xref: /openbmc/linux/drivers/gpio/gpio-mmio.c (revision cfbb9be8)
1 /*
2  * Generic driver for memory-mapped GPIO controllers.
3  *
4  * Copyright 2008 MontaVista Software, Inc.
5  * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  *
12  * ....``.```~~~~````.`.`.`.`.```````'',,,.........`````......`.......
13  * ...``                                                         ```````..
14  * ..The simplest form of a GPIO controller that the driver supports is``
15  *  `.just a single "data" register, where GPIO state can be read and/or `
16  *    `,..written. ,,..``~~~~ .....``.`.`.~~.```.`.........``````.```````
17  *        `````````
18                                     ___
19 _/~~|___/~|   . ```~~~~~~       ___/___\___     ,~.`.`.`.`````.~~...,,,,...
20 __________|~$@~~~        %~    /o*o*o*o*o*o\   .. Implementing such a GPIO .
21 o        `                     ~~~~\___/~~~~    ` controller in FPGA is ,.`
22                                                  `....trivial..'~`.```.```
23  *                                                    ```````
24  *  .```````~~~~`..`.``.``.
25  * .  The driver supports  `...       ,..```.`~~~```````````````....````.``,,
26  * .   big-endian notation, just`.  .. A bit more sophisticated controllers ,
27  *  . register the device with -be`. .with a pair of set/clear-bit registers ,
28  *   `.. suffix.  ```~~`````....`.`   . affecting the data register and the .`
29  *     ``.`.``...```                  ```.. output pins are also supported.`
30  *                        ^^             `````.`````````.,``~``~``~~``````
31  *                                                   .                  ^^
32  *   ,..`.`.`...````````````......`.`.`.`.`.`..`.`.`..
33  * .. The expectation is that in at least some cases .    ,-~~~-,
34  *  .this will be used with roll-your-own ASIC/FPGA .`     \   /
35  *  .logic in Verilog or VHDL. ~~~`````````..`````~~`       \ /
36  *  ..````````......```````````                             \o_
37  *                                                           |
38  *                              ^^                          / \
39  *
40  *           ...`````~~`.....``.`..........``````.`.``.```........``.
41  *            `  8, 16, 32 and 64 bits registers are supported, and``.
42  *            . the number of GPIOs is determined by the width of   ~
43  *             .. the registers. ,............```.`.`..`.`.~~~.`.`.`~
44  *               `.......````.```
45  */
46 
47 #include <linux/init.h>
48 #include <linux/err.h>
49 #include <linux/bug.h>
50 #include <linux/kernel.h>
51 #include <linux/module.h>
52 #include <linux/spinlock.h>
53 #include <linux/compiler.h>
54 #include <linux/types.h>
55 #include <linux/errno.h>
56 #include <linux/log2.h>
57 #include <linux/ioport.h>
58 #include <linux/io.h>
59 #include <linux/gpio/driver.h>
60 #include <linux/slab.h>
61 #include <linux/bitops.h>
62 #include <linux/platform_device.h>
63 #include <linux/mod_devicetable.h>
64 #include <linux/of.h>
65 #include <linux/of_device.h>
66 
67 static void bgpio_write8(void __iomem *reg, unsigned long data)
68 {
69 	writeb(data, reg);
70 }
71 
72 static unsigned long bgpio_read8(void __iomem *reg)
73 {
74 	return readb(reg);
75 }
76 
77 static void bgpio_write16(void __iomem *reg, unsigned long data)
78 {
79 	writew(data, reg);
80 }
81 
82 static unsigned long bgpio_read16(void __iomem *reg)
83 {
84 	return readw(reg);
85 }
86 
87 static void bgpio_write32(void __iomem *reg, unsigned long data)
88 {
89 	writel(data, reg);
90 }
91 
92 static unsigned long bgpio_read32(void __iomem *reg)
93 {
94 	return readl(reg);
95 }
96 
97 #if BITS_PER_LONG >= 64
98 static void bgpio_write64(void __iomem *reg, unsigned long data)
99 {
100 	writeq(data, reg);
101 }
102 
103 static unsigned long bgpio_read64(void __iomem *reg)
104 {
105 	return readq(reg);
106 }
107 #endif /* BITS_PER_LONG >= 64 */
108 
109 static void bgpio_write16be(void __iomem *reg, unsigned long data)
110 {
111 	iowrite16be(data, reg);
112 }
113 
114 static unsigned long bgpio_read16be(void __iomem *reg)
115 {
116 	return ioread16be(reg);
117 }
118 
119 static void bgpio_write32be(void __iomem *reg, unsigned long data)
120 {
121 	iowrite32be(data, reg);
122 }
123 
124 static unsigned long bgpio_read32be(void __iomem *reg)
125 {
126 	return ioread32be(reg);
127 }
128 
129 static unsigned long bgpio_line2mask(struct gpio_chip *gc, unsigned int line)
130 {
131 	if (gc->be_bits)
132 		return BIT(gc->bgpio_bits - 1 - line);
133 	return BIT(line);
134 }
135 
136 static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
137 {
138 	unsigned long pinmask = bgpio_line2mask(gc, gpio);
139 
140 	if (gc->bgpio_dir & pinmask)
141 		return !!(gc->read_reg(gc->reg_set) & pinmask);
142 	else
143 		return !!(gc->read_reg(gc->reg_dat) & pinmask);
144 }
145 
146 /*
147  * This assumes that the bits in the GPIO register are in native endianness.
148  * We only assign the function pointer if we have that.
149  */
150 static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
151 				  unsigned long *bits)
152 {
153 	unsigned long get_mask = 0;
154 	unsigned long set_mask = 0;
155 
156 	/* Make sure we first clear any bits that are zero when we read the register */
157 	*bits &= ~*mask;
158 
159 	/* Exploit the fact that we know which directions are set */
160 	set_mask = *mask & gc->bgpio_dir;
161 	get_mask = *mask & ~gc->bgpio_dir;
162 
163 	if (set_mask)
164 		*bits |= gc->read_reg(gc->reg_set) & set_mask;
165 	if (get_mask)
166 		*bits |= gc->read_reg(gc->reg_dat) & get_mask;
167 
168 	return 0;
169 }
170 
171 static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
172 {
173 	return !!(gc->read_reg(gc->reg_dat) & bgpio_line2mask(gc, gpio));
174 }
175 
176 /*
177  * This only works if the bits in the GPIO register are in native endianness.
178  */
179 static int bgpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
180 			      unsigned long *bits)
181 {
182 	/* Make sure we first clear any bits that are zero when we read the register */
183 	*bits &= ~*mask;
184 	*bits |= gc->read_reg(gc->reg_dat) & *mask;
185 	return 0;
186 }
187 
188 /*
189  * With big endian mirrored bit order it becomes more tedious.
190  */
191 static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask,
192 				 unsigned long *bits)
193 {
194 	unsigned long readmask = 0;
195 	unsigned long val;
196 	int bit;
197 
198 	/* Make sure we first clear any bits that are zero when we read the register */
199 	*bits &= ~*mask;
200 
201 	/* Create a mirrored mask */
202 	bit = -1;
203 	while ((bit = find_next_bit(mask, gc->ngpio, bit + 1)) < gc->ngpio)
204 		readmask |= bgpio_line2mask(gc, bit);
205 
206 	/* Read the register */
207 	val = gc->read_reg(gc->reg_dat) & readmask;
208 
209 	/*
210 	 * Mirror the result into the "bits" result, this will give line 0
211 	 * in bit 0 ... line 31 in bit 31 for a 32bit register.
212 	 */
213 	bit = -1;
214 	while ((bit = find_next_bit(&val, gc->ngpio, bit + 1)) < gc->ngpio)
215 		*bits |= bgpio_line2mask(gc, bit);
216 
217 	return 0;
218 }
219 
220 static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
221 {
222 }
223 
224 static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
225 {
226 	unsigned long mask = bgpio_line2mask(gc, gpio);
227 	unsigned long flags;
228 
229 	spin_lock_irqsave(&gc->bgpio_lock, flags);
230 
231 	if (val)
232 		gc->bgpio_data |= mask;
233 	else
234 		gc->bgpio_data &= ~mask;
235 
236 	gc->write_reg(gc->reg_dat, gc->bgpio_data);
237 
238 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
239 }
240 
241 static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
242 				 int val)
243 {
244 	unsigned long mask = bgpio_line2mask(gc, gpio);
245 
246 	if (val)
247 		gc->write_reg(gc->reg_set, mask);
248 	else
249 		gc->write_reg(gc->reg_clr, mask);
250 }
251 
252 static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
253 {
254 	unsigned long mask = bgpio_line2mask(gc, gpio);
255 	unsigned long flags;
256 
257 	spin_lock_irqsave(&gc->bgpio_lock, flags);
258 
259 	if (val)
260 		gc->bgpio_data |= mask;
261 	else
262 		gc->bgpio_data &= ~mask;
263 
264 	gc->write_reg(gc->reg_set, gc->bgpio_data);
265 
266 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
267 }
268 
269 static void bgpio_multiple_get_masks(struct gpio_chip *gc,
270 				     unsigned long *mask, unsigned long *bits,
271 				     unsigned long *set_mask,
272 				     unsigned long *clear_mask)
273 {
274 	int i;
275 
276 	*set_mask = 0;
277 	*clear_mask = 0;
278 
279 	for (i = 0; i < gc->bgpio_bits; i++) {
280 		if (*mask == 0)
281 			break;
282 		if (__test_and_clear_bit(i, mask)) {
283 			if (test_bit(i, bits))
284 				*set_mask |= bgpio_line2mask(gc, i);
285 			else
286 				*clear_mask |= bgpio_line2mask(gc, i);
287 		}
288 	}
289 }
290 
291 static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
292 					  unsigned long *mask,
293 					  unsigned long *bits,
294 					  void __iomem *reg)
295 {
296 	unsigned long flags;
297 	unsigned long set_mask, clear_mask;
298 
299 	spin_lock_irqsave(&gc->bgpio_lock, flags);
300 
301 	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
302 
303 	gc->bgpio_data |= set_mask;
304 	gc->bgpio_data &= ~clear_mask;
305 
306 	gc->write_reg(reg, gc->bgpio_data);
307 
308 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
309 }
310 
311 static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
312 			       unsigned long *bits)
313 {
314 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
315 }
316 
317 static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
318 				   unsigned long *bits)
319 {
320 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
321 }
322 
323 static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
324 					  unsigned long *mask,
325 					  unsigned long *bits)
326 {
327 	unsigned long set_mask, clear_mask;
328 
329 	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
330 
331 	if (set_mask)
332 		gc->write_reg(gc->reg_set, set_mask);
333 	if (clear_mask)
334 		gc->write_reg(gc->reg_clr, clear_mask);
335 }
336 
337 static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
338 {
339 	return 0;
340 }
341 
342 static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
343 				int val)
344 {
345 	return -EINVAL;
346 }
347 
348 static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
349 				int val)
350 {
351 	gc->set(gc, gpio, val);
352 
353 	return 0;
354 }
355 
356 static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
357 {
358 	unsigned long flags;
359 
360 	spin_lock_irqsave(&gc->bgpio_lock, flags);
361 
362 	gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
363 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
364 
365 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
366 
367 	return 0;
368 }
369 
370 static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
371 {
372 	/* Return 0 if output, 1 of input */
373 	return !(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
374 }
375 
376 static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
377 {
378 	unsigned long flags;
379 
380 	gc->set(gc, gpio, val);
381 
382 	spin_lock_irqsave(&gc->bgpio_lock, flags);
383 
384 	gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
385 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
386 
387 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
388 
389 	return 0;
390 }
391 
392 static int bgpio_dir_in_inv(struct gpio_chip *gc, unsigned int gpio)
393 {
394 	unsigned long flags;
395 
396 	spin_lock_irqsave(&gc->bgpio_lock, flags);
397 
398 	gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
399 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
400 
401 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
402 
403 	return 0;
404 }
405 
406 static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
407 {
408 	unsigned long flags;
409 
410 	gc->set(gc, gpio, val);
411 
412 	spin_lock_irqsave(&gc->bgpio_lock, flags);
413 
414 	gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
415 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
416 
417 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
418 
419 	return 0;
420 }
421 
422 static int bgpio_get_dir_inv(struct gpio_chip *gc, unsigned int gpio)
423 {
424 	/* Return 0 if output, 1 if input */
425 	return !!(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
426 }
427 
428 static int bgpio_setup_accessors(struct device *dev,
429 				 struct gpio_chip *gc,
430 				 bool byte_be)
431 {
432 
433 	switch (gc->bgpio_bits) {
434 	case 8:
435 		gc->read_reg	= bgpio_read8;
436 		gc->write_reg	= bgpio_write8;
437 		break;
438 	case 16:
439 		if (byte_be) {
440 			gc->read_reg	= bgpio_read16be;
441 			gc->write_reg	= bgpio_write16be;
442 		} else {
443 			gc->read_reg	= bgpio_read16;
444 			gc->write_reg	= bgpio_write16;
445 		}
446 		break;
447 	case 32:
448 		if (byte_be) {
449 			gc->read_reg	= bgpio_read32be;
450 			gc->write_reg	= bgpio_write32be;
451 		} else {
452 			gc->read_reg	= bgpio_read32;
453 			gc->write_reg	= bgpio_write32;
454 		}
455 		break;
456 #if BITS_PER_LONG >= 64
457 	case 64:
458 		if (byte_be) {
459 			dev_err(dev,
460 				"64 bit big endian byte order unsupported\n");
461 			return -EINVAL;
462 		} else {
463 			gc->read_reg	= bgpio_read64;
464 			gc->write_reg	= bgpio_write64;
465 		}
466 		break;
467 #endif /* BITS_PER_LONG >= 64 */
468 	default:
469 		dev_err(dev, "unsupported data width %u bits\n", gc->bgpio_bits);
470 		return -EINVAL;
471 	}
472 
473 	return 0;
474 }
475 
476 /*
477  * Create the device and allocate the resources.  For setting GPIO's there are
478  * three supported configurations:
479  *
480  *	- single input/output register resource (named "dat").
481  *	- set/clear pair (named "set" and "clr").
482  *	- single output register resource and single input resource ("set" and
483  *	dat").
484  *
485  * For the single output register, this drives a 1 by setting a bit and a zero
486  * by clearing a bit.  For the set clr pair, this drives a 1 by setting a bit
487  * in the set register and clears it by setting a bit in the clear register.
488  * The configuration is detected by which resources are present.
489  *
490  * For setting the GPIO direction, there are three supported configurations:
491  *
492  *	- simple bidirection GPIO that requires no configuration.
493  *	- an output direction register (named "dirout") where a 1 bit
494  *	indicates the GPIO is an output.
495  *	- an input direction register (named "dirin") where a 1 bit indicates
496  *	the GPIO is an input.
497  */
498 static int bgpio_setup_io(struct gpio_chip *gc,
499 			  void __iomem *dat,
500 			  void __iomem *set,
501 			  void __iomem *clr,
502 			  unsigned long flags)
503 {
504 
505 	gc->reg_dat = dat;
506 	if (!gc->reg_dat)
507 		return -EINVAL;
508 
509 	if (set && clr) {
510 		gc->reg_set = set;
511 		gc->reg_clr = clr;
512 		gc->set = bgpio_set_with_clear;
513 		gc->set_multiple = bgpio_set_multiple_with_clear;
514 	} else if (set && !clr) {
515 		gc->reg_set = set;
516 		gc->set = bgpio_set_set;
517 		gc->set_multiple = bgpio_set_multiple_set;
518 	} else if (flags & BGPIOF_NO_OUTPUT) {
519 		gc->set = bgpio_set_none;
520 		gc->set_multiple = NULL;
521 	} else {
522 		gc->set = bgpio_set;
523 		gc->set_multiple = bgpio_set_multiple;
524 	}
525 
526 	if (!(flags & BGPIOF_UNREADABLE_REG_SET) &&
527 	    (flags & BGPIOF_READ_OUTPUT_REG_SET)) {
528 		gc->get = bgpio_get_set;
529 		if (!gc->be_bits)
530 			gc->get_multiple = bgpio_get_set_multiple;
531 		/*
532 		 * We deliberately avoid assigning the ->get_multiple() call
533 		 * for big endian mirrored registers which are ALSO reflecting
534 		 * their value in the set register when used as output. It is
535 		 * simply too much complexity, let the GPIO core fall back to
536 		 * reading each line individually in that fringe case.
537 		 */
538 	} else {
539 		gc->get = bgpio_get;
540 		if (gc->be_bits)
541 			gc->get_multiple = bgpio_get_multiple_be;
542 		else
543 			gc->get_multiple = bgpio_get_multiple;
544 	}
545 
546 	return 0;
547 }
548 
549 static int bgpio_setup_direction(struct gpio_chip *gc,
550 				 void __iomem *dirout,
551 				 void __iomem *dirin,
552 				 unsigned long flags)
553 {
554 	if (dirout && dirin) {
555 		return -EINVAL;
556 	} else if (dirout) {
557 		gc->reg_dir = dirout;
558 		gc->direction_output = bgpio_dir_out;
559 		gc->direction_input = bgpio_dir_in;
560 		gc->get_direction = bgpio_get_dir;
561 	} else if (dirin) {
562 		gc->reg_dir = dirin;
563 		gc->direction_output = bgpio_dir_out_inv;
564 		gc->direction_input = bgpio_dir_in_inv;
565 		gc->get_direction = bgpio_get_dir_inv;
566 	} else {
567 		if (flags & BGPIOF_NO_OUTPUT)
568 			gc->direction_output = bgpio_dir_out_err;
569 		else
570 			gc->direction_output = bgpio_simple_dir_out;
571 		gc->direction_input = bgpio_simple_dir_in;
572 	}
573 
574 	return 0;
575 }
576 
577 static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
578 {
579 	if (gpio_pin < chip->ngpio)
580 		return 0;
581 
582 	return -EINVAL;
583 }
584 
585 int bgpio_init(struct gpio_chip *gc, struct device *dev,
586 	       unsigned long sz, void __iomem *dat, void __iomem *set,
587 	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
588 	       unsigned long flags)
589 {
590 	int ret;
591 
592 	if (!is_power_of_2(sz))
593 		return -EINVAL;
594 
595 	gc->bgpio_bits = sz * 8;
596 	if (gc->bgpio_bits > BITS_PER_LONG)
597 		return -EINVAL;
598 
599 	spin_lock_init(&gc->bgpio_lock);
600 	gc->parent = dev;
601 	gc->label = dev_name(dev);
602 	gc->base = -1;
603 	gc->ngpio = gc->bgpio_bits;
604 	gc->request = bgpio_request;
605 	gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);
606 
607 	ret = bgpio_setup_io(gc, dat, set, clr, flags);
608 	if (ret)
609 		return ret;
610 
611 	ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
612 	if (ret)
613 		return ret;
614 
615 	ret = bgpio_setup_direction(gc, dirout, dirin, flags);
616 	if (ret)
617 		return ret;
618 
619 	gc->bgpio_data = gc->read_reg(gc->reg_dat);
620 	if (gc->set == bgpio_set_set &&
621 			!(flags & BGPIOF_UNREADABLE_REG_SET))
622 		gc->bgpio_data = gc->read_reg(gc->reg_set);
623 	if (gc->reg_dir && !(flags & BGPIOF_UNREADABLE_REG_DIR))
624 		gc->bgpio_dir = gc->read_reg(gc->reg_dir);
625 
626 	return ret;
627 }
628 EXPORT_SYMBOL_GPL(bgpio_init);
629 
630 #if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
631 
632 static void __iomem *bgpio_map(struct platform_device *pdev,
633 			       const char *name,
634 			       resource_size_t sane_sz)
635 {
636 	struct resource *r;
637 	resource_size_t sz;
638 
639 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
640 	if (!r)
641 		return NULL;
642 
643 	sz = resource_size(r);
644 	if (sz != sane_sz)
645 		return IOMEM_ERR_PTR(-EINVAL);
646 
647 	return devm_ioremap_resource(&pdev->dev, r);
648 }
649 
650 #ifdef CONFIG_OF
651 static const struct of_device_id bgpio_of_match[] = {
652 	{ .compatible = "brcm,bcm6345-gpio" },
653 	{ .compatible = "wd,mbl-gpio" },
654 	{ .compatible = "ni,169445-nand-gpio" },
655 	{ }
656 };
657 MODULE_DEVICE_TABLE(of, bgpio_of_match);
658 
659 static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
660 					  unsigned long *flags)
661 {
662 	struct bgpio_pdata *pdata;
663 
664 	if (!of_match_device(bgpio_of_match, &pdev->dev))
665 		return NULL;
666 
667 	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata),
668 			     GFP_KERNEL);
669 	if (!pdata)
670 		return ERR_PTR(-ENOMEM);
671 
672 	pdata->base = -1;
673 
674 	if (of_device_is_big_endian(pdev->dev.of_node))
675 		*flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
676 
677 	if (of_property_read_bool(pdev->dev.of_node, "no-output"))
678 		*flags |= BGPIOF_NO_OUTPUT;
679 
680 	return pdata;
681 }
682 #else
683 static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
684 					  unsigned long *flags)
685 {
686 	return NULL;
687 }
688 #endif /* CONFIG_OF */
689 
690 static int bgpio_pdev_probe(struct platform_device *pdev)
691 {
692 	struct device *dev = &pdev->dev;
693 	struct resource *r;
694 	void __iomem *dat;
695 	void __iomem *set;
696 	void __iomem *clr;
697 	void __iomem *dirout;
698 	void __iomem *dirin;
699 	unsigned long sz;
700 	unsigned long flags = 0;
701 	int err;
702 	struct gpio_chip *gc;
703 	struct bgpio_pdata *pdata;
704 
705 	pdata = bgpio_parse_dt(pdev, &flags);
706 	if (IS_ERR(pdata))
707 		return PTR_ERR(pdata);
708 
709 	if (!pdata) {
710 		pdata = dev_get_platdata(dev);
711 		flags = pdev->id_entry->driver_data;
712 	}
713 
714 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
715 	if (!r)
716 		return -EINVAL;
717 
718 	sz = resource_size(r);
719 
720 	dat = bgpio_map(pdev, "dat", sz);
721 	if (IS_ERR(dat))
722 		return PTR_ERR(dat);
723 
724 	set = bgpio_map(pdev, "set", sz);
725 	if (IS_ERR(set))
726 		return PTR_ERR(set);
727 
728 	clr = bgpio_map(pdev, "clr", sz);
729 	if (IS_ERR(clr))
730 		return PTR_ERR(clr);
731 
732 	dirout = bgpio_map(pdev, "dirout", sz);
733 	if (IS_ERR(dirout))
734 		return PTR_ERR(dirout);
735 
736 	dirin = bgpio_map(pdev, "dirin", sz);
737 	if (IS_ERR(dirin))
738 		return PTR_ERR(dirin);
739 
740 	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
741 	if (!gc)
742 		return -ENOMEM;
743 
744 	err = bgpio_init(gc, dev, sz, dat, set, clr, dirout, dirin, flags);
745 	if (err)
746 		return err;
747 
748 	if (pdata) {
749 		if (pdata->label)
750 			gc->label = pdata->label;
751 		gc->base = pdata->base;
752 		if (pdata->ngpio > 0)
753 			gc->ngpio = pdata->ngpio;
754 	}
755 
756 	platform_set_drvdata(pdev, gc);
757 
758 	return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
759 }
760 
761 static const struct platform_device_id bgpio_id_table[] = {
762 	{
763 		.name		= "basic-mmio-gpio",
764 		.driver_data	= 0,
765 	}, {
766 		.name		= "basic-mmio-gpio-be",
767 		.driver_data	= BGPIOF_BIG_ENDIAN,
768 	},
769 	{ }
770 };
771 MODULE_DEVICE_TABLE(platform, bgpio_id_table);
772 
773 static struct platform_driver bgpio_driver = {
774 	.driver = {
775 		.name = "basic-mmio-gpio",
776 		.of_match_table = of_match_ptr(bgpio_of_match),
777 	},
778 	.id_table = bgpio_id_table,
779 	.probe = bgpio_pdev_probe,
780 };
781 
782 module_platform_driver(bgpio_driver);
783 
784 #endif /* CONFIG_GPIO_GENERIC_PLATFORM */
785 
786 MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
787 MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
788 MODULE_LICENSE("GPL");
789