xref: /openbmc/linux/drivers/gpio/gpio-davinci.c (revision 3d40aed8)
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 #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 	chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
229 	if (!chips)
230 		return -ENOMEM;
231 
232 	gpio_base = devm_platform_ioremap_resource(pdev, 0);
233 	if (IS_ERR(gpio_base))
234 		return PTR_ERR(gpio_base);
235 
236 	for (i = 0; i < nirq; i++) {
237 		chips->irqs[i] = platform_get_irq(pdev, i);
238 		if (chips->irqs[i] < 0)
239 			return dev_err_probe(dev, chips->irqs[i], "IRQ not populated\n");
240 	}
241 
242 	chips->chip.label = dev_name(dev);
243 
244 	chips->chip.direction_input = davinci_direction_in;
245 	chips->chip.get = davinci_gpio_get;
246 	chips->chip.direction_output = davinci_direction_out;
247 	chips->chip.set = davinci_gpio_set;
248 
249 	chips->chip.ngpio = ngpio;
250 	chips->chip.base = pdata->no_auto_base ? pdata->base : -1;
251 
252 #ifdef CONFIG_OF_GPIO
253 	chips->chip.parent = dev;
254 	chips->chip.request = gpiochip_generic_request;
255 	chips->chip.free = gpiochip_generic_free;
256 #endif
257 	spin_lock_init(&chips->lock);
258 
259 	nbank = DIV_ROUND_UP(ngpio, 32);
260 	for (bank = 0; bank < nbank; bank++)
261 		chips->regs[bank] = gpio_base + offset_array[bank];
262 
263 	ret = devm_gpiochip_add_data(dev, &chips->chip, chips);
264 	if (ret)
265 		return ret;
266 
267 	platform_set_drvdata(pdev, chips);
268 	ret = davinci_gpio_irq_setup(pdev);
269 	if (ret)
270 		return ret;
271 
272 	return 0;
273 }
274 
275 /*--------------------------------------------------------------------------*/
276 /*
277  * We expect irqs will normally be set up as input pins, but they can also be
278  * used as output pins ... which is convenient for testing.
279  *
280  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
281  * to their GPIOBNK0 irq, with a bit less overhead.
282  *
283  * All those INTC hookups (direct, plus several IRQ banks) can also
284  * serve as EDMA event triggers.
285  */
286 
287 static void gpio_irq_disable(struct irq_data *d)
288 {
289 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
290 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
291 
292 	writel_relaxed(mask, &g->clr_falling);
293 	writel_relaxed(mask, &g->clr_rising);
294 }
295 
296 static void gpio_irq_enable(struct irq_data *d)
297 {
298 	struct davinci_gpio_regs __iomem *g = irq2regs(d);
299 	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
300 	unsigned status = irqd_get_trigger_type(d);
301 
302 	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
303 	if (!status)
304 		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
305 
306 	if (status & IRQ_TYPE_EDGE_FALLING)
307 		writel_relaxed(mask, &g->set_falling);
308 	if (status & IRQ_TYPE_EDGE_RISING)
309 		writel_relaxed(mask, &g->set_rising);
310 }
311 
312 static int gpio_irq_type(struct irq_data *d, unsigned trigger)
313 {
314 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
315 		return -EINVAL;
316 
317 	return 0;
318 }
319 
320 static struct irq_chip gpio_irqchip = {
321 	.name		= "GPIO",
322 	.irq_enable	= gpio_irq_enable,
323 	.irq_disable	= gpio_irq_disable,
324 	.irq_set_type	= gpio_irq_type,
325 	.flags		= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE,
326 };
327 
328 static void gpio_irq_handler(struct irq_desc *desc)
329 {
330 	struct davinci_gpio_regs __iomem *g;
331 	u32 mask = 0xffff;
332 	int bank_num;
333 	struct davinci_gpio_controller *d;
334 	struct davinci_gpio_irq_data *irqdata;
335 
336 	irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc);
337 	bank_num = irqdata->bank_num;
338 	g = irqdata->regs;
339 	d = irqdata->chip;
340 
341 	/* we only care about one bank */
342 	if ((bank_num % 2) == 1)
343 		mask <<= 16;
344 
345 	/* temporarily mask (level sensitive) parent IRQ */
346 	chained_irq_enter(irq_desc_get_chip(desc), desc);
347 	while (1) {
348 		u32		status;
349 		int		bit;
350 		irq_hw_number_t hw_irq;
351 
352 		/* ack any irqs */
353 		status = readl_relaxed(&g->intstat) & mask;
354 		if (!status)
355 			break;
356 		writel_relaxed(status, &g->intstat);
357 
358 		/* now demux them to the right lowlevel handler */
359 
360 		while (status) {
361 			bit = __ffs(status);
362 			status &= ~BIT(bit);
363 			/* Max number of gpios per controller is 144 so
364 			 * hw_irq will be in [0..143]
365 			 */
366 			hw_irq = (bank_num / 2) * 32 + bit;
367 
368 			generic_handle_domain_irq(d->irq_domain, hw_irq);
369 		}
370 	}
371 	chained_irq_exit(irq_desc_get_chip(desc), desc);
372 	/* now it may re-trigger */
373 }
374 
375 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
376 {
377 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
378 
379 	if (d->irq_domain)
380 		return irq_create_mapping(d->irq_domain, offset);
381 	else
382 		return -ENXIO;
383 }
384 
385 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
386 {
387 	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
388 
389 	/*
390 	 * NOTE:  we assume for now that only irqs in the first gpio_chip
391 	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
392 	 */
393 	if (offset < d->gpio_unbanked)
394 		return d->irqs[offset];
395 	else
396 		return -ENODEV;
397 }
398 
399 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
400 {
401 	struct davinci_gpio_controller *d;
402 	struct davinci_gpio_regs __iomem *g;
403 	u32 mask, i;
404 
405 	d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
406 	g = (struct davinci_gpio_regs __iomem *)d->regs[0];
407 	for (i = 0; i < MAX_INT_PER_BANK; i++)
408 		if (data->irq == d->irqs[i])
409 			break;
410 
411 	if (i == MAX_INT_PER_BANK)
412 		return -EINVAL;
413 
414 	mask = __gpio_mask(i);
415 
416 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
417 		return -EINVAL;
418 
419 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
420 		     ? &g->set_falling : &g->clr_falling);
421 	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
422 		     ? &g->set_rising : &g->clr_rising);
423 
424 	return 0;
425 }
426 
427 static int
428 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
429 		     irq_hw_number_t hw)
430 {
431 	struct davinci_gpio_controller *chips =
432 				(struct davinci_gpio_controller *)d->host_data;
433 	struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32];
434 
435 	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
436 				"davinci_gpio");
437 	irq_set_irq_type(irq, IRQ_TYPE_NONE);
438 	irq_set_chip_data(irq, (__force void *)g);
439 	irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw));
440 
441 	return 0;
442 }
443 
444 static const struct irq_domain_ops davinci_gpio_irq_ops = {
445 	.map = davinci_gpio_irq_map,
446 	.xlate = irq_domain_xlate_onetwocell,
447 };
448 
449 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
450 {
451 	static struct irq_chip_type gpio_unbanked;
452 
453 	gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq));
454 
455 	return &gpio_unbanked.chip;
456 };
457 
458 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
459 {
460 	static struct irq_chip gpio_unbanked;
461 
462 	gpio_unbanked = *irq_get_chip(irq);
463 	return &gpio_unbanked;
464 };
465 
466 static const struct of_device_id davinci_gpio_ids[];
467 
468 /*
469  * NOTE:  for suspend/resume, probably best to make a platform_device with
470  * suspend_late/resume_resume calls hooking into results of the set_wake()
471  * calls ... so if no gpios are wakeup events the clock can be disabled,
472  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
473  * (dm6446) can be set appropriately for GPIOV33 pins.
474  */
475 
476 static int davinci_gpio_irq_setup(struct platform_device *pdev)
477 {
478 	unsigned	gpio, bank;
479 	int		irq;
480 	int		ret;
481 	struct clk	*clk;
482 	u32		binten = 0;
483 	unsigned	ngpio;
484 	struct device *dev = &pdev->dev;
485 	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
486 	struct davinci_gpio_platform_data *pdata = dev->platform_data;
487 	struct davinci_gpio_regs __iomem *g;
488 	struct irq_domain	*irq_domain = NULL;
489 	const struct of_device_id *match;
490 	struct irq_chip *irq_chip;
491 	struct davinci_gpio_irq_data *irqdata;
492 	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
493 
494 	/*
495 	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
496 	 */
497 	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
498 	match = of_match_device(of_match_ptr(davinci_gpio_ids),
499 				dev);
500 	if (match)
501 		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data;
502 
503 	ngpio = pdata->ngpio;
504 
505 	clk = devm_clk_get(dev, "gpio");
506 	if (IS_ERR(clk)) {
507 		dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk));
508 		return PTR_ERR(clk);
509 	}
510 
511 	ret = clk_prepare_enable(clk);
512 	if (ret)
513 		return ret;
514 
515 	if (!pdata->gpio_unbanked) {
516 		irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0);
517 		if (irq < 0) {
518 			dev_err(dev, "Couldn't allocate IRQ numbers\n");
519 			clk_disable_unprepare(clk);
520 			return irq;
521 		}
522 
523 		irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0,
524 							&davinci_gpio_irq_ops,
525 							chips);
526 		if (!irq_domain) {
527 			dev_err(dev, "Couldn't register an IRQ domain\n");
528 			clk_disable_unprepare(clk);
529 			return -ENODEV;
530 		}
531 	}
532 
533 	/*
534 	 * Arrange gpiod_to_irq() support, handling either direct IRQs or
535 	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
536 	 * IRQs, while the others use banked IRQs, would need some setup
537 	 * tweaks to recognize hardware which can do that.
538 	 */
539 	chips->chip.to_irq = gpio_to_irq_banked;
540 	chips->irq_domain = irq_domain;
541 
542 	/*
543 	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
544 	 * controller only handling trigger modes.  We currently assume no
545 	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
546 	 */
547 	if (pdata->gpio_unbanked) {
548 		/* pass "bank 0" GPIO IRQs to AINTC */
549 		chips->chip.to_irq = gpio_to_irq_unbanked;
550 		chips->gpio_unbanked = pdata->gpio_unbanked;
551 		binten = GENMASK(pdata->gpio_unbanked / 16, 0);
552 
553 		/* AINTC handles mask/unmask; GPIO handles triggering */
554 		irq = chips->irqs[0];
555 		irq_chip = gpio_get_irq_chip(irq);
556 		irq_chip->name = "GPIO-AINTC";
557 		irq_chip->irq_set_type = gpio_irq_type_unbanked;
558 
559 		/* default trigger: both edges */
560 		g = chips->regs[0];
561 		writel_relaxed(~0, &g->set_falling);
562 		writel_relaxed(~0, &g->set_rising);
563 
564 		/* set the direct IRQs up to use that irqchip */
565 		for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++) {
566 			irq_set_chip(chips->irqs[gpio], irq_chip);
567 			irq_set_handler_data(chips->irqs[gpio], chips);
568 			irq_set_status_flags(chips->irqs[gpio],
569 					     IRQ_TYPE_EDGE_BOTH);
570 		}
571 
572 		goto done;
573 	}
574 
575 	/*
576 	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
577 	 * then chain through our own handler.
578 	 */
579 	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 16) {
580 		/* disabled by default, enabled only as needed
581 		 * There are register sets for 32 GPIOs. 2 banks of 16
582 		 * GPIOs are covered by each set of registers hence divide by 2
583 		 */
584 		g = chips->regs[bank / 2];
585 		writel_relaxed(~0, &g->clr_falling);
586 		writel_relaxed(~0, &g->clr_rising);
587 
588 		/*
589 		 * Each chip handles 32 gpios, and each irq bank consists of 16
590 		 * gpio irqs. Pass the irq bank's corresponding controller to
591 		 * the chained irq handler.
592 		 */
593 		irqdata = devm_kzalloc(&pdev->dev,
594 				       sizeof(struct
595 					      davinci_gpio_irq_data),
596 					      GFP_KERNEL);
597 		if (!irqdata) {
598 			clk_disable_unprepare(clk);
599 			return -ENOMEM;
600 		}
601 
602 		irqdata->regs = g;
603 		irqdata->bank_num = bank;
604 		irqdata->chip = chips;
605 
606 		irq_set_chained_handler_and_data(chips->irqs[bank],
607 						 gpio_irq_handler, irqdata);
608 
609 		binten |= BIT(bank);
610 	}
611 
612 done:
613 	/*
614 	 * BINTEN -- per-bank interrupt enable. genirq would also let these
615 	 * bits be set/cleared dynamically.
616 	 */
617 	writel_relaxed(binten, gpio_base + BINTEN);
618 
619 	return 0;
620 }
621 
622 static void davinci_gpio_save_context(struct davinci_gpio_controller *chips,
623 				      u32 nbank)
624 {
625 	struct davinci_gpio_regs __iomem *g;
626 	struct davinci_gpio_regs *context;
627 	u32 bank;
628 	void __iomem *base;
629 
630 	base = chips->regs[0] - offset_array[0];
631 	chips->binten_context = readl_relaxed(base + BINTEN);
632 
633 	for (bank = 0; bank < nbank; bank++) {
634 		g = chips->regs[bank];
635 		context = &chips->context[bank];
636 		context->dir = readl_relaxed(&g->dir);
637 		context->set_data = readl_relaxed(&g->set_data);
638 		context->set_rising = readl_relaxed(&g->set_rising);
639 		context->set_falling = readl_relaxed(&g->set_falling);
640 	}
641 
642 	/* Clear all interrupt status registers */
643 	writel_relaxed(GENMASK(31, 0), &g->intstat);
644 }
645 
646 static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips,
647 					 u32 nbank)
648 {
649 	struct davinci_gpio_regs __iomem *g;
650 	struct davinci_gpio_regs *context;
651 	u32 bank;
652 	void __iomem *base;
653 
654 	base = chips->regs[0] - offset_array[0];
655 
656 	if (readl_relaxed(base + BINTEN) != chips->binten_context)
657 		writel_relaxed(chips->binten_context, base + BINTEN);
658 
659 	for (bank = 0; bank < nbank; bank++) {
660 		g = chips->regs[bank];
661 		context = &chips->context[bank];
662 		if (readl_relaxed(&g->dir) != context->dir)
663 			writel_relaxed(context->dir, &g->dir);
664 		if (readl_relaxed(&g->set_data) != context->set_data)
665 			writel_relaxed(context->set_data, &g->set_data);
666 		if (readl_relaxed(&g->set_rising) != context->set_rising)
667 			writel_relaxed(context->set_rising, &g->set_rising);
668 		if (readl_relaxed(&g->set_falling) != context->set_falling)
669 			writel_relaxed(context->set_falling, &g->set_falling);
670 	}
671 }
672 
673 static int davinci_gpio_suspend(struct device *dev)
674 {
675 	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
676 	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
677 	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
678 
679 	davinci_gpio_save_context(chips, nbank);
680 
681 	return 0;
682 }
683 
684 static int davinci_gpio_resume(struct device *dev)
685 {
686 	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
687 	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
688 	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
689 
690 	davinci_gpio_restore_context(chips, nbank);
691 
692 	return 0;
693 }
694 
695 static DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend,
696 			 davinci_gpio_resume);
697 
698 static const struct of_device_id davinci_gpio_ids[] = {
699 	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
700 	{ .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip},
701 	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
702 	{ /* sentinel */ },
703 };
704 MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
705 
706 static struct platform_driver davinci_gpio_driver = {
707 	.probe		= davinci_gpio_probe,
708 	.driver		= {
709 		.name		= "davinci_gpio",
710 		.pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops),
711 		.of_match_table	= of_match_ptr(davinci_gpio_ids),
712 	},
713 };
714 
715 /*
716  * GPIO driver registration needs to be done before machine_init functions
717  * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
718  */
719 static int __init davinci_gpio_drv_reg(void)
720 {
721 	return platform_driver_register(&davinci_gpio_driver);
722 }
723 postcore_initcall(davinci_gpio_drv_reg);
724 
725 static void __exit davinci_gpio_exit(void)
726 {
727 	platform_driver_unregister(&davinci_gpio_driver);
728 }
729 module_exit(davinci_gpio_exit);
730 
731 MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
732 MODULE_DESCRIPTION("DAVINCI GPIO driver");
733 MODULE_LICENSE("GPL");
734 MODULE_ALIAS("platform:gpio-davinci");
735