xref: /linux/drivers/gpio/gpio-mxc.c (revision e80a48bade619ec5a92230b3d4ae84bfc2746822)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
4 // Copyright 2008 Juergen Beisert, kernel@pengutronix.de
5 //
6 // Based on code from Freescale Semiconductor,
7 // Authors: Daniel Mack, Juergen Beisert.
8 // Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
9 
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/irqchip/chained_irq.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/syscore_ops.h>
22 #include <linux/gpio/driver.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/bug.h>
26 
27 #define IMX_SCU_WAKEUP_OFF		0
28 #define IMX_SCU_WAKEUP_LOW_LVL		4
29 #define IMX_SCU_WAKEUP_FALL_EDGE	5
30 #define IMX_SCU_WAKEUP_RISE_EDGE	6
31 #define IMX_SCU_WAKEUP_HIGH_LVL		7
32 
33 /* device type dependent stuff */
34 struct mxc_gpio_hwdata {
35 	unsigned dr_reg;
36 	unsigned gdir_reg;
37 	unsigned psr_reg;
38 	unsigned icr1_reg;
39 	unsigned icr2_reg;
40 	unsigned imr_reg;
41 	unsigned isr_reg;
42 	int edge_sel_reg;
43 	unsigned low_level;
44 	unsigned high_level;
45 	unsigned rise_edge;
46 	unsigned fall_edge;
47 };
48 
49 struct mxc_gpio_reg_saved {
50 	u32 icr1;
51 	u32 icr2;
52 	u32 imr;
53 	u32 gdir;
54 	u32 edge_sel;
55 	u32 dr;
56 };
57 
58 struct mxc_gpio_port {
59 	struct list_head node;
60 	void __iomem *base;
61 	struct clk *clk;
62 	int irq;
63 	int irq_high;
64 	struct irq_domain *domain;
65 	struct gpio_chip gc;
66 	struct device *dev;
67 	u32 both_edges;
68 	struct mxc_gpio_reg_saved gpio_saved_reg;
69 	bool power_off;
70 	u32 wakeup_pads;
71 	bool is_pad_wakeup;
72 	u32 pad_type[32];
73 	const struct mxc_gpio_hwdata *hwdata;
74 };
75 
76 static struct mxc_gpio_hwdata imx1_imx21_gpio_hwdata = {
77 	.dr_reg		= 0x1c,
78 	.gdir_reg	= 0x00,
79 	.psr_reg	= 0x24,
80 	.icr1_reg	= 0x28,
81 	.icr2_reg	= 0x2c,
82 	.imr_reg	= 0x30,
83 	.isr_reg	= 0x34,
84 	.edge_sel_reg	= -EINVAL,
85 	.low_level	= 0x03,
86 	.high_level	= 0x02,
87 	.rise_edge	= 0x00,
88 	.fall_edge	= 0x01,
89 };
90 
91 static struct mxc_gpio_hwdata imx31_gpio_hwdata = {
92 	.dr_reg		= 0x00,
93 	.gdir_reg	= 0x04,
94 	.psr_reg	= 0x08,
95 	.icr1_reg	= 0x0c,
96 	.icr2_reg	= 0x10,
97 	.imr_reg	= 0x14,
98 	.isr_reg	= 0x18,
99 	.edge_sel_reg	= -EINVAL,
100 	.low_level	= 0x00,
101 	.high_level	= 0x01,
102 	.rise_edge	= 0x02,
103 	.fall_edge	= 0x03,
104 };
105 
106 static struct mxc_gpio_hwdata imx35_gpio_hwdata = {
107 	.dr_reg		= 0x00,
108 	.gdir_reg	= 0x04,
109 	.psr_reg	= 0x08,
110 	.icr1_reg	= 0x0c,
111 	.icr2_reg	= 0x10,
112 	.imr_reg	= 0x14,
113 	.isr_reg	= 0x18,
114 	.edge_sel_reg	= 0x1c,
115 	.low_level	= 0x00,
116 	.high_level	= 0x01,
117 	.rise_edge	= 0x02,
118 	.fall_edge	= 0x03,
119 };
120 
121 #define GPIO_DR			(port->hwdata->dr_reg)
122 #define GPIO_GDIR		(port->hwdata->gdir_reg)
123 #define GPIO_PSR		(port->hwdata->psr_reg)
124 #define GPIO_ICR1		(port->hwdata->icr1_reg)
125 #define GPIO_ICR2		(port->hwdata->icr2_reg)
126 #define GPIO_IMR		(port->hwdata->imr_reg)
127 #define GPIO_ISR		(port->hwdata->isr_reg)
128 #define GPIO_EDGE_SEL		(port->hwdata->edge_sel_reg)
129 
130 #define GPIO_INT_LOW_LEV	(port->hwdata->low_level)
131 #define GPIO_INT_HIGH_LEV	(port->hwdata->high_level)
132 #define GPIO_INT_RISE_EDGE	(port->hwdata->rise_edge)
133 #define GPIO_INT_FALL_EDGE	(port->hwdata->fall_edge)
134 #define GPIO_INT_BOTH_EDGES	0x4
135 
136 static const struct of_device_id mxc_gpio_dt_ids[] = {
137 	{ .compatible = "fsl,imx1-gpio", .data =  &imx1_imx21_gpio_hwdata },
138 	{ .compatible = "fsl,imx21-gpio", .data = &imx1_imx21_gpio_hwdata },
139 	{ .compatible = "fsl,imx31-gpio", .data = &imx31_gpio_hwdata },
140 	{ .compatible = "fsl,imx35-gpio", .data = &imx35_gpio_hwdata },
141 	{ .compatible = "fsl,imx7d-gpio", .data = &imx35_gpio_hwdata },
142 	{ .compatible = "fsl,imx8dxl-gpio", .data = &imx35_gpio_hwdata },
143 	{ .compatible = "fsl,imx8qm-gpio", .data = &imx35_gpio_hwdata },
144 	{ .compatible = "fsl,imx8qxp-gpio", .data = &imx35_gpio_hwdata },
145 	{ /* sentinel */ }
146 };
147 MODULE_DEVICE_TABLE(of, mxc_gpio_dt_ids);
148 
149 /*
150  * MX2 has one interrupt *for all* gpio ports. The list is used
151  * to save the references to all ports, so that mx2_gpio_irq_handler
152  * can walk through all interrupt status registers.
153  */
154 static LIST_HEAD(mxc_gpio_ports);
155 
156 /* Note: This driver assumes 32 GPIOs are handled in one register */
157 
158 static int gpio_set_irq_type(struct irq_data *d, u32 type)
159 {
160 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
161 	struct mxc_gpio_port *port = gc->private;
162 	u32 bit, val;
163 	u32 gpio_idx = d->hwirq;
164 	int edge;
165 	void __iomem *reg = port->base;
166 
167 	port->both_edges &= ~(1 << gpio_idx);
168 	switch (type) {
169 	case IRQ_TYPE_EDGE_RISING:
170 		edge = GPIO_INT_RISE_EDGE;
171 		break;
172 	case IRQ_TYPE_EDGE_FALLING:
173 		edge = GPIO_INT_FALL_EDGE;
174 		break;
175 	case IRQ_TYPE_EDGE_BOTH:
176 		if (GPIO_EDGE_SEL >= 0) {
177 			edge = GPIO_INT_BOTH_EDGES;
178 		} else {
179 			val = port->gc.get(&port->gc, gpio_idx);
180 			if (val) {
181 				edge = GPIO_INT_LOW_LEV;
182 				pr_debug("mxc: set GPIO %d to low trigger\n", gpio_idx);
183 			} else {
184 				edge = GPIO_INT_HIGH_LEV;
185 				pr_debug("mxc: set GPIO %d to high trigger\n", gpio_idx);
186 			}
187 			port->both_edges |= 1 << gpio_idx;
188 		}
189 		break;
190 	case IRQ_TYPE_LEVEL_LOW:
191 		edge = GPIO_INT_LOW_LEV;
192 		break;
193 	case IRQ_TYPE_LEVEL_HIGH:
194 		edge = GPIO_INT_HIGH_LEV;
195 		break;
196 	default:
197 		return -EINVAL;
198 	}
199 
200 	if (GPIO_EDGE_SEL >= 0) {
201 		val = readl(port->base + GPIO_EDGE_SEL);
202 		if (edge == GPIO_INT_BOTH_EDGES)
203 			writel(val | (1 << gpio_idx),
204 				port->base + GPIO_EDGE_SEL);
205 		else
206 			writel(val & ~(1 << gpio_idx),
207 				port->base + GPIO_EDGE_SEL);
208 	}
209 
210 	if (edge != GPIO_INT_BOTH_EDGES) {
211 		reg += GPIO_ICR1 + ((gpio_idx & 0x10) >> 2); /* lower or upper register */
212 		bit = gpio_idx & 0xf;
213 		val = readl(reg) & ~(0x3 << (bit << 1));
214 		writel(val | (edge << (bit << 1)), reg);
215 	}
216 
217 	writel(1 << gpio_idx, port->base + GPIO_ISR);
218 	port->pad_type[gpio_idx] = type;
219 
220 	return 0;
221 }
222 
223 static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
224 {
225 	void __iomem *reg = port->base;
226 	u32 bit, val;
227 	int edge;
228 
229 	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
230 	bit = gpio & 0xf;
231 	val = readl(reg);
232 	edge = (val >> (bit << 1)) & 3;
233 	val &= ~(0x3 << (bit << 1));
234 	if (edge == GPIO_INT_HIGH_LEV) {
235 		edge = GPIO_INT_LOW_LEV;
236 		pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
237 	} else if (edge == GPIO_INT_LOW_LEV) {
238 		edge = GPIO_INT_HIGH_LEV;
239 		pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
240 	} else {
241 		pr_err("mxc: invalid configuration for GPIO %d: %x\n",
242 		       gpio, edge);
243 		return;
244 	}
245 	writel(val | (edge << (bit << 1)), reg);
246 }
247 
248 /* handle 32 interrupts in one status register */
249 static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
250 {
251 	while (irq_stat != 0) {
252 		int irqoffset = fls(irq_stat) - 1;
253 
254 		if (port->both_edges & (1 << irqoffset))
255 			mxc_flip_edge(port, irqoffset);
256 
257 		generic_handle_domain_irq(port->domain, irqoffset);
258 
259 		irq_stat &= ~(1 << irqoffset);
260 	}
261 }
262 
263 /* MX1 and MX3 has one interrupt *per* gpio port */
264 static void mx3_gpio_irq_handler(struct irq_desc *desc)
265 {
266 	u32 irq_stat;
267 	struct mxc_gpio_port *port = irq_desc_get_handler_data(desc);
268 	struct irq_chip *chip = irq_desc_get_chip(desc);
269 
270 	if (port->is_pad_wakeup)
271 		return;
272 
273 	chained_irq_enter(chip, desc);
274 
275 	irq_stat = readl(port->base + GPIO_ISR) & readl(port->base + GPIO_IMR);
276 
277 	mxc_gpio_irq_handler(port, irq_stat);
278 
279 	chained_irq_exit(chip, desc);
280 }
281 
282 /* MX2 has one interrupt *for all* gpio ports */
283 static void mx2_gpio_irq_handler(struct irq_desc *desc)
284 {
285 	u32 irq_msk, irq_stat;
286 	struct mxc_gpio_port *port;
287 	struct irq_chip *chip = irq_desc_get_chip(desc);
288 
289 	chained_irq_enter(chip, desc);
290 
291 	/* walk through all interrupt status registers */
292 	list_for_each_entry(port, &mxc_gpio_ports, node) {
293 		irq_msk = readl(port->base + GPIO_IMR);
294 		if (!irq_msk)
295 			continue;
296 
297 		irq_stat = readl(port->base + GPIO_ISR) & irq_msk;
298 		if (irq_stat)
299 			mxc_gpio_irq_handler(port, irq_stat);
300 	}
301 	chained_irq_exit(chip, desc);
302 }
303 
304 /*
305  * Set interrupt number "irq" in the GPIO as a wake-up source.
306  * While system is running, all registered GPIO interrupts need to have
307  * wake-up enabled. When system is suspended, only selected GPIO interrupts
308  * need to have wake-up enabled.
309  * @param  irq          interrupt source number
310  * @param  enable       enable as wake-up if equal to non-zero
311  * @return       This function returns 0 on success.
312  */
313 static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
314 {
315 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
316 	struct mxc_gpio_port *port = gc->private;
317 	u32 gpio_idx = d->hwirq;
318 	int ret;
319 
320 	if (enable) {
321 		if (port->irq_high && (gpio_idx >= 16))
322 			ret = enable_irq_wake(port->irq_high);
323 		else
324 			ret = enable_irq_wake(port->irq);
325 		port->wakeup_pads |= (1 << gpio_idx);
326 	} else {
327 		if (port->irq_high && (gpio_idx >= 16))
328 			ret = disable_irq_wake(port->irq_high);
329 		else
330 			ret = disable_irq_wake(port->irq);
331 		port->wakeup_pads &= ~(1 << gpio_idx);
332 	}
333 
334 	return ret;
335 }
336 
337 static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base)
338 {
339 	struct irq_chip_generic *gc;
340 	struct irq_chip_type *ct;
341 	int rv;
342 
343 	gc = devm_irq_alloc_generic_chip(port->dev, "gpio-mxc", 1, irq_base,
344 					 port->base, handle_level_irq);
345 	if (!gc)
346 		return -ENOMEM;
347 	gc->private = port;
348 
349 	ct = gc->chip_types;
350 	ct->chip.irq_ack = irq_gc_ack_set_bit;
351 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
352 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
353 	ct->chip.irq_set_type = gpio_set_irq_type;
354 	ct->chip.irq_set_wake = gpio_set_wake_irq;
355 	ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND;
356 	ct->regs.ack = GPIO_ISR;
357 	ct->regs.mask = GPIO_IMR;
358 
359 	rv = devm_irq_setup_generic_chip(port->dev, gc, IRQ_MSK(32),
360 					 IRQ_GC_INIT_NESTED_LOCK,
361 					 IRQ_NOREQUEST, 0);
362 
363 	return rv;
364 }
365 
366 static int mxc_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
367 {
368 	struct mxc_gpio_port *port = gpiochip_get_data(gc);
369 
370 	return irq_find_mapping(port->domain, offset);
371 }
372 
373 static int mxc_gpio_probe(struct platform_device *pdev)
374 {
375 	struct device_node *np = pdev->dev.of_node;
376 	struct mxc_gpio_port *port;
377 	int irq_count;
378 	int irq_base;
379 	int err;
380 
381 	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
382 	if (!port)
383 		return -ENOMEM;
384 
385 	port->dev = &pdev->dev;
386 	port->hwdata = device_get_match_data(&pdev->dev);
387 
388 	port->base = devm_platform_ioremap_resource(pdev, 0);
389 	if (IS_ERR(port->base))
390 		return PTR_ERR(port->base);
391 
392 	irq_count = platform_irq_count(pdev);
393 	if (irq_count < 0)
394 		return irq_count;
395 
396 	if (irq_count > 1) {
397 		port->irq_high = platform_get_irq(pdev, 1);
398 		if (port->irq_high < 0)
399 			port->irq_high = 0;
400 	}
401 
402 	port->irq = platform_get_irq(pdev, 0);
403 	if (port->irq < 0)
404 		return port->irq;
405 
406 	/* the controller clock is optional */
407 	port->clk = devm_clk_get_optional(&pdev->dev, NULL);
408 	if (IS_ERR(port->clk))
409 		return PTR_ERR(port->clk);
410 
411 	err = clk_prepare_enable(port->clk);
412 	if (err) {
413 		dev_err(&pdev->dev, "Unable to enable clock.\n");
414 		return err;
415 	}
416 
417 	if (of_device_is_compatible(np, "fsl,imx7d-gpio"))
418 		port->power_off = true;
419 
420 	/* disable the interrupt and clear the status */
421 	writel(0, port->base + GPIO_IMR);
422 	writel(~0, port->base + GPIO_ISR);
423 
424 	if (of_device_is_compatible(np, "fsl,imx21-gpio")) {
425 		/*
426 		 * Setup one handler for all GPIO interrupts. Actually setting
427 		 * the handler is needed only once, but doing it for every port
428 		 * is more robust and easier.
429 		 */
430 		irq_set_chained_handler(port->irq, mx2_gpio_irq_handler);
431 	} else {
432 		/* setup one handler for each entry */
433 		irq_set_chained_handler_and_data(port->irq,
434 						 mx3_gpio_irq_handler, port);
435 		if (port->irq_high > 0)
436 			/* setup handler for GPIO 16 to 31 */
437 			irq_set_chained_handler_and_data(port->irq_high,
438 							 mx3_gpio_irq_handler,
439 							 port);
440 	}
441 
442 	err = bgpio_init(&port->gc, &pdev->dev, 4,
443 			 port->base + GPIO_PSR,
444 			 port->base + GPIO_DR, NULL,
445 			 port->base + GPIO_GDIR, NULL,
446 			 BGPIOF_READ_OUTPUT_REG_SET);
447 	if (err)
448 		goto out_bgio;
449 
450 	port->gc.request = gpiochip_generic_request;
451 	port->gc.free = gpiochip_generic_free;
452 	port->gc.to_irq = mxc_gpio_to_irq;
453 	port->gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 :
454 					     pdev->id * 32;
455 
456 	err = devm_gpiochip_add_data(&pdev->dev, &port->gc, port);
457 	if (err)
458 		goto out_bgio;
459 
460 	irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0, 32, numa_node_id());
461 	if (irq_base < 0) {
462 		err = irq_base;
463 		goto out_bgio;
464 	}
465 
466 	port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
467 					     &irq_domain_simple_ops, NULL);
468 	if (!port->domain) {
469 		err = -ENODEV;
470 		goto out_bgio;
471 	}
472 
473 	/* gpio-mxc can be a generic irq chip */
474 	err = mxc_gpio_init_gc(port, irq_base);
475 	if (err < 0)
476 		goto out_irqdomain_remove;
477 
478 	list_add_tail(&port->node, &mxc_gpio_ports);
479 
480 	platform_set_drvdata(pdev, port);
481 
482 	return 0;
483 
484 out_irqdomain_remove:
485 	irq_domain_remove(port->domain);
486 out_bgio:
487 	clk_disable_unprepare(port->clk);
488 	dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
489 	return err;
490 }
491 
492 static void mxc_gpio_save_regs(struct mxc_gpio_port *port)
493 {
494 	if (!port->power_off)
495 		return;
496 
497 	port->gpio_saved_reg.icr1 = readl(port->base + GPIO_ICR1);
498 	port->gpio_saved_reg.icr2 = readl(port->base + GPIO_ICR2);
499 	port->gpio_saved_reg.imr = readl(port->base + GPIO_IMR);
500 	port->gpio_saved_reg.gdir = readl(port->base + GPIO_GDIR);
501 	port->gpio_saved_reg.edge_sel = readl(port->base + GPIO_EDGE_SEL);
502 	port->gpio_saved_reg.dr = readl(port->base + GPIO_DR);
503 }
504 
505 static void mxc_gpio_restore_regs(struct mxc_gpio_port *port)
506 {
507 	if (!port->power_off)
508 		return;
509 
510 	writel(port->gpio_saved_reg.icr1, port->base + GPIO_ICR1);
511 	writel(port->gpio_saved_reg.icr2, port->base + GPIO_ICR2);
512 	writel(port->gpio_saved_reg.imr, port->base + GPIO_IMR);
513 	writel(port->gpio_saved_reg.gdir, port->base + GPIO_GDIR);
514 	writel(port->gpio_saved_reg.edge_sel, port->base + GPIO_EDGE_SEL);
515 	writel(port->gpio_saved_reg.dr, port->base + GPIO_DR);
516 }
517 
518 static bool mxc_gpio_generic_config(struct mxc_gpio_port *port,
519 		unsigned int offset, unsigned long conf)
520 {
521 	struct device_node *np = port->dev->of_node;
522 
523 	if (of_device_is_compatible(np, "fsl,imx8dxl-gpio") ||
524 	    of_device_is_compatible(np, "fsl,imx8qxp-gpio") ||
525 	    of_device_is_compatible(np, "fsl,imx8qm-gpio"))
526 		return (gpiochip_generic_config(&port->gc, offset, conf) == 0);
527 
528 	return false;
529 }
530 
531 static bool mxc_gpio_set_pad_wakeup(struct mxc_gpio_port *port, bool enable)
532 {
533 	unsigned long config;
534 	bool ret = false;
535 	int i, type;
536 
537 	static const u32 pad_type_map[] = {
538 		IMX_SCU_WAKEUP_OFF,		/* 0 */
539 		IMX_SCU_WAKEUP_RISE_EDGE,	/* IRQ_TYPE_EDGE_RISING */
540 		IMX_SCU_WAKEUP_FALL_EDGE,	/* IRQ_TYPE_EDGE_FALLING */
541 		IMX_SCU_WAKEUP_FALL_EDGE,	/* IRQ_TYPE_EDGE_BOTH */
542 		IMX_SCU_WAKEUP_HIGH_LVL,	/* IRQ_TYPE_LEVEL_HIGH */
543 		IMX_SCU_WAKEUP_OFF,		/* 5 */
544 		IMX_SCU_WAKEUP_OFF,		/* 6 */
545 		IMX_SCU_WAKEUP_OFF,		/* 7 */
546 		IMX_SCU_WAKEUP_LOW_LVL,		/* IRQ_TYPE_LEVEL_LOW */
547 	};
548 
549 	for (i = 0; i < 32; i++) {
550 		if ((port->wakeup_pads & (1 << i))) {
551 			type = port->pad_type[i];
552 			if (enable)
553 				config = pad_type_map[type];
554 			else
555 				config = IMX_SCU_WAKEUP_OFF;
556 			ret |= mxc_gpio_generic_config(port, i, config);
557 		}
558 	}
559 
560 	return ret;
561 }
562 
563 static int __maybe_unused mxc_gpio_noirq_suspend(struct device *dev)
564 {
565 	struct platform_device *pdev = to_platform_device(dev);
566 	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
567 
568 	if (port->wakeup_pads > 0)
569 		port->is_pad_wakeup = mxc_gpio_set_pad_wakeup(port, true);
570 
571 	return 0;
572 }
573 
574 static int __maybe_unused mxc_gpio_noirq_resume(struct device *dev)
575 {
576 	struct platform_device *pdev = to_platform_device(dev);
577 	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
578 
579 	if (port->wakeup_pads > 0)
580 		mxc_gpio_set_pad_wakeup(port, false);
581 	port->is_pad_wakeup = false;
582 
583 	return 0;
584 }
585 
586 static const struct dev_pm_ops mxc_gpio_dev_pm_ops = {
587 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mxc_gpio_noirq_suspend, mxc_gpio_noirq_resume)
588 };
589 
590 static int mxc_gpio_syscore_suspend(void)
591 {
592 	struct mxc_gpio_port *port;
593 
594 	/* walk through all ports */
595 	list_for_each_entry(port, &mxc_gpio_ports, node) {
596 		mxc_gpio_save_regs(port);
597 		clk_disable_unprepare(port->clk);
598 	}
599 
600 	return 0;
601 }
602 
603 static void mxc_gpio_syscore_resume(void)
604 {
605 	struct mxc_gpio_port *port;
606 	int ret;
607 
608 	/* walk through all ports */
609 	list_for_each_entry(port, &mxc_gpio_ports, node) {
610 		ret = clk_prepare_enable(port->clk);
611 		if (ret) {
612 			pr_err("mxc: failed to enable gpio clock %d\n", ret);
613 			return;
614 		}
615 		mxc_gpio_restore_regs(port);
616 	}
617 }
618 
619 static struct syscore_ops mxc_gpio_syscore_ops = {
620 	.suspend = mxc_gpio_syscore_suspend,
621 	.resume = mxc_gpio_syscore_resume,
622 };
623 
624 static struct platform_driver mxc_gpio_driver = {
625 	.driver		= {
626 		.name	= "gpio-mxc",
627 		.of_match_table = mxc_gpio_dt_ids,
628 		.suppress_bind_attrs = true,
629 		.pm = &mxc_gpio_dev_pm_ops,
630 	},
631 	.probe		= mxc_gpio_probe,
632 };
633 
634 static int __init gpio_mxc_init(void)
635 {
636 	register_syscore_ops(&mxc_gpio_syscore_ops);
637 
638 	return platform_driver_register(&mxc_gpio_driver);
639 }
640 subsys_initcall(gpio_mxc_init);
641 
642 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
643 MODULE_DESCRIPTION("i.MX GPIO Driver");
644 MODULE_LICENSE("GPL");
645