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v3.15
 
  1/*
  2 * TI DaVinci GPIO Support
  3 *
  4 * Copyright (c) 2006-2007 David Brownell
  5 * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License as published by
  9 * the Free Software Foundation; either version 2 of the License, or
 10 * (at your option) any later version.
 11 */
 12#include <linux/gpio.h>
 
 13#include <linux/errno.h>
 14#include <linux/kernel.h>
 15#include <linux/clk.h>
 16#include <linux/err.h>
 17#include <linux/io.h>
 18#include <linux/irq.h>
 19#include <linux/irqdomain.h>
 20#include <linux/module.h>
 21#include <linux/of.h>
 22#include <linux/of_device.h>
 23#include <linux/platform_device.h>
 24#include <linux/platform_data/gpio-davinci.h>
 25#include <linux/irqchip/chained_irq.h>
 
 
 
 
 
 26
 27struct davinci_gpio_regs {
 28	u32	dir;
 29	u32	out_data;
 30	u32	set_data;
 31	u32	clr_data;
 32	u32	in_data;
 33	u32	set_rising;
 34	u32	clr_rising;
 35	u32	set_falling;
 36	u32	clr_falling;
 37	u32	intstat;
 38};
 39
 40typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
 41
 42#define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
 43
 44#define chip2controller(chip)	\
 45	container_of(chip, struct davinci_gpio_controller, chip)
 46
 47static void __iomem *gpio_base;
 
 48
 49static struct davinci_gpio_regs __iomem *gpio2regs(unsigned gpio)
 50{
 51	void __iomem *ptr;
 
 
 52
 53	if (gpio < 32 * 1)
 54		ptr = gpio_base + 0x10;
 55	else if (gpio < 32 * 2)
 56		ptr = gpio_base + 0x38;
 57	else if (gpio < 32 * 3)
 58		ptr = gpio_base + 0x60;
 59	else if (gpio < 32 * 4)
 60		ptr = gpio_base + 0x88;
 61	else if (gpio < 32 * 5)
 62		ptr = gpio_base + 0xb0;
 63	else
 64		ptr = NULL;
 65	return ptr;
 
 
 66}
 67
 68static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
 69{
 70	struct davinci_gpio_regs __iomem *g;
 71
 72	g = (__force struct davinci_gpio_regs __iomem *)irq_get_chip_data(irq);
 73
 74	return g;
 75}
 76
 77static int davinci_gpio_irq_setup(struct platform_device *pdev);
 78
 79/*--------------------------------------------------------------------------*/
 80
 81/* board setup code *MUST* setup pinmux and enable the GPIO clock. */
 82static inline int __davinci_direction(struct gpio_chip *chip,
 83			unsigned offset, bool out, int value)
 84{
 85	struct davinci_gpio_controller *d = chip2controller(chip);
 86	struct davinci_gpio_regs __iomem *g = d->regs;
 87	unsigned long flags;
 88	u32 temp;
 89	u32 mask = 1 << offset;
 
 90
 
 91	spin_lock_irqsave(&d->lock, flags);
 92	temp = readl_relaxed(&g->dir);
 93	if (out) {
 94		temp &= ~mask;
 95		writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
 96	} else {
 97		temp |= mask;
 98	}
 99	writel_relaxed(temp, &g->dir);
100	spin_unlock_irqrestore(&d->lock, flags);
101
102	return 0;
103}
104
105static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
106{
107	return __davinci_direction(chip, offset, false, 0);
108}
109
110static int
111davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
112{
113	return __davinci_direction(chip, offset, true, value);
114}
115
116/*
117 * Read the pin's value (works even if it's set up as output);
118 * returns zero/nonzero.
119 *
120 * Note that changes are synched to the GPIO clock, so reading values back
121 * right after you've set them may give old values.
122 */
123static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
124{
125	struct davinci_gpio_controller *d = chip2controller(chip);
126	struct davinci_gpio_regs __iomem *g = d->regs;
 
 
 
127
128	return (1 << offset) & readl_relaxed(&g->in_data);
129}
130
131/*
132 * Assuming the pin is muxed as a gpio output, set its output value.
133 */
134static void
135davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
136{
137	struct davinci_gpio_controller *d = chip2controller(chip);
138	struct davinci_gpio_regs __iomem *g = d->regs;
139
140	writel_relaxed((1 << offset), value ? &g->set_data : &g->clr_data);
141}
142
143static struct davinci_gpio_platform_data *
144davinci_gpio_get_pdata(struct platform_device *pdev)
145{
146	struct device_node *dn = pdev->dev.of_node;
147	struct davinci_gpio_platform_data *pdata;
148	int ret;
149	u32 val;
150
151	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
152		return pdev->dev.platform_data;
153
154	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
155	if (!pdata)
156		return NULL;
157
158	ret = of_property_read_u32(dn, "ti,ngpio", &val);
159	if (ret)
160		goto of_err;
161
162	pdata->ngpio = val;
163
164	ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
165	if (ret)
166		goto of_err;
167
168	pdata->gpio_unbanked = val;
169
170	return pdata;
171
172of_err:
173	dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
174	return NULL;
175}
176
177#ifdef CONFIG_OF_GPIO
178static int davinci_gpio_of_xlate(struct gpio_chip *gc,
179			     const struct of_phandle_args *gpiospec,
180			     u32 *flags)
181{
182	struct davinci_gpio_controller *chips = dev_get_drvdata(gc->dev);
183	struct davinci_gpio_platform_data *pdata = dev_get_platdata(gc->dev);
184
185	if (gpiospec->args[0] > pdata->ngpio)
186		return -EINVAL;
187
188	if (gc != &chips[gpiospec->args[0] / 32].chip)
189		return -EINVAL;
190
191	if (flags)
192		*flags = gpiospec->args[1];
193
194	return gpiospec->args[0] % 32;
 
195}
196#endif
197
198static int davinci_gpio_probe(struct platform_device *pdev)
199{
200	int i, base;
201	unsigned ngpio;
202	struct davinci_gpio_controller *chips;
203	struct davinci_gpio_platform_data *pdata;
204	struct davinci_gpio_regs __iomem *regs;
205	struct device *dev = &pdev->dev;
206	struct resource *res;
207
208	pdata = davinci_gpio_get_pdata(pdev);
209	if (!pdata) {
210		dev_err(dev, "No platform data found\n");
211		return -EINVAL;
212	}
213
214	dev->platform_data = pdata;
215
216	/*
217	 * The gpio banks conceptually expose a segmented bitmap,
218	 * and "ngpio" is one more than the largest zero-based
219	 * bit index that's valid.
220	 */
221	ngpio = pdata->ngpio;
222	if (ngpio == 0) {
223		dev_err(dev, "How many GPIOs?\n");
224		return -EINVAL;
225	}
226
227	if (WARN_ON(ARCH_NR_GPIOS < ngpio))
228		ngpio = ARCH_NR_GPIOS;
 
 
 
 
 
 
 
229
230	chips = devm_kzalloc(dev,
231			     ngpio * sizeof(struct davinci_gpio_controller),
232			     GFP_KERNEL);
233	if (!chips) {
234		dev_err(dev, "Memory allocation failed\n");
235		return -ENOMEM;
236	}
237
238	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
239	if (!res) {
240		dev_err(dev, "Invalid memory resource\n");
241		return -EBUSY;
242	}
243
244	gpio_base = devm_ioremap_resource(dev, res);
 
 
 
 
245	if (IS_ERR(gpio_base))
246		return PTR_ERR(gpio_base);
247
248	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
249		chips[i].chip.label = "DaVinci";
 
 
 
 
 
 
 
 
 
 
250
251		chips[i].chip.direction_input = davinci_direction_in;
252		chips[i].chip.get = davinci_gpio_get;
253		chips[i].chip.direction_output = davinci_direction_out;
254		chips[i].chip.set = davinci_gpio_set;
255
256		chips[i].chip.base = base;
257		chips[i].chip.ngpio = ngpio - base;
258		if (chips[i].chip.ngpio > 32)
259			chips[i].chip.ngpio = 32;
260
261#ifdef CONFIG_OF_GPIO
262		chips[i].chip.of_gpio_n_cells = 2;
263		chips[i].chip.of_xlate = davinci_gpio_of_xlate;
264		chips[i].chip.dev = dev;
265		chips[i].chip.of_node = dev->of_node;
266#endif
267		spin_lock_init(&chips[i].lock);
268
269		regs = gpio2regs(base);
270		chips[i].regs = regs;
271		chips[i].set_data = &regs->set_data;
272		chips[i].clr_data = &regs->clr_data;
273		chips[i].in_data = &regs->in_data;
274
275		gpiochip_add(&chips[i].chip);
276	}
 
 
 
 
 
277
278	platform_set_drvdata(pdev, chips);
279	davinci_gpio_irq_setup(pdev);
 
 
 
280	return 0;
281}
282
283/*--------------------------------------------------------------------------*/
284/*
285 * We expect irqs will normally be set up as input pins, but they can also be
286 * used as output pins ... which is convenient for testing.
287 *
288 * NOTE:  The first few GPIOs also have direct INTC hookups in addition
289 * to their GPIOBNK0 irq, with a bit less overhead.
290 *
291 * All those INTC hookups (direct, plus several IRQ banks) can also
292 * serve as EDMA event triggers.
293 */
294
295static void gpio_irq_disable(struct irq_data *d)
296{
297	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
298	u32 mask = (u32) irq_data_get_irq_handler_data(d);
299
300	writel_relaxed(mask, &g->clr_falling);
301	writel_relaxed(mask, &g->clr_rising);
302}
303
304static void gpio_irq_enable(struct irq_data *d)
305{
306	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
307	u32 mask = (u32) irq_data_get_irq_handler_data(d);
308	unsigned status = irqd_get_trigger_type(d);
309
310	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
311	if (!status)
312		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
313
314	if (status & IRQ_TYPE_EDGE_FALLING)
315		writel_relaxed(mask, &g->set_falling);
316	if (status & IRQ_TYPE_EDGE_RISING)
317		writel_relaxed(mask, &g->set_rising);
318}
319
320static int gpio_irq_type(struct irq_data *d, unsigned trigger)
321{
322	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
323		return -EINVAL;
324
325	return 0;
326}
327
328static struct irq_chip gpio_irqchip = {
329	.name		= "GPIO",
330	.irq_enable	= gpio_irq_enable,
331	.irq_disable	= gpio_irq_disable,
332	.irq_set_type	= gpio_irq_type,
333	.flags		= IRQCHIP_SET_TYPE_MASKED,
334};
335
336static void
337gpio_irq_handler(unsigned irq, struct irq_desc *desc)
338{
339	struct davinci_gpio_regs __iomem *g;
340	u32 mask = 0xffff;
 
341	struct davinci_gpio_controller *d;
 
342
343	d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc);
344	g = (struct davinci_gpio_regs __iomem *)d->regs;
 
 
345
346	/* we only care about one bank */
347	if (irq & 1)
348		mask <<= 16;
349
350	/* temporarily mask (level sensitive) parent IRQ */
351	chained_irq_enter(irq_desc_get_chip(desc), desc);
352	while (1) {
353		u32		status;
354		int		bit;
 
355
356		/* ack any irqs */
357		status = readl_relaxed(&g->intstat) & mask;
358		if (!status)
359			break;
360		writel_relaxed(status, &g->intstat);
361
362		/* now demux them to the right lowlevel handler */
363
364		while (status) {
365			bit = __ffs(status);
366			status &= ~BIT(bit);
367			generic_handle_irq(
368				irq_find_mapping(d->irq_domain,
369						 d->chip.base + bit));
 
 
 
370		}
371	}
372	chained_irq_exit(irq_desc_get_chip(desc), desc);
373	/* now it may re-trigger */
374}
375
376static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
377{
378	struct davinci_gpio_controller *d = chip2controller(chip);
379
380	if (d->irq_domain)
381		return irq_create_mapping(d->irq_domain, d->chip.base + offset);
382	else
383		return -ENXIO;
384}
385
386static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
387{
388	struct davinci_gpio_controller *d = chip2controller(chip);
389
390	/*
391	 * NOTE:  we assume for now that only irqs in the first gpio_chip
392	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
393	 */
394	if (offset < d->gpio_unbanked)
395		return d->gpio_irq + offset;
396	else
397		return -ENODEV;
398}
399
400static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
401{
402	struct davinci_gpio_controller *d;
403	struct davinci_gpio_regs __iomem *g;
404	u32 mask;
405
406	d = (struct davinci_gpio_controller *)data->handler_data;
407	g = (struct davinci_gpio_regs __iomem *)d->regs;
408	mask = __gpio_mask(data->irq - d->gpio_irq);
 
 
 
 
 
 
 
409
410	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
411		return -EINVAL;
412
413	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
414		     ? &g->set_falling : &g->clr_falling);
415	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
416		     ? &g->set_rising : &g->clr_rising);
417
418	return 0;
419}
420
421static int
422davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
423		     irq_hw_number_t hw)
424{
425	struct davinci_gpio_regs __iomem *g = gpio2regs(hw);
 
 
426
427	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
428				"davinci_gpio");
429	irq_set_irq_type(irq, IRQ_TYPE_NONE);
430	irq_set_chip_data(irq, (__force void *)g);
431	irq_set_handler_data(irq, (void *)__gpio_mask(hw));
432	set_irq_flags(irq, IRQF_VALID);
433
434	return 0;
435}
436
437static const struct irq_domain_ops davinci_gpio_irq_ops = {
438	.map = davinci_gpio_irq_map,
439	.xlate = irq_domain_xlate_onetwocell,
440};
441
442static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
443{
444	static struct irq_chip_type gpio_unbanked;
445
446	gpio_unbanked = *container_of(irq_get_chip(irq),
447				      struct irq_chip_type, chip);
448
449	return &gpio_unbanked.chip;
450};
451
452static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
453{
454	static struct irq_chip gpio_unbanked;
455
456	gpio_unbanked = *irq_get_chip(irq);
457	return &gpio_unbanked;
458};
459
460static const struct of_device_id davinci_gpio_ids[];
461
462/*
463 * NOTE:  for suspend/resume, probably best to make a platform_device with
464 * suspend_late/resume_resume calls hooking into results of the set_wake()
465 * calls ... so if no gpios are wakeup events the clock can be disabled,
466 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
467 * (dm6446) can be set appropriately for GPIOV33 pins.
468 */
469
470static int davinci_gpio_irq_setup(struct platform_device *pdev)
471{
472	unsigned	gpio, bank;
473	int		irq;
474	struct clk	*clk;
475	u32		binten = 0;
476	unsigned	ngpio, bank_irq;
477	struct device *dev = &pdev->dev;
478	struct resource	*res;
479	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
480	struct davinci_gpio_platform_data *pdata = dev->platform_data;
481	struct davinci_gpio_regs __iomem *g;
482	struct irq_domain	*irq_domain = NULL;
483	const struct of_device_id *match;
484	struct irq_chip *irq_chip;
 
485	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
486
487	/*
488	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
489	 */
490	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
491	match = of_match_device(of_match_ptr(davinci_gpio_ids),
492				dev);
493	if (match)
494		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data;
495
496	ngpio = pdata->ngpio;
497	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
498	if (!res) {
499		dev_err(dev, "Invalid IRQ resource\n");
500		return -EBUSY;
501	}
502
503	bank_irq = res->start;
504
505	if (!bank_irq) {
506		dev_err(dev, "Invalid IRQ resource\n");
507		return -ENODEV;
508	}
509
510	clk = devm_clk_get(dev, "gpio");
511	if (IS_ERR(clk)) {
512		printk(KERN_ERR "Error %ld getting gpio clock?\n",
513		       PTR_ERR(clk));
514		return PTR_ERR(clk);
515	}
516	clk_prepare_enable(clk);
517
518	if (!pdata->gpio_unbanked) {
519		irq = irq_alloc_descs(-1, 0, ngpio, 0);
520		if (irq < 0) {
521			dev_err(dev, "Couldn't allocate IRQ numbers\n");
522			return irq;
523		}
524
525		irq_domain = irq_domain_add_legacy(NULL, ngpio, irq, 0,
526							&davinci_gpio_irq_ops,
527							chips);
528		if (!irq_domain) {
529			dev_err(dev, "Couldn't register an IRQ domain\n");
530			return -ENODEV;
531		}
532	}
533
534	/*
535	 * Arrange gpio_to_irq() support, handling either direct IRQs or
536	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
537	 * IRQs, while the others use banked IRQs, would need some setup
538	 * tweaks to recognize hardware which can do that.
539	 */
540	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
541		chips[bank].chip.to_irq = gpio_to_irq_banked;
542		chips[bank].irq_domain = irq_domain;
543	}
544
545	/*
546	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
547	 * controller only handling trigger modes.  We currently assume no
548	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
549	 */
550	if (pdata->gpio_unbanked) {
551		/* pass "bank 0" GPIO IRQs to AINTC */
552		chips[0].chip.to_irq = gpio_to_irq_unbanked;
553		chips[0].gpio_irq = bank_irq;
554		chips[0].gpio_unbanked = pdata->gpio_unbanked;
555		binten = BIT(0);
556
557		/* AINTC handles mask/unmask; GPIO handles triggering */
558		irq = bank_irq;
559		irq_chip = gpio_get_irq_chip(irq);
560		irq_chip->name = "GPIO-AINTC";
561		irq_chip->irq_set_type = gpio_irq_type_unbanked;
562
563		/* default trigger: both edges */
564		g = gpio2regs(0);
565		writel_relaxed(~0, &g->set_falling);
566		writel_relaxed(~0, &g->set_rising);
567
568		/* set the direct IRQs up to use that irqchip */
569		for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) {
570			irq_set_chip(irq, irq_chip);
571			irq_set_handler_data(irq, &chips[gpio / 32]);
572			irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
 
573		}
574
575		goto done;
576	}
577
578	/*
579	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
580	 * then chain through our own handler.
581	 */
582	for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) {
583		/* disabled by default, enabled only as needed */
584		g = gpio2regs(gpio);
 
 
 
585		writel_relaxed(~0, &g->clr_falling);
586		writel_relaxed(~0, &g->clr_rising);
587
588		/* set up all irqs in this bank */
589		irq_set_chained_handler(bank_irq, gpio_irq_handler);
590
591		/*
592		 * Each chip handles 32 gpios, and each irq bank consists of 16
593		 * gpio irqs. Pass the irq bank's corresponding controller to
594		 * the chained irq handler.
595		 */
596		irq_set_handler_data(bank_irq, &chips[gpio / 32]);
 
 
 
 
 
 
 
 
 
 
 
 
597
598		binten |= BIT(bank);
599	}
600
601done:
602	/*
603	 * BINTEN -- per-bank interrupt enable. genirq would also let these
604	 * bits be set/cleared dynamically.
605	 */
606	writel_relaxed(binten, gpio_base + BINTEN);
607
608	return 0;
609}
610
611#if IS_ENABLED(CONFIG_OF)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
612static const struct of_device_id davinci_gpio_ids[] = {
613	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
 
614	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
615	{ /* sentinel */ },
616};
617MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
618#endif
619
620static struct platform_driver davinci_gpio_driver = {
621	.probe		= davinci_gpio_probe,
622	.driver		= {
623		.name		= "davinci_gpio",
624		.owner		= THIS_MODULE,
625		.of_match_table	= of_match_ptr(davinci_gpio_ids),
626	},
627};
628
629/**
630 * GPIO driver registration needs to be done before machine_init functions
631 * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
632 */
633static int __init davinci_gpio_drv_reg(void)
634{
635	return platform_driver_register(&davinci_gpio_driver);
636}
637postcore_initcall(davinci_gpio_drv_reg);
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * TI DaVinci GPIO Support
  4 *
  5 * Copyright (c) 2006-2007 David Brownell
  6 * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
 
 
 
 
 
  7 */
  8
  9#include <linux/gpio/driver.h>
 10#include <linux/errno.h>
 11#include <linux/kernel.h>
 12#include <linux/clk.h>
 13#include <linux/err.h>
 14#include <linux/io.h>
 15#include <linux/irq.h>
 16#include <linux/irqdomain.h>
 17#include <linux/module.h>
 18#include <linux/pinctrl/consumer.h>
 
 19#include <linux/platform_device.h>
 20#include <linux/property.h>
 21#include <linux/irqchip/chained_irq.h>
 22#include <linux/spinlock.h>
 23#include <linux/pm_runtime.h>
 24
 25#define MAX_REGS_BANKS 5
 26#define MAX_INT_PER_BANK 32
 27
 28struct davinci_gpio_regs {
 29	u32	dir;
 30	u32	out_data;
 31	u32	set_data;
 32	u32	clr_data;
 33	u32	in_data;
 34	u32	set_rising;
 35	u32	clr_rising;
 36	u32	set_falling;
 37	u32	clr_falling;
 38	u32	intstat;
 39};
 40
 41typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
 42
 43#define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
 44
 
 
 
 45static void __iomem *gpio_base;
 46static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0};
 47
 48struct davinci_gpio_irq_data {
 49	void __iomem			*regs;
 50	struct davinci_gpio_controller	*chip;
 51	int				bank_num;
 52};
 53
 54struct davinci_gpio_controller {
 55	struct gpio_chip	chip;
 56	struct irq_domain	*irq_domain;
 57	/* Serialize access to GPIO registers */
 58	spinlock_t		lock;
 59	void __iomem		*regs[MAX_REGS_BANKS];
 60	int			gpio_unbanked;
 61	int			irqs[MAX_INT_PER_BANK];
 62	struct davinci_gpio_regs context[MAX_REGS_BANKS];
 63	u32			binten_context;
 64};
 65
 66static inline u32 __gpio_mask(unsigned gpio)
 67{
 68	return 1 << (gpio % 32);
 69}
 70
 71static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d)
 72{
 73	struct davinci_gpio_regs __iomem *g;
 74
 75	g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d);
 76
 77	return g;
 78}
 79
 80static int davinci_gpio_irq_setup(struct platform_device *pdev);
 81
 82/*--------------------------------------------------------------------------*/
 83
 84/* board setup code *MUST* setup pinmux and enable the GPIO clock. */
 85static inline int __davinci_direction(struct gpio_chip *chip,
 86			unsigned offset, bool out, int value)
 87{
 88	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
 89	struct davinci_gpio_regs __iomem *g;
 90	unsigned long flags;
 91	u32 temp;
 92	int bank = offset / 32;
 93	u32 mask = __gpio_mask(offset);
 94
 95	g = d->regs[bank];
 96	spin_lock_irqsave(&d->lock, flags);
 97	temp = readl_relaxed(&g->dir);
 98	if (out) {
 99		temp &= ~mask;
100		writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
101	} else {
102		temp |= mask;
103	}
104	writel_relaxed(temp, &g->dir);
105	spin_unlock_irqrestore(&d->lock, flags);
106
107	return 0;
108}
109
110static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
111{
112	return __davinci_direction(chip, offset, false, 0);
113}
114
115static int
116davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
117{
118	return __davinci_direction(chip, offset, true, value);
119}
120
121/*
122 * Read the pin's value (works even if it's set up as output);
123 * returns zero/nonzero.
124 *
125 * Note that changes are synched to the GPIO clock, so reading values back
126 * right after you've set them may give old values.
127 */
128static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
129{
130	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
131	struct davinci_gpio_regs __iomem *g;
132	int bank = offset / 32;
133
134	g = d->regs[bank];
135
136	return !!(__gpio_mask(offset) & readl_relaxed(&g->in_data));
137}
138
139/*
140 * Assuming the pin is muxed as a gpio output, set its output value.
141 */
142static void
143davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
144{
145	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
146	struct davinci_gpio_regs __iomem *g;
147	int bank = offset / 32;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
148
149	g = d->regs[bank];
 
150
151	writel_relaxed(__gpio_mask(offset),
152		       value ? &g->set_data : &g->clr_data);
153}
 
154
155static int davinci_gpio_probe(struct platform_device *pdev)
156{
157	int bank, i, ret = 0;
158	unsigned int ngpio, nbank, nirq, gpio_unbanked;
159	struct davinci_gpio_controller *chips;
 
 
160	struct device *dev = &pdev->dev;
 
 
 
 
 
 
 
 
 
161
162	/*
163	 * The gpio banks conceptually expose a segmented bitmap,
164	 * and "ngpio" is one more than the largest zero-based
165	 * bit index that's valid.
166	 */
167	ret = device_property_read_u32(dev, "ti,ngpio", &ngpio);
168	if (ret)
169		return dev_err_probe(dev, ret, "Failed to get the number of GPIOs\n");
170	if (ngpio == 0)
171		return dev_err_probe(dev, -EINVAL, "How many GPIOs?\n");
172
173	/*
174	 * If there are unbanked interrupts then the number of
175	 * interrupts is equal to number of gpios else all are banked so
176	 * number of interrupts is equal to number of banks(each with 16 gpios)
177	 */
178	ret = device_property_read_u32(dev, "ti,davinci-gpio-unbanked",
179				       &gpio_unbanked);
180	if (ret)
181		return dev_err_probe(dev, ret, "Failed to get the unbanked GPIOs property\n");
182
183	if (gpio_unbanked)
184		nirq = gpio_unbanked;
185	else
186		nirq = DIV_ROUND_UP(ngpio, 16);
 
 
 
187
188	if (nirq > MAX_INT_PER_BANK) {
189		dev_err(dev, "Too many IRQs!\n");
190		return -EINVAL;
 
191	}
192
193	chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
194	if (!chips)
195		return -ENOMEM;
196
197	gpio_base = devm_platform_ioremap_resource(pdev, 0);
198	if (IS_ERR(gpio_base))
199		return PTR_ERR(gpio_base);
200
201	for (i = 0; i < nirq; i++) {
202		chips->irqs[i] = platform_get_irq(pdev, i);
203		if (chips->irqs[i] < 0)
204			return chips->irqs[i];
205	}
206
207	chips->chip.label = dev_name(dev);
208
209	chips->chip.direction_input = davinci_direction_in;
210	chips->chip.get = davinci_gpio_get;
211	chips->chip.direction_output = davinci_direction_out;
212	chips->chip.set = davinci_gpio_set;
213
214	chips->chip.ngpio = ngpio;
215	chips->chip.base = -1;
 
 
 
 
 
 
 
216
217#ifdef CONFIG_OF_GPIO
218	chips->chip.parent = dev;
219	chips->chip.request = gpiochip_generic_request;
220	chips->chip.free = gpiochip_generic_free;
 
221#endif
222	spin_lock_init(&chips->lock);
223
224	chips->gpio_unbanked = gpio_unbanked;
 
 
 
 
225
226	nbank = DIV_ROUND_UP(ngpio, 32);
227	for (bank = 0; bank < nbank; bank++)
228		chips->regs[bank] = gpio_base + offset_array[bank];
229
230	ret = devm_gpiochip_add_data(dev, &chips->chip, chips);
231	if (ret)
232		return ret;
233
234	platform_set_drvdata(pdev, chips);
235	ret = davinci_gpio_irq_setup(pdev);
236	if (ret)
237		return ret;
238
239	return 0;
240}
241
242/*--------------------------------------------------------------------------*/
243/*
244 * We expect irqs will normally be set up as input pins, but they can also be
245 * used as output pins ... which is convenient for testing.
246 *
247 * NOTE:  The first few GPIOs also have direct INTC hookups in addition
248 * to their GPIOBNK0 irq, with a bit less overhead.
249 *
250 * All those INTC hookups (direct, plus several IRQ banks) can also
251 * serve as EDMA event triggers.
252 */
253
254static void gpio_irq_mask(struct irq_data *d)
255{
256	struct davinci_gpio_regs __iomem *g = irq2regs(d);
257	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
258
259	writel_relaxed(mask, &g->clr_falling);
260	writel_relaxed(mask, &g->clr_rising);
261}
262
263static void gpio_irq_unmask(struct irq_data *d)
264{
265	struct davinci_gpio_regs __iomem *g = irq2regs(d);
266	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
267	unsigned status = irqd_get_trigger_type(d);
268
269	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
270	if (!status)
271		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
272
273	if (status & IRQ_TYPE_EDGE_FALLING)
274		writel_relaxed(mask, &g->set_falling);
275	if (status & IRQ_TYPE_EDGE_RISING)
276		writel_relaxed(mask, &g->set_rising);
277}
278
279static int gpio_irq_type(struct irq_data *d, unsigned trigger)
280{
281	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
282		return -EINVAL;
283
284	return 0;
285}
286
287static struct irq_chip gpio_irqchip = {
288	.name		= "GPIO",
289	.irq_unmask	= gpio_irq_unmask,
290	.irq_mask	= gpio_irq_mask,
291	.irq_set_type	= gpio_irq_type,
292	.flags		= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE,
293};
294
295static void gpio_irq_handler(struct irq_desc *desc)
 
296{
297	struct davinci_gpio_regs __iomem *g;
298	u32 mask = 0xffff;
299	int bank_num;
300	struct davinci_gpio_controller *d;
301	struct davinci_gpio_irq_data *irqdata;
302
303	irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc);
304	bank_num = irqdata->bank_num;
305	g = irqdata->regs;
306	d = irqdata->chip;
307
308	/* we only care about one bank */
309	if ((bank_num % 2) == 1)
310		mask <<= 16;
311
312	/* temporarily mask (level sensitive) parent IRQ */
313	chained_irq_enter(irq_desc_get_chip(desc), desc);
314	while (1) {
315		u32		status;
316		int		bit;
317		irq_hw_number_t hw_irq;
318
319		/* ack any irqs */
320		status = readl_relaxed(&g->intstat) & mask;
321		if (!status)
322			break;
323		writel_relaxed(status, &g->intstat);
324
325		/* now demux them to the right lowlevel handler */
326
327		while (status) {
328			bit = __ffs(status);
329			status &= ~BIT(bit);
330			/* Max number of gpios per controller is 144 so
331			 * hw_irq will be in [0..143]
332			 */
333			hw_irq = (bank_num / 2) * 32 + bit;
334
335			generic_handle_domain_irq(d->irq_domain, hw_irq);
336		}
337	}
338	chained_irq_exit(irq_desc_get_chip(desc), desc);
339	/* now it may re-trigger */
340}
341
342static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
343{
344	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
345
346	if (d->irq_domain)
347		return irq_create_mapping(d->irq_domain, offset);
348	else
349		return -ENXIO;
350}
351
352static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
353{
354	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
355
356	/*
357	 * NOTE:  we assume for now that only irqs in the first gpio_chip
358	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
359	 */
360	if (offset < d->gpio_unbanked)
361		return d->irqs[offset];
362	else
363		return -ENODEV;
364}
365
366static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
367{
368	struct davinci_gpio_controller *d;
369	struct davinci_gpio_regs __iomem *g;
370	u32 mask, i;
371
372	d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
373	g = (struct davinci_gpio_regs __iomem *)d->regs[0];
374	for (i = 0; i < MAX_INT_PER_BANK; i++)
375		if (data->irq == d->irqs[i])
376			break;
377
378	if (i == MAX_INT_PER_BANK)
379		return -EINVAL;
380
381	mask = __gpio_mask(i);
382
383	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
384		return -EINVAL;
385
386	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
387		     ? &g->set_falling : &g->clr_falling);
388	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
389		     ? &g->set_rising : &g->clr_rising);
390
391	return 0;
392}
393
394static int
395davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
396		     irq_hw_number_t hw)
397{
398	struct davinci_gpio_controller *chips =
399				(struct davinci_gpio_controller *)d->host_data;
400	struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32];
401
402	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
403				"davinci_gpio");
404	irq_set_irq_type(irq, IRQ_TYPE_NONE);
405	irq_set_chip_data(irq, (__force void *)g);
406	irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw));
 
407
408	return 0;
409}
410
411static const struct irq_domain_ops davinci_gpio_irq_ops = {
412	.map = davinci_gpio_irq_map,
413	.xlate = irq_domain_xlate_onetwocell,
414};
415
416static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
417{
418	static struct irq_chip_type gpio_unbanked;
419
420	gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq));
 
421
422	return &gpio_unbanked.chip;
423};
424
425static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
426{
427	static struct irq_chip gpio_unbanked;
428
429	gpio_unbanked = *irq_get_chip(irq);
430	return &gpio_unbanked;
431};
432
433static const struct of_device_id davinci_gpio_ids[];
434
435/*
436 * NOTE:  for suspend/resume, probably best to make a platform_device with
437 * suspend_late/resume_resume calls hooking into results of the set_wake()
438 * calls ... so if no gpios are wakeup events the clock can be disabled,
439 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
440 * (dm6446) can be set appropriately for GPIOV33 pins.
441 */
442
443static int davinci_gpio_irq_setup(struct platform_device *pdev)
444{
445	unsigned	gpio, bank;
446	int		irq;
447	struct clk	*clk;
448	u32		binten = 0;
449	unsigned	ngpio;
450	struct device *dev = &pdev->dev;
 
451	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
 
452	struct davinci_gpio_regs __iomem *g;
453	struct irq_domain	*irq_domain = NULL;
 
454	struct irq_chip *irq_chip;
455	struct davinci_gpio_irq_data *irqdata;
456	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
457
458	/*
459	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
460	 */
461	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
462	if (dev->of_node)
463		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)device_get_match_data(dev);
 
 
 
 
 
 
 
 
 
 
 
464
465	ngpio = chips->chip.ngpio;
 
 
 
466
467	clk = devm_clk_get_enabled(dev, "gpio");
468	if (IS_ERR(clk)) {
469		dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk));
 
470		return PTR_ERR(clk);
471	}
 
472
473	if (!chips->gpio_unbanked) {
474		irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0);
475		if (irq < 0) {
476			dev_err(dev, "Couldn't allocate IRQ numbers\n");
477			return irq;
478		}
479
480		irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0,
481							&davinci_gpio_irq_ops,
482							chips);
483		if (!irq_domain) {
484			dev_err(dev, "Couldn't register an IRQ domain\n");
485			return -ENODEV;
486		}
487	}
488
489	/*
490	 * Arrange gpiod_to_irq() support, handling either direct IRQs or
491	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
492	 * IRQs, while the others use banked IRQs, would need some setup
493	 * tweaks to recognize hardware which can do that.
494	 */
495	chips->chip.to_irq = gpio_to_irq_banked;
496	chips->irq_domain = irq_domain;
 
 
497
498	/*
499	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
500	 * controller only handling trigger modes.  We currently assume no
501	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
502	 */
503	if (chips->gpio_unbanked) {
504		/* pass "bank 0" GPIO IRQs to AINTC */
505		chips->chip.to_irq = gpio_to_irq_unbanked;
506
507		binten = GENMASK(chips->gpio_unbanked / 16, 0);
 
508
509		/* AINTC handles mask/unmask; GPIO handles triggering */
510		irq = chips->irqs[0];
511		irq_chip = gpio_get_irq_chip(irq);
512		irq_chip->name = "GPIO-AINTC";
513		irq_chip->irq_set_type = gpio_irq_type_unbanked;
514
515		/* default trigger: both edges */
516		g = chips->regs[0];
517		writel_relaxed(~0, &g->set_falling);
518		writel_relaxed(~0, &g->set_rising);
519
520		/* set the direct IRQs up to use that irqchip */
521		for (gpio = 0; gpio < chips->gpio_unbanked; gpio++) {
522			irq_set_chip(chips->irqs[gpio], irq_chip);
523			irq_set_handler_data(chips->irqs[gpio], chips);
524			irq_set_status_flags(chips->irqs[gpio],
525					     IRQ_TYPE_EDGE_BOTH);
526		}
527
528		goto done;
529	}
530
531	/*
532	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
533	 * then chain through our own handler.
534	 */
535	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 16) {
536		/* disabled by default, enabled only as needed
537		 * There are register sets for 32 GPIOs. 2 banks of 16
538		 * GPIOs are covered by each set of registers hence divide by 2
539		 */
540		g = chips->regs[bank / 2];
541		writel_relaxed(~0, &g->clr_falling);
542		writel_relaxed(~0, &g->clr_rising);
543
 
 
 
544		/*
545		 * Each chip handles 32 gpios, and each irq bank consists of 16
546		 * gpio irqs. Pass the irq bank's corresponding controller to
547		 * the chained irq handler.
548		 */
549		irqdata = devm_kzalloc(&pdev->dev,
550				       sizeof(struct
551					      davinci_gpio_irq_data),
552					      GFP_KERNEL);
553		if (!irqdata)
554			return -ENOMEM;
555
556		irqdata->regs = g;
557		irqdata->bank_num = bank;
558		irqdata->chip = chips;
559
560		irq_set_chained_handler_and_data(chips->irqs[bank],
561						 gpio_irq_handler, irqdata);
562
563		binten |= BIT(bank);
564	}
565
566done:
567	/*
568	 * BINTEN -- per-bank interrupt enable. genirq would also let these
569	 * bits be set/cleared dynamically.
570	 */
571	writel_relaxed(binten, gpio_base + BINTEN);
572
573	return 0;
574}
575
576static void davinci_gpio_save_context(struct davinci_gpio_controller *chips,
577				      u32 nbank)
578{
579	struct davinci_gpio_regs __iomem *g;
580	struct davinci_gpio_regs *context;
581	u32 bank;
582	void __iomem *base;
583
584	base = chips->regs[0] - offset_array[0];
585	chips->binten_context = readl_relaxed(base + BINTEN);
586
587	for (bank = 0; bank < nbank; bank++) {
588		g = chips->regs[bank];
589		context = &chips->context[bank];
590		context->dir = readl_relaxed(&g->dir);
591		context->set_data = readl_relaxed(&g->set_data);
592		context->set_rising = readl_relaxed(&g->set_rising);
593		context->set_falling = readl_relaxed(&g->set_falling);
594	}
595
596	/* Clear all interrupt status registers */
597	writel_relaxed(GENMASK(31, 0), &g->intstat);
598}
599
600static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips,
601					 u32 nbank)
602{
603	struct davinci_gpio_regs __iomem *g;
604	struct davinci_gpio_regs *context;
605	u32 bank;
606	void __iomem *base;
607
608	base = chips->regs[0] - offset_array[0];
609
610	if (readl_relaxed(base + BINTEN) != chips->binten_context)
611		writel_relaxed(chips->binten_context, base + BINTEN);
612
613	for (bank = 0; bank < nbank; bank++) {
614		g = chips->regs[bank];
615		context = &chips->context[bank];
616		if (readl_relaxed(&g->dir) != context->dir)
617			writel_relaxed(context->dir, &g->dir);
618		if (readl_relaxed(&g->set_data) != context->set_data)
619			writel_relaxed(context->set_data, &g->set_data);
620		if (readl_relaxed(&g->set_rising) != context->set_rising)
621			writel_relaxed(context->set_rising, &g->set_rising);
622		if (readl_relaxed(&g->set_falling) != context->set_falling)
623			writel_relaxed(context->set_falling, &g->set_falling);
624	}
625}
626
627static int davinci_gpio_suspend(struct device *dev)
628{
629	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
630	u32 nbank = DIV_ROUND_UP(chips->chip.ngpio, 32);
631
632	davinci_gpio_save_context(chips, nbank);
633
634	return 0;
635}
636
637static int davinci_gpio_resume(struct device *dev)
638{
639	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
640	u32 nbank = DIV_ROUND_UP(chips->chip.ngpio, 32);
641
642	davinci_gpio_restore_context(chips, nbank);
643
644	return 0;
645}
646
647static DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend,
648			 davinci_gpio_resume);
649
650static const struct of_device_id davinci_gpio_ids[] = {
651	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
652	{ .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip},
653	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
654	{ /* sentinel */ },
655};
656MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
 
657
658static struct platform_driver davinci_gpio_driver = {
659	.probe		= davinci_gpio_probe,
660	.driver		= {
661		.name		= "davinci_gpio",
662		.pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops),
663		.of_match_table	= davinci_gpio_ids,
664	},
665};
666
667/*
668 * GPIO driver registration needs to be done before machine_init functions
669 * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
670 */
671static int __init davinci_gpio_drv_reg(void)
672{
673	return platform_driver_register(&davinci_gpio_driver);
674}
675postcore_initcall(davinci_gpio_drv_reg);
676
677static void __exit davinci_gpio_exit(void)
678{
679	platform_driver_unregister(&davinci_gpio_driver);
680}
681module_exit(davinci_gpio_exit);
682
683MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
684MODULE_DESCRIPTION("DAVINCI GPIO driver");
685MODULE_LICENSE("GPL");
686MODULE_ALIAS("platform:gpio-davinci");