xref: /openbmc/linux/drivers/gpio/gpio-mmio.c (revision dc0d1c45)
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 	bool dir = !!(gc->bgpio_dir & pinmask);
140 
141 	/*
142 	 * If the direction is OUT we read the value from the SET
143 	 * register, and if the direction is IN we read the value
144 	 * from the DAT register.
145 	 *
146 	 * If the direction bits are inverted, naturally this gets
147 	 * inverted too.
148 	 */
149 	if (gc->bgpio_dir_inverted)
150 		dir = !dir;
151 
152 	if (dir)
153 		return !!(gc->read_reg(gc->reg_set) & pinmask);
154 	else
155 		return !!(gc->read_reg(gc->reg_dat) & pinmask);
156 }
157 
158 /*
159  * This assumes that the bits in the GPIO register are in native endianness.
160  * We only assign the function pointer if we have that.
161  */
162 static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
163 				  unsigned long *bits)
164 {
165 	unsigned long get_mask = 0;
166 	unsigned long set_mask = 0;
167 
168 	/* Make sure we first clear any bits that are zero when we read the register */
169 	*bits &= ~*mask;
170 
171 	/* Exploit the fact that we know which directions are set */
172 	if (gc->bgpio_dir_inverted) {
173 		set_mask = *mask & ~gc->bgpio_dir;
174 		get_mask = *mask & gc->bgpio_dir;
175 	} else {
176 		set_mask = *mask & gc->bgpio_dir;
177 		get_mask = *mask & ~gc->bgpio_dir;
178 	}
179 
180 	if (set_mask)
181 		*bits |= gc->read_reg(gc->reg_set) & set_mask;
182 	if (get_mask)
183 		*bits |= gc->read_reg(gc->reg_dat) & get_mask;
184 
185 	return 0;
186 }
187 
188 static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
189 {
190 	return !!(gc->read_reg(gc->reg_dat) & bgpio_line2mask(gc, gpio));
191 }
192 
193 /*
194  * This only works if the bits in the GPIO register are in native endianness.
195  */
196 static int bgpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
197 			      unsigned long *bits)
198 {
199 	/* Make sure we first clear any bits that are zero when we read the register */
200 	*bits &= ~*mask;
201 	*bits |= gc->read_reg(gc->reg_dat) & *mask;
202 	return 0;
203 }
204 
205 /*
206  * With big endian mirrored bit order it becomes more tedious.
207  */
208 static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask,
209 				 unsigned long *bits)
210 {
211 	unsigned long readmask = 0;
212 	unsigned long val;
213 	int bit;
214 
215 	/* Make sure we first clear any bits that are zero when we read the register */
216 	*bits &= ~*mask;
217 
218 	/* Create a mirrored mask */
219 	bit = -1;
220 	while ((bit = find_next_bit(mask, gc->ngpio, bit + 1)) < gc->ngpio)
221 		readmask |= bgpio_line2mask(gc, bit);
222 
223 	/* Read the register */
224 	val = gc->read_reg(gc->reg_dat) & readmask;
225 
226 	/*
227 	 * Mirror the result into the "bits" result, this will give line 0
228 	 * in bit 0 ... line 31 in bit 31 for a 32bit register.
229 	 */
230 	bit = -1;
231 	while ((bit = find_next_bit(&val, gc->ngpio, bit + 1)) < gc->ngpio)
232 		*bits |= bgpio_line2mask(gc, bit);
233 
234 	return 0;
235 }
236 
237 static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
238 {
239 }
240 
241 static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
242 {
243 	unsigned long mask = bgpio_line2mask(gc, gpio);
244 	unsigned long flags;
245 
246 	spin_lock_irqsave(&gc->bgpio_lock, flags);
247 
248 	if (val)
249 		gc->bgpio_data |= mask;
250 	else
251 		gc->bgpio_data &= ~mask;
252 
253 	gc->write_reg(gc->reg_dat, gc->bgpio_data);
254 
255 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
256 }
257 
258 static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
259 				 int val)
260 {
261 	unsigned long mask = bgpio_line2mask(gc, gpio);
262 
263 	if (val)
264 		gc->write_reg(gc->reg_set, mask);
265 	else
266 		gc->write_reg(gc->reg_clr, mask);
267 }
268 
269 static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
270 {
271 	unsigned long mask = bgpio_line2mask(gc, gpio);
272 	unsigned long flags;
273 
274 	spin_lock_irqsave(&gc->bgpio_lock, flags);
275 
276 	if (val)
277 		gc->bgpio_data |= mask;
278 	else
279 		gc->bgpio_data &= ~mask;
280 
281 	gc->write_reg(gc->reg_set, gc->bgpio_data);
282 
283 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
284 }
285 
286 static void bgpio_multiple_get_masks(struct gpio_chip *gc,
287 				     unsigned long *mask, unsigned long *bits,
288 				     unsigned long *set_mask,
289 				     unsigned long *clear_mask)
290 {
291 	int i;
292 
293 	*set_mask = 0;
294 	*clear_mask = 0;
295 
296 	for (i = 0; i < gc->bgpio_bits; i++) {
297 		if (*mask == 0)
298 			break;
299 		if (__test_and_clear_bit(i, mask)) {
300 			if (test_bit(i, bits))
301 				*set_mask |= bgpio_line2mask(gc, i);
302 			else
303 				*clear_mask |= bgpio_line2mask(gc, i);
304 		}
305 	}
306 }
307 
308 static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
309 					  unsigned long *mask,
310 					  unsigned long *bits,
311 					  void __iomem *reg)
312 {
313 	unsigned long flags;
314 	unsigned long set_mask, clear_mask;
315 
316 	spin_lock_irqsave(&gc->bgpio_lock, flags);
317 
318 	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
319 
320 	gc->bgpio_data |= set_mask;
321 	gc->bgpio_data &= ~clear_mask;
322 
323 	gc->write_reg(reg, gc->bgpio_data);
324 
325 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
326 }
327 
328 static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
329 			       unsigned long *bits)
330 {
331 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
332 }
333 
334 static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
335 				   unsigned long *bits)
336 {
337 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
338 }
339 
340 static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
341 					  unsigned long *mask,
342 					  unsigned long *bits)
343 {
344 	unsigned long set_mask, clear_mask;
345 
346 	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
347 
348 	if (set_mask)
349 		gc->write_reg(gc->reg_set, set_mask);
350 	if (clear_mask)
351 		gc->write_reg(gc->reg_clr, clear_mask);
352 }
353 
354 static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
355 {
356 	return 0;
357 }
358 
359 static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
360 				int val)
361 {
362 	return -EINVAL;
363 }
364 
365 static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
366 				int val)
367 {
368 	gc->set(gc, gpio, val);
369 
370 	return 0;
371 }
372 
373 static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
374 {
375 	unsigned long flags;
376 
377 	spin_lock_irqsave(&gc->bgpio_lock, flags);
378 
379 	if (gc->bgpio_dir_inverted)
380 		gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
381 	else
382 		gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
383 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
384 
385 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
386 
387 	return 0;
388 }
389 
390 static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
391 {
392 	/* Return 0 if output, 1 of input */
393 	if (gc->bgpio_dir_inverted)
394 		return !!(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
395 	else
396 		return !(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
397 }
398 
399 static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
400 {
401 	unsigned long flags;
402 
403 	gc->set(gc, gpio, val);
404 
405 	spin_lock_irqsave(&gc->bgpio_lock, flags);
406 
407 	if (gc->bgpio_dir_inverted)
408 		gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
409 	else
410 		gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
411 	gc->write_reg(gc->reg_dir, gc->bgpio_dir);
412 
413 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
414 
415 	return 0;
416 }
417 
418 static int bgpio_setup_accessors(struct device *dev,
419 				 struct gpio_chip *gc,
420 				 bool byte_be)
421 {
422 
423 	switch (gc->bgpio_bits) {
424 	case 8:
425 		gc->read_reg	= bgpio_read8;
426 		gc->write_reg	= bgpio_write8;
427 		break;
428 	case 16:
429 		if (byte_be) {
430 			gc->read_reg	= bgpio_read16be;
431 			gc->write_reg	= bgpio_write16be;
432 		} else {
433 			gc->read_reg	= bgpio_read16;
434 			gc->write_reg	= bgpio_write16;
435 		}
436 		break;
437 	case 32:
438 		if (byte_be) {
439 			gc->read_reg	= bgpio_read32be;
440 			gc->write_reg	= bgpio_write32be;
441 		} else {
442 			gc->read_reg	= bgpio_read32;
443 			gc->write_reg	= bgpio_write32;
444 		}
445 		break;
446 #if BITS_PER_LONG >= 64
447 	case 64:
448 		if (byte_be) {
449 			dev_err(dev,
450 				"64 bit big endian byte order unsupported\n");
451 			return -EINVAL;
452 		} else {
453 			gc->read_reg	= bgpio_read64;
454 			gc->write_reg	= bgpio_write64;
455 		}
456 		break;
457 #endif /* BITS_PER_LONG >= 64 */
458 	default:
459 		dev_err(dev, "unsupported data width %u bits\n", gc->bgpio_bits);
460 		return -EINVAL;
461 	}
462 
463 	return 0;
464 }
465 
466 /*
467  * Create the device and allocate the resources.  For setting GPIO's there are
468  * three supported configurations:
469  *
470  *	- single input/output register resource (named "dat").
471  *	- set/clear pair (named "set" and "clr").
472  *	- single output register resource and single input resource ("set" and
473  *	dat").
474  *
475  * For the single output register, this drives a 1 by setting a bit and a zero
476  * by clearing a bit.  For the set clr pair, this drives a 1 by setting a bit
477  * in the set register and clears it by setting a bit in the clear register.
478  * The configuration is detected by which resources are present.
479  *
480  * For setting the GPIO direction, there are three supported configurations:
481  *
482  *	- simple bidirection GPIO that requires no configuration.
483  *	- an output direction register (named "dirout") where a 1 bit
484  *	indicates the GPIO is an output.
485  *	- an input direction register (named "dirin") where a 1 bit indicates
486  *	the GPIO is an input.
487  */
488 static int bgpio_setup_io(struct gpio_chip *gc,
489 			  void __iomem *dat,
490 			  void __iomem *set,
491 			  void __iomem *clr,
492 			  unsigned long flags)
493 {
494 
495 	gc->reg_dat = dat;
496 	if (!gc->reg_dat)
497 		return -EINVAL;
498 
499 	if (set && clr) {
500 		gc->reg_set = set;
501 		gc->reg_clr = clr;
502 		gc->set = bgpio_set_with_clear;
503 		gc->set_multiple = bgpio_set_multiple_with_clear;
504 	} else if (set && !clr) {
505 		gc->reg_set = set;
506 		gc->set = bgpio_set_set;
507 		gc->set_multiple = bgpio_set_multiple_set;
508 	} else if (flags & BGPIOF_NO_OUTPUT) {
509 		gc->set = bgpio_set_none;
510 		gc->set_multiple = NULL;
511 	} else {
512 		gc->set = bgpio_set;
513 		gc->set_multiple = bgpio_set_multiple;
514 	}
515 
516 	if (!(flags & BGPIOF_UNREADABLE_REG_SET) &&
517 	    (flags & BGPIOF_READ_OUTPUT_REG_SET)) {
518 		gc->get = bgpio_get_set;
519 		if (!gc->be_bits)
520 			gc->get_multiple = bgpio_get_set_multiple;
521 		/*
522 		 * We deliberately avoid assigning the ->get_multiple() call
523 		 * for big endian mirrored registers which are ALSO reflecting
524 		 * their value in the set register when used as output. It is
525 		 * simply too much complexity, let the GPIO core fall back to
526 		 * reading each line individually in that fringe case.
527 		 */
528 	} else {
529 		gc->get = bgpio_get;
530 		if (gc->be_bits)
531 			gc->get_multiple = bgpio_get_multiple_be;
532 		else
533 			gc->get_multiple = bgpio_get_multiple;
534 	}
535 
536 	return 0;
537 }
538 
539 static int bgpio_setup_direction(struct gpio_chip *gc,
540 				 void __iomem *dirout,
541 				 void __iomem *dirin,
542 				 unsigned long flags)
543 {
544 	if (dirout && dirin) {
545 		return -EINVAL;
546 	} else if (dirout) {
547 		gc->reg_dir = dirout;
548 		gc->direction_output = bgpio_dir_out;
549 		gc->direction_input = bgpio_dir_in;
550 		gc->get_direction = bgpio_get_dir;
551 	} else if (dirin) {
552 		gc->reg_dir = dirin;
553 		gc->direction_output = bgpio_dir_out;
554 		gc->direction_input = bgpio_dir_in;
555 		gc->get_direction = bgpio_get_dir;
556 		gc->bgpio_dir_inverted = true;
557 	} else {
558 		if (flags & BGPIOF_NO_OUTPUT)
559 			gc->direction_output = bgpio_dir_out_err;
560 		else
561 			gc->direction_output = bgpio_simple_dir_out;
562 		gc->direction_input = bgpio_simple_dir_in;
563 	}
564 
565 	return 0;
566 }
567 
568 static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
569 {
570 	if (gpio_pin < chip->ngpio)
571 		return 0;
572 
573 	return -EINVAL;
574 }
575 
576 /**
577  * bgpio_init() - Initialize generic GPIO accessor functions
578  * @gc: the GPIO chip to set up
579  * @dev: the parent device of the new GPIO chip (compulsory)
580  * @sz: the size (width) of the MMIO registers in bytes, typically 1, 2 or 4
581  * @dat: MMIO address for the register to READ the value of the GPIO lines, it
582  *	is expected that a 1 in the corresponding bit in this register means the
583  *	line is asserted
584  * @set: MMIO address for the register to SET the value of the GPIO lines, it is
585  *	expected that we write the line with 1 in this register to drive the GPIO line
586  *	high.
587  * @clr: MMIO address for the register to CLEAR the value of the GPIO lines, it is
588  *	expected that we write the line with 1 in this register to drive the GPIO line
589  *	low. It is allowed to leave this address as NULL, in that case the SET register
590  *	will be assumed to also clear the GPIO lines, by actively writing the line
591  *	with 0.
592  * @dirout: MMIO address for the register to set the line as OUTPUT. It is assumed
593  *	that setting a line to 1 in this register will turn that line into an
594  *	output line. Conversely, setting the line to 0 will turn that line into
595  *	an input. Either this or @dirin can be defined, but never both.
596  * @dirin: MMIO address for the register to set this line as INPUT. It is assumed
597  *	that setting a line to 1 in this register will turn that line into an
598  *	input line. Conversely, setting the line to 0 will turn that line into
599  *	an output. Either this or @dirout can be defined, but never both.
600  * @flags: Different flags that will affect the behaviour of the device, such as
601  *	endianness etc.
602  */
603 int bgpio_init(struct gpio_chip *gc, struct device *dev,
604 	       unsigned long sz, void __iomem *dat, void __iomem *set,
605 	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
606 	       unsigned long flags)
607 {
608 	int ret;
609 
610 	if (!is_power_of_2(sz))
611 		return -EINVAL;
612 
613 	gc->bgpio_bits = sz * 8;
614 	if (gc->bgpio_bits > BITS_PER_LONG)
615 		return -EINVAL;
616 
617 	spin_lock_init(&gc->bgpio_lock);
618 	gc->parent = dev;
619 	gc->label = dev_name(dev);
620 	gc->base = -1;
621 	gc->ngpio = gc->bgpio_bits;
622 	gc->request = bgpio_request;
623 	gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);
624 
625 	ret = bgpio_setup_io(gc, dat, set, clr, flags);
626 	if (ret)
627 		return ret;
628 
629 	ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
630 	if (ret)
631 		return ret;
632 
633 	ret = bgpio_setup_direction(gc, dirout, dirin, flags);
634 	if (ret)
635 		return ret;
636 
637 	gc->bgpio_data = gc->read_reg(gc->reg_dat);
638 	if (gc->set == bgpio_set_set &&
639 			!(flags & BGPIOF_UNREADABLE_REG_SET))
640 		gc->bgpio_data = gc->read_reg(gc->reg_set);
641 	if (gc->reg_dir && !(flags & BGPIOF_UNREADABLE_REG_DIR))
642 		gc->bgpio_dir = gc->read_reg(gc->reg_dir);
643 
644 	return ret;
645 }
646 EXPORT_SYMBOL_GPL(bgpio_init);
647 
648 #if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
649 
650 static void __iomem *bgpio_map(struct platform_device *pdev,
651 			       const char *name,
652 			       resource_size_t sane_sz)
653 {
654 	struct resource *r;
655 	resource_size_t sz;
656 
657 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
658 	if (!r)
659 		return NULL;
660 
661 	sz = resource_size(r);
662 	if (sz != sane_sz)
663 		return IOMEM_ERR_PTR(-EINVAL);
664 
665 	return devm_ioremap_resource(&pdev->dev, r);
666 }
667 
668 #ifdef CONFIG_OF
669 static const struct of_device_id bgpio_of_match[] = {
670 	{ .compatible = "brcm,bcm6345-gpio" },
671 	{ .compatible = "wd,mbl-gpio" },
672 	{ .compatible = "ni,169445-nand-gpio" },
673 	{ }
674 };
675 MODULE_DEVICE_TABLE(of, bgpio_of_match);
676 
677 static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
678 					  unsigned long *flags)
679 {
680 	struct bgpio_pdata *pdata;
681 
682 	if (!of_match_device(bgpio_of_match, &pdev->dev))
683 		return NULL;
684 
685 	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata),
686 			     GFP_KERNEL);
687 	if (!pdata)
688 		return ERR_PTR(-ENOMEM);
689 
690 	pdata->base = -1;
691 
692 	if (of_device_is_big_endian(pdev->dev.of_node))
693 		*flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
694 
695 	if (of_property_read_bool(pdev->dev.of_node, "no-output"))
696 		*flags |= BGPIOF_NO_OUTPUT;
697 
698 	return pdata;
699 }
700 #else
701 static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
702 					  unsigned long *flags)
703 {
704 	return NULL;
705 }
706 #endif /* CONFIG_OF */
707 
708 static int bgpio_pdev_probe(struct platform_device *pdev)
709 {
710 	struct device *dev = &pdev->dev;
711 	struct resource *r;
712 	void __iomem *dat;
713 	void __iomem *set;
714 	void __iomem *clr;
715 	void __iomem *dirout;
716 	void __iomem *dirin;
717 	unsigned long sz;
718 	unsigned long flags = 0;
719 	int err;
720 	struct gpio_chip *gc;
721 	struct bgpio_pdata *pdata;
722 
723 	pdata = bgpio_parse_dt(pdev, &flags);
724 	if (IS_ERR(pdata))
725 		return PTR_ERR(pdata);
726 
727 	if (!pdata) {
728 		pdata = dev_get_platdata(dev);
729 		flags = pdev->id_entry->driver_data;
730 	}
731 
732 	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
733 	if (!r)
734 		return -EINVAL;
735 
736 	sz = resource_size(r);
737 
738 	dat = bgpio_map(pdev, "dat", sz);
739 	if (IS_ERR(dat))
740 		return PTR_ERR(dat);
741 
742 	set = bgpio_map(pdev, "set", sz);
743 	if (IS_ERR(set))
744 		return PTR_ERR(set);
745 
746 	clr = bgpio_map(pdev, "clr", sz);
747 	if (IS_ERR(clr))
748 		return PTR_ERR(clr);
749 
750 	dirout = bgpio_map(pdev, "dirout", sz);
751 	if (IS_ERR(dirout))
752 		return PTR_ERR(dirout);
753 
754 	dirin = bgpio_map(pdev, "dirin", sz);
755 	if (IS_ERR(dirin))
756 		return PTR_ERR(dirin);
757 
758 	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
759 	if (!gc)
760 		return -ENOMEM;
761 
762 	err = bgpio_init(gc, dev, sz, dat, set, clr, dirout, dirin, flags);
763 	if (err)
764 		return err;
765 
766 	if (pdata) {
767 		if (pdata->label)
768 			gc->label = pdata->label;
769 		gc->base = pdata->base;
770 		if (pdata->ngpio > 0)
771 			gc->ngpio = pdata->ngpio;
772 	}
773 
774 	platform_set_drvdata(pdev, gc);
775 
776 	return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
777 }
778 
779 static const struct platform_device_id bgpio_id_table[] = {
780 	{
781 		.name		= "basic-mmio-gpio",
782 		.driver_data	= 0,
783 	}, {
784 		.name		= "basic-mmio-gpio-be",
785 		.driver_data	= BGPIOF_BIG_ENDIAN,
786 	},
787 	{ }
788 };
789 MODULE_DEVICE_TABLE(platform, bgpio_id_table);
790 
791 static struct platform_driver bgpio_driver = {
792 	.driver = {
793 		.name = "basic-mmio-gpio",
794 		.of_match_table = of_match_ptr(bgpio_of_match),
795 	},
796 	.id_table = bgpio_id_table,
797 	.probe = bgpio_pdev_probe,
798 };
799 
800 module_platform_driver(bgpio_driver);
801 
802 #endif /* CONFIG_GPIO_GENERIC_PLATFORM */
803 
804 MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
805 MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
806 MODULE_LICENSE("GPL");
807