xref: /linux/drivers/gpio/gpio-omap.c (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda) 
1 /*
2  * Support functions for OMAP GPIO
3  *
4  * Copyright (C) 2003-2005 Nokia Corporation
5  * Written by Juha Yrjölä <juha.yrjola@nokia.com>
6  *
7  * Copyright (C) 2009 Texas Instruments
8  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/syscore_ops.h>
19 #include <linux/err.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pm.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/gpio.h>
28 #include <linux/bitops.h>
29 #include <linux/platform_data/gpio-omap.h>
30 
31 #define OFF_MODE	1
32 #define OMAP4_GPIO_DEBOUNCINGTIME_MASK 0xFF
33 
34 static LIST_HEAD(omap_gpio_list);
35 
36 struct gpio_regs {
37 	u32 irqenable1;
38 	u32 irqenable2;
39 	u32 wake_en;
40 	u32 ctrl;
41 	u32 oe;
42 	u32 leveldetect0;
43 	u32 leveldetect1;
44 	u32 risingdetect;
45 	u32 fallingdetect;
46 	u32 dataout;
47 	u32 debounce;
48 	u32 debounce_en;
49 };
50 
51 struct gpio_bank {
52 	struct list_head node;
53 	void __iomem *base;
54 	int irq;
55 	u32 non_wakeup_gpios;
56 	u32 enabled_non_wakeup_gpios;
57 	struct gpio_regs context;
58 	u32 saved_datain;
59 	u32 level_mask;
60 	u32 toggle_mask;
61 	raw_spinlock_t lock;
62 	raw_spinlock_t wa_lock;
63 	struct gpio_chip chip;
64 	struct clk *dbck;
65 	u32 mod_usage;
66 	u32 irq_usage;
67 	u32 dbck_enable_mask;
68 	bool dbck_enabled;
69 	bool is_mpuio;
70 	bool dbck_flag;
71 	bool loses_context;
72 	bool context_valid;
73 	int stride;
74 	u32 width;
75 	int context_loss_count;
76 	int power_mode;
77 	bool workaround_enabled;
78 
79 	void (*set_dataout)(struct gpio_bank *bank, unsigned gpio, int enable);
80 	int (*get_context_loss_count)(struct device *dev);
81 
82 	struct omap_gpio_reg_offs *regs;
83 };
84 
85 #define GPIO_MOD_CTRL_BIT	BIT(0)
86 
87 #define BANK_USED(bank) (bank->mod_usage || bank->irq_usage)
88 #define LINE_USED(line, offset) (line & (BIT(offset)))
89 
90 static void omap_gpio_unmask_irq(struct irq_data *d);
91 
92 static inline struct gpio_bank *omap_irq_data_get_bank(struct irq_data *d)
93 {
94 	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
95 	return gpiochip_get_data(chip);
96 }
97 
98 static void omap_set_gpio_direction(struct gpio_bank *bank, int gpio,
99 				    int is_input)
100 {
101 	void __iomem *reg = bank->base;
102 	u32 l;
103 
104 	reg += bank->regs->direction;
105 	l = readl_relaxed(reg);
106 	if (is_input)
107 		l |= BIT(gpio);
108 	else
109 		l &= ~(BIT(gpio));
110 	writel_relaxed(l, reg);
111 	bank->context.oe = l;
112 }
113 
114 
115 /* set data out value using dedicate set/clear register */
116 static void omap_set_gpio_dataout_reg(struct gpio_bank *bank, unsigned offset,
117 				      int enable)
118 {
119 	void __iomem *reg = bank->base;
120 	u32 l = BIT(offset);
121 
122 	if (enable) {
123 		reg += bank->regs->set_dataout;
124 		bank->context.dataout |= l;
125 	} else {
126 		reg += bank->regs->clr_dataout;
127 		bank->context.dataout &= ~l;
128 	}
129 
130 	writel_relaxed(l, reg);
131 }
132 
133 /* set data out value using mask register */
134 static void omap_set_gpio_dataout_mask(struct gpio_bank *bank, unsigned offset,
135 				       int enable)
136 {
137 	void __iomem *reg = bank->base + bank->regs->dataout;
138 	u32 gpio_bit = BIT(offset);
139 	u32 l;
140 
141 	l = readl_relaxed(reg);
142 	if (enable)
143 		l |= gpio_bit;
144 	else
145 		l &= ~gpio_bit;
146 	writel_relaxed(l, reg);
147 	bank->context.dataout = l;
148 }
149 
150 static int omap_get_gpio_datain(struct gpio_bank *bank, int offset)
151 {
152 	void __iomem *reg = bank->base + bank->regs->datain;
153 
154 	return (readl_relaxed(reg) & (BIT(offset))) != 0;
155 }
156 
157 static int omap_get_gpio_dataout(struct gpio_bank *bank, int offset)
158 {
159 	void __iomem *reg = bank->base + bank->regs->dataout;
160 
161 	return (readl_relaxed(reg) & (BIT(offset))) != 0;
162 }
163 
164 static inline void omap_gpio_rmw(void __iomem *base, u32 reg, u32 mask, bool set)
165 {
166 	int l = readl_relaxed(base + reg);
167 
168 	if (set)
169 		l |= mask;
170 	else
171 		l &= ~mask;
172 
173 	writel_relaxed(l, base + reg);
174 }
175 
176 static inline void omap_gpio_dbck_enable(struct gpio_bank *bank)
177 {
178 	if (bank->dbck_enable_mask && !bank->dbck_enabled) {
179 		clk_enable(bank->dbck);
180 		bank->dbck_enabled = true;
181 
182 		writel_relaxed(bank->dbck_enable_mask,
183 			     bank->base + bank->regs->debounce_en);
184 	}
185 }
186 
187 static inline void omap_gpio_dbck_disable(struct gpio_bank *bank)
188 {
189 	if (bank->dbck_enable_mask && bank->dbck_enabled) {
190 		/*
191 		 * Disable debounce before cutting it's clock. If debounce is
192 		 * enabled but the clock is not, GPIO module seems to be unable
193 		 * to detect events and generate interrupts at least on OMAP3.
194 		 */
195 		writel_relaxed(0, bank->base + bank->regs->debounce_en);
196 
197 		clk_disable(bank->dbck);
198 		bank->dbck_enabled = false;
199 	}
200 }
201 
202 /**
203  * omap2_set_gpio_debounce - low level gpio debounce time
204  * @bank: the gpio bank we're acting upon
205  * @offset: the gpio number on this @bank
206  * @debounce: debounce time to use
207  *
208  * OMAP's debounce time is in 31us steps
209  *   <debounce time> = (GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) x 31
210  * so we need to convert and round up to the closest unit.
211  */
212 static void omap2_set_gpio_debounce(struct gpio_bank *bank, unsigned offset,
213 				    unsigned debounce)
214 {
215 	void __iomem		*reg;
216 	u32			val;
217 	u32			l;
218 	bool			enable = !!debounce;
219 
220 	if (!bank->dbck_flag)
221 		return;
222 
223 	if (enable) {
224 		debounce = DIV_ROUND_UP(debounce, 31) - 1;
225 		debounce &= OMAP4_GPIO_DEBOUNCINGTIME_MASK;
226 	}
227 
228 	l = BIT(offset);
229 
230 	clk_enable(bank->dbck);
231 	reg = bank->base + bank->regs->debounce;
232 	writel_relaxed(debounce, reg);
233 
234 	reg = bank->base + bank->regs->debounce_en;
235 	val = readl_relaxed(reg);
236 
237 	if (enable)
238 		val |= l;
239 	else
240 		val &= ~l;
241 	bank->dbck_enable_mask = val;
242 
243 	writel_relaxed(val, reg);
244 	clk_disable(bank->dbck);
245 	/*
246 	 * Enable debounce clock per module.
247 	 * This call is mandatory because in omap_gpio_request() when
248 	 * *_runtime_get_sync() is called,  _gpio_dbck_enable() within
249 	 * runtime callbck fails to turn on dbck because dbck_enable_mask
250 	 * used within _gpio_dbck_enable() is still not initialized at
251 	 * that point. Therefore we have to enable dbck here.
252 	 */
253 	omap_gpio_dbck_enable(bank);
254 	if (bank->dbck_enable_mask) {
255 		bank->context.debounce = debounce;
256 		bank->context.debounce_en = val;
257 	}
258 }
259 
260 /**
261  * omap_clear_gpio_debounce - clear debounce settings for a gpio
262  * @bank: the gpio bank we're acting upon
263  * @offset: the gpio number on this @bank
264  *
265  * If a gpio is using debounce, then clear the debounce enable bit and if
266  * this is the only gpio in this bank using debounce, then clear the debounce
267  * time too. The debounce clock will also be disabled when calling this function
268  * if this is the only gpio in the bank using debounce.
269  */
270 static void omap_clear_gpio_debounce(struct gpio_bank *bank, unsigned offset)
271 {
272 	u32 gpio_bit = BIT(offset);
273 
274 	if (!bank->dbck_flag)
275 		return;
276 
277 	if (!(bank->dbck_enable_mask & gpio_bit))
278 		return;
279 
280 	bank->dbck_enable_mask &= ~gpio_bit;
281 	bank->context.debounce_en &= ~gpio_bit;
282         writel_relaxed(bank->context.debounce_en,
283 		     bank->base + bank->regs->debounce_en);
284 
285 	if (!bank->dbck_enable_mask) {
286 		bank->context.debounce = 0;
287 		writel_relaxed(bank->context.debounce, bank->base +
288 			     bank->regs->debounce);
289 		clk_disable(bank->dbck);
290 		bank->dbck_enabled = false;
291 	}
292 }
293 
294 static inline void omap_set_gpio_trigger(struct gpio_bank *bank, int gpio,
295 						unsigned trigger)
296 {
297 	void __iomem *base = bank->base;
298 	u32 gpio_bit = BIT(gpio);
299 
300 	omap_gpio_rmw(base, bank->regs->leveldetect0, gpio_bit,
301 		      trigger & IRQ_TYPE_LEVEL_LOW);
302 	omap_gpio_rmw(base, bank->regs->leveldetect1, gpio_bit,
303 		      trigger & IRQ_TYPE_LEVEL_HIGH);
304 	omap_gpio_rmw(base, bank->regs->risingdetect, gpio_bit,
305 		      trigger & IRQ_TYPE_EDGE_RISING);
306 	omap_gpio_rmw(base, bank->regs->fallingdetect, gpio_bit,
307 		      trigger & IRQ_TYPE_EDGE_FALLING);
308 
309 	bank->context.leveldetect0 =
310 			readl_relaxed(bank->base + bank->regs->leveldetect0);
311 	bank->context.leveldetect1 =
312 			readl_relaxed(bank->base + bank->regs->leveldetect1);
313 	bank->context.risingdetect =
314 			readl_relaxed(bank->base + bank->regs->risingdetect);
315 	bank->context.fallingdetect =
316 			readl_relaxed(bank->base + bank->regs->fallingdetect);
317 
318 	if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
319 		omap_gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0);
320 		bank->context.wake_en =
321 			readl_relaxed(bank->base + bank->regs->wkup_en);
322 	}
323 
324 	/* This part needs to be executed always for OMAP{34xx, 44xx} */
325 	if (!bank->regs->irqctrl) {
326 		/* On omap24xx proceed only when valid GPIO bit is set */
327 		if (bank->non_wakeup_gpios) {
328 			if (!(bank->non_wakeup_gpios & gpio_bit))
329 				goto exit;
330 		}
331 
332 		/*
333 		 * Log the edge gpio and manually trigger the IRQ
334 		 * after resume if the input level changes
335 		 * to avoid irq lost during PER RET/OFF mode
336 		 * Applies for omap2 non-wakeup gpio and all omap3 gpios
337 		 */
338 		if (trigger & IRQ_TYPE_EDGE_BOTH)
339 			bank->enabled_non_wakeup_gpios |= gpio_bit;
340 		else
341 			bank->enabled_non_wakeup_gpios &= ~gpio_bit;
342 	}
343 
344 exit:
345 	bank->level_mask =
346 		readl_relaxed(bank->base + bank->regs->leveldetect0) |
347 		readl_relaxed(bank->base + bank->regs->leveldetect1);
348 }
349 
350 #ifdef CONFIG_ARCH_OMAP1
351 /*
352  * This only applies to chips that can't do both rising and falling edge
353  * detection at once.  For all other chips, this function is a noop.
354  */
355 static void omap_toggle_gpio_edge_triggering(struct gpio_bank *bank, int gpio)
356 {
357 	void __iomem *reg = bank->base;
358 	u32 l = 0;
359 
360 	if (!bank->regs->irqctrl)
361 		return;
362 
363 	reg += bank->regs->irqctrl;
364 
365 	l = readl_relaxed(reg);
366 	if ((l >> gpio) & 1)
367 		l &= ~(BIT(gpio));
368 	else
369 		l |= BIT(gpio);
370 
371 	writel_relaxed(l, reg);
372 }
373 #else
374 static void omap_toggle_gpio_edge_triggering(struct gpio_bank *bank, int gpio) {}
375 #endif
376 
377 static int omap_set_gpio_triggering(struct gpio_bank *bank, int gpio,
378 				    unsigned trigger)
379 {
380 	void __iomem *reg = bank->base;
381 	void __iomem *base = bank->base;
382 	u32 l = 0;
383 
384 	if (bank->regs->leveldetect0 && bank->regs->wkup_en) {
385 		omap_set_gpio_trigger(bank, gpio, trigger);
386 	} else if (bank->regs->irqctrl) {
387 		reg += bank->regs->irqctrl;
388 
389 		l = readl_relaxed(reg);
390 		if ((trigger & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH)
391 			bank->toggle_mask |= BIT(gpio);
392 		if (trigger & IRQ_TYPE_EDGE_RISING)
393 			l |= BIT(gpio);
394 		else if (trigger & IRQ_TYPE_EDGE_FALLING)
395 			l &= ~(BIT(gpio));
396 		else
397 			return -EINVAL;
398 
399 		writel_relaxed(l, reg);
400 	} else if (bank->regs->edgectrl1) {
401 		if (gpio & 0x08)
402 			reg += bank->regs->edgectrl2;
403 		else
404 			reg += bank->regs->edgectrl1;
405 
406 		gpio &= 0x07;
407 		l = readl_relaxed(reg);
408 		l &= ~(3 << (gpio << 1));
409 		if (trigger & IRQ_TYPE_EDGE_RISING)
410 			l |= 2 << (gpio << 1);
411 		if (trigger & IRQ_TYPE_EDGE_FALLING)
412 			l |= BIT(gpio << 1);
413 
414 		/* Enable wake-up during idle for dynamic tick */
415 		omap_gpio_rmw(base, bank->regs->wkup_en, BIT(gpio), trigger);
416 		bank->context.wake_en =
417 			readl_relaxed(bank->base + bank->regs->wkup_en);
418 		writel_relaxed(l, reg);
419 	}
420 	return 0;
421 }
422 
423 static void omap_enable_gpio_module(struct gpio_bank *bank, unsigned offset)
424 {
425 	if (bank->regs->pinctrl) {
426 		void __iomem *reg = bank->base + bank->regs->pinctrl;
427 
428 		/* Claim the pin for MPU */
429 		writel_relaxed(readl_relaxed(reg) | (BIT(offset)), reg);
430 	}
431 
432 	if (bank->regs->ctrl && !BANK_USED(bank)) {
433 		void __iomem *reg = bank->base + bank->regs->ctrl;
434 		u32 ctrl;
435 
436 		ctrl = readl_relaxed(reg);
437 		/* Module is enabled, clocks are not gated */
438 		ctrl &= ~GPIO_MOD_CTRL_BIT;
439 		writel_relaxed(ctrl, reg);
440 		bank->context.ctrl = ctrl;
441 	}
442 }
443 
444 static void omap_disable_gpio_module(struct gpio_bank *bank, unsigned offset)
445 {
446 	void __iomem *base = bank->base;
447 
448 	if (bank->regs->wkup_en &&
449 	    !LINE_USED(bank->mod_usage, offset) &&
450 	    !LINE_USED(bank->irq_usage, offset)) {
451 		/* Disable wake-up during idle for dynamic tick */
452 		omap_gpio_rmw(base, bank->regs->wkup_en, BIT(offset), 0);
453 		bank->context.wake_en =
454 			readl_relaxed(bank->base + bank->regs->wkup_en);
455 	}
456 
457 	if (bank->regs->ctrl && !BANK_USED(bank)) {
458 		void __iomem *reg = bank->base + bank->regs->ctrl;
459 		u32 ctrl;
460 
461 		ctrl = readl_relaxed(reg);
462 		/* Module is disabled, clocks are gated */
463 		ctrl |= GPIO_MOD_CTRL_BIT;
464 		writel_relaxed(ctrl, reg);
465 		bank->context.ctrl = ctrl;
466 	}
467 }
468 
469 static int omap_gpio_is_input(struct gpio_bank *bank, unsigned offset)
470 {
471 	void __iomem *reg = bank->base + bank->regs->direction;
472 
473 	return readl_relaxed(reg) & BIT(offset);
474 }
475 
476 static void omap_gpio_init_irq(struct gpio_bank *bank, unsigned offset)
477 {
478 	if (!LINE_USED(bank->mod_usage, offset)) {
479 		omap_enable_gpio_module(bank, offset);
480 		omap_set_gpio_direction(bank, offset, 1);
481 	}
482 	bank->irq_usage |= BIT(offset);
483 }
484 
485 static int omap_gpio_irq_type(struct irq_data *d, unsigned type)
486 {
487 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
488 	int retval;
489 	unsigned long flags;
490 	unsigned offset = d->hwirq;
491 
492 	if (type & ~IRQ_TYPE_SENSE_MASK)
493 		return -EINVAL;
494 
495 	if (!bank->regs->leveldetect0 &&
496 		(type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
497 		return -EINVAL;
498 
499 	raw_spin_lock_irqsave(&bank->lock, flags);
500 	retval = omap_set_gpio_triggering(bank, offset, type);
501 	if (retval) {
502 		raw_spin_unlock_irqrestore(&bank->lock, flags);
503 		goto error;
504 	}
505 	omap_gpio_init_irq(bank, offset);
506 	if (!omap_gpio_is_input(bank, offset)) {
507 		raw_spin_unlock_irqrestore(&bank->lock, flags);
508 		retval = -EINVAL;
509 		goto error;
510 	}
511 	raw_spin_unlock_irqrestore(&bank->lock, flags);
512 
513 	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
514 		irq_set_handler_locked(d, handle_level_irq);
515 	else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
516 		irq_set_handler_locked(d, handle_edge_irq);
517 
518 	return 0;
519 
520 error:
521 	return retval;
522 }
523 
524 static void omap_clear_gpio_irqbank(struct gpio_bank *bank, int gpio_mask)
525 {
526 	void __iomem *reg = bank->base;
527 
528 	reg += bank->regs->irqstatus;
529 	writel_relaxed(gpio_mask, reg);
530 
531 	/* Workaround for clearing DSP GPIO interrupts to allow retention */
532 	if (bank->regs->irqstatus2) {
533 		reg = bank->base + bank->regs->irqstatus2;
534 		writel_relaxed(gpio_mask, reg);
535 	}
536 
537 	/* Flush posted write for the irq status to avoid spurious interrupts */
538 	readl_relaxed(reg);
539 }
540 
541 static inline void omap_clear_gpio_irqstatus(struct gpio_bank *bank,
542 					     unsigned offset)
543 {
544 	omap_clear_gpio_irqbank(bank, BIT(offset));
545 }
546 
547 static u32 omap_get_gpio_irqbank_mask(struct gpio_bank *bank)
548 {
549 	void __iomem *reg = bank->base;
550 	u32 l;
551 	u32 mask = (BIT(bank->width)) - 1;
552 
553 	reg += bank->regs->irqenable;
554 	l = readl_relaxed(reg);
555 	if (bank->regs->irqenable_inv)
556 		l = ~l;
557 	l &= mask;
558 	return l;
559 }
560 
561 static void omap_enable_gpio_irqbank(struct gpio_bank *bank, int gpio_mask)
562 {
563 	void __iomem *reg = bank->base;
564 	u32 l;
565 
566 	if (bank->regs->set_irqenable) {
567 		reg += bank->regs->set_irqenable;
568 		l = gpio_mask;
569 		bank->context.irqenable1 |= gpio_mask;
570 	} else {
571 		reg += bank->regs->irqenable;
572 		l = readl_relaxed(reg);
573 		if (bank->regs->irqenable_inv)
574 			l &= ~gpio_mask;
575 		else
576 			l |= gpio_mask;
577 		bank->context.irqenable1 = l;
578 	}
579 
580 	writel_relaxed(l, reg);
581 }
582 
583 static void omap_disable_gpio_irqbank(struct gpio_bank *bank, int gpio_mask)
584 {
585 	void __iomem *reg = bank->base;
586 	u32 l;
587 
588 	if (bank->regs->clr_irqenable) {
589 		reg += bank->regs->clr_irqenable;
590 		l = gpio_mask;
591 		bank->context.irqenable1 &= ~gpio_mask;
592 	} else {
593 		reg += bank->regs->irqenable;
594 		l = readl_relaxed(reg);
595 		if (bank->regs->irqenable_inv)
596 			l |= gpio_mask;
597 		else
598 			l &= ~gpio_mask;
599 		bank->context.irqenable1 = l;
600 	}
601 
602 	writel_relaxed(l, reg);
603 }
604 
605 static inline void omap_set_gpio_irqenable(struct gpio_bank *bank,
606 					   unsigned offset, int enable)
607 {
608 	if (enable)
609 		omap_enable_gpio_irqbank(bank, BIT(offset));
610 	else
611 		omap_disable_gpio_irqbank(bank, BIT(offset));
612 }
613 
614 /* Use disable_irq_wake() and enable_irq_wake() functions from drivers */
615 static int omap_gpio_wake_enable(struct irq_data *d, unsigned int enable)
616 {
617 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
618 
619 	return irq_set_irq_wake(bank->irq, enable);
620 }
621 
622 static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
623 {
624 	struct gpio_bank *bank = gpiochip_get_data(chip);
625 	unsigned long flags;
626 
627 	/*
628 	 * If this is the first gpio_request for the bank,
629 	 * enable the bank module.
630 	 */
631 	if (!BANK_USED(bank))
632 		pm_runtime_get_sync(chip->parent);
633 
634 	raw_spin_lock_irqsave(&bank->lock, flags);
635 	omap_enable_gpio_module(bank, offset);
636 	bank->mod_usage |= BIT(offset);
637 	raw_spin_unlock_irqrestore(&bank->lock, flags);
638 
639 	return 0;
640 }
641 
642 static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)
643 {
644 	struct gpio_bank *bank = gpiochip_get_data(chip);
645 	unsigned long flags;
646 
647 	raw_spin_lock_irqsave(&bank->lock, flags);
648 	bank->mod_usage &= ~(BIT(offset));
649 	if (!LINE_USED(bank->irq_usage, offset)) {
650 		omap_set_gpio_direction(bank, offset, 1);
651 		omap_clear_gpio_debounce(bank, offset);
652 	}
653 	omap_disable_gpio_module(bank, offset);
654 	raw_spin_unlock_irqrestore(&bank->lock, flags);
655 
656 	/*
657 	 * If this is the last gpio to be freed in the bank,
658 	 * disable the bank module.
659 	 */
660 	if (!BANK_USED(bank))
661 		pm_runtime_put(chip->parent);
662 }
663 
664 /*
665  * We need to unmask the GPIO bank interrupt as soon as possible to
666  * avoid missing GPIO interrupts for other lines in the bank.
667  * Then we need to mask-read-clear-unmask the triggered GPIO lines
668  * in the bank to avoid missing nested interrupts for a GPIO line.
669  * If we wait to unmask individual GPIO lines in the bank after the
670  * line's interrupt handler has been run, we may miss some nested
671  * interrupts.
672  */
673 static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank)
674 {
675 	void __iomem *isr_reg = NULL;
676 	u32 isr;
677 	unsigned int bit;
678 	struct gpio_bank *bank = gpiobank;
679 	unsigned long wa_lock_flags;
680 	unsigned long lock_flags;
681 
682 	isr_reg = bank->base + bank->regs->irqstatus;
683 	if (WARN_ON(!isr_reg))
684 		goto exit;
685 
686 	pm_runtime_get_sync(bank->chip.parent);
687 
688 	while (1) {
689 		u32 isr_saved, level_mask = 0;
690 		u32 enabled;
691 
692 		raw_spin_lock_irqsave(&bank->lock, lock_flags);
693 
694 		enabled = omap_get_gpio_irqbank_mask(bank);
695 		isr_saved = isr = readl_relaxed(isr_reg) & enabled;
696 
697 		if (bank->level_mask)
698 			level_mask = bank->level_mask & enabled;
699 
700 		/* clear edge sensitive interrupts before handler(s) are
701 		called so that we don't miss any interrupt occurred while
702 		executing them */
703 		omap_disable_gpio_irqbank(bank, isr_saved & ~level_mask);
704 		omap_clear_gpio_irqbank(bank, isr_saved & ~level_mask);
705 		omap_enable_gpio_irqbank(bank, isr_saved & ~level_mask);
706 
707 		raw_spin_unlock_irqrestore(&bank->lock, lock_flags);
708 
709 		if (!isr)
710 			break;
711 
712 		while (isr) {
713 			bit = __ffs(isr);
714 			isr &= ~(BIT(bit));
715 
716 			raw_spin_lock_irqsave(&bank->lock, lock_flags);
717 			/*
718 			 * Some chips can't respond to both rising and falling
719 			 * at the same time.  If this irq was requested with
720 			 * both flags, we need to flip the ICR data for the IRQ
721 			 * to respond to the IRQ for the opposite direction.
722 			 * This will be indicated in the bank toggle_mask.
723 			 */
724 			if (bank->toggle_mask & (BIT(bit)))
725 				omap_toggle_gpio_edge_triggering(bank, bit);
726 
727 			raw_spin_unlock_irqrestore(&bank->lock, lock_flags);
728 
729 			raw_spin_lock_irqsave(&bank->wa_lock, wa_lock_flags);
730 
731 			generic_handle_irq(irq_find_mapping(bank->chip.irqdomain,
732 							    bit));
733 
734 			raw_spin_unlock_irqrestore(&bank->wa_lock,
735 						   wa_lock_flags);
736 		}
737 	}
738 exit:
739 	pm_runtime_put(bank->chip.parent);
740 	return IRQ_HANDLED;
741 }
742 
743 static unsigned int omap_gpio_irq_startup(struct irq_data *d)
744 {
745 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
746 	unsigned long flags;
747 	unsigned offset = d->hwirq;
748 
749 	raw_spin_lock_irqsave(&bank->lock, flags);
750 
751 	if (!LINE_USED(bank->mod_usage, offset))
752 		omap_set_gpio_direction(bank, offset, 1);
753 	else if (!omap_gpio_is_input(bank, offset))
754 		goto err;
755 	omap_enable_gpio_module(bank, offset);
756 	bank->irq_usage |= BIT(offset);
757 
758 	raw_spin_unlock_irqrestore(&bank->lock, flags);
759 	omap_gpio_unmask_irq(d);
760 
761 	return 0;
762 err:
763 	raw_spin_unlock_irqrestore(&bank->lock, flags);
764 	return -EINVAL;
765 }
766 
767 static void omap_gpio_irq_shutdown(struct irq_data *d)
768 {
769 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
770 	unsigned long flags;
771 	unsigned offset = d->hwirq;
772 
773 	raw_spin_lock_irqsave(&bank->lock, flags);
774 	bank->irq_usage &= ~(BIT(offset));
775 	omap_set_gpio_irqenable(bank, offset, 0);
776 	omap_clear_gpio_irqstatus(bank, offset);
777 	omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
778 	if (!LINE_USED(bank->mod_usage, offset))
779 		omap_clear_gpio_debounce(bank, offset);
780 	omap_disable_gpio_module(bank, offset);
781 	raw_spin_unlock_irqrestore(&bank->lock, flags);
782 }
783 
784 static void omap_gpio_irq_bus_lock(struct irq_data *data)
785 {
786 	struct gpio_bank *bank = omap_irq_data_get_bank(data);
787 
788 	if (!BANK_USED(bank))
789 		pm_runtime_get_sync(bank->chip.parent);
790 }
791 
792 static void gpio_irq_bus_sync_unlock(struct irq_data *data)
793 {
794 	struct gpio_bank *bank = omap_irq_data_get_bank(data);
795 
796 	/*
797 	 * If this is the last IRQ to be freed in the bank,
798 	 * disable the bank module.
799 	 */
800 	if (!BANK_USED(bank))
801 		pm_runtime_put(bank->chip.parent);
802 }
803 
804 static void omap_gpio_ack_irq(struct irq_data *d)
805 {
806 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
807 	unsigned offset = d->hwirq;
808 
809 	omap_clear_gpio_irqstatus(bank, offset);
810 }
811 
812 static void omap_gpio_mask_irq(struct irq_data *d)
813 {
814 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
815 	unsigned offset = d->hwirq;
816 	unsigned long flags;
817 
818 	raw_spin_lock_irqsave(&bank->lock, flags);
819 	omap_set_gpio_irqenable(bank, offset, 0);
820 	omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
821 	raw_spin_unlock_irqrestore(&bank->lock, flags);
822 }
823 
824 static void omap_gpio_unmask_irq(struct irq_data *d)
825 {
826 	struct gpio_bank *bank = omap_irq_data_get_bank(d);
827 	unsigned offset = d->hwirq;
828 	u32 trigger = irqd_get_trigger_type(d);
829 	unsigned long flags;
830 
831 	raw_spin_lock_irqsave(&bank->lock, flags);
832 	if (trigger)
833 		omap_set_gpio_triggering(bank, offset, trigger);
834 
835 	/* For level-triggered GPIOs, the clearing must be done after
836 	 * the HW source is cleared, thus after the handler has run */
837 	if (bank->level_mask & BIT(offset)) {
838 		omap_set_gpio_irqenable(bank, offset, 0);
839 		omap_clear_gpio_irqstatus(bank, offset);
840 	}
841 
842 	omap_set_gpio_irqenable(bank, offset, 1);
843 	raw_spin_unlock_irqrestore(&bank->lock, flags);
844 }
845 
846 /*---------------------------------------------------------------------*/
847 
848 static int omap_mpuio_suspend_noirq(struct device *dev)
849 {
850 	struct platform_device *pdev = to_platform_device(dev);
851 	struct gpio_bank	*bank = platform_get_drvdata(pdev);
852 	void __iomem		*mask_reg = bank->base +
853 					OMAP_MPUIO_GPIO_MASKIT / bank->stride;
854 	unsigned long		flags;
855 
856 	raw_spin_lock_irqsave(&bank->lock, flags);
857 	writel_relaxed(0xffff & ~bank->context.wake_en, mask_reg);
858 	raw_spin_unlock_irqrestore(&bank->lock, flags);
859 
860 	return 0;
861 }
862 
863 static int omap_mpuio_resume_noirq(struct device *dev)
864 {
865 	struct platform_device *pdev = to_platform_device(dev);
866 	struct gpio_bank	*bank = platform_get_drvdata(pdev);
867 	void __iomem		*mask_reg = bank->base +
868 					OMAP_MPUIO_GPIO_MASKIT / bank->stride;
869 	unsigned long		flags;
870 
871 	raw_spin_lock_irqsave(&bank->lock, flags);
872 	writel_relaxed(bank->context.wake_en, mask_reg);
873 	raw_spin_unlock_irqrestore(&bank->lock, flags);
874 
875 	return 0;
876 }
877 
878 static const struct dev_pm_ops omap_mpuio_dev_pm_ops = {
879 	.suspend_noirq = omap_mpuio_suspend_noirq,
880 	.resume_noirq = omap_mpuio_resume_noirq,
881 };
882 
883 /* use platform_driver for this. */
884 static struct platform_driver omap_mpuio_driver = {
885 	.driver		= {
886 		.name	= "mpuio",
887 		.pm	= &omap_mpuio_dev_pm_ops,
888 	},
889 };
890 
891 static struct platform_device omap_mpuio_device = {
892 	.name		= "mpuio",
893 	.id		= -1,
894 	.dev = {
895 		.driver = &omap_mpuio_driver.driver,
896 	}
897 	/* could list the /proc/iomem resources */
898 };
899 
900 static inline void omap_mpuio_init(struct gpio_bank *bank)
901 {
902 	platform_set_drvdata(&omap_mpuio_device, bank);
903 
904 	if (platform_driver_register(&omap_mpuio_driver) == 0)
905 		(void) platform_device_register(&omap_mpuio_device);
906 }
907 
908 /*---------------------------------------------------------------------*/
909 
910 static int omap_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
911 {
912 	struct gpio_bank *bank;
913 	unsigned long flags;
914 	void __iomem *reg;
915 	int dir;
916 
917 	bank = gpiochip_get_data(chip);
918 	reg = bank->base + bank->regs->direction;
919 	raw_spin_lock_irqsave(&bank->lock, flags);
920 	dir = !!(readl_relaxed(reg) & BIT(offset));
921 	raw_spin_unlock_irqrestore(&bank->lock, flags);
922 	return dir;
923 }
924 
925 static int omap_gpio_input(struct gpio_chip *chip, unsigned offset)
926 {
927 	struct gpio_bank *bank;
928 	unsigned long flags;
929 
930 	bank = gpiochip_get_data(chip);
931 	raw_spin_lock_irqsave(&bank->lock, flags);
932 	omap_set_gpio_direction(bank, offset, 1);
933 	raw_spin_unlock_irqrestore(&bank->lock, flags);
934 	return 0;
935 }
936 
937 static int omap_gpio_get(struct gpio_chip *chip, unsigned offset)
938 {
939 	struct gpio_bank *bank;
940 
941 	bank = gpiochip_get_data(chip);
942 
943 	if (omap_gpio_is_input(bank, offset))
944 		return omap_get_gpio_datain(bank, offset);
945 	else
946 		return omap_get_gpio_dataout(bank, offset);
947 }
948 
949 static int omap_gpio_output(struct gpio_chip *chip, unsigned offset, int value)
950 {
951 	struct gpio_bank *bank;
952 	unsigned long flags;
953 
954 	bank = gpiochip_get_data(chip);
955 	raw_spin_lock_irqsave(&bank->lock, flags);
956 	bank->set_dataout(bank, offset, value);
957 	omap_set_gpio_direction(bank, offset, 0);
958 	raw_spin_unlock_irqrestore(&bank->lock, flags);
959 	return 0;
960 }
961 
962 static int omap_gpio_debounce(struct gpio_chip *chip, unsigned offset,
963 			      unsigned debounce)
964 {
965 	struct gpio_bank *bank;
966 	unsigned long flags;
967 
968 	bank = gpiochip_get_data(chip);
969 
970 	raw_spin_lock_irqsave(&bank->lock, flags);
971 	omap2_set_gpio_debounce(bank, offset, debounce);
972 	raw_spin_unlock_irqrestore(&bank->lock, flags);
973 
974 	return 0;
975 }
976 
977 static int omap_gpio_set_config(struct gpio_chip *chip, unsigned offset,
978 				unsigned long config)
979 {
980 	u32 debounce;
981 
982 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
983 		return -ENOTSUPP;
984 
985 	debounce = pinconf_to_config_argument(config);
986 	return omap_gpio_debounce(chip, offset, debounce);
987 }
988 
989 static void omap_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
990 {
991 	struct gpio_bank *bank;
992 	unsigned long flags;
993 
994 	bank = gpiochip_get_data(chip);
995 	raw_spin_lock_irqsave(&bank->lock, flags);
996 	bank->set_dataout(bank, offset, value);
997 	raw_spin_unlock_irqrestore(&bank->lock, flags);
998 }
999 
1000 /*---------------------------------------------------------------------*/
1001 
1002 static void __init omap_gpio_show_rev(struct gpio_bank *bank)
1003 {
1004 	static bool called;
1005 	u32 rev;
1006 
1007 	if (called || bank->regs->revision == USHRT_MAX)
1008 		return;
1009 
1010 	rev = readw_relaxed(bank->base + bank->regs->revision);
1011 	pr_info("OMAP GPIO hardware version %d.%d\n",
1012 		(rev >> 4) & 0x0f, rev & 0x0f);
1013 
1014 	called = true;
1015 }
1016 
1017 static void omap_gpio_mod_init(struct gpio_bank *bank)
1018 {
1019 	void __iomem *base = bank->base;
1020 	u32 l = 0xffffffff;
1021 
1022 	if (bank->width == 16)
1023 		l = 0xffff;
1024 
1025 	if (bank->is_mpuio) {
1026 		writel_relaxed(l, bank->base + bank->regs->irqenable);
1027 		return;
1028 	}
1029 
1030 	omap_gpio_rmw(base, bank->regs->irqenable, l,
1031 		      bank->regs->irqenable_inv);
1032 	omap_gpio_rmw(base, bank->regs->irqstatus, l,
1033 		      !bank->regs->irqenable_inv);
1034 	if (bank->regs->debounce_en)
1035 		writel_relaxed(0, base + bank->regs->debounce_en);
1036 
1037 	/* Save OE default value (0xffffffff) in the context */
1038 	bank->context.oe = readl_relaxed(bank->base + bank->regs->direction);
1039 	 /* Initialize interface clk ungated, module enabled */
1040 	if (bank->regs->ctrl)
1041 		writel_relaxed(0, base + bank->regs->ctrl);
1042 }
1043 
1044 static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
1045 {
1046 	static int gpio;
1047 	int irq_base = 0;
1048 	int ret;
1049 
1050 	/*
1051 	 * REVISIT eventually switch from OMAP-specific gpio structs
1052 	 * over to the generic ones
1053 	 */
1054 	bank->chip.request = omap_gpio_request;
1055 	bank->chip.free = omap_gpio_free;
1056 	bank->chip.get_direction = omap_gpio_get_direction;
1057 	bank->chip.direction_input = omap_gpio_input;
1058 	bank->chip.get = omap_gpio_get;
1059 	bank->chip.direction_output = omap_gpio_output;
1060 	bank->chip.set_config = omap_gpio_set_config;
1061 	bank->chip.set = omap_gpio_set;
1062 	if (bank->is_mpuio) {
1063 		bank->chip.label = "mpuio";
1064 		if (bank->regs->wkup_en)
1065 			bank->chip.parent = &omap_mpuio_device.dev;
1066 		bank->chip.base = OMAP_MPUIO(0);
1067 	} else {
1068 		bank->chip.label = "gpio";
1069 		bank->chip.base = gpio;
1070 	}
1071 	bank->chip.ngpio = bank->width;
1072 
1073 	ret = gpiochip_add_data(&bank->chip, bank);
1074 	if (ret) {
1075 		dev_err(bank->chip.parent,
1076 			"Could not register gpio chip %d\n", ret);
1077 		return ret;
1078 	}
1079 
1080 	if (!bank->is_mpuio)
1081 		gpio += bank->width;
1082 
1083 #ifdef CONFIG_ARCH_OMAP1
1084 	/*
1085 	 * REVISIT: Once we have OMAP1 supporting SPARSE_IRQ, we can drop
1086 	 * irq_alloc_descs() since a base IRQ offset will no longer be needed.
1087 	 */
1088 	irq_base = irq_alloc_descs(-1, 0, bank->width, 0);
1089 	if (irq_base < 0) {
1090 		dev_err(bank->chip.parent, "Couldn't allocate IRQ numbers\n");
1091 		return -ENODEV;
1092 	}
1093 #endif
1094 
1095 	/* MPUIO is a bit different, reading IRQ status clears it */
1096 	if (bank->is_mpuio) {
1097 		irqc->irq_ack = dummy_irq_chip.irq_ack;
1098 		if (!bank->regs->wkup_en)
1099 			irqc->irq_set_wake = NULL;
1100 	}
1101 
1102 	ret = gpiochip_irqchip_add(&bank->chip, irqc,
1103 				   irq_base, handle_bad_irq,
1104 				   IRQ_TYPE_NONE);
1105 
1106 	if (ret) {
1107 		dev_err(bank->chip.parent,
1108 			"Couldn't add irqchip to gpiochip %d\n", ret);
1109 		gpiochip_remove(&bank->chip);
1110 		return -ENODEV;
1111 	}
1112 
1113 	gpiochip_set_chained_irqchip(&bank->chip, irqc, bank->irq, NULL);
1114 
1115 	ret = devm_request_irq(bank->chip.parent, bank->irq,
1116 			       omap_gpio_irq_handler,
1117 			       0, dev_name(bank->chip.parent), bank);
1118 	if (ret)
1119 		gpiochip_remove(&bank->chip);
1120 
1121 	return ret;
1122 }
1123 
1124 static const struct of_device_id omap_gpio_match[];
1125 
1126 static int omap_gpio_probe(struct platform_device *pdev)
1127 {
1128 	struct device *dev = &pdev->dev;
1129 	struct device_node *node = dev->of_node;
1130 	const struct of_device_id *match;
1131 	const struct omap_gpio_platform_data *pdata;
1132 	struct resource *res;
1133 	struct gpio_bank *bank;
1134 	struct irq_chip *irqc;
1135 	int ret;
1136 
1137 	match = of_match_device(of_match_ptr(omap_gpio_match), dev);
1138 
1139 	pdata = match ? match->data : dev_get_platdata(dev);
1140 	if (!pdata)
1141 		return -EINVAL;
1142 
1143 	bank = devm_kzalloc(dev, sizeof(struct gpio_bank), GFP_KERNEL);
1144 	if (!bank) {
1145 		dev_err(dev, "Memory alloc failed\n");
1146 		return -ENOMEM;
1147 	}
1148 
1149 	irqc = devm_kzalloc(dev, sizeof(*irqc), GFP_KERNEL);
1150 	if (!irqc)
1151 		return -ENOMEM;
1152 
1153 	irqc->irq_startup = omap_gpio_irq_startup,
1154 	irqc->irq_shutdown = omap_gpio_irq_shutdown,
1155 	irqc->irq_ack = omap_gpio_ack_irq,
1156 	irqc->irq_mask = omap_gpio_mask_irq,
1157 	irqc->irq_unmask = omap_gpio_unmask_irq,
1158 	irqc->irq_set_type = omap_gpio_irq_type,
1159 	irqc->irq_set_wake = omap_gpio_wake_enable,
1160 	irqc->irq_bus_lock = omap_gpio_irq_bus_lock,
1161 	irqc->irq_bus_sync_unlock = gpio_irq_bus_sync_unlock,
1162 	irqc->name = dev_name(&pdev->dev);
1163 	irqc->flags = IRQCHIP_MASK_ON_SUSPEND;
1164 
1165 	bank->irq = platform_get_irq(pdev, 0);
1166 	if (bank->irq <= 0) {
1167 		if (!bank->irq)
1168 			bank->irq = -ENXIO;
1169 		if (bank->irq != -EPROBE_DEFER)
1170 			dev_err(dev,
1171 				"can't get irq resource ret=%d\n", bank->irq);
1172 		return bank->irq;
1173 	}
1174 
1175 	bank->chip.parent = dev;
1176 	bank->chip.owner = THIS_MODULE;
1177 	bank->dbck_flag = pdata->dbck_flag;
1178 	bank->stride = pdata->bank_stride;
1179 	bank->width = pdata->bank_width;
1180 	bank->is_mpuio = pdata->is_mpuio;
1181 	bank->non_wakeup_gpios = pdata->non_wakeup_gpios;
1182 	bank->regs = pdata->regs;
1183 #ifdef CONFIG_OF_GPIO
1184 	bank->chip.of_node = of_node_get(node);
1185 #endif
1186 	if (node) {
1187 		if (!of_property_read_bool(node, "ti,gpio-always-on"))
1188 			bank->loses_context = true;
1189 	} else {
1190 		bank->loses_context = pdata->loses_context;
1191 
1192 		if (bank->loses_context)
1193 			bank->get_context_loss_count =
1194 				pdata->get_context_loss_count;
1195 	}
1196 
1197 	if (bank->regs->set_dataout && bank->regs->clr_dataout)
1198 		bank->set_dataout = omap_set_gpio_dataout_reg;
1199 	else
1200 		bank->set_dataout = omap_set_gpio_dataout_mask;
1201 
1202 	raw_spin_lock_init(&bank->lock);
1203 	raw_spin_lock_init(&bank->wa_lock);
1204 
1205 	/* Static mapping, never released */
1206 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1207 	bank->base = devm_ioremap_resource(dev, res);
1208 	if (IS_ERR(bank->base)) {
1209 		return PTR_ERR(bank->base);
1210 	}
1211 
1212 	if (bank->dbck_flag) {
1213 		bank->dbck = devm_clk_get(dev, "dbclk");
1214 		if (IS_ERR(bank->dbck)) {
1215 			dev_err(dev,
1216 				"Could not get gpio dbck. Disable debounce\n");
1217 			bank->dbck_flag = false;
1218 		} else {
1219 			clk_prepare(bank->dbck);
1220 		}
1221 	}
1222 
1223 	platform_set_drvdata(pdev, bank);
1224 
1225 	pm_runtime_enable(dev);
1226 	pm_runtime_irq_safe(dev);
1227 	pm_runtime_get_sync(dev);
1228 
1229 	if (bank->is_mpuio)
1230 		omap_mpuio_init(bank);
1231 
1232 	omap_gpio_mod_init(bank);
1233 
1234 	ret = omap_gpio_chip_init(bank, irqc);
1235 	if (ret) {
1236 		pm_runtime_put_sync(dev);
1237 		pm_runtime_disable(dev);
1238 		return ret;
1239 	}
1240 
1241 	omap_gpio_show_rev(bank);
1242 
1243 	pm_runtime_put(dev);
1244 
1245 	list_add_tail(&bank->node, &omap_gpio_list);
1246 
1247 	return 0;
1248 }
1249 
1250 static int omap_gpio_remove(struct platform_device *pdev)
1251 {
1252 	struct gpio_bank *bank = platform_get_drvdata(pdev);
1253 
1254 	list_del(&bank->node);
1255 	gpiochip_remove(&bank->chip);
1256 	pm_runtime_disable(&pdev->dev);
1257 	if (bank->dbck_flag)
1258 		clk_unprepare(bank->dbck);
1259 
1260 	return 0;
1261 }
1262 
1263 #ifdef CONFIG_ARCH_OMAP2PLUS
1264 
1265 #if defined(CONFIG_PM)
1266 static void omap_gpio_restore_context(struct gpio_bank *bank);
1267 
1268 static int omap_gpio_runtime_suspend(struct device *dev)
1269 {
1270 	struct platform_device *pdev = to_platform_device(dev);
1271 	struct gpio_bank *bank = platform_get_drvdata(pdev);
1272 	u32 l1 = 0, l2 = 0;
1273 	unsigned long flags;
1274 	u32 wake_low, wake_hi;
1275 
1276 	raw_spin_lock_irqsave(&bank->lock, flags);
1277 
1278 	/*
1279 	 * Only edges can generate a wakeup event to the PRCM.
1280 	 *
1281 	 * Therefore, ensure any wake-up capable GPIOs have
1282 	 * edge-detection enabled before going idle to ensure a wakeup
1283 	 * to the PRCM is generated on a GPIO transition. (c.f. 34xx
1284 	 * NDA TRM 25.5.3.1)
1285 	 *
1286 	 * The normal values will be restored upon ->runtime_resume()
1287 	 * by writing back the values saved in bank->context.
1288 	 */
1289 	wake_low = bank->context.leveldetect0 & bank->context.wake_en;
1290 	if (wake_low)
1291 		writel_relaxed(wake_low | bank->context.fallingdetect,
1292 			     bank->base + bank->regs->fallingdetect);
1293 	wake_hi = bank->context.leveldetect1 & bank->context.wake_en;
1294 	if (wake_hi)
1295 		writel_relaxed(wake_hi | bank->context.risingdetect,
1296 			     bank->base + bank->regs->risingdetect);
1297 
1298 	if (!bank->enabled_non_wakeup_gpios)
1299 		goto update_gpio_context_count;
1300 
1301 	if (bank->power_mode != OFF_MODE) {
1302 		bank->power_mode = 0;
1303 		goto update_gpio_context_count;
1304 	}
1305 	/*
1306 	 * If going to OFF, remove triggering for all
1307 	 * non-wakeup GPIOs.  Otherwise spurious IRQs will be
1308 	 * generated.  See OMAP2420 Errata item 1.101.
1309 	 */
1310 	bank->saved_datain = readl_relaxed(bank->base +
1311 						bank->regs->datain);
1312 	l1 = bank->context.fallingdetect;
1313 	l2 = bank->context.risingdetect;
1314 
1315 	l1 &= ~bank->enabled_non_wakeup_gpios;
1316 	l2 &= ~bank->enabled_non_wakeup_gpios;
1317 
1318 	writel_relaxed(l1, bank->base + bank->regs->fallingdetect);
1319 	writel_relaxed(l2, bank->base + bank->regs->risingdetect);
1320 
1321 	bank->workaround_enabled = true;
1322 
1323 update_gpio_context_count:
1324 	if (bank->get_context_loss_count)
1325 		bank->context_loss_count =
1326 				bank->get_context_loss_count(dev);
1327 
1328 	omap_gpio_dbck_disable(bank);
1329 	raw_spin_unlock_irqrestore(&bank->lock, flags);
1330 
1331 	return 0;
1332 }
1333 
1334 static void omap_gpio_init_context(struct gpio_bank *p);
1335 
1336 static int omap_gpio_runtime_resume(struct device *dev)
1337 {
1338 	struct platform_device *pdev = to_platform_device(dev);
1339 	struct gpio_bank *bank = platform_get_drvdata(pdev);
1340 	u32 l = 0, gen, gen0, gen1;
1341 	unsigned long flags;
1342 	int c;
1343 
1344 	raw_spin_lock_irqsave(&bank->lock, flags);
1345 
1346 	/*
1347 	 * On the first resume during the probe, the context has not
1348 	 * been initialised and so initialise it now. Also initialise
1349 	 * the context loss count.
1350 	 */
1351 	if (bank->loses_context && !bank->context_valid) {
1352 		omap_gpio_init_context(bank);
1353 
1354 		if (bank->get_context_loss_count)
1355 			bank->context_loss_count =
1356 				bank->get_context_loss_count(dev);
1357 	}
1358 
1359 	omap_gpio_dbck_enable(bank);
1360 
1361 	/*
1362 	 * In ->runtime_suspend(), level-triggered, wakeup-enabled
1363 	 * GPIOs were set to edge trigger also in order to be able to
1364 	 * generate a PRCM wakeup.  Here we restore the
1365 	 * pre-runtime_suspend() values for edge triggering.
1366 	 */
1367 	writel_relaxed(bank->context.fallingdetect,
1368 		     bank->base + bank->regs->fallingdetect);
1369 	writel_relaxed(bank->context.risingdetect,
1370 		     bank->base + bank->regs->risingdetect);
1371 
1372 	if (bank->loses_context) {
1373 		if (!bank->get_context_loss_count) {
1374 			omap_gpio_restore_context(bank);
1375 		} else {
1376 			c = bank->get_context_loss_count(dev);
1377 			if (c != bank->context_loss_count) {
1378 				omap_gpio_restore_context(bank);
1379 			} else {
1380 				raw_spin_unlock_irqrestore(&bank->lock, flags);
1381 				return 0;
1382 			}
1383 		}
1384 	}
1385 
1386 	if (!bank->workaround_enabled) {
1387 		raw_spin_unlock_irqrestore(&bank->lock, flags);
1388 		return 0;
1389 	}
1390 
1391 	l = readl_relaxed(bank->base + bank->regs->datain);
1392 
1393 	/*
1394 	 * Check if any of the non-wakeup interrupt GPIOs have changed
1395 	 * state.  If so, generate an IRQ by software.  This is
1396 	 * horribly racy, but it's the best we can do to work around
1397 	 * this silicon bug.
1398 	 */
1399 	l ^= bank->saved_datain;
1400 	l &= bank->enabled_non_wakeup_gpios;
1401 
1402 	/*
1403 	 * No need to generate IRQs for the rising edge for gpio IRQs
1404 	 * configured with falling edge only; and vice versa.
1405 	 */
1406 	gen0 = l & bank->context.fallingdetect;
1407 	gen0 &= bank->saved_datain;
1408 
1409 	gen1 = l & bank->context.risingdetect;
1410 	gen1 &= ~(bank->saved_datain);
1411 
1412 	/* FIXME: Consider GPIO IRQs with level detections properly! */
1413 	gen = l & (~(bank->context.fallingdetect) &
1414 					 ~(bank->context.risingdetect));
1415 	/* Consider all GPIO IRQs needed to be updated */
1416 	gen |= gen0 | gen1;
1417 
1418 	if (gen) {
1419 		u32 old0, old1;
1420 
1421 		old0 = readl_relaxed(bank->base + bank->regs->leveldetect0);
1422 		old1 = readl_relaxed(bank->base + bank->regs->leveldetect1);
1423 
1424 		if (!bank->regs->irqstatus_raw0) {
1425 			writel_relaxed(old0 | gen, bank->base +
1426 						bank->regs->leveldetect0);
1427 			writel_relaxed(old1 | gen, bank->base +
1428 						bank->regs->leveldetect1);
1429 		}
1430 
1431 		if (bank->regs->irqstatus_raw0) {
1432 			writel_relaxed(old0 | l, bank->base +
1433 						bank->regs->leveldetect0);
1434 			writel_relaxed(old1 | l, bank->base +
1435 						bank->regs->leveldetect1);
1436 		}
1437 		writel_relaxed(old0, bank->base + bank->regs->leveldetect0);
1438 		writel_relaxed(old1, bank->base + bank->regs->leveldetect1);
1439 	}
1440 
1441 	bank->workaround_enabled = false;
1442 	raw_spin_unlock_irqrestore(&bank->lock, flags);
1443 
1444 	return 0;
1445 }
1446 #endif /* CONFIG_PM */
1447 
1448 #if IS_BUILTIN(CONFIG_GPIO_OMAP)
1449 void omap2_gpio_prepare_for_idle(int pwr_mode)
1450 {
1451 	struct gpio_bank *bank;
1452 
1453 	list_for_each_entry(bank, &omap_gpio_list, node) {
1454 		if (!BANK_USED(bank) || !bank->loses_context)
1455 			continue;
1456 
1457 		bank->power_mode = pwr_mode;
1458 
1459 		pm_runtime_put_sync_suspend(bank->chip.parent);
1460 	}
1461 }
1462 
1463 void omap2_gpio_resume_after_idle(void)
1464 {
1465 	struct gpio_bank *bank;
1466 
1467 	list_for_each_entry(bank, &omap_gpio_list, node) {
1468 		if (!BANK_USED(bank) || !bank->loses_context)
1469 			continue;
1470 
1471 		pm_runtime_get_sync(bank->chip.parent);
1472 	}
1473 }
1474 #endif
1475 
1476 #if defined(CONFIG_PM)
1477 static void omap_gpio_init_context(struct gpio_bank *p)
1478 {
1479 	struct omap_gpio_reg_offs *regs = p->regs;
1480 	void __iomem *base = p->base;
1481 
1482 	p->context.ctrl		= readl_relaxed(base + regs->ctrl);
1483 	p->context.oe		= readl_relaxed(base + regs->direction);
1484 	p->context.wake_en	= readl_relaxed(base + regs->wkup_en);
1485 	p->context.leveldetect0	= readl_relaxed(base + regs->leveldetect0);
1486 	p->context.leveldetect1	= readl_relaxed(base + regs->leveldetect1);
1487 	p->context.risingdetect	= readl_relaxed(base + regs->risingdetect);
1488 	p->context.fallingdetect = readl_relaxed(base + regs->fallingdetect);
1489 	p->context.irqenable1	= readl_relaxed(base + regs->irqenable);
1490 	p->context.irqenable2	= readl_relaxed(base + regs->irqenable2);
1491 
1492 	if (regs->set_dataout && p->regs->clr_dataout)
1493 		p->context.dataout = readl_relaxed(base + regs->set_dataout);
1494 	else
1495 		p->context.dataout = readl_relaxed(base + regs->dataout);
1496 
1497 	p->context_valid = true;
1498 }
1499 
1500 static void omap_gpio_restore_context(struct gpio_bank *bank)
1501 {
1502 	writel_relaxed(bank->context.wake_en,
1503 				bank->base + bank->regs->wkup_en);
1504 	writel_relaxed(bank->context.ctrl, bank->base + bank->regs->ctrl);
1505 	writel_relaxed(bank->context.leveldetect0,
1506 				bank->base + bank->regs->leveldetect0);
1507 	writel_relaxed(bank->context.leveldetect1,
1508 				bank->base + bank->regs->leveldetect1);
1509 	writel_relaxed(bank->context.risingdetect,
1510 				bank->base + bank->regs->risingdetect);
1511 	writel_relaxed(bank->context.fallingdetect,
1512 				bank->base + bank->regs->fallingdetect);
1513 	if (bank->regs->set_dataout && bank->regs->clr_dataout)
1514 		writel_relaxed(bank->context.dataout,
1515 				bank->base + bank->regs->set_dataout);
1516 	else
1517 		writel_relaxed(bank->context.dataout,
1518 				bank->base + bank->regs->dataout);
1519 	writel_relaxed(bank->context.oe, bank->base + bank->regs->direction);
1520 
1521 	if (bank->dbck_enable_mask) {
1522 		writel_relaxed(bank->context.debounce, bank->base +
1523 					bank->regs->debounce);
1524 		writel_relaxed(bank->context.debounce_en,
1525 					bank->base + bank->regs->debounce_en);
1526 	}
1527 
1528 	writel_relaxed(bank->context.irqenable1,
1529 				bank->base + bank->regs->irqenable);
1530 	writel_relaxed(bank->context.irqenable2,
1531 				bank->base + bank->regs->irqenable2);
1532 }
1533 #endif /* CONFIG_PM */
1534 #else
1535 #define omap_gpio_runtime_suspend NULL
1536 #define omap_gpio_runtime_resume NULL
1537 static inline void omap_gpio_init_context(struct gpio_bank *p) {}
1538 #endif
1539 
1540 static const struct dev_pm_ops gpio_pm_ops = {
1541 	SET_RUNTIME_PM_OPS(omap_gpio_runtime_suspend, omap_gpio_runtime_resume,
1542 									NULL)
1543 };
1544 
1545 #if defined(CONFIG_OF)
1546 static struct omap_gpio_reg_offs omap2_gpio_regs = {
1547 	.revision =		OMAP24XX_GPIO_REVISION,
1548 	.direction =		OMAP24XX_GPIO_OE,
1549 	.datain =		OMAP24XX_GPIO_DATAIN,
1550 	.dataout =		OMAP24XX_GPIO_DATAOUT,
1551 	.set_dataout =		OMAP24XX_GPIO_SETDATAOUT,
1552 	.clr_dataout =		OMAP24XX_GPIO_CLEARDATAOUT,
1553 	.irqstatus =		OMAP24XX_GPIO_IRQSTATUS1,
1554 	.irqstatus2 =		OMAP24XX_GPIO_IRQSTATUS2,
1555 	.irqenable =		OMAP24XX_GPIO_IRQENABLE1,
1556 	.irqenable2 =		OMAP24XX_GPIO_IRQENABLE2,
1557 	.set_irqenable =	OMAP24XX_GPIO_SETIRQENABLE1,
1558 	.clr_irqenable =	OMAP24XX_GPIO_CLEARIRQENABLE1,
1559 	.debounce =		OMAP24XX_GPIO_DEBOUNCE_VAL,
1560 	.debounce_en =		OMAP24XX_GPIO_DEBOUNCE_EN,
1561 	.ctrl =			OMAP24XX_GPIO_CTRL,
1562 	.wkup_en =		OMAP24XX_GPIO_WAKE_EN,
1563 	.leveldetect0 =		OMAP24XX_GPIO_LEVELDETECT0,
1564 	.leveldetect1 =		OMAP24XX_GPIO_LEVELDETECT1,
1565 	.risingdetect =		OMAP24XX_GPIO_RISINGDETECT,
1566 	.fallingdetect =	OMAP24XX_GPIO_FALLINGDETECT,
1567 };
1568 
1569 static struct omap_gpio_reg_offs omap4_gpio_regs = {
1570 	.revision =		OMAP4_GPIO_REVISION,
1571 	.direction =		OMAP4_GPIO_OE,
1572 	.datain =		OMAP4_GPIO_DATAIN,
1573 	.dataout =		OMAP4_GPIO_DATAOUT,
1574 	.set_dataout =		OMAP4_GPIO_SETDATAOUT,
1575 	.clr_dataout =		OMAP4_GPIO_CLEARDATAOUT,
1576 	.irqstatus =		OMAP4_GPIO_IRQSTATUS0,
1577 	.irqstatus2 =		OMAP4_GPIO_IRQSTATUS1,
1578 	.irqenable =		OMAP4_GPIO_IRQSTATUSSET0,
1579 	.irqenable2 =		OMAP4_GPIO_IRQSTATUSSET1,
1580 	.set_irqenable =	OMAP4_GPIO_IRQSTATUSSET0,
1581 	.clr_irqenable =	OMAP4_GPIO_IRQSTATUSCLR0,
1582 	.debounce =		OMAP4_GPIO_DEBOUNCINGTIME,
1583 	.debounce_en =		OMAP4_GPIO_DEBOUNCENABLE,
1584 	.ctrl =			OMAP4_GPIO_CTRL,
1585 	.wkup_en =		OMAP4_GPIO_IRQWAKEN0,
1586 	.leveldetect0 =		OMAP4_GPIO_LEVELDETECT0,
1587 	.leveldetect1 =		OMAP4_GPIO_LEVELDETECT1,
1588 	.risingdetect =		OMAP4_GPIO_RISINGDETECT,
1589 	.fallingdetect =	OMAP4_GPIO_FALLINGDETECT,
1590 };
1591 
1592 static const struct omap_gpio_platform_data omap2_pdata = {
1593 	.regs = &omap2_gpio_regs,
1594 	.bank_width = 32,
1595 	.dbck_flag = false,
1596 };
1597 
1598 static const struct omap_gpio_platform_data omap3_pdata = {
1599 	.regs = &omap2_gpio_regs,
1600 	.bank_width = 32,
1601 	.dbck_flag = true,
1602 };
1603 
1604 static const struct omap_gpio_platform_data omap4_pdata = {
1605 	.regs = &omap4_gpio_regs,
1606 	.bank_width = 32,
1607 	.dbck_flag = true,
1608 };
1609 
1610 static const struct of_device_id omap_gpio_match[] = {
1611 	{
1612 		.compatible = "ti,omap4-gpio",
1613 		.data = &omap4_pdata,
1614 	},
1615 	{
1616 		.compatible = "ti,omap3-gpio",
1617 		.data = &omap3_pdata,
1618 	},
1619 	{
1620 		.compatible = "ti,omap2-gpio",
1621 		.data = &omap2_pdata,
1622 	},
1623 	{ },
1624 };
1625 MODULE_DEVICE_TABLE(of, omap_gpio_match);
1626 #endif
1627 
1628 static struct platform_driver omap_gpio_driver = {
1629 	.probe		= omap_gpio_probe,
1630 	.remove		= omap_gpio_remove,
1631 	.driver		= {
1632 		.name	= "omap_gpio",
1633 		.pm	= &gpio_pm_ops,
1634 		.of_match_table = of_match_ptr(omap_gpio_match),
1635 	},
1636 };
1637 
1638 /*
1639  * gpio driver register needs to be done before
1640  * machine_init functions access gpio APIs.
1641  * Hence omap_gpio_drv_reg() is a postcore_initcall.
1642  */
1643 static int __init omap_gpio_drv_reg(void)
1644 {
1645 	return platform_driver_register(&omap_gpio_driver);
1646 }
1647 postcore_initcall(omap_gpio_drv_reg);
1648 
1649 static void __exit omap_gpio_exit(void)
1650 {
1651 	platform_driver_unregister(&omap_gpio_driver);
1652 }
1653 module_exit(omap_gpio_exit);
1654 
1655 MODULE_DESCRIPTION("omap gpio driver");
1656 MODULE_ALIAS("platform:gpio-omap");
1657 MODULE_LICENSE("GPL v2");
1658