Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
  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	for_each_set_bit(bit, mask, gc->ngpio)
199		readmask |= bgpio_line2mask(gc, bit);
200
201	/* Read the register */
202	val = gc->read_reg(gc->reg_dat) & readmask;
203
204	/*
205	 * Mirror the result into the "bits" result, this will give line 0
206	 * in bit 0 ... line 31 in bit 31 for a 32bit register.
207	 */
208	for_each_set_bit(bit, &val, gc->ngpio)
209		*bits |= bgpio_line2mask(gc, bit);
210
211	return 0;
212}
213
214static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
215{
216}
217
218static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
219{
220	unsigned long mask = bgpio_line2mask(gc, gpio);
221	unsigned long flags;
222
223	spin_lock_irqsave(&gc->bgpio_lock, flags);
224
225	if (val)
226		gc->bgpio_data |= mask;
227	else
228		gc->bgpio_data &= ~mask;
229
230	gc->write_reg(gc->reg_dat, gc->bgpio_data);
231
232	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
233}
234
235static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
236				 int val)
237{
238	unsigned long mask = bgpio_line2mask(gc, gpio);
239
240	if (val)
241		gc->write_reg(gc->reg_set, mask);
242	else
243		gc->write_reg(gc->reg_clr, mask);
244}
245
246static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
247{
248	unsigned long mask = bgpio_line2mask(gc, gpio);
249	unsigned long flags;
250
251	spin_lock_irqsave(&gc->bgpio_lock, flags);
252
253	if (val)
254		gc->bgpio_data |= mask;
255	else
256		gc->bgpio_data &= ~mask;
257
258	gc->write_reg(gc->reg_set, gc->bgpio_data);
259
260	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
261}
262
263static void bgpio_multiple_get_masks(struct gpio_chip *gc,
264				     unsigned long *mask, unsigned long *bits,
265				     unsigned long *set_mask,
266				     unsigned long *clear_mask)
267{
268	int i;
269
270	*set_mask = 0;
271	*clear_mask = 0;
272
273	for_each_set_bit(i, mask, gc->bgpio_bits) {
274		if (test_bit(i, bits))
275			*set_mask |= bgpio_line2mask(gc, i);
276		else
277			*clear_mask |= bgpio_line2mask(gc, i);
278	}
279}
280
281static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
282					  unsigned long *mask,
283					  unsigned long *bits,
284					  void __iomem *reg)
285{
286	unsigned long flags;
287	unsigned long set_mask, clear_mask;
288
289	spin_lock_irqsave(&gc->bgpio_lock, flags);
290
291	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
292
293	gc->bgpio_data |= set_mask;
294	gc->bgpio_data &= ~clear_mask;
295
296	gc->write_reg(reg, gc->bgpio_data);
297
298	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
299}
300
301static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
302			       unsigned long *bits)
303{
304	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);
305}
306
307static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
308				   unsigned long *bits)
309{
310	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);
311}
312
313static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
314					  unsigned long *mask,
315					  unsigned long *bits)
316{
317	unsigned long set_mask, clear_mask;
318
319	bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
320
321	if (set_mask)
322		gc->write_reg(gc->reg_set, set_mask);
323	if (clear_mask)
324		gc->write_reg(gc->reg_clr, clear_mask);
325}
326
327static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
328{
329	return 0;
330}
331
332static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
333				int val)
334{
335	return -EINVAL;
336}
337
338static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
339				int val)
340{
341	gc->set(gc, gpio, val);
342
343	return 0;
344}
345
346static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
347{
348	unsigned long flags;
349
350	spin_lock_irqsave(&gc->bgpio_lock, flags);
351
352	gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
353
354	if (gc->reg_dir_in)
355		gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);
356	if (gc->reg_dir_out)
357		gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);
358
359	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
360
361	return 0;
362}
363
364static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
365{
366	/* Return 0 if output, 1 if input */
367	if (gc->bgpio_dir_unreadable) {
368		if (gc->bgpio_dir & bgpio_line2mask(gc, gpio))
369			return GPIO_LINE_DIRECTION_OUT;
370		return GPIO_LINE_DIRECTION_IN;
371	}
372
373	if (gc->reg_dir_out) {
374		if (gc->read_reg(gc->reg_dir_out) & bgpio_line2mask(gc, gpio))
375			return GPIO_LINE_DIRECTION_OUT;
376		return GPIO_LINE_DIRECTION_IN;
377	}
378
379	if (gc->reg_dir_in)
380		if (!(gc->read_reg(gc->reg_dir_in) & bgpio_line2mask(gc, gpio)))
381			return GPIO_LINE_DIRECTION_OUT;
382
383	return GPIO_LINE_DIRECTION_IN;
384}
385
386static void bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
387{
388	unsigned long flags;
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
402static int bgpio_dir_out_dir_first(struct gpio_chip *gc, unsigned int gpio,
403				   int val)
404{
405	bgpio_dir_out(gc, gpio, val);
406	gc->set(gc, gpio, val);
407	return 0;
408}
409
410static int bgpio_dir_out_val_first(struct gpio_chip *gc, unsigned int gpio,
411				   int val)
412{
413	gc->set(gc, gpio, val);
414	bgpio_dir_out(gc, gpio, val);
415	return 0;
416}
417
418static 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 */
488static 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
539static 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		gc->reg_dir_out = dirout;
546		gc->reg_dir_in = dirin;
547		if (flags & BGPIOF_NO_SET_ON_INPUT)
548			gc->direction_output = bgpio_dir_out_dir_first;
549		else
550			gc->direction_output = bgpio_dir_out_val_first;
551		gc->direction_input = bgpio_dir_in;
552		gc->get_direction = bgpio_get_dir;
553	} else {
554		if (flags & BGPIOF_NO_OUTPUT)
555			gc->direction_output = bgpio_dir_out_err;
556		else
557			gc->direction_output = bgpio_simple_dir_out;
558		gc->direction_input = bgpio_simple_dir_in;
559	}
560
561	return 0;
562}
563
564static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
565{
566	if (gpio_pin < chip->ngpio)
567		return 0;
568
569	return -EINVAL;
570}
571
572/**
573 * bgpio_init() - Initialize generic GPIO accessor functions
574 * @gc: the GPIO chip to set up
575 * @dev: the parent device of the new GPIO chip (compulsory)
576 * @sz: the size (width) of the MMIO registers in bytes, typically 1, 2 or 4
577 * @dat: MMIO address for the register to READ the value of the GPIO lines, it
578 *	is expected that a 1 in the corresponding bit in this register means the
579 *	line is asserted
580 * @set: MMIO address for the register to SET the value of the GPIO lines, it is
581 *	expected that we write the line with 1 in this register to drive the GPIO line
582 *	high.
583 * @clr: MMIO address for the register to CLEAR the value of the GPIO lines, it is
584 *	expected that we write the line with 1 in this register to drive the GPIO line
585 *	low. It is allowed to leave this address as NULL, in that case the SET register
586 *	will be assumed to also clear the GPIO lines, by actively writing the line
587 *	with 0.
588 * @dirout: MMIO address for the register to set the line as OUTPUT. It is assumed
589 *	that setting a line to 1 in this register will turn that line into an
590 *	output line. Conversely, setting the line to 0 will turn that line into
591 *	an input.
592 * @dirin: MMIO address for the register to set this line as INPUT. It is assumed
593 *	that setting a line to 1 in this register will turn that line into an
594 *	input line. Conversely, setting the line to 0 will turn that line into
595 *	an output.
596 * @flags: Different flags that will affect the behaviour of the device, such as
597 *	endianness etc.
598 */
599int bgpio_init(struct gpio_chip *gc, struct device *dev,
600	       unsigned long sz, void __iomem *dat, void __iomem *set,
601	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
602	       unsigned long flags)
603{
604	int ret;
605
606	if (!is_power_of_2(sz))
607		return -EINVAL;
608
609	gc->bgpio_bits = sz * 8;
610	if (gc->bgpio_bits > BITS_PER_LONG)
611		return -EINVAL;
612
613	spin_lock_init(&gc->bgpio_lock);
614	gc->parent = dev;
615	gc->label = dev_name(dev);
616	gc->base = -1;
617	gc->ngpio = gc->bgpio_bits;
618	gc->request = bgpio_request;
619	gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);
620
621	ret = bgpio_setup_io(gc, dat, set, clr, flags);
622	if (ret)
623		return ret;
624
625	ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
626	if (ret)
627		return ret;
628
629	ret = bgpio_setup_direction(gc, dirout, dirin, flags);
630	if (ret)
631		return ret;
632
633	gc->bgpio_data = gc->read_reg(gc->reg_dat);
634	if (gc->set == bgpio_set_set &&
635			!(flags & BGPIOF_UNREADABLE_REG_SET))
636		gc->bgpio_data = gc->read_reg(gc->reg_set);
637
638	if (flags & BGPIOF_UNREADABLE_REG_DIR)
639		gc->bgpio_dir_unreadable = true;
640
641	/*
642	 * Inspect hardware to find initial direction setting.
643	 */
644	if ((gc->reg_dir_out || gc->reg_dir_in) &&
645	    !(flags & BGPIOF_UNREADABLE_REG_DIR)) {
646		if (gc->reg_dir_out)
647			gc->bgpio_dir = gc->read_reg(gc->reg_dir_out);
648		else if (gc->reg_dir_in)
649			gc->bgpio_dir = ~gc->read_reg(gc->reg_dir_in);
650		/*
651		 * If we have two direction registers, synchronise
652		 * input setting to output setting, the library
653		 * can not handle a line being input and output at
654		 * the same time.
655		 */
656		if (gc->reg_dir_out && gc->reg_dir_in)
657			gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);
658	}
659
660	return ret;
661}
662EXPORT_SYMBOL_GPL(bgpio_init);
663
664#if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
665
666static void __iomem *bgpio_map(struct platform_device *pdev,
667			       const char *name,
668			       resource_size_t sane_sz)
669{
670	struct resource *r;
671	resource_size_t sz;
672
673	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
674	if (!r)
675		return NULL;
676
677	sz = resource_size(r);
678	if (sz != sane_sz)
679		return IOMEM_ERR_PTR(-EINVAL);
680
681	return devm_ioremap_resource(&pdev->dev, r);
682}
683
684#ifdef CONFIG_OF
685static const struct of_device_id bgpio_of_match[] = {
686	{ .compatible = "brcm,bcm6345-gpio" },
687	{ .compatible = "wd,mbl-gpio" },
688	{ .compatible = "ni,169445-nand-gpio" },
689	{ }
690};
691MODULE_DEVICE_TABLE(of, bgpio_of_match);
692
693static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
694					  unsigned long *flags)
695{
696	struct bgpio_pdata *pdata;
697
698	if (!of_match_device(bgpio_of_match, &pdev->dev))
699		return NULL;
700
701	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bgpio_pdata),
702			     GFP_KERNEL);
703	if (!pdata)
704		return ERR_PTR(-ENOMEM);
705
706	pdata->base = -1;
707
708	if (of_device_is_big_endian(pdev->dev.of_node))
709		*flags |= BGPIOF_BIG_ENDIAN_BYTE_ORDER;
710
711	if (of_property_read_bool(pdev->dev.of_node, "no-output"))
712		*flags |= BGPIOF_NO_OUTPUT;
713
714	return pdata;
715}
716#else
717static struct bgpio_pdata *bgpio_parse_dt(struct platform_device *pdev,
718					  unsigned long *flags)
719{
720	return NULL;
721}
722#endif /* CONFIG_OF */
723
724static int bgpio_pdev_probe(struct platform_device *pdev)
725{
726	struct device *dev = &pdev->dev;
727	struct resource *r;
728	void __iomem *dat;
729	void __iomem *set;
730	void __iomem *clr;
731	void __iomem *dirout;
732	void __iomem *dirin;
733	unsigned long sz;
734	unsigned long flags = 0;
735	int err;
736	struct gpio_chip *gc;
737	struct bgpio_pdata *pdata;
738
739	pdata = bgpio_parse_dt(pdev, &flags);
740	if (IS_ERR(pdata))
741		return PTR_ERR(pdata);
742
743	if (!pdata) {
744		pdata = dev_get_platdata(dev);
745		flags = pdev->id_entry->driver_data;
746	}
747
748	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
749	if (!r)
750		return -EINVAL;
751
752	sz = resource_size(r);
753
754	dat = bgpio_map(pdev, "dat", sz);
755	if (IS_ERR(dat))
756		return PTR_ERR(dat);
757
758	set = bgpio_map(pdev, "set", sz);
759	if (IS_ERR(set))
760		return PTR_ERR(set);
761
762	clr = bgpio_map(pdev, "clr", sz);
763	if (IS_ERR(clr))
764		return PTR_ERR(clr);
765
766	dirout = bgpio_map(pdev, "dirout", sz);
767	if (IS_ERR(dirout))
768		return PTR_ERR(dirout);
769
770	dirin = bgpio_map(pdev, "dirin", sz);
771	if (IS_ERR(dirin))
772		return PTR_ERR(dirin);
773
774	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
775	if (!gc)
776		return -ENOMEM;
777
778	err = bgpio_init(gc, dev, sz, dat, set, clr, dirout, dirin, flags);
779	if (err)
780		return err;
781
782	if (pdata) {
783		if (pdata->label)
784			gc->label = pdata->label;
785		gc->base = pdata->base;
786		if (pdata->ngpio > 0)
787			gc->ngpio = pdata->ngpio;
788	}
789
790	platform_set_drvdata(pdev, gc);
791
792	return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
793}
794
795static const struct platform_device_id bgpio_id_table[] = {
796	{
797		.name		= "basic-mmio-gpio",
798		.driver_data	= 0,
799	}, {
800		.name		= "basic-mmio-gpio-be",
801		.driver_data	= BGPIOF_BIG_ENDIAN,
802	},
803	{ }
804};
805MODULE_DEVICE_TABLE(platform, bgpio_id_table);
806
807static struct platform_driver bgpio_driver = {
808	.driver = {
809		.name = "basic-mmio-gpio",
810		.of_match_table = of_match_ptr(bgpio_of_match),
811	},
812	.id_table = bgpio_id_table,
813	.probe = bgpio_pdev_probe,
814};
815
816module_platform_driver(bgpio_driver);
817
818#endif /* CONFIG_GPIO_GENERIC_PLATFORM */
819
820MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
821MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
822MODULE_LICENSE("GPL");