xref: /openbmc/linux/drivers/gpio/gpio-davinci.c (revision d54151aa)
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/of_device.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/platform_data/gpio-davinci.h>
23 #include <linux/irqchip/chained_irq.h>
24 #include <linux/spinlock.h>
25 #include <linux/pm_runtime.h>
26 
27 #include <asm-generic/gpio.h>
28 
29 #define MAX_REGS_BANKS 5
30 #define MAX_INT_PER_BANK 32
31 
32 struct davinci_gpio_regs {
33 	u32	dir;
34 	u32	out_data;
35 	u32	set_data;
36 	u32	clr_data;
37 	u32	in_data;
38 	u32	set_rising;
39 	u32	clr_rising;
40 	u32	set_falling;
41 	u32	clr_falling;
42 	u32	intstat;
43 };
44 
45 typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
46 
47 #define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
48 
49 static void __iomem *gpio_base;
50 static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0};
51 
52 struct davinci_gpio_irq_data {
53 	void __iomem			*regs;
54 	struct davinci_gpio_controller	*chip;
55 	int				bank_num;
56 };
57 
58 struct davinci_gpio_controller {
59 	struct gpio_chip	chip;
60 	struct irq_domain	*irq_domain;
61 	/* Serialize access to GPIO registers */
62 	spinlock_t		lock;
63 	void __iomem		*regs[MAX_REGS_BANKS];
64 	int			gpio_unbanked;
65 	int			irqs[MAX_INT_PER_BANK];
66 	struct davinci_gpio_regs context[MAX_REGS_BANKS];
67 	u32			binten_context;
68 };
69 
70 static inline u32 __gpio_mask(unsigned gpio)
71 {
72 	return 1 << (gpio % 32);
73 }
74 
75 static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d)
76 {
77 	struct davinci_gpio_regs __iomem *g;
78 
79 	g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d);
80 
81 	return g;
82 }
83 
84 static int davinci_gpio_irq_setup(struct platform_device *pdev);
85 
86 /*--------------------------------------------------------------------------*/
87 
88 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */
89 static inline int __davinci_direction(struct gpio_chip *chip,
90 			unsigned offset, bool out, int value)
91 {
92 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
93 	struct davinci_gpio_regs __iomem *g;
94 	unsigned long flags;
95 	u32 temp;
96 	int bank = offset / 32;
97 	u32 mask = __gpio_mask(offset);
98 
99 	g = d->regs[bank];
100 	spin_lock_irqsave(&d->lock, flags);
101 	temp = readl_relaxed(&g->dir);
102 	if (out) {
103 		temp &= ~mask;
104 		writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
105 	} else {
106 		temp |= mask;
107 	}
108 	writel_relaxed(temp, &g->dir);
109 	spin_unlock_irqrestore(&d->lock, flags);
110 
111 	return 0;
112 }
113 
114 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
115 {
116 	return __davinci_direction(chip, offset, false, 0);
117 }
118 
119 static int
120 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
121 {
122 	return __davinci_direction(chip, offset, true, value);
123 }
124 
125 /*
126  * Read the pin's value (works even if it's set up as output);
127  * returns zero/nonzero.
128  *
129  * Note that changes are synched to the GPIO clock, so reading values back
130  * right after you've set them may give old values.
131  */
132 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
133 {
134 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
135 	struct davinci_gpio_regs __iomem *g;
136 	int bank = offset / 32;
137 
138 	g = d->regs[bank];
139 
140 	return !!(__gpio_mask(offset) & readl_relaxed(&g->in_data));
141 }
142 
143 /*
144  * Assuming the pin is muxed as a gpio output, set its output value.
145  */
146 static void
147 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
148 {
149 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
150 	struct davinci_gpio_regs __iomem *g;
151 	int bank = offset / 32;
152 
153 	g = d->regs[bank];
154 
155 	writel_relaxed(__gpio_mask(offset),
156 		       value ? &g->set_data : &g->clr_data);
157 }
158 
159 static struct davinci_gpio_platform_data *
160 davinci_gpio_get_pdata(struct platform_device *pdev)
161 {
162 	struct device_node *dn = pdev->dev.of_node;
163 	struct davinci_gpio_platform_data *pdata;
164 	int ret;
165 	u32 val;
166 
167 	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
168 		return dev_get_platdata(&pdev->dev);
169 
170 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
171 	if (!pdata)
172 		return NULL;
173 
174 	ret = of_property_read_u32(dn, "ti,ngpio", &val);
175 	if (ret)
176 		goto of_err;
177 
178 	pdata->ngpio = val;
179 
180 	ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
181 	if (ret)
182 		goto of_err;
183 
184 	pdata->gpio_unbanked = val;
185 
186 	return pdata;
187 
188 of_err:
189 	dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
190 	return NULL;
191 }
192 
193 static int davinci_gpio_probe(struct platform_device *pdev)
194 {
195 	int bank, i, ret = 0;
196 	unsigned int ngpio, nbank, nirq;
197 	struct davinci_gpio_controller *chips;
198 	struct davinci_gpio_platform_data *pdata;
199 	struct device *dev = &pdev->dev;
200 
201 	pdata = davinci_gpio_get_pdata(pdev);
202 	if (!pdata) {
203 		dev_err(dev, "No platform data found\n");
204 		return -EINVAL;
205 	}
206 
207 	dev->platform_data = pdata;
208 
209 	/*
210 	 * The gpio banks conceptually expose a segmented bitmap,
211 	 * and "ngpio" is one more than the largest zero-based
212 	 * bit index that's valid.
213 	 */
214 	ngpio = pdata->ngpio;
215 	if (ngpio == 0) {
216 		dev_err(dev, "How many GPIOs?\n");
217 		return -EINVAL;
218 	}
219 
220 	/*
221 	 * If there are unbanked interrupts then the number of
222 	 * interrupts is equal to number of gpios else all are banked so
223 	 * number of interrupts is equal to number of banks(each with 16 gpios)
224 	 */
225 	if (pdata->gpio_unbanked)
226 		nirq = pdata->gpio_unbanked;
227 	else
228 		nirq = DIV_ROUND_UP(ngpio, 16);
229 
230 	chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
231 	if (!chips)
232 		return -ENOMEM;
233 
234 	gpio_base = devm_platform_ioremap_resource(pdev, 0);
235 	if (IS_ERR(gpio_base))
236 		return PTR_ERR(gpio_base);
237 
238 	for (i = 0; i < nirq; i++) {
239 		chips->irqs[i] = platform_get_irq(pdev, i);
240 		if (chips->irqs[i] < 0)
241 			return dev_err_probe(dev, chips->irqs[i], "IRQ not populated\n");
242 	}
243 
244 	chips->chip.label = dev_name(dev);
245 
246 	chips->chip.direction_input = davinci_direction_in;
247 	chips->chip.get = davinci_gpio_get;
248 	chips->chip.direction_output = davinci_direction_out;
249 	chips->chip.set = davinci_gpio_set;
250 
251 	chips->chip.ngpio = ngpio;
252 	chips->chip.base = pdata->no_auto_base ? pdata->base : -1;
253 
254 #ifdef CONFIG_OF_GPIO
255 	chips->chip.parent = dev;
256 	chips->chip.request = gpiochip_generic_request;
257 	chips->chip.free = gpiochip_generic_free;
258 #endif
259 	spin_lock_init(&chips->lock);
260 
261 	nbank = DIV_ROUND_UP(ngpio, 32);
262 	for (bank = 0; bank < nbank; bank++)
263 		chips->regs[bank] = gpio_base + offset_array[bank];
264 
265 	ret = devm_gpiochip_add_data(dev, &chips->chip, chips);
266 	if (ret)
267 		return ret;
268 
269 	platform_set_drvdata(pdev, chips);
270 	ret = davinci_gpio_irq_setup(pdev);
271 	if (ret)
272 		return ret;
273 
274 	return 0;
275 }
276 
277 /*--------------------------------------------------------------------------*/
278 /*
279  * We expect irqs will normally be set up as input pins, but they can also be
280  * used as output pins ... which is convenient for testing.
281  *
282  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
283  * to their GPIOBNK0 irq, with a bit less overhead.
284  *
285  * All those INTC hookups (direct, plus several IRQ banks) can also
286  * serve as EDMA event triggers.
287  */
288 
289 static void gpio_irq_disable(struct irq_data *d)
290 {
291 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
292 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
293 
294 	writel_relaxed(mask, &g->clr_falling);
295 	writel_relaxed(mask, &g->clr_rising);
296 }
297 
298 static void gpio_irq_enable(struct irq_data *d)
299 {
300 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
301 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
302 	unsigned status = irqd_get_trigger_type(d);
303 
304 	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
305 	if (!status)
306 		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
307 
308 	if (status & IRQ_TYPE_EDGE_FALLING)
309 		writel_relaxed(mask, &g->set_falling);
310 	if (status & IRQ_TYPE_EDGE_RISING)
311 		writel_relaxed(mask, &g->set_rising);
312 }
313 
314 static int gpio_irq_type(struct irq_data *d, unsigned trigger)
315 {
316 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
317 		return -EINVAL;
318 
319 	return 0;
320 }
321 
322 static struct irq_chip gpio_irqchip = {
323 	.name		= "GPIO",
324 	.irq_enable	= gpio_irq_enable,
325 	.irq_disable	= gpio_irq_disable,
326 	.irq_set_type	= gpio_irq_type,
327 	.flags		= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE,
328 };
329 
330 static void gpio_irq_handler(struct irq_desc *desc)
331 {
332 	struct davinci_gpio_regs __iomem *g;
333 	u32 mask = 0xffff;
334 	int bank_num;
335 	struct davinci_gpio_controller *d;
336 	struct davinci_gpio_irq_data *irqdata;
337 
338 	irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc);
339 	bank_num = irqdata->bank_num;
340 	g = irqdata->regs;
341 	d = irqdata->chip;
342 
343 	/* we only care about one bank */
344 	if ((bank_num % 2) == 1)
345 		mask <<= 16;
346 
347 	/* temporarily mask (level sensitive) parent IRQ */
348 	chained_irq_enter(irq_desc_get_chip(desc), desc);
349 	while (1) {
350 		u32		status;
351 		int		bit;
352 		irq_hw_number_t hw_irq;
353 
354 		/* ack any irqs */
355 		status = readl_relaxed(&g->intstat) & mask;
356 		if (!status)
357 			break;
358 		writel_relaxed(status, &g->intstat);
359 
360 		/* now demux them to the right lowlevel handler */
361 
362 		while (status) {
363 			bit = __ffs(status);
364 			status &= ~BIT(bit);
365 			/* Max number of gpios per controller is 144 so
366 			 * hw_irq will be in [0..143]
367 			 */
368 			hw_irq = (bank_num / 2) * 32 + bit;
369 
370 			generic_handle_domain_irq(d->irq_domain, hw_irq);
371 		}
372 	}
373 	chained_irq_exit(irq_desc_get_chip(desc), desc);
374 	/* now it may re-trigger */
375 }
376 
377 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
378 {
379 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
380 
381 	if (d->irq_domain)
382 		return irq_create_mapping(d->irq_domain, offset);
383 	else
384 		return -ENXIO;
385 }
386 
387 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
388 {
389 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
390 
391 	/*
392 	 * NOTE:  we assume for now that only irqs in the first gpio_chip
393 	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
394 	 */
395 	if (offset < d->gpio_unbanked)
396 		return d->irqs[offset];
397 	else
398 		return -ENODEV;
399 }
400 
401 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
402 {
403 	struct davinci_gpio_controller *d;
404 	struct davinci_gpio_regs __iomem *g;
405 	u32 mask, i;
406 
407 	d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
408 	g = (struct davinci_gpio_regs __iomem *)d->regs[0];
409 	for (i = 0; i < MAX_INT_PER_BANK; i++)
410 		if (data->irq == d->irqs[i])
411 			break;
412 
413 	if (i == MAX_INT_PER_BANK)
414 		return -EINVAL;
415 
416 	mask = __gpio_mask(i);
417 
418 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
419 		return -EINVAL;
420 
421 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
422 		     ? &g->set_falling : &g->clr_falling);
423 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
424 		     ? &g->set_rising : &g->clr_rising);
425 
426 	return 0;
427 }
428 
429 static int
430 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
431 		     irq_hw_number_t hw)
432 {
433 	struct davinci_gpio_controller *chips =
434 				(struct davinci_gpio_controller *)d->host_data;
435 	struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32];
436 
437 	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
438 				"davinci_gpio");
439 	irq_set_irq_type(irq, IRQ_TYPE_NONE);
440 	irq_set_chip_data(irq, (__force void *)g);
441 	irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw));
442 
443 	return 0;
444 }
445 
446 static const struct irq_domain_ops davinci_gpio_irq_ops = {
447 	.map = davinci_gpio_irq_map,
448 	.xlate = irq_domain_xlate_onetwocell,
449 };
450 
451 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
452 {
453 	static struct irq_chip_type gpio_unbanked;
454 
455 	gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq));
456 
457 	return &gpio_unbanked.chip;
458 };
459 
460 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
461 {
462 	static struct irq_chip gpio_unbanked;
463 
464 	gpio_unbanked = *irq_get_chip(irq);
465 	return &gpio_unbanked;
466 };
467 
468 static const struct of_device_id davinci_gpio_ids[];
469 
470 /*
471  * NOTE:  for suspend/resume, probably best to make a platform_device with
472  * suspend_late/resume_resume calls hooking into results of the set_wake()
473  * calls ... so if no gpios are wakeup events the clock can be disabled,
474  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
475  * (dm6446) can be set appropriately for GPIOV33 pins.
476  */
477 
478 static int davinci_gpio_irq_setup(struct platform_device *pdev)
479 {
480 	unsigned	gpio, bank;
481 	int		irq;
482 	int		ret;
483 	struct clk	*clk;
484 	u32		binten = 0;
485 	unsigned	ngpio;
486 	struct device *dev = &pdev->dev;
487 	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
488 	struct davinci_gpio_platform_data *pdata = dev->platform_data;
489 	struct davinci_gpio_regs __iomem *g;
490 	struct irq_domain	*irq_domain = NULL;
491 	const struct of_device_id *match;
492 	struct irq_chip *irq_chip;
493 	struct davinci_gpio_irq_data *irqdata;
494 	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
495 
496 	/*
497 	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
498 	 */
499 	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
500 	match = of_match_device(of_match_ptr(davinci_gpio_ids),
501 				dev);
502 	if (match)
503 		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data;
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 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