xref: /openbmc/linux/drivers/gpio/gpio-tangier.c (revision 84e6da7a) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel Tangier GPIO driver
4  *
5  * Copyright (c) 2016, 2021, 2023 Intel Corporation.
6  *
7  * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
8  *          Pandith N <pandith.n@intel.com>
9  *          Raag Jadav <raag.jadav@intel.com>
10  */
11 
12 #include <linux/bitops.h>
13 #include <linux/device.h>
14 #include <linux/errno.h>
15 #include <linux/export.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/irq.h>
19 #include <linux/module.h>
20 #include <linux/pinctrl/pinconf-generic.h>
21 #include <linux/spinlock.h>
22 #include <linux/string_helpers.h>
23 #include <linux/types.h>
24 
25 #include <linux/gpio/driver.h>
26 
27 #include "gpio-tangier.h"
28 
29 #define GCCR		0x000	/* Controller configuration */
30 #define GPLR		0x004	/* Pin level r/o */
31 #define GPDR		0x01c	/* Pin direction */
32 #define GPSR		0x034	/* Pin set w/o */
33 #define GPCR		0x04c	/* Pin clear w/o */
34 #define GRER		0x064	/* Rising edge detect */
35 #define GFER		0x07c	/* Falling edge detect */
36 #define GFBR		0x094	/* Glitch filter bypass */
37 #define GIMR		0x0ac	/* Interrupt mask */
38 #define GISR		0x0c4	/* Interrupt source */
39 #define GITR		0x300	/* Input type */
40 #define GLPR		0x318	/* Level input polarity */
41 
42 /**
43  * struct tng_gpio_context - Context to be saved during suspend-resume
44  * @level: Pin level
45  * @gpdr: Pin direction
46  * @grer: Rising edge detect enable
47  * @gfer: Falling edge detect enable
48  * @gimr: Interrupt mask
49  * @gwmr: Wake mask
50  */
51 struct tng_gpio_context {
52 	u32 level;
53 	u32 gpdr;
54 	u32 grer;
55 	u32 gfer;
56 	u32 gimr;
57 	u32 gwmr;
58 };
59 
60 static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned int offset,
61 			      unsigned int reg)
62 {
63 	struct tng_gpio *priv = gpiochip_get_data(chip);
64 	u8 reg_offset = offset / 32;
65 
66 	return priv->reg_base + reg + reg_offset * 4;
67 }
68 
69 static void __iomem *gpio_reg_and_bit(struct gpio_chip *chip, unsigned int offset,
70 				      unsigned int reg, u8 *bit)
71 {
72 	struct tng_gpio *priv = gpiochip_get_data(chip);
73 	u8 reg_offset = offset / 32;
74 	u8 shift = offset % 32;
75 
76 	*bit = shift;
77 	return priv->reg_base + reg + reg_offset * 4;
78 }
79 
80 static int tng_gpio_get(struct gpio_chip *chip, unsigned int offset)
81 {
82 	void __iomem *gplr;
83 	u8 shift;
84 
85 	gplr = gpio_reg_and_bit(chip, offset, GPLR, &shift);
86 
87 	return !!(readl(gplr) & BIT(shift));
88 }
89 
90 static void tng_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
91 {
92 	struct tng_gpio *priv = gpiochip_get_data(chip);
93 	unsigned long flags;
94 	void __iomem *reg;
95 	u8 shift;
96 
97 	reg = gpio_reg_and_bit(chip, offset, value ? GPSR : GPCR, &shift);
98 
99 	raw_spin_lock_irqsave(&priv->lock, flags);
100 
101 	writel(BIT(shift), reg);
102 
103 	raw_spin_unlock_irqrestore(&priv->lock, flags);
104 }
105 
106 static int tng_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
107 {
108 	struct tng_gpio *priv = gpiochip_get_data(chip);
109 	unsigned long flags;
110 	void __iomem *gpdr;
111 	u32 value;
112 	u8 shift;
113 
114 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
115 
116 	raw_spin_lock_irqsave(&priv->lock, flags);
117 
118 	value = readl(gpdr);
119 	value &= ~BIT(shift);
120 	writel(value, gpdr);
121 
122 	raw_spin_unlock_irqrestore(&priv->lock, flags);
123 
124 	return 0;
125 }
126 
127 static int tng_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
128 				     int value)
129 {
130 	struct tng_gpio *priv = gpiochip_get_data(chip);
131 	unsigned long flags;
132 	void __iomem *gpdr;
133 	u8 shift;
134 
135 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
136 	tng_gpio_set(chip, offset, value);
137 
138 	raw_spin_lock_irqsave(&priv->lock, flags);
139 
140 	value = readl(gpdr);
141 	value |= BIT(shift);
142 	writel(value, gpdr);
143 
144 	raw_spin_unlock_irqrestore(&priv->lock, flags);
145 
146 	return 0;
147 }
148 
149 static int tng_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
150 {
151 	void __iomem *gpdr;
152 	u8 shift;
153 
154 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
155 
156 	if (readl(gpdr) & BIT(shift))
157 		return GPIO_LINE_DIRECTION_OUT;
158 
159 	return GPIO_LINE_DIRECTION_IN;
160 }
161 
162 static int tng_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
163 				 unsigned int debounce)
164 {
165 	struct tng_gpio *priv = gpiochip_get_data(chip);
166 	unsigned long flags;
167 	void __iomem *gfbr;
168 	u32 value;
169 	u8 shift;
170 
171 	gfbr = gpio_reg_and_bit(chip, offset, GFBR, &shift);
172 
173 	raw_spin_lock_irqsave(&priv->lock, flags);
174 
175 	value = readl(gfbr);
176 	if (debounce)
177 		value &= ~BIT(shift);
178 	else
179 		value |= BIT(shift);
180 	writel(value, gfbr);
181 
182 	raw_spin_unlock_irqrestore(&priv->lock, flags);
183 
184 	return 0;
185 }
186 
187 static int tng_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
188 			       unsigned long config)
189 {
190 	u32 debounce;
191 
192 	switch (pinconf_to_config_param(config)) {
193 	case PIN_CONFIG_BIAS_DISABLE:
194 	case PIN_CONFIG_BIAS_PULL_UP:
195 	case PIN_CONFIG_BIAS_PULL_DOWN:
196 		return gpiochip_generic_config(chip, offset, config);
197 	case PIN_CONFIG_INPUT_DEBOUNCE:
198 		debounce = pinconf_to_config_argument(config);
199 		return tng_gpio_set_debounce(chip, offset, debounce);
200 	default:
201 		return -ENOTSUPP;
202 	}
203 }
204 
205 static void tng_irq_ack(struct irq_data *d)
206 {
207 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
208 	irq_hw_number_t gpio = irqd_to_hwirq(d);
209 	unsigned long flags;
210 	void __iomem *gisr;
211 	u8 shift;
212 
213 	gisr = gpio_reg_and_bit(&priv->chip, gpio, GISR, &shift);
214 
215 	raw_spin_lock_irqsave(&priv->lock, flags);
216 	writel(BIT(shift), gisr);
217 	raw_spin_unlock_irqrestore(&priv->lock, flags);
218 }
219 
220 static void tng_irq_unmask_mask(struct tng_gpio *priv, u32 gpio, bool unmask)
221 {
222 	unsigned long flags;
223 	void __iomem *gimr;
224 	u32 value;
225 	u8 shift;
226 
227 	gimr = gpio_reg_and_bit(&priv->chip, gpio, GIMR, &shift);
228 
229 	raw_spin_lock_irqsave(&priv->lock, flags);
230 
231 	value = readl(gimr);
232 	if (unmask)
233 		value |= BIT(shift);
234 	else
235 		value &= ~BIT(shift);
236 	writel(value, gimr);
237 
238 	raw_spin_unlock_irqrestore(&priv->lock, flags);
239 }
240 
241 static void tng_irq_mask(struct irq_data *d)
242 {
243 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
244 	irq_hw_number_t gpio = irqd_to_hwirq(d);
245 
246 	tng_irq_unmask_mask(priv, gpio, false);
247 	gpiochip_disable_irq(&priv->chip, gpio);
248 }
249 
250 static void tng_irq_unmask(struct irq_data *d)
251 {
252 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
253 	irq_hw_number_t gpio = irqd_to_hwirq(d);
254 
255 	gpiochip_enable_irq(&priv->chip, gpio);
256 	tng_irq_unmask_mask(priv, gpio, true);
257 }
258 
259 static int tng_irq_set_type(struct irq_data *d, unsigned int type)
260 {
261 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
262 	struct tng_gpio *priv = gpiochip_get_data(gc);
263 	irq_hw_number_t gpio = irqd_to_hwirq(d);
264 	void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
265 	void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
266 	void __iomem *gitr = gpio_reg(&priv->chip, gpio, GITR);
267 	void __iomem *glpr = gpio_reg(&priv->chip, gpio, GLPR);
268 	u8 shift = gpio % 32;
269 	unsigned long flags;
270 	u32 value;
271 
272 	raw_spin_lock_irqsave(&priv->lock, flags);
273 
274 	value = readl(grer);
275 	if (type & IRQ_TYPE_EDGE_RISING)
276 		value |= BIT(shift);
277 	else
278 		value &= ~BIT(shift);
279 	writel(value, grer);
280 
281 	value = readl(gfer);
282 	if (type & IRQ_TYPE_EDGE_FALLING)
283 		value |= BIT(shift);
284 	else
285 		value &= ~BIT(shift);
286 	writel(value, gfer);
287 
288 	/*
289 	 * To prevent glitches from triggering an unintended level interrupt,
290 	 * configure GLPR register first and then configure GITR.
291 	 */
292 	value = readl(glpr);
293 	if (type & IRQ_TYPE_LEVEL_LOW)
294 		value |= BIT(shift);
295 	else
296 		value &= ~BIT(shift);
297 	writel(value, glpr);
298 
299 	if (type & IRQ_TYPE_LEVEL_MASK) {
300 		value = readl(gitr);
301 		value |= BIT(shift);
302 		writel(value, gitr);
303 
304 		irq_set_handler_locked(d, handle_level_irq);
305 	} else if (type & IRQ_TYPE_EDGE_BOTH) {
306 		value = readl(gitr);
307 		value &= ~BIT(shift);
308 		writel(value, gitr);
309 
310 		irq_set_handler_locked(d, handle_edge_irq);
311 	}
312 
313 	raw_spin_unlock_irqrestore(&priv->lock, flags);
314 
315 	return 0;
316 }
317 
318 static int tng_irq_set_wake(struct irq_data *d, unsigned int on)
319 {
320 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
321 	struct tng_gpio *priv = gpiochip_get_data(gc);
322 	irq_hw_number_t gpio = irqd_to_hwirq(d);
323 	void __iomem *gwmr = gpio_reg(&priv->chip, gpio, priv->wake_regs.gwmr);
324 	void __iomem *gwsr = gpio_reg(&priv->chip, gpio, priv->wake_regs.gwsr);
325 	u8 shift = gpio % 32;
326 	unsigned long flags;
327 	u32 value;
328 
329 	raw_spin_lock_irqsave(&priv->lock, flags);
330 
331 	/* Clear the existing wake status */
332 	writel(BIT(shift), gwsr);
333 
334 	value = readl(gwmr);
335 	if (on)
336 		value |= BIT(shift);
337 	else
338 		value &= ~BIT(shift);
339 	writel(value, gwmr);
340 
341 	raw_spin_unlock_irqrestore(&priv->lock, flags);
342 
343 	dev_dbg(priv->dev, "%s wake for gpio %lu\n", str_enable_disable(on), gpio);
344 	return 0;
345 }
346 
347 static const struct irq_chip tng_irqchip = {
348 	.name		= "gpio-tangier",
349 	.irq_ack	= tng_irq_ack,
350 	.irq_mask	= tng_irq_mask,
351 	.irq_unmask	= tng_irq_unmask,
352 	.irq_set_type	= tng_irq_set_type,
353 	.irq_set_wake	= tng_irq_set_wake,
354 	.flags          = IRQCHIP_IMMUTABLE,
355 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
356 };
357 
358 static void tng_irq_handler(struct irq_desc *desc)
359 {
360 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
361 	struct tng_gpio *priv = gpiochip_get_data(gc);
362 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
363 	unsigned long base, gpio;
364 
365 	chained_irq_enter(irqchip, desc);
366 
367 	/* Check GPIO controller to check which pin triggered the interrupt */
368 	for (base = 0; base < priv->chip.ngpio; base += 32) {
369 		void __iomem *gisr = gpio_reg(&priv->chip, base, GISR);
370 		void __iomem *gimr = gpio_reg(&priv->chip, base, GIMR);
371 		unsigned long pending, enabled;
372 
373 		pending = readl(gisr);
374 		enabled = readl(gimr);
375 
376 		/* Only interrupts that are enabled */
377 		pending &= enabled;
378 
379 		for_each_set_bit(gpio, &pending, 32)
380 			generic_handle_domain_irq(gc->irq.domain, base + gpio);
381 	}
382 
383 	chained_irq_exit(irqchip, desc);
384 }
385 
386 static int tng_irq_init_hw(struct gpio_chip *chip)
387 {
388 	struct tng_gpio *priv = gpiochip_get_data(chip);
389 	void __iomem *reg;
390 	unsigned int base;
391 
392 	for (base = 0; base < priv->chip.ngpio; base += 32) {
393 		/* Clear the rising-edge detect register */
394 		reg = gpio_reg(&priv->chip, base, GRER);
395 		writel(0, reg);
396 
397 		/* Clear the falling-edge detect register */
398 		reg = gpio_reg(&priv->chip, base, GFER);
399 		writel(0, reg);
400 	}
401 
402 	return 0;
403 }
404 
405 static int tng_gpio_add_pin_ranges(struct gpio_chip *chip)
406 {
407 	struct tng_gpio *priv = gpiochip_get_data(chip);
408 	const struct tng_gpio_pinrange *range;
409 	unsigned int i;
410 	int ret;
411 
412 	for (i = 0; i < priv->pin_info.nranges; i++) {
413 		range = &priv->pin_info.pin_ranges[i];
414 		ret = gpiochip_add_pin_range(&priv->chip,
415 					     priv->pin_info.name,
416 					     range->gpio_base,
417 					     range->pin_base,
418 					     range->npins);
419 		if (ret) {
420 			dev_err(priv->dev, "failed to add GPIO pin range\n");
421 			return ret;
422 		}
423 	}
424 
425 	return 0;
426 }
427 
428 int devm_tng_gpio_probe(struct device *dev, struct tng_gpio *gpio)
429 {
430 	const struct tng_gpio_info *info = &gpio->info;
431 	struct gpio_irq_chip *girq;
432 	int ret;
433 
434 	gpio->ctx = devm_kcalloc(dev, DIV_ROUND_UP(info->ngpio, 32), sizeof(*gpio->ctx), GFP_KERNEL);
435 	if (!gpio->ctx)
436 		return -ENOMEM;
437 
438 	gpio->chip.label = dev_name(dev);
439 	gpio->chip.parent = dev;
440 	gpio->chip.request = gpiochip_generic_request;
441 	gpio->chip.free = gpiochip_generic_free;
442 	gpio->chip.direction_input = tng_gpio_direction_input;
443 	gpio->chip.direction_output = tng_gpio_direction_output;
444 	gpio->chip.get = tng_gpio_get;
445 	gpio->chip.set = tng_gpio_set;
446 	gpio->chip.get_direction = tng_gpio_get_direction;
447 	gpio->chip.set_config = tng_gpio_set_config;
448 	gpio->chip.base = info->base;
449 	gpio->chip.ngpio = info->ngpio;
450 	gpio->chip.can_sleep = false;
451 	gpio->chip.add_pin_ranges = tng_gpio_add_pin_ranges;
452 
453 	raw_spin_lock_init(&gpio->lock);
454 
455 	girq = &gpio->chip.irq;
456 	gpio_irq_chip_set_chip(girq, &tng_irqchip);
457 	girq->init_hw = tng_irq_init_hw;
458 	girq->parent_handler = tng_irq_handler;
459 	girq->num_parents = 1;
460 	girq->parents = devm_kcalloc(dev, girq->num_parents,
461 				     sizeof(*girq->parents), GFP_KERNEL);
462 	if (!girq->parents)
463 		return -ENOMEM;
464 
465 	girq->parents[0] = gpio->irq;
466 	girq->first = info->first;
467 	girq->default_type = IRQ_TYPE_NONE;
468 	girq->handler = handle_bad_irq;
469 
470 	ret = devm_gpiochip_add_data(dev, &gpio->chip, gpio);
471 	if (ret)
472 		return dev_err_probe(dev, ret, "gpiochip_add error\n");
473 
474 	return 0;
475 }
476 EXPORT_SYMBOL_NS_GPL(devm_tng_gpio_probe, GPIO_TANGIER);
477 
478 int tng_gpio_suspend(struct device *dev)
479 {
480 	struct tng_gpio *priv = dev_get_drvdata(dev);
481 	struct tng_gpio_context *ctx = priv->ctx;
482 	unsigned long flags;
483 	unsigned int base;
484 
485 	raw_spin_lock_irqsave(&priv->lock, flags);
486 
487 	for (base = 0; base < priv->chip.ngpio; base += 32, ctx++) {
488 		/* GPLR is RO, values read will be restored using GPSR */
489 		ctx->level = readl(gpio_reg(&priv->chip, base, GPLR));
490 
491 		ctx->gpdr = readl(gpio_reg(&priv->chip, base, GPDR));
492 		ctx->grer = readl(gpio_reg(&priv->chip, base, GRER));
493 		ctx->gfer = readl(gpio_reg(&priv->chip, base, GFER));
494 		ctx->gimr = readl(gpio_reg(&priv->chip, base, GIMR));
495 
496 		ctx->gwmr = readl(gpio_reg(&priv->chip, base, priv->wake_regs.gwmr));
497 	}
498 
499 	raw_spin_unlock_irqrestore(&priv->lock, flags);
500 
501 	return 0;
502 }
503 EXPORT_SYMBOL_NS_GPL(tng_gpio_suspend, GPIO_TANGIER);
504 
505 int tng_gpio_resume(struct device *dev)
506 {
507 	struct tng_gpio *priv = dev_get_drvdata(dev);
508 	struct tng_gpio_context *ctx = priv->ctx;
509 	unsigned long flags;
510 	unsigned int base;
511 
512 	raw_spin_lock_irqsave(&priv->lock, flags);
513 
514 	for (base = 0; base < priv->chip.ngpio; base += 32, ctx++) {
515 		/* GPLR is RO, values read will be restored using GPSR */
516 		writel(ctx->level, gpio_reg(&priv->chip, base, GPSR));
517 
518 		writel(ctx->gpdr, gpio_reg(&priv->chip, base, GPDR));
519 		writel(ctx->grer, gpio_reg(&priv->chip, base, GRER));
520 		writel(ctx->gfer, gpio_reg(&priv->chip, base, GFER));
521 		writel(ctx->gimr, gpio_reg(&priv->chip, base, GIMR));
522 
523 		writel(ctx->gwmr, gpio_reg(&priv->chip, base, priv->wake_regs.gwmr));
524 	}
525 
526 	raw_spin_unlock_irqrestore(&priv->lock, flags);
527 
528 	return 0;
529 }
530 EXPORT_SYMBOL_NS_GPL(tng_gpio_resume, GPIO_TANGIER);
531 
532 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
533 MODULE_AUTHOR("Pandith N <pandith.n@intel.com>");
534 MODULE_AUTHOR("Raag Jadav <raag.jadav@intel.com>");
535 MODULE_DESCRIPTION("Intel Tangier GPIO driver");
536 MODULE_LICENSE("GPL");
537