xref: /linux/drivers/gpio/gpio-tangier.c (revision e7d759f31ca295d589f7420719c311870bb3166f) 
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/cleanup.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/export.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/irq.h>
20 #include <linux/math.h>
21 #include <linux/module.h>
22 #include <linux/pinctrl/pinconf-generic.h>
23 #include <linux/pm.h>
24 #include <linux/spinlock.h>
25 #include <linux/string_helpers.h>
26 #include <linux/types.h>
27 
28 #include <linux/gpio/driver.h>
29 
30 #include "gpio-tangier.h"
31 
32 #define GCCR		0x000	/* Controller configuration */
33 #define GPLR		0x004	/* Pin level r/o */
34 #define GPDR		0x01c	/* Pin direction */
35 #define GPSR		0x034	/* Pin set w/o */
36 #define GPCR		0x04c	/* Pin clear w/o */
37 #define GRER		0x064	/* Rising edge detect */
38 #define GFER		0x07c	/* Falling edge detect */
39 #define GFBR		0x094	/* Glitch filter bypass */
40 #define GIMR		0x0ac	/* Interrupt mask */
41 #define GISR		0x0c4	/* Interrupt source */
42 #define GITR		0x300	/* Input type */
43 #define GLPR		0x318	/* Level input polarity */
44 
45 /**
46  * struct tng_gpio_context - Context to be saved during suspend-resume
47  * @level: Pin level
48  * @gpdr: Pin direction
49  * @grer: Rising edge detect enable
50  * @gfer: Falling edge detect enable
51  * @gimr: Interrupt mask
52  * @gwmr: Wake mask
53  */
54 struct tng_gpio_context {
55 	u32 level;
56 	u32 gpdr;
57 	u32 grer;
58 	u32 gfer;
59 	u32 gimr;
60 	u32 gwmr;
61 };
62 
63 static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned int offset,
64 			      unsigned int reg)
65 {
66 	struct tng_gpio *priv = gpiochip_get_data(chip);
67 	u8 reg_offset = offset / 32;
68 
69 	return priv->reg_base + reg + reg_offset * 4;
70 }
71 
72 static void __iomem *gpio_reg_and_bit(struct gpio_chip *chip, unsigned int offset,
73 				      unsigned int reg, u8 *bit)
74 {
75 	struct tng_gpio *priv = gpiochip_get_data(chip);
76 	u8 reg_offset = offset / 32;
77 	u8 shift = offset % 32;
78 
79 	*bit = shift;
80 	return priv->reg_base + reg + reg_offset * 4;
81 }
82 
83 static int tng_gpio_get(struct gpio_chip *chip, unsigned int offset)
84 {
85 	void __iomem *gplr;
86 	u8 shift;
87 
88 	gplr = gpio_reg_and_bit(chip, offset, GPLR, &shift);
89 
90 	return !!(readl(gplr) & BIT(shift));
91 }
92 
93 static void tng_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
94 {
95 	struct tng_gpio *priv = gpiochip_get_data(chip);
96 	void __iomem *reg;
97 	u8 shift;
98 
99 	reg = gpio_reg_and_bit(chip, offset, value ? GPSR : GPCR, &shift);
100 
101 	guard(raw_spinlock_irqsave)(&priv->lock);
102 
103 	writel(BIT(shift), reg);
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 	void __iomem *gpdr;
110 	u32 value;
111 	u8 shift;
112 
113 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
114 
115 	guard(raw_spinlock_irqsave)(&priv->lock);
116 
117 	value = readl(gpdr);
118 	value &= ~BIT(shift);
119 	writel(value, gpdr);
120 
121 	return 0;
122 }
123 
124 static int tng_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
125 				     int value)
126 {
127 	struct tng_gpio *priv = gpiochip_get_data(chip);
128 	void __iomem *gpdr;
129 	u8 shift;
130 
131 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
132 	tng_gpio_set(chip, offset, value);
133 
134 	guard(raw_spinlock_irqsave)(&priv->lock);
135 
136 	value = readl(gpdr);
137 	value |= BIT(shift);
138 	writel(value, gpdr);
139 
140 	return 0;
141 }
142 
143 static int tng_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
144 {
145 	void __iomem *gpdr;
146 	u8 shift;
147 
148 	gpdr = gpio_reg_and_bit(chip, offset, GPDR, &shift);
149 
150 	if (readl(gpdr) & BIT(shift))
151 		return GPIO_LINE_DIRECTION_OUT;
152 
153 	return GPIO_LINE_DIRECTION_IN;
154 }
155 
156 static int tng_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
157 				 unsigned int debounce)
158 {
159 	struct tng_gpio *priv = gpiochip_get_data(chip);
160 	void __iomem *gfbr;
161 	u32 value;
162 	u8 shift;
163 
164 	gfbr = gpio_reg_and_bit(chip, offset, GFBR, &shift);
165 
166 	guard(raw_spinlock_irqsave)(&priv->lock);
167 
168 	value = readl(gfbr);
169 	if (debounce)
170 		value &= ~BIT(shift);
171 	else
172 		value |= BIT(shift);
173 	writel(value, gfbr);
174 
175 	return 0;
176 }
177 
178 static int tng_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
179 			       unsigned long config)
180 {
181 	u32 debounce;
182 
183 	switch (pinconf_to_config_param(config)) {
184 	case PIN_CONFIG_BIAS_DISABLE:
185 	case PIN_CONFIG_BIAS_PULL_UP:
186 	case PIN_CONFIG_BIAS_PULL_DOWN:
187 		return gpiochip_generic_config(chip, offset, config);
188 	case PIN_CONFIG_INPUT_DEBOUNCE:
189 		debounce = pinconf_to_config_argument(config);
190 		return tng_gpio_set_debounce(chip, offset, debounce);
191 	default:
192 		return -ENOTSUPP;
193 	}
194 }
195 
196 static void tng_irq_ack(struct irq_data *d)
197 {
198 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
199 	irq_hw_number_t gpio = irqd_to_hwirq(d);
200 	void __iomem *gisr;
201 	u8 shift;
202 
203 	gisr = gpio_reg_and_bit(&priv->chip, gpio, GISR, &shift);
204 
205 	guard(raw_spinlock_irqsave)(&priv->lock);
206 
207 	writel(BIT(shift), gisr);
208 }
209 
210 static void tng_irq_unmask_mask(struct tng_gpio *priv, u32 gpio, bool unmask)
211 {
212 	void __iomem *gimr;
213 	u32 value;
214 	u8 shift;
215 
216 	gimr = gpio_reg_and_bit(&priv->chip, gpio, GIMR, &shift);
217 
218 	guard(raw_spinlock_irqsave)(&priv->lock);
219 
220 	value = readl(gimr);
221 	if (unmask)
222 		value |= BIT(shift);
223 	else
224 		value &= ~BIT(shift);
225 	writel(value, gimr);
226 }
227 
228 static void tng_irq_mask(struct irq_data *d)
229 {
230 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
231 	irq_hw_number_t gpio = irqd_to_hwirq(d);
232 
233 	tng_irq_unmask_mask(priv, gpio, false);
234 	gpiochip_disable_irq(&priv->chip, gpio);
235 }
236 
237 static void tng_irq_unmask(struct irq_data *d)
238 {
239 	struct tng_gpio *priv = irq_data_get_irq_chip_data(d);
240 	irq_hw_number_t gpio = irqd_to_hwirq(d);
241 
242 	gpiochip_enable_irq(&priv->chip, gpio);
243 	tng_irq_unmask_mask(priv, gpio, true);
244 }
245 
246 static int tng_irq_set_type(struct irq_data *d, unsigned int type)
247 {
248 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
249 	struct tng_gpio *priv = gpiochip_get_data(gc);
250 	irq_hw_number_t gpio = irqd_to_hwirq(d);
251 	void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
252 	void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
253 	void __iomem *gitr = gpio_reg(&priv->chip, gpio, GITR);
254 	void __iomem *glpr = gpio_reg(&priv->chip, gpio, GLPR);
255 	u8 shift = gpio % 32;
256 	u32 value;
257 
258 	guard(raw_spinlock_irqsave)(&priv->lock);
259 
260 	value = readl(grer);
261 	if (type & IRQ_TYPE_EDGE_RISING)
262 		value |= BIT(shift);
263 	else
264 		value &= ~BIT(shift);
265 	writel(value, grer);
266 
267 	value = readl(gfer);
268 	if (type & IRQ_TYPE_EDGE_FALLING)
269 		value |= BIT(shift);
270 	else
271 		value &= ~BIT(shift);
272 	writel(value, gfer);
273 
274 	/*
275 	 * To prevent glitches from triggering an unintended level interrupt,
276 	 * configure GLPR register first and then configure GITR.
277 	 */
278 	value = readl(glpr);
279 	if (type & IRQ_TYPE_LEVEL_LOW)
280 		value |= BIT(shift);
281 	else
282 		value &= ~BIT(shift);
283 	writel(value, glpr);
284 
285 	if (type & IRQ_TYPE_LEVEL_MASK) {
286 		value = readl(gitr);
287 		value |= BIT(shift);
288 		writel(value, gitr);
289 
290 		irq_set_handler_locked(d, handle_level_irq);
291 	} else if (type & IRQ_TYPE_EDGE_BOTH) {
292 		value = readl(gitr);
293 		value &= ~BIT(shift);
294 		writel(value, gitr);
295 
296 		irq_set_handler_locked(d, handle_edge_irq);
297 	}
298 
299 	return 0;
300 }
301 
302 static int tng_irq_set_wake(struct irq_data *d, unsigned int on)
303 {
304 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
305 	struct tng_gpio *priv = gpiochip_get_data(gc);
306 	irq_hw_number_t gpio = irqd_to_hwirq(d);
307 	void __iomem *gwmr = gpio_reg(&priv->chip, gpio, priv->wake_regs.gwmr);
308 	void __iomem *gwsr = gpio_reg(&priv->chip, gpio, priv->wake_regs.gwsr);
309 	u8 shift = gpio % 32;
310 	u32 value;
311 
312 	dev_dbg(priv->dev, "%s wake for gpio %lu\n", str_enable_disable(on), gpio);
313 
314 	guard(raw_spinlock_irqsave)(&priv->lock);
315 
316 	/* Clear the existing wake status */
317 	writel(BIT(shift), gwsr);
318 
319 	value = readl(gwmr);
320 	if (on)
321 		value |= BIT(shift);
322 	else
323 		value &= ~BIT(shift);
324 	writel(value, gwmr);
325 
326 	return 0;
327 }
328 
329 static const struct irq_chip tng_irqchip = {
330 	.name		= "gpio-tangier",
331 	.irq_ack	= tng_irq_ack,
332 	.irq_mask	= tng_irq_mask,
333 	.irq_unmask	= tng_irq_unmask,
334 	.irq_set_type	= tng_irq_set_type,
335 	.irq_set_wake	= tng_irq_set_wake,
336 	.flags          = IRQCHIP_IMMUTABLE,
337 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
338 };
339 
340 static void tng_irq_handler(struct irq_desc *desc)
341 {
342 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
343 	struct tng_gpio *priv = gpiochip_get_data(gc);
344 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
345 	unsigned long base, gpio;
346 
347 	chained_irq_enter(irqchip, desc);
348 
349 	/* Check GPIO controller to check which pin triggered the interrupt */
350 	for (base = 0; base < priv->chip.ngpio; base += 32) {
351 		void __iomem *gisr = gpio_reg(&priv->chip, base, GISR);
352 		void __iomem *gimr = gpio_reg(&priv->chip, base, GIMR);
353 		unsigned long pending, enabled;
354 
355 		pending = readl(gisr);
356 		enabled = readl(gimr);
357 
358 		/* Only interrupts that are enabled */
359 		pending &= enabled;
360 
361 		for_each_set_bit(gpio, &pending, 32)
362 			generic_handle_domain_irq(gc->irq.domain, base + gpio);
363 	}
364 
365 	chained_irq_exit(irqchip, desc);
366 }
367 
368 static int tng_irq_init_hw(struct gpio_chip *chip)
369 {
370 	struct tng_gpio *priv = gpiochip_get_data(chip);
371 	void __iomem *reg;
372 	unsigned int base;
373 
374 	for (base = 0; base < priv->chip.ngpio; base += 32) {
375 		/* Clear the rising-edge detect register */
376 		reg = gpio_reg(&priv->chip, base, GRER);
377 		writel(0, reg);
378 
379 		/* Clear the falling-edge detect register */
380 		reg = gpio_reg(&priv->chip, base, GFER);
381 		writel(0, reg);
382 	}
383 
384 	return 0;
385 }
386 
387 static int tng_gpio_add_pin_ranges(struct gpio_chip *chip)
388 {
389 	struct tng_gpio *priv = gpiochip_get_data(chip);
390 	const struct tng_gpio_pinrange *range;
391 	unsigned int i;
392 	int ret;
393 
394 	for (i = 0; i < priv->pin_info.nranges; i++) {
395 		range = &priv->pin_info.pin_ranges[i];
396 		ret = gpiochip_add_pin_range(&priv->chip,
397 					     priv->pin_info.name,
398 					     range->gpio_base,
399 					     range->pin_base,
400 					     range->npins);
401 		if (ret) {
402 			dev_err(priv->dev, "failed to add GPIO pin range\n");
403 			return ret;
404 		}
405 	}
406 
407 	return 0;
408 }
409 
410 int devm_tng_gpio_probe(struct device *dev, struct tng_gpio *gpio)
411 {
412 	const struct tng_gpio_info *info = &gpio->info;
413 	size_t nctx = DIV_ROUND_UP(info->ngpio, 32);
414 	struct gpio_irq_chip *girq;
415 	int ret;
416 
417 	gpio->ctx = devm_kcalloc(dev, nctx, sizeof(*gpio->ctx), GFP_KERNEL);
418 	if (!gpio->ctx)
419 		return -ENOMEM;
420 
421 	gpio->chip.label = dev_name(dev);
422 	gpio->chip.parent = dev;
423 	gpio->chip.request = gpiochip_generic_request;
424 	gpio->chip.free = gpiochip_generic_free;
425 	gpio->chip.direction_input = tng_gpio_direction_input;
426 	gpio->chip.direction_output = tng_gpio_direction_output;
427 	gpio->chip.get = tng_gpio_get;
428 	gpio->chip.set = tng_gpio_set;
429 	gpio->chip.get_direction = tng_gpio_get_direction;
430 	gpio->chip.set_config = tng_gpio_set_config;
431 	gpio->chip.base = info->base;
432 	gpio->chip.ngpio = info->ngpio;
433 	gpio->chip.can_sleep = false;
434 	gpio->chip.add_pin_ranges = tng_gpio_add_pin_ranges;
435 
436 	raw_spin_lock_init(&gpio->lock);
437 
438 	girq = &gpio->chip.irq;
439 	gpio_irq_chip_set_chip(girq, &tng_irqchip);
440 	girq->init_hw = tng_irq_init_hw;
441 	girq->parent_handler = tng_irq_handler;
442 	girq->num_parents = 1;
443 	girq->parents = devm_kcalloc(dev, girq->num_parents,
444 				     sizeof(*girq->parents), GFP_KERNEL);
445 	if (!girq->parents)
446 		return -ENOMEM;
447 
448 	girq->parents[0] = gpio->irq;
449 	girq->first = info->first;
450 	girq->default_type = IRQ_TYPE_NONE;
451 	girq->handler = handle_bad_irq;
452 
453 	ret = devm_gpiochip_add_data(dev, &gpio->chip, gpio);
454 	if (ret)
455 		return dev_err_probe(dev, ret, "gpiochip_add error\n");
456 
457 	return 0;
458 }
459 EXPORT_SYMBOL_NS_GPL(devm_tng_gpio_probe, GPIO_TANGIER);
460 
461 static int tng_gpio_suspend(struct device *dev)
462 {
463 	struct tng_gpio *priv = dev_get_drvdata(dev);
464 	struct tng_gpio_context *ctx = priv->ctx;
465 	unsigned int base;
466 
467 	guard(raw_spinlock_irqsave)(&priv->lock);
468 
469 	for (base = 0; base < priv->chip.ngpio; base += 32, ctx++) {
470 		/* GPLR is RO, values read will be restored using GPSR */
471 		ctx->level = readl(gpio_reg(&priv->chip, base, GPLR));
472 
473 		ctx->gpdr = readl(gpio_reg(&priv->chip, base, GPDR));
474 		ctx->grer = readl(gpio_reg(&priv->chip, base, GRER));
475 		ctx->gfer = readl(gpio_reg(&priv->chip, base, GFER));
476 		ctx->gimr = readl(gpio_reg(&priv->chip, base, GIMR));
477 
478 		ctx->gwmr = readl(gpio_reg(&priv->chip, base, priv->wake_regs.gwmr));
479 	}
480 
481 	return 0;
482 }
483 
484 static int tng_gpio_resume(struct device *dev)
485 {
486 	struct tng_gpio *priv = dev_get_drvdata(dev);
487 	struct tng_gpio_context *ctx = priv->ctx;
488 	unsigned int base;
489 
490 	guard(raw_spinlock_irqsave)(&priv->lock);
491 
492 	for (base = 0; base < priv->chip.ngpio; base += 32, ctx++) {
493 		/* GPLR is RO, values read will be restored using GPSR */
494 		writel(ctx->level, gpio_reg(&priv->chip, base, GPSR));
495 
496 		writel(ctx->gpdr, gpio_reg(&priv->chip, base, GPDR));
497 		writel(ctx->grer, gpio_reg(&priv->chip, base, GRER));
498 		writel(ctx->gfer, gpio_reg(&priv->chip, base, GFER));
499 		writel(ctx->gimr, gpio_reg(&priv->chip, base, GIMR));
500 
501 		writel(ctx->gwmr, gpio_reg(&priv->chip, base, priv->wake_regs.gwmr));
502 	}
503 
504 	return 0;
505 }
506 
507 EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(tng_gpio_pm_ops, tng_gpio_suspend, tng_gpio_resume, GPIO_TANGIER);
508 
509 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
510 MODULE_AUTHOR("Pandith N <pandith.n@intel.com>");
511 MODULE_AUTHOR("Raag Jadav <raag.jadav@intel.com>");
512 MODULE_DESCRIPTION("Intel Tangier GPIO driver");
513 MODULE_LICENSE("GPL");
514