked interrupts then the number of
220 	 * interrupts is equal to number of gpios else all are banked so
221 	 * number of interrupts is equal to number of banks(each with 16 gpios)
222 	 */
223 	if (pdata->gpio_unbanked)
224 		nirq = pdata->gpio_unbanked;
225 	else
226 		nirq = DIV_ROUND_UP(ngpio, 16);
227 
228 	if (nirq > MAX_INT_PER_BANK) {
229 		dev_err(dev, "Too many IRQs!\n");
230 		return -EINVAL;
231 	}
232 
233 	chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
234 	if (!chips)
235 		return -ENOMEM;
236 
237 	gpio_base = devm_platform_ioremap_resource(pdev, 0);
238 	if (IS_ERR(gpio_base))
239 		return PTR_ERR(gpio_base);
240 
241 	for (i = 0; i < nirq; i++) {
242 		chips->irqs[i] = platform_get_irq(pdev, i);
243 		if (chips->irqs[i] < 0)
244 			return chips->irqs[i];
245 	}
246 
247 	chips->chip.label = dev_name(dev);
248 
249 	chips->chip.direction_input = davinci_direction_in;
250 	chips->chip.get = davinci_gpio_get;
251 	chips->chip.direction_output = davinci_direction_out;
252 	chips->chip.set = davinci_gpio_set;
253 
254 	chips->chip.ngpio = ngpio;
255 	chips->chip.base = pdata->no_auto_base ? pdata->base : -1;
256 
257 #ifdef CONFIG_OF_GPIO
258 	chips->chip.parent = dev;
259 	chips->chip.request = gpiochip_generic_request;
260 	chips->chip.free = gpiochip_generic_free;
261 #endif
262 	spin_lock_init(&chips->lock);
263 
264 	nbank = DIV_ROUND_UP(ngpio, 32);
265 	for (bank = 0; bank < nbank; bank++)
266 		chips->regs[bank] = gpio_base + offset_array[bank];
267 
268 	ret = devm_gpiochip_add_data(dev, &chips->chip, chips);
269 	if (ret)
270 		return ret;
271 
272 	platform_set_drvdata(pdev, chips);
273 	ret = davinci_gpio_irq_setup(pdev);
274 	if (ret)
275 		return ret;
276 
277 	return 0;
278 }
279 
280 /*--------------------------------------------------------------------------*/
281 /*
282  * We expect irqs will normally be set up as input pins, but they can also be
283  * used as output pins ... which is convenient for testing.
284  *
285  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
286  * to their GPIOBNK0 irq, with a bit less overhead.
287  *
288  * All those INTC hookups (direct, plus several IRQ banks) can also
289  * serve as EDMA event triggers.
290  */
291 
292 static void gpio_irq_disable(struct irq_data *d)
293 {
294 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
295 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
296 
297 	writel_relaxed(mask, &g->clr_falling);
298 	writel_relaxed(mask, &g->clr_rising);
299 }
300 
301 static void gpio_irq_enable(struct irq_data *d)
302 {
303 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
304 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
305 	unsigned status = irqd_get_trigger_type(d);
306 
307 	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
308 	if (!status)
309 		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
310 
311 	if (status & IRQ_TYPE_EDGE_FALLING)
312 		writel_relaxed(mask, &g->set_falling);
313 	if (status & IRQ_TYPE_EDGE_RISING)
314 		writel_relaxed(mask, &g->set_rising);
315 }
316 
317 static int gpio_irq_type(struct irq_data *d, unsigned trigger)
318 {
319 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
320 		return -EINVAL;
321 
322 	return 0;
323 }
324 
325 static struct irq_chip gpio_irqchip = {
326 	.name		= "GPIO",
327 	.irq_enable	= gpio_irq_enable,
328 	.irq_disable	= gpio_irq_disable,
329 	.irq_set_type	= gpio_irq_type,
330 	.flags		= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE,
331 };
332 
333 static void gpio_irq_handler(struct irq_desc *desc)
334 {
335 	struct davinci_gpio_regs __iomem *g;
336 	u32 mask = 0xffff;
337 	int bank_num;
338 	struct davinci_gpio_controller *d;
339 	struct davinci_gpio_irq_data *irqdata;
340 
341 	irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc);
342 	bank_num = irqdata->bank_num;
343 	g = irqdata->regs;
344 	d = irqdata->chip;
345 
346 	/* we only care about one bank */
347 	if ((bank_num % 2) == 1)
348 		mask <<= 16;
349 
350 	/* temporarily mask (level sensitive) parent IRQ */
351 	chained_irq_enter(irq_desc_get_chip(desc), desc);
352 	while (1) {
353 		u32		status;
354 		int		bit;
355 		irq_hw_number_t hw_irq;
356 
357 		/* ack any irqs */
358 		status = readl_relaxed(&g->intstat) & mask;
359 		if (!status)
360 			break;
361 		writel_relaxed(status, &g->intstat);
362 
363 		/* now demux them to the right lowlevel handler */
364 
365 		while (status) {
366 			bit = __ffs(status);
367 			status &= ~BIT(bit);
368 			/* Max number of gpios per controller is 144 so
369 			 * hw_irq will be in [0..143]
370 			 */
371 			hw_irq = (bank_num / 2) * 32 + bit;
372 
373 			generic_handle_domain_irq(d->irq_domain, hw_irq);
374 		}
375 	}
376 	chained_irq_exit(irq_desc_get_chip(desc), desc);
377 	/* now it may re-trigger */
378 }
379 
380 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
381 {
382 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
383 
384 	if (d->irq_domain)
385 		return irq_create_mapping(d->irq_domain, offset);
386 	else
387 		return -ENXIO;
388 }
389 
390 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
391 {
392 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
393 
394 	/*
395 	 * NOTE:  we assume for now that only irqs in the first gpio_chip
396 	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
397 	 */
398 	if (offset < d->gpio_unbanked)
399 		return d->irqs[offset];
400 	else
401 		return -ENODEV;
402 }
403 
404 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
405 {
406 	struct davinci_gpio_controller *d;
407 	struct davinci_gpio_regs __iomem *g;
408 	u32 mask, i;
409 
410 	d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
411 	g = (struct davinci_gpio_regs __iomem *)d->regs[0];
412 	for (i = 0; i < MAX_INT_PER_BANK; i++)
413 		if (data->irq == d->irqs[i])
414 			break;
415 
416 	if (i == MAX_INT_PER_BANK)
417 		return -EINVAL;
418 
419 	mask = __gpio_mask(i);
420 
421 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
422 		return -EINVAL;
423 
424 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
425 		     ? &g->set_falling : &g->clr_falling);
426 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
427 		     ? &g->set_rising : &g->clr_rising);
428 
429 	return 0;
430 }
431 
432 static int
433 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
434 		     irq_hw_number_t hw)
435 {
436 	struct davinci_gpio_controller *chips =
437 				(struct davinci_gpio_controller *)d->host_data;
438 	struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32];
439 
440 	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
441 				"davinci_gpio");
442 	irq_set_irq_type(irq, IRQ_TYPE_NONE);
443 	irq_set_chip_data(irq, (__force void *)g);
444 	irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw));
445 
446 	return 0;
447 }
448 
449 static const struct irq_domain_ops davinci_gpio_irq_ops = {
450 	.map = davinci_gpio_irq_map,
451 	.xlate = irq_domain_xlate_onetwocell,
452 };
453 
454 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
455 {
456 	static struct irq_chip_type gpio_unbanked;
457 
458 	gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq));
459 
460 	return &gpio_unbanked.chip;
461 };
462 
463 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
464 {
465 	static struct irq_chip gpio_unbanked;
466 
467 	gpio_unbanked = *irq_get_chip(irq);
468 	return &gpio_unbanked;
469 };
470 
471 static const struct of_device_id davinci_gpio_ids[];
472 
473 /*
474  * NOTE:  for suspend/resume, probably best to make a platform_device with
475  * suspend_late/resume_resume calls hooking into results of the set_wake()
476  * calls ... so if no gpios are wakeup events the clock can be disabled,
477  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
478  * (dm6446) can be set appropriately for GPIOV33 pins.
479  */
480 
481 static int davinci_gpio_irq_setup(struct platform_device *pdev)
482 {
483 	unsigned	gpio, bank;
484 	int		irq;
485 	int		ret;
486 	struct clk	*clk;
487 	u32		binten = 0;
488 	unsigned	ngpio;
489 	struct device *dev = &pdev->dev;
490 	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
491 	struct davinci_gpio_platform_data *pdata = dev->platform_data;
492 	struct davinci_gpio_regs __iomem *g;
493 	struct irq_domain	*irq_domain = NULL;
494 	struct irq_chip *irq_chip;
495 	struct davinci_gpio_irq_data *irqdata;
496 	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
497 
498 	/*
499 	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
500 	 */
501 	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
502 	if (dev->of_node)
503 		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)device_get_match_data(dev);
504 
505 	ngpio = pdata->ngpio;
506 
507 	clk = devm_clk_get(dev, "gpio");
508 	if (IS_ERR(clk)) {
509 		dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk));
510 		return PTR_ERR(clk);
511 	}
512 
513 	ret = clk_prepare_enable(clk);
514 	if (ret)
515 		return ret;
516 
517 	if (!pdata->gpio_unbanked) {
518 		irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0);
519 		if (irq < 0) {
520 			dev_err(dev, "Couldn't allocate IRQ numbers\n");
521 			clk_disable_unprepare(clk);
522 			return irq;
523 		}
524 
525 		irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0,
526 							&davinci_gpio_irq_ops,
527 							chips);
528 		if (!irq_domain) {
529 			dev_err(dev, "Couldn't register an IRQ domain\n");
530 			clk_disable_unprepare(clk);
531 			return -ENODEV;
532 		}
533 	}
534 
535 	/*
536 	 * Arrange gpiod_to_irq() support, handling either direct IRQs or
537 	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
538 	 * IRQs, while the others use banked IRQs, would need some setup
539 	 * tweaks to recognize hardware which can do that.
540 	 */
541 	chips->chip.to_irq = gpio_to_irq_banked;
542 	chips->irq_domain = irq_domain;
543 
544 	/*
545 	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
546 	 * controller only handling trigger modes.  We currently assume no
547 	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
548 	 */
549 	if (pdata->gpio_unbanked) {
550 		/* pass "bank 0" GPIO IRQs to AINTC */
551 		chips->chip.to_irq = gpio_to_irq_unbanked;
552 		chips->gpio_unbanked = pdata->gpio_unbanked;
553 		binten = GENMASK(pdata->gpio_unbanked / 16, 0);
554 
555 		/* AINTC handles mask/unmask; GPIO handles triggering */
556 		irq = chips->irqs[0];
557 		irq_chip = gpio_get_irq_chip(irq);
558 		irq_chip->name = "GPIO-AINTC";
559 		irq_chip->irq_set_type = gpio_irq_type_unbanked;
560 
561 		/* default trigger: both edges */
562 		g = chips->regs[0];
563 		writel_relaxed(~0, &g->set_falling);
564 		writel_relaxed(~0, &g->set_rising);
565 
566 		/* set the direct IRQs up to use that irqchip */
567 		for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++) {
568 			irq_set_chip(chips->irqs[gpio], irq_chip);
569 			irq_set_handler_data(chips->irqs[gpio], chips);
570 			irq_set_status_flags(chips->irqs[gpio],
571 					     IRQ_TYPE_EDGE_BOTH);
572 		}
573 
574 		goto done;
575 	}
576 
577 	/*
578 	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
579 	 * then chain through our own handler.
580 	 */
581 	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 16) {
582 		/* disabled by default, enabled only as needed
583 		 * There are register sets for 32 GPIOs. 2 banks of 16
584 		 * GPIOs are covered by each set of registers hence divide by 2
585 		 */
586 		g = chips->regs[bank / 2];
587 		writel_relaxed(~0, &g->clr_falling);
588 		writel_relaxed(~0, &g->clr_rising);
589 
590 		/*
591 		 * Each chip handles 32 gpios, and each irq bank consists of 16
592 		 * gpio irqs. Pass the irq bank's corresponding controller to
593 		 * the chained irq handler.
594 		 */
595 		irqdata = devm_kzalloc(&pdev->dev,
596 				       sizeof(struct
597 					      davinci_gpio_irq_data),
598 					      GFP_KERNEL);
599 		if (!irqdata) {
600 			clk_disable_unprepare(clk);
601 			return -ENOMEM;
602 		}
603 
604 		irqdata->regs = g;
605 		irqdata->bank_num = bank;
606 		irqdata->chip = chips;
607 
608 		irq_set_chained_handler_and_data(chips->irqs[bank],
609 						 gpio_irq_handler, irqdata);
610 
611 		binten |= BIT(bank);
612 	}
613 
614 done:
615 	/*
616 	 * BINTEN -- per-bank interrupt enable. genirq would also let these
617 	 * bits be set/cleared dynamically.
618 	 */
619 	writel_relaxed(binten, gpio_base + BINTEN);
620 
621 	return 0;
622 }
623 
624 static void davinci_gpio_save_context(struct davinci_gpio_controller *chips,
625 				      u32 nbank)
626 {
627 	struct davinci_gpio_regs __iomem *g;
628 	struct davinci_gpio_regs *context;
629 	u32 bank;
630 	void __iomem *base;
631 
632 	base = chips->regs[0] - offset_array[0];
633 	chips->binten_context = readl_relaxed(base + BINTEN);
634 
635 	for (bank = 0; bank < nbank; bank++) {
636 		g = chips->regs[bank];
637 		context = &chips->context[bank];
638 		context->dir = readl_relaxed(&g->dir);
639 		context->set_data = readl_relaxed(&g->set_data);
640 		context->set_rising = readl_relaxed(&g->set_rising);
641 		context->set_falling = readl_relaxed(&g->set_falling);
642 	}
643 
644 	/* Clear all interrupt status registers */
645 	writel_relaxed(GENMASK(31, 0), &g->intstat);
646 }
647 
648 static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips,
649 					 u32 nbank)
650 {
651 	struct davinci_gpio_regs __iomem *g;
652 	struct davinci_gpio_regs *context;
653 	u32 bank;
654 	void __iomem *base;
655 
656 	base = chips->regs[0] - offset_array[0];
657 
658 	if (readl_relaxed(base + BINTEN) != chips->binten_context)
659 		writel_relaxed(chips->binten_context, base + BINTEN);
660 
661 	for (bank = 0; bank < nbank; bank++) {
662 		g = chips->regs[bank];
663 		context = &chips->context[bank];
664 		if (readl_relaxed(&g->dir) != context->dir)
665 			writel_relaxed(context->dir, &g->dir);
666 		if (readl_relaxed(&g->set_data) != context->set_data)
667 			writel_relaxed(context->set_data, &g->set_data);
668 		if (readl_relaxed(&g->set_rising) != context->set_rising)
669 			writel_relaxed(context->set_rising, &g->set_rising);
670 		if (readl_relaxed(&g->set_falling) != context->set_falling)
671 			writel_relaxed(context->set_falling, &g->set_falling);
672 	}
673 }
674 
675 static int davinci_gpio_suspend(struct device *dev)
676 {
677 	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
678 	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
679 	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
680 
681 	davinci_gpio_save_context(chips, nbank);
682 
683 	return 0;
684 }
685 
686 static int davinci_gpio_resume(struct device *dev)
687 {
688 	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
689 	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
690 	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
691 
692 	davinci_gpio_restore_context(chips, nbank);
693 
694 	return 0;
695 }
696 
697 static DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend,
698 			 davinci_gpio_resume);
699 
700 static const struct of_device_id davinci_gpio_ids[] = {
701 	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
702 	{ .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip},
703 	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
704 	{ /* sentinel */ },
705 };
706 MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
707 
708 static struct platform_driver davinci_gpio_driver = {
709 	.probe		= davinci_gpio_probe,
710 	.driver		= {
711 		.name		= "davinci_gpio",
712 		.pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops),
713 		.of_match_table	= of_match_ptr(davinci_gpio_ids),
714 	},
715 };
716 
717 /*
718  * GPIO driver registration needs to be done before machine_init functions
719  * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
720  */
721 static int __init davinci_gpio_drv_reg(void)
722 {
723 	return platform_driver_register(&davinci_gpio_driver);
724 }
725 postcore_initcall(davinci_gpio_drv_reg);
726 
727 static void __exit davinci_gpio_exit(void)
728 {
729 	platform_driver_unregister(&davinci_gpio_driver);
730 }
731 module_exit(davinci_gpio_exit);
732 
733 MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
734 MODULE_DESCRIPTION("DAVINCI GPIO driver");
735 MODULE_LICENSE("GPL");
736 MODULE_ALIAS("platform:gpio-davinci");
737