xref: /linux/drivers/pinctrl/intel/pinctrl-baytrail.c (revision a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec)
1 /*
2  * Pinctrl GPIO driver for Intel Baytrail
3  * Copyright (c) 2012-2013, Intel Corporation.
4  *
5  * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  */
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/types.h>
26 #include <linux/bitops.h>
27 #include <linux/interrupt.h>
28 #include <linux/gpio.h>
29 #include <linux/acpi.h>
30 #include <linux/platform_device.h>
31 #include <linux/seq_file.h>
32 #include <linux/io.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/pinctrl/pinctrl.h>
35 
36 /* memory mapped register offsets */
37 #define BYT_CONF0_REG		0x000
38 #define BYT_CONF1_REG		0x004
39 #define BYT_VAL_REG		0x008
40 #define BYT_DFT_REG		0x00c
41 #define BYT_INT_STAT_REG	0x800
42 
43 /* BYT_CONF0_REG register bits */
44 #define BYT_IODEN		BIT(31)
45 #define BYT_DIRECT_IRQ_EN	BIT(27)
46 #define BYT_TRIG_NEG		BIT(26)
47 #define BYT_TRIG_POS		BIT(25)
48 #define BYT_TRIG_LVL		BIT(24)
49 #define BYT_PULL_STR_SHIFT	9
50 #define BYT_PULL_STR_MASK	(3 << BYT_PULL_STR_SHIFT)
51 #define BYT_PULL_STR_2K		(0 << BYT_PULL_STR_SHIFT)
52 #define BYT_PULL_STR_10K	(1 << BYT_PULL_STR_SHIFT)
53 #define BYT_PULL_STR_20K	(2 << BYT_PULL_STR_SHIFT)
54 #define BYT_PULL_STR_40K	(3 << BYT_PULL_STR_SHIFT)
55 #define BYT_PULL_ASSIGN_SHIFT	7
56 #define BYT_PULL_ASSIGN_MASK	(3 << BYT_PULL_ASSIGN_SHIFT)
57 #define BYT_PULL_ASSIGN_UP	(1 << BYT_PULL_ASSIGN_SHIFT)
58 #define BYT_PULL_ASSIGN_DOWN	(2 << BYT_PULL_ASSIGN_SHIFT)
59 #define BYT_PIN_MUX		0x07
60 
61 /* BYT_VAL_REG register bits */
62 #define BYT_INPUT_EN		BIT(2)  /* 0: input enabled (active low)*/
63 #define BYT_OUTPUT_EN		BIT(1)  /* 0: output enabled (active low)*/
64 #define BYT_LEVEL		BIT(0)
65 
66 #define BYT_DIR_MASK		(BIT(1) | BIT(2))
67 #define BYT_TRIG_MASK		(BIT(26) | BIT(25) | BIT(24))
68 
69 #define BYT_CONF0_RESTORE_MASK	(BYT_DIRECT_IRQ_EN | BYT_TRIG_MASK | \
70 				 BYT_PIN_MUX)
71 #define BYT_VAL_RESTORE_MASK	(BYT_DIR_MASK | BYT_LEVEL)
72 
73 #define BYT_NGPIO_SCORE		102
74 #define BYT_NGPIO_NCORE		28
75 #define BYT_NGPIO_SUS		44
76 
77 #define BYT_SCORE_ACPI_UID	"1"
78 #define BYT_NCORE_ACPI_UID	"2"
79 #define BYT_SUS_ACPI_UID	"3"
80 
81 /*
82  * Baytrail gpio controller consist of three separate sub-controllers called
83  * SCORE, NCORE and SUS. The sub-controllers are identified by their acpi UID.
84  *
85  * GPIO numbering is _not_ ordered meaning that gpio # 0 in ACPI namespace does
86  * _not_ correspond to the first gpio register at controller's gpio base.
87  * There is no logic or pattern in mapping gpio numbers to registers (pads) so
88  * each sub-controller needs to have its own mapping table
89  */
90 
91 /* score_pins[gpio_nr] = pad_nr */
92 
93 static unsigned const score_pins[BYT_NGPIO_SCORE] = {
94 	85, 89, 93, 96, 99, 102, 98, 101, 34, 37,
95 	36, 38, 39, 35, 40, 84, 62, 61, 64, 59,
96 	54, 56, 60, 55, 63, 57, 51, 50, 53, 47,
97 	52, 49, 48, 43, 46, 41, 45, 42, 58, 44,
98 	95, 105, 70, 68, 67, 66, 69, 71, 65, 72,
99 	86, 90, 88, 92, 103, 77, 79, 83, 78, 81,
100 	80, 82, 13, 12, 15, 14, 17, 18, 19, 16,
101 	2, 1, 0, 4, 6, 7, 9, 8, 33, 32,
102 	31, 30, 29, 27, 25, 28, 26, 23, 21, 20,
103 	24, 22, 5, 3, 10, 11, 106, 87, 91, 104,
104 	97, 100,
105 };
106 
107 static unsigned const ncore_pins[BYT_NGPIO_NCORE] = {
108 	19, 18, 17, 20, 21, 22, 24, 25, 23, 16,
109 	14, 15, 12, 26, 27, 1, 4, 8, 11, 0,
110 	3, 6, 10, 13, 2, 5, 9, 7,
111 };
112 
113 static unsigned const sus_pins[BYT_NGPIO_SUS] = {
114 	29, 33, 30, 31, 32, 34, 36, 35, 38, 37,
115 	18, 7, 11, 20, 17, 1, 8, 10, 19, 12,
116 	0, 2, 23, 39, 28, 27, 22, 21, 24, 25,
117 	26, 51, 56, 54, 49, 55, 48, 57, 50, 58,
118 	52, 53, 59, 40,
119 };
120 
121 static struct pinctrl_gpio_range byt_ranges[] = {
122 	{
123 		.name = BYT_SCORE_ACPI_UID, /* match with acpi _UID in probe */
124 		.npins = BYT_NGPIO_SCORE,
125 		.pins = score_pins,
126 	},
127 	{
128 		.name = BYT_NCORE_ACPI_UID,
129 		.npins = BYT_NGPIO_NCORE,
130 		.pins = ncore_pins,
131 	},
132 	{
133 		.name = BYT_SUS_ACPI_UID,
134 		.npins = BYT_NGPIO_SUS,
135 		.pins = sus_pins,
136 	},
137 	{
138 	},
139 };
140 
141 struct byt_gpio_pin_context {
142 	u32 conf0;
143 	u32 val;
144 };
145 
146 struct byt_gpio {
147 	struct gpio_chip		chip;
148 	struct platform_device		*pdev;
149 	spinlock_t			lock;
150 	void __iomem			*reg_base;
151 	struct pinctrl_gpio_range	*range;
152 	struct byt_gpio_pin_context	*saved_context;
153 };
154 
155 #define to_byt_gpio(c)	container_of(c, struct byt_gpio, chip)
156 
157 static void __iomem *byt_gpio_reg(struct gpio_chip *chip, unsigned offset,
158 				 int reg)
159 {
160 	struct byt_gpio *vg = to_byt_gpio(chip);
161 	u32 reg_offset;
162 
163 	if (reg == BYT_INT_STAT_REG)
164 		reg_offset = (offset / 32) * 4;
165 	else
166 		reg_offset = vg->range->pins[offset] * 16;
167 
168 	return vg->reg_base + reg_offset + reg;
169 }
170 
171 static void byt_gpio_clear_triggering(struct byt_gpio *vg, unsigned offset)
172 {
173 	void __iomem *reg = byt_gpio_reg(&vg->chip, offset, BYT_CONF0_REG);
174 	unsigned long flags;
175 	u32 value;
176 
177 	spin_lock_irqsave(&vg->lock, flags);
178 	value = readl(reg);
179 	value &= ~(BYT_TRIG_POS | BYT_TRIG_NEG | BYT_TRIG_LVL);
180 	writel(value, reg);
181 	spin_unlock_irqrestore(&vg->lock, flags);
182 }
183 
184 static u32 byt_get_gpio_mux(struct byt_gpio *vg, unsigned offset)
185 {
186 	/* SCORE pin 92-93 */
187 	if (!strcmp(vg->range->name, BYT_SCORE_ACPI_UID) &&
188 		offset >= 92 && offset <= 93)
189 		return 1;
190 
191 	/* SUS pin 11-21 */
192 	if (!strcmp(vg->range->name, BYT_SUS_ACPI_UID) &&
193 		offset >= 11 && offset <= 21)
194 		return 1;
195 
196 	return 0;
197 }
198 
199 static int byt_gpio_request(struct gpio_chip *chip, unsigned offset)
200 {
201 	struct byt_gpio *vg = to_byt_gpio(chip);
202 	void __iomem *reg = byt_gpio_reg(chip, offset, BYT_CONF0_REG);
203 	u32 value, gpio_mux;
204 
205 	/*
206 	 * In most cases, func pin mux 000 means GPIO function.
207 	 * But, some pins may have func pin mux 001 represents
208 	 * GPIO function.
209 	 *
210 	 * Because there are devices out there where some pins were not
211 	 * configured correctly we allow changing the mux value from
212 	 * request (but print out warning about that).
213 	 */
214 	value = readl(reg) & BYT_PIN_MUX;
215 	gpio_mux = byt_get_gpio_mux(vg, offset);
216 	if (WARN_ON(gpio_mux != value)) {
217 		unsigned long flags;
218 
219 		spin_lock_irqsave(&vg->lock, flags);
220 		value = readl(reg) & ~BYT_PIN_MUX;
221 		value |= gpio_mux;
222 		writel(value, reg);
223 		spin_unlock_irqrestore(&vg->lock, flags);
224 
225 		dev_warn(&vg->pdev->dev,
226 			 "pin %u forcibly re-configured as GPIO\n", offset);
227 	}
228 
229 	pm_runtime_get(&vg->pdev->dev);
230 
231 	return 0;
232 }
233 
234 static void byt_gpio_free(struct gpio_chip *chip, unsigned offset)
235 {
236 	struct byt_gpio *vg = to_byt_gpio(chip);
237 
238 	byt_gpio_clear_triggering(vg, offset);
239 	pm_runtime_put(&vg->pdev->dev);
240 }
241 
242 static int byt_irq_type(struct irq_data *d, unsigned type)
243 {
244 	struct byt_gpio *vg = to_byt_gpio(irq_data_get_irq_chip_data(d));
245 	u32 offset = irqd_to_hwirq(d);
246 	u32 value;
247 	unsigned long flags;
248 	void __iomem *reg = byt_gpio_reg(&vg->chip, offset, BYT_CONF0_REG);
249 
250 	if (offset >= vg->chip.ngpio)
251 		return -EINVAL;
252 
253 	spin_lock_irqsave(&vg->lock, flags);
254 	value = readl(reg);
255 
256 	WARN(value & BYT_DIRECT_IRQ_EN,
257 		"Bad pad config for io mode, force direct_irq_en bit clearing");
258 
259 	/* For level trigges the BYT_TRIG_POS and BYT_TRIG_NEG bits
260 	 * are used to indicate high and low level triggering
261 	 */
262 	value &= ~(BYT_DIRECT_IRQ_EN | BYT_TRIG_POS | BYT_TRIG_NEG |
263 		   BYT_TRIG_LVL);
264 
265 	writel(value, reg);
266 
267 	if (type & IRQ_TYPE_EDGE_BOTH)
268 		__irq_set_handler_locked(d->irq, handle_edge_irq);
269 	else if (type & IRQ_TYPE_LEVEL_MASK)
270 		__irq_set_handler_locked(d->irq, handle_level_irq);
271 
272 	spin_unlock_irqrestore(&vg->lock, flags);
273 
274 	return 0;
275 }
276 
277 static int byt_gpio_get(struct gpio_chip *chip, unsigned offset)
278 {
279 	void __iomem *reg = byt_gpio_reg(chip, offset, BYT_VAL_REG);
280 	return readl(reg) & BYT_LEVEL;
281 }
282 
283 static void byt_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
284 {
285 	struct byt_gpio *vg = to_byt_gpio(chip);
286 	void __iomem *reg = byt_gpio_reg(chip, offset, BYT_VAL_REG);
287 	unsigned long flags;
288 	u32 old_val;
289 
290 	spin_lock_irqsave(&vg->lock, flags);
291 
292 	old_val = readl(reg);
293 
294 	if (value)
295 		writel(old_val | BYT_LEVEL, reg);
296 	else
297 		writel(old_val & ~BYT_LEVEL, reg);
298 
299 	spin_unlock_irqrestore(&vg->lock, flags);
300 }
301 
302 static int byt_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
303 {
304 	struct byt_gpio *vg = to_byt_gpio(chip);
305 	void __iomem *reg = byt_gpio_reg(chip, offset, BYT_VAL_REG);
306 	unsigned long flags;
307 	u32 value;
308 
309 	spin_lock_irqsave(&vg->lock, flags);
310 
311 	value = readl(reg) | BYT_DIR_MASK;
312 	value &= ~BYT_INPUT_EN;		/* active low */
313 	writel(value, reg);
314 
315 	spin_unlock_irqrestore(&vg->lock, flags);
316 
317 	return 0;
318 }
319 
320 static int byt_gpio_direction_output(struct gpio_chip *chip,
321 				     unsigned gpio, int value)
322 {
323 	struct byt_gpio *vg = to_byt_gpio(chip);
324 	void __iomem *conf_reg = byt_gpio_reg(chip, gpio, BYT_CONF0_REG);
325 	void __iomem *reg = byt_gpio_reg(chip, gpio, BYT_VAL_REG);
326 	unsigned long flags;
327 	u32 reg_val;
328 
329 	spin_lock_irqsave(&vg->lock, flags);
330 
331 	/*
332 	 * Before making any direction modifications, do a check if gpio
333 	 * is set for direct IRQ.  On baytrail, setting GPIO to output does
334 	 * not make sense, so let's at least warn the caller before they shoot
335 	 * themselves in the foot.
336 	 */
337 	WARN(readl(conf_reg) & BYT_DIRECT_IRQ_EN,
338 		"Potential Error: Setting GPIO with direct_irq_en to output");
339 
340 	reg_val = readl(reg) | BYT_DIR_MASK;
341 	reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN);
342 
343 	if (value)
344 		writel(reg_val | BYT_LEVEL, reg);
345 	else
346 		writel(reg_val & ~BYT_LEVEL, reg);
347 
348 	spin_unlock_irqrestore(&vg->lock, flags);
349 
350 	return 0;
351 }
352 
353 static void byt_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
354 {
355 	struct byt_gpio *vg = to_byt_gpio(chip);
356 	int i;
357 	unsigned long flags;
358 	u32 conf0, val, offs;
359 
360 	spin_lock_irqsave(&vg->lock, flags);
361 
362 	for (i = 0; i < vg->chip.ngpio; i++) {
363 		const char *pull_str = NULL;
364 		const char *pull = NULL;
365 		const char *label;
366 		offs = vg->range->pins[i] * 16;
367 		conf0 = readl(vg->reg_base + offs + BYT_CONF0_REG);
368 		val = readl(vg->reg_base + offs + BYT_VAL_REG);
369 
370 		label = gpiochip_is_requested(chip, i);
371 		if (!label)
372 			label = "Unrequested";
373 
374 		switch (conf0 & BYT_PULL_ASSIGN_MASK) {
375 		case BYT_PULL_ASSIGN_UP:
376 			pull = "up";
377 			break;
378 		case BYT_PULL_ASSIGN_DOWN:
379 			pull = "down";
380 			break;
381 		}
382 
383 		switch (conf0 & BYT_PULL_STR_MASK) {
384 		case BYT_PULL_STR_2K:
385 			pull_str = "2k";
386 			break;
387 		case BYT_PULL_STR_10K:
388 			pull_str = "10k";
389 			break;
390 		case BYT_PULL_STR_20K:
391 			pull_str = "20k";
392 			break;
393 		case BYT_PULL_STR_40K:
394 			pull_str = "40k";
395 			break;
396 		}
397 
398 		seq_printf(s,
399 			   " gpio-%-3d (%-20.20s) %s %s %s pad-%-3d offset:0x%03x mux:%d %s%s%s",
400 			   i,
401 			   label,
402 			   val & BYT_INPUT_EN ? "  " : "in",
403 			   val & BYT_OUTPUT_EN ? "   " : "out",
404 			   val & BYT_LEVEL ? "hi" : "lo",
405 			   vg->range->pins[i], offs,
406 			   conf0 & 0x7,
407 			   conf0 & BYT_TRIG_NEG ? " fall" : "     ",
408 			   conf0 & BYT_TRIG_POS ? " rise" : "     ",
409 			   conf0 & BYT_TRIG_LVL ? " level" : "      ");
410 
411 		if (pull && pull_str)
412 			seq_printf(s, " %-4s %-3s", pull, pull_str);
413 		else
414 			seq_puts(s, "          ");
415 
416 		if (conf0 & BYT_IODEN)
417 			seq_puts(s, " open-drain");
418 
419 		seq_puts(s, "\n");
420 	}
421 	spin_unlock_irqrestore(&vg->lock, flags);
422 }
423 
424 static void byt_gpio_irq_handler(unsigned irq, struct irq_desc *desc)
425 {
426 	struct irq_data *data = irq_desc_get_irq_data(desc);
427 	struct byt_gpio *vg = to_byt_gpio(irq_desc_get_handler_data(desc));
428 	struct irq_chip *chip = irq_data_get_irq_chip(data);
429 	u32 base, pin;
430 	void __iomem *reg;
431 	unsigned long pending;
432 	unsigned virq;
433 
434 	/* check from GPIO controller which pin triggered the interrupt */
435 	for (base = 0; base < vg->chip.ngpio; base += 32) {
436 		reg = byt_gpio_reg(&vg->chip, base, BYT_INT_STAT_REG);
437 		pending = readl(reg);
438 		for_each_set_bit(pin, &pending, 32) {
439 			virq = irq_find_mapping(vg->chip.irqdomain, base + pin);
440 			generic_handle_irq(virq);
441 		}
442 	}
443 	chip->irq_eoi(data);
444 }
445 
446 static void byt_irq_ack(struct irq_data *d)
447 {
448 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
449 	struct byt_gpio *vg = to_byt_gpio(gc);
450 	unsigned offset = irqd_to_hwirq(d);
451 	void __iomem *reg;
452 
453 	reg = byt_gpio_reg(&vg->chip, offset, BYT_INT_STAT_REG);
454 	writel(BIT(offset % 32), reg);
455 }
456 
457 static void byt_irq_unmask(struct irq_data *d)
458 {
459 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
460 	struct byt_gpio *vg = to_byt_gpio(gc);
461 	unsigned offset = irqd_to_hwirq(d);
462 	unsigned long flags;
463 	void __iomem *reg;
464 	u32 value;
465 
466 	spin_lock_irqsave(&vg->lock, flags);
467 
468 	reg = byt_gpio_reg(&vg->chip, offset, BYT_CONF0_REG);
469 	value = readl(reg);
470 
471 	switch (irqd_get_trigger_type(d)) {
472 	case IRQ_TYPE_LEVEL_HIGH:
473 		value |= BYT_TRIG_LVL;
474 	case IRQ_TYPE_EDGE_RISING:
475 		value |= BYT_TRIG_POS;
476 		break;
477 	case IRQ_TYPE_LEVEL_LOW:
478 		value |= BYT_TRIG_LVL;
479 	case IRQ_TYPE_EDGE_FALLING:
480 		value |= BYT_TRIG_NEG;
481 		break;
482 	case IRQ_TYPE_EDGE_BOTH:
483 		value |= (BYT_TRIG_NEG | BYT_TRIG_POS);
484 		break;
485 	}
486 
487 	writel(value, reg);
488 
489 	spin_unlock_irqrestore(&vg->lock, flags);
490 }
491 
492 static void byt_irq_mask(struct irq_data *d)
493 {
494 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
495 	struct byt_gpio *vg = to_byt_gpio(gc);
496 
497 	byt_gpio_clear_triggering(vg, irqd_to_hwirq(d));
498 }
499 
500 static struct irq_chip byt_irqchip = {
501 	.name = "BYT-GPIO",
502 	.irq_ack = byt_irq_ack,
503 	.irq_mask = byt_irq_mask,
504 	.irq_unmask = byt_irq_unmask,
505 	.irq_set_type = byt_irq_type,
506 	.flags = IRQCHIP_SKIP_SET_WAKE,
507 };
508 
509 static void byt_gpio_irq_init_hw(struct byt_gpio *vg)
510 {
511 	void __iomem *reg;
512 	u32 base, value;
513 	int i;
514 
515 	/*
516 	 * Clear interrupt triggers for all pins that are GPIOs and
517 	 * do not use direct IRQ mode. This will prevent spurious
518 	 * interrupts from misconfigured pins.
519 	 */
520 	for (i = 0; i < vg->chip.ngpio; i++) {
521 		value = readl(byt_gpio_reg(&vg->chip, i, BYT_CONF0_REG));
522 		if ((value & BYT_PIN_MUX) == byt_get_gpio_mux(vg, i) &&
523 		    !(value & BYT_DIRECT_IRQ_EN)) {
524 			byt_gpio_clear_triggering(vg, i);
525 			dev_dbg(&vg->pdev->dev, "disabling GPIO %d\n", i);
526 		}
527 	}
528 
529 	/* clear interrupt status trigger registers */
530 	for (base = 0; base < vg->chip.ngpio; base += 32) {
531 		reg = byt_gpio_reg(&vg->chip, base, BYT_INT_STAT_REG);
532 		writel(0xffffffff, reg);
533 		/* make sure trigger bits are cleared, if not then a pin
534 		   might be misconfigured in bios */
535 		value = readl(reg);
536 		if (value)
537 			dev_err(&vg->pdev->dev,
538 				"GPIO interrupt error, pins misconfigured\n");
539 	}
540 }
541 
542 static int byt_gpio_probe(struct platform_device *pdev)
543 {
544 	struct byt_gpio *vg;
545 	struct gpio_chip *gc;
546 	struct resource *mem_rc, *irq_rc;
547 	struct device *dev = &pdev->dev;
548 	struct acpi_device *acpi_dev;
549 	struct pinctrl_gpio_range *range;
550 	acpi_handle handle = ACPI_HANDLE(dev);
551 	int ret;
552 
553 	if (acpi_bus_get_device(handle, &acpi_dev))
554 		return -ENODEV;
555 
556 	vg = devm_kzalloc(dev, sizeof(struct byt_gpio), GFP_KERNEL);
557 	if (!vg) {
558 		dev_err(&pdev->dev, "can't allocate byt_gpio chip data\n");
559 		return -ENOMEM;
560 	}
561 
562 	for (range = byt_ranges; range->name; range++) {
563 		if (!strcmp(acpi_dev->pnp.unique_id, range->name)) {
564 			vg->chip.ngpio = range->npins;
565 			vg->range = range;
566 			break;
567 		}
568 	}
569 
570 	if (!vg->chip.ngpio || !vg->range)
571 		return -ENODEV;
572 
573 	vg->pdev = pdev;
574 	platform_set_drvdata(pdev, vg);
575 
576 	mem_rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
577 	vg->reg_base = devm_ioremap_resource(dev, mem_rc);
578 	if (IS_ERR(vg->reg_base))
579 		return PTR_ERR(vg->reg_base);
580 
581 	spin_lock_init(&vg->lock);
582 
583 	gc = &vg->chip;
584 	gc->label = dev_name(&pdev->dev);
585 	gc->owner = THIS_MODULE;
586 	gc->request = byt_gpio_request;
587 	gc->free = byt_gpio_free;
588 	gc->direction_input = byt_gpio_direction_input;
589 	gc->direction_output = byt_gpio_direction_output;
590 	gc->get = byt_gpio_get;
591 	gc->set = byt_gpio_set;
592 	gc->dbg_show = byt_gpio_dbg_show;
593 	gc->base = -1;
594 	gc->can_sleep = false;
595 	gc->dev = dev;
596 
597 #ifdef CONFIG_PM_SLEEP
598 	vg->saved_context = devm_kcalloc(&pdev->dev, gc->ngpio,
599 				       sizeof(*vg->saved_context), GFP_KERNEL);
600 #endif
601 
602 	ret = gpiochip_add(gc);
603 	if (ret) {
604 		dev_err(&pdev->dev, "failed adding byt-gpio chip\n");
605 		return ret;
606 	}
607 
608 	/* set up interrupts  */
609 	irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
610 	if (irq_rc && irq_rc->start) {
611 		byt_gpio_irq_init_hw(vg);
612 		ret = gpiochip_irqchip_add(gc, &byt_irqchip, 0,
613 					   handle_simple_irq, IRQ_TYPE_NONE);
614 		if (ret) {
615 			dev_err(dev, "failed to add irqchip\n");
616 			gpiochip_remove(gc);
617 			return ret;
618 		}
619 
620 		gpiochip_set_chained_irqchip(gc, &byt_irqchip,
621 					     (unsigned)irq_rc->start,
622 					     byt_gpio_irq_handler);
623 	}
624 
625 	pm_runtime_enable(dev);
626 
627 	return 0;
628 }
629 
630 #ifdef CONFIG_PM_SLEEP
631 static int byt_gpio_suspend(struct device *dev)
632 {
633 	struct platform_device *pdev = to_platform_device(dev);
634 	struct byt_gpio *vg = platform_get_drvdata(pdev);
635 	int i;
636 
637 	for (i = 0; i < vg->chip.ngpio; i++) {
638 		void __iomem *reg;
639 		u32 value;
640 
641 		reg = byt_gpio_reg(&vg->chip, i, BYT_CONF0_REG);
642 		value = readl(reg) & BYT_CONF0_RESTORE_MASK;
643 		vg->saved_context[i].conf0 = value;
644 
645 		reg = byt_gpio_reg(&vg->chip, i, BYT_VAL_REG);
646 		value = readl(reg) & BYT_VAL_RESTORE_MASK;
647 		vg->saved_context[i].val = value;
648 	}
649 
650 	return 0;
651 }
652 
653 static int byt_gpio_resume(struct device *dev)
654 {
655 	struct platform_device *pdev = to_platform_device(dev);
656 	struct byt_gpio *vg = platform_get_drvdata(pdev);
657 	int i;
658 
659 	for (i = 0; i < vg->chip.ngpio; i++) {
660 		void __iomem *reg;
661 		u32 value;
662 
663 		reg = byt_gpio_reg(&vg->chip, i, BYT_CONF0_REG);
664 		value = readl(reg);
665 		if ((value & BYT_CONF0_RESTORE_MASK) !=
666 		     vg->saved_context[i].conf0) {
667 			value &= ~BYT_CONF0_RESTORE_MASK;
668 			value |= vg->saved_context[i].conf0;
669 			writel(value, reg);
670 			dev_info(dev, "restored pin %d conf0 %#08x", i, value);
671 		}
672 
673 		reg = byt_gpio_reg(&vg->chip, i, BYT_VAL_REG);
674 		value = readl(reg);
675 		if ((value & BYT_VAL_RESTORE_MASK) !=
676 		     vg->saved_context[i].val) {
677 			u32 v;
678 
679 			v = value & ~BYT_VAL_RESTORE_MASK;
680 			v |= vg->saved_context[i].val;
681 			if (v != value) {
682 				writel(v, reg);
683 				dev_dbg(dev, "restored pin %d val %#08x\n",
684 					i, v);
685 			}
686 		}
687 	}
688 
689 	return 0;
690 }
691 #endif
692 
693 static int byt_gpio_runtime_suspend(struct device *dev)
694 {
695 	return 0;
696 }
697 
698 static int byt_gpio_runtime_resume(struct device *dev)
699 {
700 	return 0;
701 }
702 
703 static const struct dev_pm_ops byt_gpio_pm_ops = {
704 	SET_LATE_SYSTEM_SLEEP_PM_OPS(byt_gpio_suspend, byt_gpio_resume)
705 	SET_RUNTIME_PM_OPS(byt_gpio_runtime_suspend, byt_gpio_runtime_resume,
706 			   NULL)
707 };
708 
709 static const struct acpi_device_id byt_gpio_acpi_match[] = {
710 	{ "INT33B2", 0 },
711 	{ "INT33FC", 0 },
712 	{ }
713 };
714 MODULE_DEVICE_TABLE(acpi, byt_gpio_acpi_match);
715 
716 static int byt_gpio_remove(struct platform_device *pdev)
717 {
718 	struct byt_gpio *vg = platform_get_drvdata(pdev);
719 
720 	pm_runtime_disable(&pdev->dev);
721 	gpiochip_remove(&vg->chip);
722 
723 	return 0;
724 }
725 
726 static struct platform_driver byt_gpio_driver = {
727 	.probe          = byt_gpio_probe,
728 	.remove         = byt_gpio_remove,
729 	.driver         = {
730 		.name   = "byt_gpio",
731 		.pm	= &byt_gpio_pm_ops,
732 		.acpi_match_table = ACPI_PTR(byt_gpio_acpi_match),
733 	},
734 };
735 
736 static int __init byt_gpio_init(void)
737 {
738 	return platform_driver_register(&byt_gpio_driver);
739 }
740 subsys_initcall(byt_gpio_init);
741 
742 static void __exit byt_gpio_exit(void)
743 {
744 	platform_driver_unregister(&byt_gpio_driver);
745 }
746 module_exit(byt_gpio_exit);
747