xref: /linux/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014-2017 Broadcom
4  */
5 
6 /*
7  * This file contains the Broadcom Iproc GPIO driver that supports 3
8  * GPIO controllers on Iproc including the ASIU GPIO controller, the
9  * chipCommonG GPIO controller, and the always-on GPIO controller. Basic
10  * PINCONF such as bias pull up/down, and drive strength are also supported
11  * in this driver.
12  *
13  * It provides the functionality where pins from the GPIO can be
14  * individually muxed to GPIO function, if individual pad
15  * configuration is supported, through the interaction with respective
16  * SoCs IOMUX controller.
17  */
18 
19 #include <linux/gpio/driver.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/ioport.h>
23 #include <linux/kernel.h>
24 #include <linux/of.h>
25 #include <linux/platform_device.h>
26 #include <linux/seq_file.h>
27 #include <linux/slab.h>
28 
29 #include <linux/pinctrl/consumer.h>
30 #include <linux/pinctrl/pinconf-generic.h>
31 #include <linux/pinctrl/pinconf.h>
32 #include <linux/pinctrl/pinctrl.h>
33 
34 #include "../pinctrl-utils.h"
35 
36 #define IPROC_GPIO_DATA_IN_OFFSET   0x00
37 #define IPROC_GPIO_DATA_OUT_OFFSET  0x04
38 #define IPROC_GPIO_OUT_EN_OFFSET    0x08
39 #define IPROC_GPIO_INT_TYPE_OFFSET  0x0c
40 #define IPROC_GPIO_INT_DE_OFFSET    0x10
41 #define IPROC_GPIO_INT_EDGE_OFFSET  0x14
42 #define IPROC_GPIO_INT_MSK_OFFSET   0x18
43 #define IPROC_GPIO_INT_STAT_OFFSET  0x1c
44 #define IPROC_GPIO_INT_MSTAT_OFFSET 0x20
45 #define IPROC_GPIO_INT_CLR_OFFSET   0x24
46 #define IPROC_GPIO_PAD_RES_OFFSET   0x34
47 #define IPROC_GPIO_RES_EN_OFFSET    0x38
48 
49 /* drive strength control for ASIU GPIO */
50 #define IPROC_GPIO_ASIU_DRV0_CTRL_OFFSET 0x58
51 
52 /* pinconf for CCM GPIO */
53 #define IPROC_GPIO_PULL_DN_OFFSET   0x10
54 #define IPROC_GPIO_PULL_UP_OFFSET   0x14
55 
56 /* pinconf for CRMU(aon) GPIO and CCM GPIO*/
57 #define IPROC_GPIO_DRV_CTRL_OFFSET  0x00
58 
59 #define GPIO_BANK_SIZE 0x200
60 #define NGPIOS_PER_BANK 32
61 #define GPIO_BANK(pin) ((pin) / NGPIOS_PER_BANK)
62 
63 #define IPROC_GPIO_REG(pin, reg) (GPIO_BANK(pin) * GPIO_BANK_SIZE + (reg))
64 #define IPROC_GPIO_SHIFT(pin) ((pin) % NGPIOS_PER_BANK)
65 
66 #define GPIO_DRV_STRENGTH_BIT_SHIFT  20
67 #define GPIO_DRV_STRENGTH_BITS       3
68 #define GPIO_DRV_STRENGTH_BIT_MASK   ((1 << GPIO_DRV_STRENGTH_BITS) - 1)
69 
70 enum iproc_pinconf_param {
71 	IPROC_PINCONF_DRIVE_STRENGTH = 0,
72 	IPROC_PINCONF_BIAS_DISABLE,
73 	IPROC_PINCONF_BIAS_PULL_UP,
74 	IPROC_PINCONF_BIAS_PULL_DOWN,
75 	IPROC_PINCON_MAX,
76 };
77 
78 enum iproc_pinconf_ctrl_type {
79 	IOCTRL_TYPE_AON = 1,
80 	IOCTRL_TYPE_CDRU,
81 	IOCTRL_TYPE_INVALID,
82 };
83 
84 /*
85  * Iproc GPIO core
86  *
87  * @dev: pointer to device
88  * @base: I/O register base for Iproc GPIO controller
89  * @io_ctrl: I/O register base for certain type of Iproc GPIO controller that
90  * has the PINCONF support implemented outside of the GPIO block
91  * @lock: lock to protect access to I/O registers
92  * @gc: GPIO chip
93  * @num_banks: number of GPIO banks, each bank supports up to 32 GPIOs
94  * @pinmux_is_supported: flag to indicate this GPIO controller contains pins
95  * that can be individually muxed to GPIO
96  * @pinconf_disable: contains a list of PINCONF parameters that need to be
97  * disabled
98  * @nr_pinconf_disable: total number of PINCONF parameters that need to be
99  * disabled
100  * @pctl: pointer to pinctrl_dev
101  * @pctldesc: pinctrl descriptor
102  */
103 struct iproc_gpio {
104 	struct device *dev;
105 
106 	void __iomem *base;
107 	void __iomem *io_ctrl;
108 	enum iproc_pinconf_ctrl_type io_ctrl_type;
109 
110 	raw_spinlock_t lock;
111 
112 	struct gpio_chip gc;
113 	unsigned num_banks;
114 
115 	bool pinmux_is_supported;
116 
117 	enum pin_config_param *pinconf_disable;
118 	unsigned int nr_pinconf_disable;
119 
120 	struct pinctrl_dev *pctl;
121 	struct pinctrl_desc pctldesc;
122 };
123 
124 /*
125  * Mapping from PINCONF pins to GPIO pins is 1-to-1
126  */
127 static inline unsigned iproc_pin_to_gpio(unsigned pin)
128 {
129 	return pin;
130 }
131 
132 /**
133  *  iproc_set_bit - set or clear one bit (corresponding to the GPIO pin) in a
134  *  Iproc GPIO register
135  *
136  *  @chip: Iproc GPIO device
137  *  @reg: register offset
138  *  @gpio: GPIO pin
139  *  @set: set or clear
140  */
141 static inline void iproc_set_bit(struct iproc_gpio *chip, unsigned int reg,
142 				  unsigned gpio, bool set)
143 {
144 	unsigned int offset = IPROC_GPIO_REG(gpio, reg);
145 	unsigned int shift = IPROC_GPIO_SHIFT(gpio);
146 	u32 val;
147 
148 	val = readl(chip->base + offset);
149 	if (set)
150 		val |= BIT(shift);
151 	else
152 		val &= ~BIT(shift);
153 	writel(val, chip->base + offset);
154 }
155 
156 static inline bool iproc_get_bit(struct iproc_gpio *chip, unsigned int reg,
157 				  unsigned gpio)
158 {
159 	unsigned int offset = IPROC_GPIO_REG(gpio, reg);
160 	unsigned int shift = IPROC_GPIO_SHIFT(gpio);
161 
162 	return !!(readl(chip->base + offset) & BIT(shift));
163 }
164 
165 static void iproc_gpio_irq_handler(struct irq_desc *desc)
166 {
167 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
168 	struct iproc_gpio *chip = gpiochip_get_data(gc);
169 	struct irq_chip *irq_chip = irq_desc_get_chip(desc);
170 	int i, bit;
171 
172 	chained_irq_enter(irq_chip, desc);
173 
174 	/* go through the entire GPIO banks and handle all interrupts */
175 	for (i = 0; i < chip->num_banks; i++) {
176 		unsigned long val = readl(chip->base + (i * GPIO_BANK_SIZE) +
177 					  IPROC_GPIO_INT_MSTAT_OFFSET);
178 
179 		for_each_set_bit(bit, &val, NGPIOS_PER_BANK) {
180 			unsigned pin = NGPIOS_PER_BANK * i + bit;
181 
182 			/*
183 			 * Clear the interrupt before invoking the
184 			 * handler, so we do not leave any window
185 			 */
186 			writel(BIT(bit), chip->base + (i * GPIO_BANK_SIZE) +
187 			       IPROC_GPIO_INT_CLR_OFFSET);
188 
189 			generic_handle_domain_irq(gc->irq.domain, pin);
190 		}
191 	}
192 
193 	chained_irq_exit(irq_chip, desc);
194 }
195 
196 
197 static void iproc_gpio_irq_ack(struct irq_data *d)
198 {
199 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
200 	struct iproc_gpio *chip = gpiochip_get_data(gc);
201 	unsigned gpio = d->hwirq;
202 	unsigned int offset = IPROC_GPIO_REG(gpio,
203 			IPROC_GPIO_INT_CLR_OFFSET);
204 	unsigned int shift = IPROC_GPIO_SHIFT(gpio);
205 	u32 val = BIT(shift);
206 
207 	writel(val, chip->base + offset);
208 }
209 
210 /**
211  *  iproc_gpio_irq_set_mask - mask/unmask a GPIO interrupt
212  *
213  *  @d: IRQ chip data
214  *  @unmask: mask/unmask GPIO interrupt
215  */
216 static void iproc_gpio_irq_set_mask(struct irq_data *d, bool unmask)
217 {
218 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
219 	struct iproc_gpio *chip = gpiochip_get_data(gc);
220 	unsigned gpio = irqd_to_hwirq(d);
221 
222 	iproc_set_bit(chip, IPROC_GPIO_INT_MSK_OFFSET, gpio, unmask);
223 }
224 
225 static void iproc_gpio_irq_mask(struct irq_data *d)
226 {
227 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
228 	struct iproc_gpio *chip = gpiochip_get_data(gc);
229 	unsigned long flags;
230 
231 	raw_spin_lock_irqsave(&chip->lock, flags);
232 	iproc_gpio_irq_set_mask(d, false);
233 	raw_spin_unlock_irqrestore(&chip->lock, flags);
234 	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
235 }
236 
237 static void iproc_gpio_irq_unmask(struct irq_data *d)
238 {
239 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
240 	struct iproc_gpio *chip = gpiochip_get_data(gc);
241 	unsigned long flags;
242 
243 	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
244 	raw_spin_lock_irqsave(&chip->lock, flags);
245 	iproc_gpio_irq_set_mask(d, true);
246 	raw_spin_unlock_irqrestore(&chip->lock, flags);
247 }
248 
249 static int iproc_gpio_irq_set_type(struct irq_data *d, unsigned int type)
250 {
251 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
252 	struct iproc_gpio *chip = gpiochip_get_data(gc);
253 	unsigned gpio = d->hwirq;
254 	bool level_triggered = false;
255 	bool dual_edge = false;
256 	bool rising_or_high = false;
257 	unsigned long flags;
258 
259 	switch (type & IRQ_TYPE_SENSE_MASK) {
260 	case IRQ_TYPE_EDGE_RISING:
261 		rising_or_high = true;
262 		break;
263 
264 	case IRQ_TYPE_EDGE_FALLING:
265 		break;
266 
267 	case IRQ_TYPE_EDGE_BOTH:
268 		dual_edge = true;
269 		break;
270 
271 	case IRQ_TYPE_LEVEL_HIGH:
272 		level_triggered = true;
273 		rising_or_high = true;
274 		break;
275 
276 	case IRQ_TYPE_LEVEL_LOW:
277 		level_triggered = true;
278 		break;
279 
280 	default:
281 		dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
282 			type);
283 		return -EINVAL;
284 	}
285 
286 	raw_spin_lock_irqsave(&chip->lock, flags);
287 	iproc_set_bit(chip, IPROC_GPIO_INT_TYPE_OFFSET, gpio,
288 		       level_triggered);
289 	iproc_set_bit(chip, IPROC_GPIO_INT_DE_OFFSET, gpio, dual_edge);
290 	iproc_set_bit(chip, IPROC_GPIO_INT_EDGE_OFFSET, gpio,
291 		       rising_or_high);
292 
293 	if (type & IRQ_TYPE_EDGE_BOTH)
294 		irq_set_handler_locked(d, handle_edge_irq);
295 	else
296 		irq_set_handler_locked(d, handle_level_irq);
297 
298 	raw_spin_unlock_irqrestore(&chip->lock, flags);
299 
300 	dev_dbg(chip->dev,
301 		"gpio:%u level_triggered:%d dual_edge:%d rising_or_high:%d\n",
302 		gpio, level_triggered, dual_edge, rising_or_high);
303 
304 	return 0;
305 }
306 
307 static void iproc_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
308 {
309 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
310 	struct iproc_gpio *chip = gpiochip_get_data(gc);
311 
312 	seq_printf(p, dev_name(chip->dev));
313 }
314 
315 static const struct irq_chip iproc_gpio_irq_chip = {
316 	.irq_ack = iproc_gpio_irq_ack,
317 	.irq_mask = iproc_gpio_irq_mask,
318 	.irq_unmask = iproc_gpio_irq_unmask,
319 	.irq_set_type = iproc_gpio_irq_set_type,
320 	.irq_enable = iproc_gpio_irq_unmask,
321 	.irq_disable = iproc_gpio_irq_mask,
322 	.irq_print_chip = iproc_gpio_irq_print_chip,
323 	.flags = IRQCHIP_IMMUTABLE,
324 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
325 };
326 
327 /*
328  * Request the Iproc IOMUX pinmux controller to mux individual pins to GPIO
329  */
330 static int iproc_gpio_request(struct gpio_chip *gc, unsigned offset)
331 {
332 	struct iproc_gpio *chip = gpiochip_get_data(gc);
333 
334 	/* not all Iproc GPIO pins can be muxed individually */
335 	if (!chip->pinmux_is_supported)
336 		return 0;
337 
338 	return pinctrl_gpio_request(gc, offset);
339 }
340 
341 static void iproc_gpio_free(struct gpio_chip *gc, unsigned offset)
342 {
343 	struct iproc_gpio *chip = gpiochip_get_data(gc);
344 
345 	if (!chip->pinmux_is_supported)
346 		return;
347 
348 	pinctrl_gpio_free(gc, offset);
349 }
350 
351 static int iproc_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
352 {
353 	struct iproc_gpio *chip = gpiochip_get_data(gc);
354 	unsigned long flags;
355 
356 	raw_spin_lock_irqsave(&chip->lock, flags);
357 	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, false);
358 	raw_spin_unlock_irqrestore(&chip->lock, flags);
359 
360 	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
361 
362 	return 0;
363 }
364 
365 static int iproc_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
366 					int val)
367 {
368 	struct iproc_gpio *chip = gpiochip_get_data(gc);
369 	unsigned long flags;
370 
371 	raw_spin_lock_irqsave(&chip->lock, flags);
372 	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true);
373 	iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
374 	raw_spin_unlock_irqrestore(&chip->lock, flags);
375 
376 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
377 
378 	return 0;
379 }
380 
381 static int iproc_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
382 {
383 	struct iproc_gpio *chip = gpiochip_get_data(gc);
384 	unsigned int offset = IPROC_GPIO_REG(gpio, IPROC_GPIO_OUT_EN_OFFSET);
385 	unsigned int shift = IPROC_GPIO_SHIFT(gpio);
386 
387 	if (readl(chip->base + offset) & BIT(shift))
388 		return GPIO_LINE_DIRECTION_OUT;
389 
390 	return GPIO_LINE_DIRECTION_IN;
391 }
392 
393 static void iproc_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
394 {
395 	struct iproc_gpio *chip = gpiochip_get_data(gc);
396 	unsigned long flags;
397 
398 	raw_spin_lock_irqsave(&chip->lock, flags);
399 	iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
400 	raw_spin_unlock_irqrestore(&chip->lock, flags);
401 
402 	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
403 }
404 
405 static int iproc_gpio_get(struct gpio_chip *gc, unsigned gpio)
406 {
407 	struct iproc_gpio *chip = gpiochip_get_data(gc);
408 	unsigned int offset = IPROC_GPIO_REG(gpio,
409 					      IPROC_GPIO_DATA_IN_OFFSET);
410 	unsigned int shift = IPROC_GPIO_SHIFT(gpio);
411 
412 	return !!(readl(chip->base + offset) & BIT(shift));
413 }
414 
415 /*
416  * Mapping of the iProc PINCONF parameters to the generic pin configuration
417  * parameters
418  */
419 static const enum pin_config_param iproc_pinconf_disable_map[] = {
420 	[IPROC_PINCONF_DRIVE_STRENGTH] = PIN_CONFIG_DRIVE_STRENGTH,
421 	[IPROC_PINCONF_BIAS_DISABLE] = PIN_CONFIG_BIAS_DISABLE,
422 	[IPROC_PINCONF_BIAS_PULL_UP] = PIN_CONFIG_BIAS_PULL_UP,
423 	[IPROC_PINCONF_BIAS_PULL_DOWN] = PIN_CONFIG_BIAS_PULL_DOWN,
424 };
425 
426 static bool iproc_pinconf_param_is_disabled(struct iproc_gpio *chip,
427 					    enum pin_config_param param)
428 {
429 	unsigned int i;
430 
431 	if (!chip->nr_pinconf_disable)
432 		return false;
433 
434 	for (i = 0; i < chip->nr_pinconf_disable; i++)
435 		if (chip->pinconf_disable[i] == param)
436 			return true;
437 
438 	return false;
439 }
440 
441 static int iproc_pinconf_disable_map_create(struct iproc_gpio *chip,
442 					    unsigned long disable_mask)
443 {
444 	unsigned int map_size = ARRAY_SIZE(iproc_pinconf_disable_map);
445 	unsigned int bit, nbits = 0;
446 
447 	/* figure out total number of PINCONF parameters to disable */
448 	for_each_set_bit(bit, &disable_mask, map_size)
449 		nbits++;
450 
451 	if (!nbits)
452 		return 0;
453 
454 	/*
455 	 * Allocate an array to store PINCONF parameters that need to be
456 	 * disabled
457 	 */
458 	chip->pinconf_disable = devm_kcalloc(chip->dev, nbits,
459 					     sizeof(*chip->pinconf_disable),
460 					     GFP_KERNEL);
461 	if (!chip->pinconf_disable)
462 		return -ENOMEM;
463 
464 	chip->nr_pinconf_disable = nbits;
465 
466 	/* now store these parameters */
467 	nbits = 0;
468 	for_each_set_bit(bit, &disable_mask, map_size)
469 		chip->pinconf_disable[nbits++] = iproc_pinconf_disable_map[bit];
470 
471 	return 0;
472 }
473 
474 static int iproc_get_groups_count(struct pinctrl_dev *pctldev)
475 {
476 	return 1;
477 }
478 
479 /*
480  * Only one group: "gpio_grp", since this local pinctrl device only performs
481  * GPIO specific PINCONF configurations
482  */
483 static const char *iproc_get_group_name(struct pinctrl_dev *pctldev,
484 					 unsigned selector)
485 {
486 	return "gpio_grp";
487 }
488 
489 static const struct pinctrl_ops iproc_pctrl_ops = {
490 	.get_groups_count = iproc_get_groups_count,
491 	.get_group_name = iproc_get_group_name,
492 	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
493 	.dt_free_map = pinctrl_utils_free_map,
494 };
495 
496 static int iproc_gpio_set_pull(struct iproc_gpio *chip, unsigned gpio,
497 				bool disable, bool pull_up)
498 {
499 	void __iomem *base;
500 	unsigned long flags;
501 	unsigned int shift;
502 	u32 val_1, val_2;
503 
504 	raw_spin_lock_irqsave(&chip->lock, flags);
505 	if (chip->io_ctrl_type == IOCTRL_TYPE_CDRU) {
506 		base = chip->io_ctrl;
507 		shift = IPROC_GPIO_SHIFT(gpio);
508 
509 		val_1 = readl(base + IPROC_GPIO_PULL_UP_OFFSET);
510 		val_2 = readl(base + IPROC_GPIO_PULL_DN_OFFSET);
511 		if (disable) {
512 			/* no pull-up or pull-down */
513 			val_1 &= ~BIT(shift);
514 			val_2 &= ~BIT(shift);
515 		} else if (pull_up) {
516 			val_1 |= BIT(shift);
517 			val_2 &= ~BIT(shift);
518 		} else {
519 			val_1 &= ~BIT(shift);
520 			val_2 |= BIT(shift);
521 		}
522 		writel(val_1, base + IPROC_GPIO_PULL_UP_OFFSET);
523 		writel(val_2, base + IPROC_GPIO_PULL_DN_OFFSET);
524 	} else {
525 		if (disable) {
526 			iproc_set_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio,
527 				      false);
528 		} else {
529 			iproc_set_bit(chip, IPROC_GPIO_PAD_RES_OFFSET, gpio,
530 				      pull_up);
531 			iproc_set_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio,
532 				      true);
533 		}
534 	}
535 
536 	raw_spin_unlock_irqrestore(&chip->lock, flags);
537 	dev_dbg(chip->dev, "gpio:%u set pullup:%d\n", gpio, pull_up);
538 
539 	return 0;
540 }
541 
542 static void iproc_gpio_get_pull(struct iproc_gpio *chip, unsigned gpio,
543 				 bool *disable, bool *pull_up)
544 {
545 	void __iomem *base;
546 	unsigned long flags;
547 	unsigned int shift;
548 	u32 val_1, val_2;
549 
550 	raw_spin_lock_irqsave(&chip->lock, flags);
551 	if (chip->io_ctrl_type == IOCTRL_TYPE_CDRU) {
552 		base = chip->io_ctrl;
553 		shift = IPROC_GPIO_SHIFT(gpio);
554 
555 		val_1 = readl(base + IPROC_GPIO_PULL_UP_OFFSET) & BIT(shift);
556 		val_2 = readl(base + IPROC_GPIO_PULL_DN_OFFSET) & BIT(shift);
557 
558 		*pull_up = val_1 ? true : false;
559 		*disable = (val_1 | val_2) ? false : true;
560 
561 	} else {
562 		*disable = !iproc_get_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio);
563 		*pull_up = iproc_get_bit(chip, IPROC_GPIO_PAD_RES_OFFSET, gpio);
564 	}
565 	raw_spin_unlock_irqrestore(&chip->lock, flags);
566 }
567 
568 #define DRV_STRENGTH_OFFSET(gpio, bit, type)  ((type) == IOCTRL_TYPE_AON ? \
569 	((2 - (bit)) * 4 + IPROC_GPIO_DRV_CTRL_OFFSET) : \
570 	((type) == IOCTRL_TYPE_CDRU) ? \
571 	((bit) * 4 + IPROC_GPIO_DRV_CTRL_OFFSET) : \
572 	((bit) * 4 + IPROC_GPIO_REG(gpio, IPROC_GPIO_ASIU_DRV0_CTRL_OFFSET)))
573 
574 static int iproc_gpio_set_strength(struct iproc_gpio *chip, unsigned gpio,
575 				    unsigned strength)
576 {
577 	void __iomem *base;
578 	unsigned int i, offset, shift;
579 	u32 val;
580 	unsigned long flags;
581 
582 	/* make sure drive strength is supported */
583 	if (strength < 2 ||  strength > 16 || (strength % 2))
584 		return -ENOTSUPP;
585 
586 	if (chip->io_ctrl) {
587 		base = chip->io_ctrl;
588 	} else {
589 		base = chip->base;
590 	}
591 
592 	shift = IPROC_GPIO_SHIFT(gpio);
593 
594 	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
595 		strength);
596 
597 	raw_spin_lock_irqsave(&chip->lock, flags);
598 	strength = (strength / 2) - 1;
599 	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
600 		offset = DRV_STRENGTH_OFFSET(gpio, i, chip->io_ctrl_type);
601 		val = readl(base + offset);
602 		val &= ~BIT(shift);
603 		val |= ((strength >> i) & 0x1) << shift;
604 		writel(val, base + offset);
605 	}
606 	raw_spin_unlock_irqrestore(&chip->lock, flags);
607 
608 	return 0;
609 }
610 
611 static int iproc_gpio_get_strength(struct iproc_gpio *chip, unsigned gpio,
612 				    u16 *strength)
613 {
614 	void __iomem *base;
615 	unsigned int i, offset, shift;
616 	u32 val;
617 	unsigned long flags;
618 
619 	if (chip->io_ctrl) {
620 		base = chip->io_ctrl;
621 	} else {
622 		base = chip->base;
623 	}
624 
625 	shift = IPROC_GPIO_SHIFT(gpio);
626 
627 	raw_spin_lock_irqsave(&chip->lock, flags);
628 	*strength = 0;
629 	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
630 		offset = DRV_STRENGTH_OFFSET(gpio, i, chip->io_ctrl_type);
631 		val = readl(base + offset) & BIT(shift);
632 		val >>= shift;
633 		*strength += (val << i);
634 	}
635 
636 	/* convert to mA */
637 	*strength = (*strength + 1) * 2;
638 	raw_spin_unlock_irqrestore(&chip->lock, flags);
639 
640 	return 0;
641 }
642 
643 static int iproc_pin_config_get(struct pinctrl_dev *pctldev, unsigned pin,
644 				 unsigned long *config)
645 {
646 	struct iproc_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
647 	enum pin_config_param param = pinconf_to_config_param(*config);
648 	unsigned gpio = iproc_pin_to_gpio(pin);
649 	u16 arg;
650 	bool disable, pull_up;
651 	int ret;
652 
653 	if (iproc_pinconf_param_is_disabled(chip, param))
654 		return -ENOTSUPP;
655 
656 	switch (param) {
657 	case PIN_CONFIG_BIAS_DISABLE:
658 		iproc_gpio_get_pull(chip, gpio, &disable, &pull_up);
659 		if (disable)
660 			return 0;
661 		else
662 			return -EINVAL;
663 
664 	case PIN_CONFIG_BIAS_PULL_UP:
665 		iproc_gpio_get_pull(chip, gpio, &disable, &pull_up);
666 		if (!disable && pull_up)
667 			return 0;
668 		else
669 			return -EINVAL;
670 
671 	case PIN_CONFIG_BIAS_PULL_DOWN:
672 		iproc_gpio_get_pull(chip, gpio, &disable, &pull_up);
673 		if (!disable && !pull_up)
674 			return 0;
675 		else
676 			return -EINVAL;
677 
678 	case PIN_CONFIG_DRIVE_STRENGTH:
679 		ret = iproc_gpio_get_strength(chip, gpio, &arg);
680 		if (ret)
681 			return ret;
682 		*config = pinconf_to_config_packed(param, arg);
683 
684 		return 0;
685 
686 	default:
687 		return -ENOTSUPP;
688 	}
689 
690 	return -ENOTSUPP;
691 }
692 
693 static int iproc_pin_config_set(struct pinctrl_dev *pctldev, unsigned pin,
694 				 unsigned long *configs, unsigned num_configs)
695 {
696 	struct iproc_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
697 	enum pin_config_param param;
698 	u32 arg;
699 	unsigned i, gpio = iproc_pin_to_gpio(pin);
700 	int ret = -ENOTSUPP;
701 
702 	for (i = 0; i < num_configs; i++) {
703 		param = pinconf_to_config_param(configs[i]);
704 
705 		if (iproc_pinconf_param_is_disabled(chip, param))
706 			return -ENOTSUPP;
707 
708 		arg = pinconf_to_config_argument(configs[i]);
709 
710 		switch (param) {
711 		case PIN_CONFIG_BIAS_DISABLE:
712 			ret = iproc_gpio_set_pull(chip, gpio, true, false);
713 			if (ret < 0)
714 				goto out;
715 			break;
716 
717 		case PIN_CONFIG_BIAS_PULL_UP:
718 			ret = iproc_gpio_set_pull(chip, gpio, false, true);
719 			if (ret < 0)
720 				goto out;
721 			break;
722 
723 		case PIN_CONFIG_BIAS_PULL_DOWN:
724 			ret = iproc_gpio_set_pull(chip, gpio, false, false);
725 			if (ret < 0)
726 				goto out;
727 			break;
728 
729 		case PIN_CONFIG_DRIVE_STRENGTH:
730 			ret = iproc_gpio_set_strength(chip, gpio, arg);
731 			if (ret < 0)
732 				goto out;
733 			break;
734 
735 		default:
736 			dev_err(chip->dev, "invalid configuration\n");
737 			return -ENOTSUPP;
738 		}
739 	} /* for each config */
740 
741 out:
742 	return ret;
743 }
744 
745 static const struct pinconf_ops iproc_pconf_ops = {
746 	.is_generic = true,
747 	.pin_config_get = iproc_pin_config_get,
748 	.pin_config_set = iproc_pin_config_set,
749 };
750 
751 /*
752  * Iproc GPIO controller supports some PINCONF related configurations such as
753  * pull up, pull down, and drive strength, when the pin is configured to GPIO
754  *
755  * Here a local pinctrl device is created with simple 1-to-1 pin mapping to the
756  * local GPIO pins
757  */
758 static int iproc_gpio_register_pinconf(struct iproc_gpio *chip)
759 {
760 	struct pinctrl_desc *pctldesc = &chip->pctldesc;
761 	struct pinctrl_pin_desc *pins;
762 	struct gpio_chip *gc = &chip->gc;
763 	int i;
764 
765 	pins = devm_kcalloc(chip->dev, gc->ngpio, sizeof(*pins), GFP_KERNEL);
766 	if (!pins)
767 		return -ENOMEM;
768 
769 	for (i = 0; i < gc->ngpio; i++) {
770 		pins[i].number = i;
771 		pins[i].name = devm_kasprintf(chip->dev, GFP_KERNEL,
772 					      "gpio-%d", i);
773 		if (!pins[i].name)
774 			return -ENOMEM;
775 	}
776 
777 	pctldesc->name = dev_name(chip->dev);
778 	pctldesc->pctlops = &iproc_pctrl_ops;
779 	pctldesc->pins = pins;
780 	pctldesc->npins = gc->ngpio;
781 	pctldesc->confops = &iproc_pconf_ops;
782 
783 	chip->pctl = devm_pinctrl_register(chip->dev, pctldesc, chip);
784 	if (IS_ERR(chip->pctl)) {
785 		dev_err(chip->dev, "unable to register pinctrl device\n");
786 		return PTR_ERR(chip->pctl);
787 	}
788 
789 	return 0;
790 }
791 
792 static const struct of_device_id iproc_gpio_of_match[] = {
793 	{ .compatible = "brcm,iproc-gpio" },
794 	{ .compatible = "brcm,cygnus-ccm-gpio" },
795 	{ .compatible = "brcm,cygnus-asiu-gpio" },
796 	{ .compatible = "brcm,cygnus-crmu-gpio" },
797 	{ .compatible = "brcm,iproc-nsp-gpio" },
798 	{ .compatible = "brcm,iproc-stingray-gpio" },
799 	{ /* sentinel */ }
800 };
801 
802 static int iproc_gpio_probe(struct platform_device *pdev)
803 {
804 	struct device *dev = &pdev->dev;
805 	struct resource *res;
806 	struct iproc_gpio *chip;
807 	struct gpio_chip *gc;
808 	u32 ngpios, pinconf_disable_mask = 0;
809 	int irq, ret;
810 	bool no_pinconf = false;
811 	enum iproc_pinconf_ctrl_type io_ctrl_type = IOCTRL_TYPE_INVALID;
812 
813 	/* NSP does not support drive strength config */
814 	if (of_device_is_compatible(dev->of_node, "brcm,iproc-nsp-gpio"))
815 		pinconf_disable_mask = BIT(IPROC_PINCONF_DRIVE_STRENGTH);
816 	/* Stingray does not support pinconf in this controller */
817 	else if (of_device_is_compatible(dev->of_node,
818 					 "brcm,iproc-stingray-gpio"))
819 		no_pinconf = true;
820 
821 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
822 	if (!chip)
823 		return -ENOMEM;
824 
825 	chip->dev = dev;
826 	platform_set_drvdata(pdev, chip);
827 
828 	chip->base = devm_platform_ioremap_resource(pdev, 0);
829 	if (IS_ERR(chip->base)) {
830 		dev_err(dev, "unable to map I/O memory\n");
831 		return PTR_ERR(chip->base);
832 	}
833 
834 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
835 	if (res) {
836 		chip->io_ctrl = devm_ioremap_resource(dev, res);
837 		if (IS_ERR(chip->io_ctrl))
838 			return PTR_ERR(chip->io_ctrl);
839 		if (of_device_is_compatible(dev->of_node,
840 					    "brcm,cygnus-ccm-gpio"))
841 			io_ctrl_type = IOCTRL_TYPE_CDRU;
842 		else
843 			io_ctrl_type = IOCTRL_TYPE_AON;
844 	}
845 
846 	chip->io_ctrl_type = io_ctrl_type;
847 
848 	if (of_property_read_u32(dev->of_node, "ngpios", &ngpios)) {
849 		dev_err(&pdev->dev, "missing ngpios DT property\n");
850 		return -ENODEV;
851 	}
852 
853 	raw_spin_lock_init(&chip->lock);
854 
855 	gc = &chip->gc;
856 	gc->base = -1;
857 	gc->ngpio = ngpios;
858 	chip->num_banks = (ngpios + NGPIOS_PER_BANK - 1) / NGPIOS_PER_BANK;
859 	gc->label = dev_name(dev);
860 	gc->parent = dev;
861 	gc->request = iproc_gpio_request;
862 	gc->free = iproc_gpio_free;
863 	gc->direction_input = iproc_gpio_direction_input;
864 	gc->direction_output = iproc_gpio_direction_output;
865 	gc->get_direction = iproc_gpio_get_direction;
866 	gc->set = iproc_gpio_set;
867 	gc->get = iproc_gpio_get;
868 
869 	chip->pinmux_is_supported = of_property_read_bool(dev->of_node,
870 							"gpio-ranges");
871 
872 	/* optional GPIO interrupt support */
873 	irq = platform_get_irq_optional(pdev, 0);
874 	if (irq > 0) {
875 		struct gpio_irq_chip *girq;
876 
877 		girq = &gc->irq;
878 		gpio_irq_chip_set_chip(girq, &iproc_gpio_irq_chip);
879 		girq->parent_handler = iproc_gpio_irq_handler;
880 		girq->num_parents = 1;
881 		girq->parents = devm_kcalloc(dev, 1,
882 					     sizeof(*girq->parents),
883 					     GFP_KERNEL);
884 		if (!girq->parents)
885 			return -ENOMEM;
886 		girq->parents[0] = irq;
887 		girq->default_type = IRQ_TYPE_NONE;
888 		girq->handler = handle_bad_irq;
889 	}
890 
891 	ret = gpiochip_add_data(gc, chip);
892 	if (ret < 0)
893 		return dev_err_probe(dev, ret, "unable to add GPIO chip\n");
894 
895 	if (!no_pinconf) {
896 		ret = iproc_gpio_register_pinconf(chip);
897 		if (ret) {
898 			dev_err(dev, "unable to register pinconf\n");
899 			goto err_rm_gpiochip;
900 		}
901 
902 		if (pinconf_disable_mask) {
903 			ret = iproc_pinconf_disable_map_create(chip,
904 							 pinconf_disable_mask);
905 			if (ret) {
906 				dev_err(dev,
907 					"unable to create pinconf disable map\n");
908 				goto err_rm_gpiochip;
909 			}
910 		}
911 	}
912 
913 	return 0;
914 
915 err_rm_gpiochip:
916 	gpiochip_remove(gc);
917 
918 	return ret;
919 }
920 
921 static struct platform_driver iproc_gpio_driver = {
922 	.driver = {
923 		.name = "iproc-gpio",
924 		.of_match_table = iproc_gpio_of_match,
925 	},
926 	.probe = iproc_gpio_probe,
927 };
928 
929 static int __init iproc_gpio_init(void)
930 {
931 	return platform_driver_register(&iproc_gpio_driver);
932 }
933 arch_initcall_sync(iproc_gpio_init);
934