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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Generic driver for memory-mapped GPIO controllers.
  4 *
  5 * Copyright 2008 MontaVista Software, Inc.
  6 * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
  7 *
  8 * ....``.```~~~~````.`.`.`.`.```````'',,,.........`````......`.......
  9 * ...``                                                         ```````..
 10 * ..The simplest form of a GPIO controller that the driver supports is``
 11 *  `.just a single "data" register, where GPIO state can be read and/or `
 12 *    `,..written. ,,..``~~~~ .....``.`.`.~~.```.`.........``````.```````
 13 *        `````````
 14                                    ___
 15_/~~|___/~|   . ```~~~~~~       ___/___\___     ,~.`.`.`.`````.~~...,,,,...
 16__________|~$@~~~        %~    /o*o*o*o*o*o\   .. Implementing such a GPIO .
 17o        `                     ~~~~\___/~~~~    ` controller in FPGA is ,.`
 18                                                 `....trivial..'~`.```.```
 19 *                                                    ```````
 20 *  .```````~~~~`..`.``.``.
 21 * .  The driver supports  `...       ,..```.`~~~```````````````....````.``,,
 22 * .   big-endian notation, just`.  .. A bit more sophisticated controllers ,
 23 *  . register the device with -be`. .with a pair of set/clear-bit registers ,
 24 *   `.. suffix.  ```~~`````....`.`   . affecting the data register and the .`
 25 *     ``.`.``...```                  ```.. output pins are also supported.`
 26 *                        ^^             `````.`````````.,``~``~``~~``````
 27 *                                                   .                  ^^
 28 *   ,..`.`.`...````````````......`.`.`.`.`.`..`.`.`..
 29 * .. The expectation is that in at least some cases .    ,-~~~-,
 30 *  .this will be used with roll-your-own ASIC/FPGA .`     \   /
 31 *  .logic in Verilog or VHDL. ~~~`````````..`````~~`       \ /
 32 *  ..````````......```````````                             \o_
 33 *                                                           |
 34 *                              ^^                          / \
 35 *
 36 *           ...`````~~`.....``.`..........``````.`.``.```........``.
 37 *            `  8, 16, 32 and 64 bits registers are supported, and``.
 38 *            . the number of GPIOs is determined by the width of   ~
 39 *             .. the registers. ,............```.`.`..`.`.~~~.`.`.`~
 40 *               `.......````.```
 41 */
 42
 43#include <linux/init.h>
 44#include <linux/err.h>
 45#include <linux/bug.h>
 46#include <linux/kernel.h>
 47#include <linux/module.h>
 48#include <linux/spinlock.h>
 49#include <linux/compiler.h>
 50#include <linux/types.h>
 51#include <linux/errno.h>
 52#include <linux/log2.h>
 53#include <linux/ioport.h>
 54#include <linux/io.h>
 55#include <linux/gpio/driver.h>
 56#include <linux/slab.h>
 57#include <linux/bitops.h>
 58#include <linux/platform_device.h>
 59#include <linux/mod_devicetable.h>
 60#include <linux/of.h>
 61#include <linux/of_device.h>
 62
 63static void bgpio_write8(void __iomem *reg, unsigned long data)
 64{
 65	writeb(data, reg);
 66}
 67
 68static unsigned long bgpio_read8(void __iomem *reg)
 69{
 70	return readb(reg);
 71}
 72
 73static void bgpio_write16(void __iomem *reg, unsigned long data)
 74{
 75	writew(data, reg);
 76}
 77
 78static unsigned long bgpio_read16(void __iomem *reg)
 79{
 80	return readw(reg);
 81}
 82
 83static void bgpio_write32(void __iomem *reg, unsigned long data)
 84{
 85	writel(data, reg);
 86}
 87
 88static unsigned long bgpio_read32(void __iomem *reg)
 89{
 90	return readl(reg);
 91}
 92
 93#if BITS_PER_LONG >= 64
 94static void bgpio_write64(void __iomem *reg, unsigned long data)
 95{
 96	writeq(data, reg);
 97}
 98
 99static unsigned long bgpio_read64(void __iomem *reg)
100{
101	return readq(reg);
102}
103#endif /* BITS_PER_LONG >= 64 */
104
105static void bgpio_write16be(void __iomem *reg, unsigned long data)
106{
107	iowrite16be(data, reg);
108}
109
110static unsigned long bgpio_read16be(void __iomem *reg)
111{
112	return ioread16be(reg);
113}
114
115static void bgpio_write32be(void __iomem *reg, unsigned long data)
116{
117	iowrite32be(data, reg);
118}
119
120static unsigned long bgpio_read32be(void __iomem *reg)
121{
122	return ioread32be(reg);
123}
124
125static unsigned long bgpio_line2mask(struct gpio_chip *gc, unsigned int line)
126{
127	if (gc->be_bits)
128		return BIT(gc->bgpio_bits - 1 - line);
129	return BIT(line);
130}
131
132static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
133{
134	unsigned long pinmask = bgpio_line2mask(gc, gpio);
135	bool dir = !!(gc->bgpio_dir & pinmask);
136
137	if (dir)
138		return !!(gc->read_reg(gc->reg_set) & pinmask);
139	else
140		return !!(gc->read_reg(gc->reg_dat) & pinmask);
141}
142
143/*
144 * This assumes that the bits in the GPIO register are in native endianness.
145 * We only assign the function pointer if we have that.
146 */
147static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
148				  unsigned long *bits)
149{
150	unsigned long get_mask = 0;
151	unsigned long set_mask = 0;
152
153	/* Make sure we first clear any bits that are zero when we read the register */
154	*bits &= ~*mask;
155
156	set_mask = *mask & gc->bgpio_dir;
157	get_mask = *mask & ~gc->bgpio_dir;
158
159	if (set_mask)
160		*bits |= gc->read_reg(gc->reg_set) & set_mask;
161	if (get_mask)
162		*bits |= gc->read_reg(gc->reg_dat) & get_mask;
163
164	return 0;
165}
166
167static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
168{
169	return !!(gc->read_reg(gc->reg_dat) & bgpio_line2mask(gc, gpio));
170}
171
172/*
173 * This only works if the bits in the GPIO register are in native endianness.
174 */
175static int bgpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
176			      unsigned long *bits)
177{
178	/* Make sure we first clear any bits that are zero when we read the register */
179	*bits &= ~*mask;
180	*bits |= gc->read_reg(gc->reg_dat) & *mask;
181	return 0;
182}
183
184/*
185 * With big endian mirrored bit order it becomes more tedious.
186 */
187static int bgpio_get_multiple_be(struct gpio_chip *gc, unsigned long *mask,
188				 unsigned long *bits)
189{
190	unsigned long readmask = 0;
191	unsigned long val;
192	int bit;
193
194	/* Make sure we first clear any bits that are zero when we read the register */
195	*bits &= ~*mask;
196
197	/* Create a mirrored mask */
198	bit = -1;
199	while ((bit = find_next_bit(mask, gc->ngpio, bit + 1)) < gc->ngpio)
200		readmask |= bgpio_line2mask(gc, bit);
201
202	/* Read the register */
203	val = gc->read_reg(gc->reg_dat) & readmask;
204
205	/*
206	 * Mirror the result into the "bits" result, this will give line 0
207	 * in bit 0 ... line 31 in bit 31 for a 32bit register.
208	 */
209	bit = -1;
210	while ((bit = find_next_bit(&val, gc->ngpio, bit + 1)) < gc->ngpio)
211		*bits |= bgpio_line2mask(gc, bit);
212
213	return 0;
214}
215
216static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
217{
218}
219
220static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
221{
222	unsigned long mask = bgpio_line2mask(gc, gpio);
223	unsigned long flags;
224
225	spin_lock_irqsave(&gc->bgpio_lock, flags);
226
227	if (val)
228		gc->bgpio_data |= mask;
229	else
230		gc->bgpio_data &= ~mask;
231
232	gc->write_reg(gc->reg_dat, gc->bgpio_data);
233
234	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
235}
236
237static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
238				 int val)
239{
240	unsigned long mask = bgpio_line2mask(gc, gpio);
241
242	if (val)
243		gc->write_reg(gc->reg_set, mask);
244	else
245		gc->write_reg(gc->reg_clr, mask);
246}
247
248static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
249{
250	unsigned long mask = bgpio_line2mask(gc, gpio);
251	unsigned long flags;
252
253	spin_lock_irqsave(&gc->bgpio_lock, flags);
254
255	if (val)
256		gc->bgpio_data |= mask;
257	else
258		gc->bgpio_data &= ~mask;
259
260	gc->write_reg(gc->reg_set, gc->bgpio_data);
261
262	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
263}
264
265static void bgpio_multiple_get_masks(struct gpio_chip *gc,
266				     unsigned long *mask, unsigned long *bits,
267				     unsigned long *set_mask,
268				     unsigned long *clear_mask)
269{
270	int i;
271
272	*set_mask = 0;
273	*clear_mask = 0;
274
275	for (i = 0; i < gc->bgpio_bits; i++) {
276		if (*mask == 0)
277			break;
278		if (__test_and_clear_bit(i, mask)) {
279			if (test_bit(i, bits))
280				*set_mask |= bgpio_line2mask(gc, i);
281			else
282				*clear_mask |= bgpio_line2mask(gc, i);
283		}
284	}
285}
286
287static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
288					  unsigned long *mask,
289					  unsigned long *bits,
290					  void __iomem *reg)
291{
292	unsigned long flags;
293	unsigned long set_mask, clear_mask;
294
295	spin_lock_irqsave(&gc->bgpio_lock, flags);
296
297	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
298
299	gc->bgpio_data |= set_mask;
300	gc->bgpio_data &= ~clear_mask;
301
302	gc->write_reg(reg, gc->bgpio_data);
303
304	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
305}
306
307static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
308			       unsigned long *bits)
309{
310	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
311}
312
313static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
314				   unsigned long *bits)
315{
316	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
317}
318
319static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
320					  unsigned long *mask,
321					  unsigned long *bits)
322{
323	unsigned long set_mask, clear_mask;
324
325	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
326
327	if (set_mask)
328		gc->write_reg(gc->reg_set, set_mask);
329	if (clear_mask)
330		gc->write_reg(gc->reg_clr, clear_mask);
331}
332
333static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
334{
335	return 0;
336}
337
338static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
339				int val)
340{
341	return -EINVAL;
342}
343
344static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
345				int val)
346{
347	gc->set(gc, gpio, val);
348
349	return 0;
350}
351
352static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
353{
354	unsigned long flags;
355
356	spin_lock_irqsave(&gc->bgpio_lock, flags);
357
358	gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
359
360	if (gc->reg_dir_in)
361		gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);
362	if (gc->reg_dir_out)
363		gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);
364
365	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
366
367	return 0;
368}
369
370static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
371{
372	/* Return 0 if output, 1 if input */
373	if (gc->bgpio_dir_unreadable)
374		return !(gc->bgpio_dir & bgpio_line2mask(gc, gpio));
375	if (gc->reg_dir_out)
376		return !(gc->read_reg(gc->reg_dir_out) & bgpio_line2mask(gc, gpio));
377	if (gc->reg_dir_in)
378		return !!(gc->read_reg(gc->reg_dir_in) & bgpio_line2mask(gc, gpio));
379
380	/* This should not happen */
381	return 1;
382}
383
384static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
385{
386	unsigned long flags;
387
388	gc->set(gc, gpio, val);
389
390	spin_lock_irqsave(&gc->bgpio_lock, flags);
391
392	gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
393
394	if (gc->reg_dir_in)
395		gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);
396	if (gc->reg_dir_out)
397		gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);
398
399	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
400
401	return 0;
402}
403
404static int bgpio_setup_accessors(struct device *dev,
405				 struct gpio_chip *gc,
406				 bool byte_be)
407{
408
409	switch (gc->bgpio_bits) {
410	case 8:
411		gc->read_reg	= bgpio_read8;
412		gc->write_reg	= bgpio_write8;
413		break;
414	case 16:
415		if (byte_be) {
416			gc->read_reg	= bgpio_read16be;
417			gc->write_reg	= bgpio_write16be;
418		} else {
419			gc->read_reg	= bgpio_read16;
420			gc->write_reg	= bgpio_write16;
421		}
422		break;
423	case 32:
424		if (byte_be) {
425			gc->read_reg	= bgpio_read32be;
426			gc->write_reg	= bgpio_write32be;
427		} else {
428			gc->read_reg	= bgpio_read32;
429			gc->write_reg	= bgpio_write32;
430		}
431		break;
432#if BITS_PER_LONG >= 64
433	case 64:
434		if (byte_be) {
435			dev_err(dev,
436				"64 bit big endian byte order unsupported\n");
437			return -EINVAL;
438		} else {
439			gc->read_reg	= bgpio_read64;
440			gc->write_reg	= bgpio_write64;
441		}
442		break;
443#endif /* BITS_PER_LONG >= 64 */
444	default:
445		dev_err(dev, "unsupported data width %u bits\n", gc->bgpio_bits);
446		return -EINVAL;
447	}
448
449	return 0;
450}
451
452/*
453 * Create the device and allocate the resources.  For setting GPIO's there are
454 * three supported configurations:
455 *
456 *	- single input/output register resource (named "dat").
457 *	- set/clear pair (named "set" and "clr").
458 *	- single output register resource and single input resource ("set" and
459 *	dat").
460 *
461 * For the single output register, this drives a 1 by setting a bit and a zero
462 * by clearing a bit.  For the set clr pair, this drives a 1 by setting a bit
463 * in the set register and clears it by setting a bit in the clear register.
464 * The configuration is detected by which resources are present.
465 *
466 * For setting the GPIO direction, there are three supported configurations:
467 *
468 *	- simple bidirection GPIO that requires no configuration.
469 *	- an output direction register (named "dirout") where a 1 bit
470 *	indicates the GPIO is an output.
471 *	- an input direction register (named "dirin") where a 1 bit indicates
472 *	the GPIO is an input.
473 */
474static int bgpio_setup_io(struct gpio_chip *gc,
475			  void __iomem *dat,
476			  void __iomem *set,
477			  void __iomem *clr,
478			  unsigned long flags)
479{
480
481	gc->reg_dat = dat;
482	if (!gc->reg_dat)
483		return -EINVAL;
484
485	if (set && clr) {
486		gc->reg_set = set;
487		gc->reg_clr = clr;
488		gc->set = bgpio_set_with_clear;
489		gc->set_multiple = bgpio_set_multiple_with_clear;
490	} else if (set && !clr) {
491		gc->reg_set = set;
492		gc->set = bgpio_set_set;
493		gc->set_multiple = bgpio_set_multiple_set;
494	} else if (flags & BGPIOF_NO_OUTPUT) {
495		gc->set = bgpio_set_none;
496		gc->set_multiple = NULL;
497	} else {
498		gc->set = bgpio_set;
499		gc->set_multiple = bgpio_set_multiple;
500	}
501
502	if (!(flags & BGPIOF_UNREADABLE_REG_SET) &&
503	    (flags & BGPIOF_READ_OUTPUT_REG_SET)) {
504		gc->get = bgpio_get_set;
505		if (!gc->be_bits)
506			gc->get_multiple = bgpio_get_set_multiple;
507		/*
508		 * We deliberately avoid assigning the ->get_multiple() call
509		 * for big endian mirrored registers which are ALSO reflecting
510		 * their value in the set register when used as output. It is
511		 * simply too much complexity, let the GPIO core fall back to
512		 * reading each line individually in that fringe case.
513		 */
514	} else {
515		gc->get = bgpio_get;
516		if (gc->be_bits)
517			gc->get_multiple = bgpio_get_multiple_be;
518		else
519			gc->get_multiple = bgpio_get_multiple;
520	}
521
522	return 0;
523}
524
525static int bgpio_setup_direction(struct gpio_chip *gc,
526				 void __iomem *dirout,
527				 void __iomem *dirin,
528				 unsigned long flags)
529{
530	if (dirout || dirin) {
531		gc->reg_dir_out = dirout;
532		gc->reg_dir_in = dirin;
533		gc->direction_output = bgpio_dir_out;
534		gc->direction_input = bgpio_dir_in;
535		gc->get_direction = bgpio_get_dir;
536	} else {
537		if (flags & BGPIOF_NO_OUTPUT)
538			gc->direction_output = bgpio_dir_out_err;
539		else
540			gc->direction_output = bgpio_simple_dir_out;
541		gc->direction_input = bgpio_simple_dir_in;
542	}
543
544	return 0;
545}
546
547static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
548{
549	if (gpio_pin < chip->ngpio)
550		return 0;
551
552	return -EINVAL;
553}
554
555/**
556 * bgpio_init() - Initialize generic GPIO accessor functions
557 * @gc: the GPIO chip to set up
558 * @dev: the parent device of the new GPIO chip (compulsory)
559 * @sz: the size (width) of the MMIO registers in bytes, typically 1, 2 or 4
560 * @dat: MMIO address for the register to READ the value of the GPIO lines, it
561 *	is expected that a 1 in the corresponding bit in this register means the
562 *	line is asserted
563 * @set: MMIO address for the register to SET the value of the GPIO lines, it is
564 *	expected that we write the line with 1 in this register to drive the GPIO line
565 *	high.
566 * @clr: MMIO address for the register to CLEAR the value of the GPIO lines, it is
567 *	expected that we write the line with 1 in this register to drive the GPIO line
568 *	low. It is allowed to leave this address as NULL, in that case the SET register
569 *	will be assumed to also clear the GPIO lines, by actively writing the line
570 *	with 0.
571 * @dirout: MMIO address for the register to set the line as OUTPUT. It is assumed
572 *	that setting a line to 1 in this register will turn that line into an
573 *	output line. Conversely, setting the line to 0 will turn that line into
574 *	an input.
575 * @dirin: MMIO address for the register to set this line as INPUT. It is assumed
576 *	that setting a line to 1 in this register will turn that line into an
577 *	input line. Conversely, setting the line to 0 will turn that line into
578 *	an output.
579 * @flags: Different flags that will affect the behaviour of the device, such as
580 *	endianness etc.
581 */
582int bgpio_init(struct gpio_chip *gc, struct device *dev,
583	       unsigned long sz, void __iomem *dat, void __iomem *set,
584	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
585	       unsigned long flags)
586{
587	int ret;
588
589	if (!is_power_of_2(sz))
590		return -EINVAL;
591
592	gc->bgpio_bits = sz * 8;
593	if (gc->bgpio_bits > BITS_PER_LONG)
594		return -EINVAL;
595
596	spin_lock_init(&gc->bgpio_lock);
597	gc->parent = dev;
598	gc->label = dev_name(dev);
599	gc->base = -1;
600	gc->ngpio = gc->bgpio_bits;
601	gc->request = bgpio_request;
602	gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);
603
604	ret = bgpio_setup_io(gc, dat, set, clr, flags);
605	if (ret)
606		return ret;
607
608	ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
609	if (ret)
610		return ret;
611
612	ret = bgpio_setup_direction(gc, dirout, dirin, flags);
613	if (ret)
614		return ret;
615
616	gc->bgpio_data = gc->read_reg(gc->reg_dat);
617	if (gc->set == bgpio_set_set &&
618			!(flags & BGPIOF_UNREADABLE_REG_SET))
619		gc->bgpio_data = gc->read_reg(gc->reg_set);
620
621	if (flags & BGPIOF_UNREADABLE_REG_DIR)
622		gc->bgpio_dir_unreadable = true;
623
624	/*
625	 * Inspect hardware to find initial direction setting.
626	 */
627	if ((gc->reg_dir_out || gc->reg_dir_in) &&
628	    !(flags & BGPIOF_UNREADABLE_REG_DIR)) {
629		if (gc->reg_dir_out)
630			gc->bgpio_dir = gc->read_reg(gc->reg_dir_out);
631		else if (gc->reg_dir_in)
632			gc->bgpio_dir = ~gc->read_reg(gc->reg_dir_in);
633		/*
634		 * If we have two direction registers, synchronise
635		 * input setting to output setting, the library
636		 * can not handle a line being input and output at
637		 * the same time.
638		 */
639		if (gc->reg_dir_out && gc->reg_dir_in)
640			gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);
641	}
642
643	return ret;
644}
645EXPORT_SYMBOL_GPL(bgpio_init);
646
647#if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
648
649static void __iomem *bgpio_map(struct platform_device *pdev,
650			       const char *name,
651			       resource_size_t sane_sz)
652{
653	struct resource *r;
654	resource_size_t sz;
655
656	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
657	if (!r)
658		return NULL;
659
660	sz = resource_size(r);
661	if (sz != sane_sz)
662		return IOMEM_ERR_PTR(-EINVAL);
663
664	return devm_ioremap_resource(&pdev->dev, r);
665}
666
667#ifdef CONFIG_OF
668static const struct of_device_id bgpio_of_match[] = {
669	{ .compatible = "brcm,bcm6345-gpio" },
670	{ .compatible = "wd,mbl-gpio" },
671	{ .compatible = "ni,169445-nand-gpio" },
672	{ }
673};
674MODULE_DEVICE_TABLE(of, bgpio_of_match);
675
676static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
677					  unsigned long *flags)
678{
679	struct bgpio_pdata *pdata;
680
681	if (!of_match_device(bgpio_of_match, &pdev->dev))
682		return NULL;
683
684	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata),
685			     GFP_KERNEL);
686	if (!pdata)
687		return ERR_PTR(-ENOMEM);
688
689	pdata->base = -1;
690
691	if (of_device_is_big_endian(pdev->dev.of_node))
692		*flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
693
694	if (of_property_read_bool(pdev->dev.of_node, "no-output"))
695		*flags |= BGPIOF_NO_OUTPUT;
696
697	return pdata;
698}
699#else
700static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
701					  unsigned long *flags)
702{
703	return NULL;
704}
705#endif /* CONFIG_OF */
706
707static int bgpio_pdev_probe(struct platform_device *pdev)
708{
709	struct device *dev = &pdev->dev;
710	struct resource *r;
711	void __iomem *dat;
712	void __iomem *set;
713	void __iomem *clr;
714	void __iomem *dirout;
715	void __iomem *dirin;
716	unsigned long sz;
717	unsigned long flags = 0;
718	int err;
719	struct gpio_chip *gc;
720	struct bgpio_pdata *pdata;
721
722	pdata = bgpio_parse_dt(pdev, &flags);
723	if (IS_ERR(pdata))
724		return PTR_ERR(pdata);
725
726	if (!pdata) {
727		pdata = dev_get_platdata(dev);
728		flags = pdev->id_entry->driver_data;
729	}
730
731	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
732	if (!r)
733		return -EINVAL;
734
735	sz = resource_size(r);
736
737	dat = bgpio_map(pdev, "dat", sz);
738	if (IS_ERR(dat))
739		return PTR_ERR(dat);
740
741	set = bgpio_map(pdev, "set", sz);
742	if (IS_ERR(set))
743		return PTR_ERR(set);
744
745	clr = bgpio_map(pdev, "clr", sz);
746	if (IS_ERR(clr))
747		return PTR_ERR(clr);
748
749	dirout = bgpio_map(pdev, "dirout", sz);
750	if (IS_ERR(dirout))
751		return PTR_ERR(dirout);
752
753	dirin = bgpio_map(pdev, "dirin", sz);
754	if (IS_ERR(dirin))
755		return PTR_ERR(dirin);
756
757	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
758	if (!gc)
759		return -ENOMEM;
760
761	err = bgpio_init(gc, dev, sz, dat, set, clr, dirout, dirin, flags);
762	if (err)
763		return err;
764
765	if (pdata) {
766		if (pdata->label)
767			gc->label = pdata->label;
768		gc->base = pdata->base;
769		if (pdata->ngpio > 0)
770			gc->ngpio = pdata->ngpio;
771	}
772
773	platform_set_drvdata(pdev, gc);
774
775	return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
776}
777
778static const struct platform_device_id bgpio_id_table[] = {
779	{
780		.name		= "basic-mmio-gpio",
781		.driver_data	= 0,
782	}, {
783		.name		= "basic-mmio-gpio-be",
784		.driver_data	= BGPIOF_BIG_ENDIAN,
785	},
786	{ }
787};
788MODULE_DEVICE_TABLE(platform, bgpio_id_table);
789
790static struct platform_driver bgpio_driver = {
791	.driver = {
792		.name = "basic-mmio-gpio",
793		.of_match_table = of_match_ptr(bgpio_of_match),
794	},
795	.id_table = bgpio_id_table,
796	.probe = bgpio_pdev_probe,
797};
798
799module_platform_driver(bgpio_driver);
800
801#endif /* CONFIG_GPIO_GENERIC_PLATFORM */
802
803MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
804MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
805MODULE_LICENSE("GPL");