xref: /openbmc/linux/drivers/gpio/gpio-rcar.c (revision 930c429a)
1 /*
2  * Renesas R-Car GPIO Support
3  *
4  *  Copyright (C) 2014 Renesas Electronics Corporation
5  *  Copyright (C) 2013 Magnus Damm
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/err.h>
18 #include <linux/gpio.h>
19 #include <linux/init.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/ioport.h>
23 #include <linux/irq.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/spinlock.h>
31 #include <linux/slab.h>
32 
33 struct gpio_rcar_priv {
34 	void __iomem *base;
35 	spinlock_t lock;
36 	struct platform_device *pdev;
37 	struct gpio_chip gpio_chip;
38 	struct irq_chip irq_chip;
39 	unsigned int irq_parent;
40 	atomic_t wakeup_path;
41 	bool has_both_edge_trigger;
42 };
43 
44 #define IOINTSEL 0x00	/* General IO/Interrupt Switching Register */
45 #define INOUTSEL 0x04	/* General Input/Output Switching Register */
46 #define OUTDT 0x08	/* General Output Register */
47 #define INDT 0x0c	/* General Input Register */
48 #define INTDT 0x10	/* Interrupt Display Register */
49 #define INTCLR 0x14	/* Interrupt Clear Register */
50 #define INTMSK 0x18	/* Interrupt Mask Register */
51 #define MSKCLR 0x1c	/* Interrupt Mask Clear Register */
52 #define POSNEG 0x20	/* Positive/Negative Logic Select Register */
53 #define EDGLEVEL 0x24	/* Edge/level Select Register */
54 #define FILONOFF 0x28	/* Chattering Prevention On/Off Register */
55 #define BOTHEDGE 0x4c	/* One Edge/Both Edge Select Register */
56 
57 #define RCAR_MAX_GPIO_PER_BANK		32
58 
59 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
60 {
61 	return ioread32(p->base + offs);
62 }
63 
64 static inline void gpio_rcar_write(struct gpio_rcar_priv *p, int offs,
65 				   u32 value)
66 {
67 	iowrite32(value, p->base + offs);
68 }
69 
70 static void gpio_rcar_modify_bit(struct gpio_rcar_priv *p, int offs,
71 				 int bit, bool value)
72 {
73 	u32 tmp = gpio_rcar_read(p, offs);
74 
75 	if (value)
76 		tmp |= BIT(bit);
77 	else
78 		tmp &= ~BIT(bit);
79 
80 	gpio_rcar_write(p, offs, tmp);
81 }
82 
83 static void gpio_rcar_irq_disable(struct irq_data *d)
84 {
85 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
86 	struct gpio_rcar_priv *p = gpiochip_get_data(gc);
87 
88 	gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
89 }
90 
91 static void gpio_rcar_irq_enable(struct irq_data *d)
92 {
93 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
94 	struct gpio_rcar_priv *p = gpiochip_get_data(gc);
95 
96 	gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
97 }
98 
99 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
100 						  unsigned int hwirq,
101 						  bool active_high_rising_edge,
102 						  bool level_trigger,
103 						  bool both)
104 {
105 	unsigned long flags;
106 
107 	/* follow steps in the GPIO documentation for
108 	 * "Setting Edge-Sensitive Interrupt Input Mode" and
109 	 * "Setting Level-Sensitive Interrupt Input Mode"
110 	 */
111 
112 	spin_lock_irqsave(&p->lock, flags);
113 
114 	/* Configure postive or negative logic in POSNEG */
115 	gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
116 
117 	/* Configure edge or level trigger in EDGLEVEL */
118 	gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
119 
120 	/* Select one edge or both edges in BOTHEDGE */
121 	if (p->has_both_edge_trigger)
122 		gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
123 
124 	/* Select "Interrupt Input Mode" in IOINTSEL */
125 	gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
126 
127 	/* Write INTCLR in case of edge trigger */
128 	if (!level_trigger)
129 		gpio_rcar_write(p, INTCLR, BIT(hwirq));
130 
131 	spin_unlock_irqrestore(&p->lock, flags);
132 }
133 
134 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
135 {
136 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
137 	struct gpio_rcar_priv *p = gpiochip_get_data(gc);
138 	unsigned int hwirq = irqd_to_hwirq(d);
139 
140 	dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
141 
142 	switch (type & IRQ_TYPE_SENSE_MASK) {
143 	case IRQ_TYPE_LEVEL_HIGH:
144 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true,
145 						      false);
146 		break;
147 	case IRQ_TYPE_LEVEL_LOW:
148 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true,
149 						      false);
150 		break;
151 	case IRQ_TYPE_EDGE_RISING:
152 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
153 						      false);
154 		break;
155 	case IRQ_TYPE_EDGE_FALLING:
156 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false,
157 						      false);
158 		break;
159 	case IRQ_TYPE_EDGE_BOTH:
160 		if (!p->has_both_edge_trigger)
161 			return -EINVAL;
162 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
163 						      true);
164 		break;
165 	default:
166 		return -EINVAL;
167 	}
168 	return 0;
169 }
170 
171 static int gpio_rcar_irq_set_wake(struct irq_data *d, unsigned int on)
172 {
173 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
174 	struct gpio_rcar_priv *p = gpiochip_get_data(gc);
175 	int error;
176 
177 	if (p->irq_parent) {
178 		error = irq_set_irq_wake(p->irq_parent, on);
179 		if (error) {
180 			dev_dbg(&p->pdev->dev,
181 				"irq %u doesn't support irq_set_wake\n",
182 				p->irq_parent);
183 			p->irq_parent = 0;
184 		}
185 	}
186 
187 	if (on)
188 		atomic_inc(&p->wakeup_path);
189 	else
190 		atomic_dec(&p->wakeup_path);
191 
192 	return 0;
193 }
194 
195 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
196 {
197 	struct gpio_rcar_priv *p = dev_id;
198 	u32 pending;
199 	unsigned int offset, irqs_handled = 0;
200 
201 	while ((pending = gpio_rcar_read(p, INTDT) &
202 			  gpio_rcar_read(p, INTMSK))) {
203 		offset = __ffs(pending);
204 		gpio_rcar_write(p, INTCLR, BIT(offset));
205 		generic_handle_irq(irq_find_mapping(p->gpio_chip.irq.domain,
206 						    offset));
207 		irqs_handled++;
208 	}
209 
210 	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
211 }
212 
213 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
214 						       unsigned int gpio,
215 						       bool output)
216 {
217 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
218 	unsigned long flags;
219 
220 	/* follow steps in the GPIO documentation for
221 	 * "Setting General Output Mode" and
222 	 * "Setting General Input Mode"
223 	 */
224 
225 	spin_lock_irqsave(&p->lock, flags);
226 
227 	/* Configure postive logic in POSNEG */
228 	gpio_rcar_modify_bit(p, POSNEG, gpio, false);
229 
230 	/* Select "General Input/Output Mode" in IOINTSEL */
231 	gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
232 
233 	/* Select Input Mode or Output Mode in INOUTSEL */
234 	gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
235 
236 	spin_unlock_irqrestore(&p->lock, flags);
237 }
238 
239 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
240 {
241 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
242 	int error;
243 
244 	error = pm_runtime_get_sync(&p->pdev->dev);
245 	if (error < 0)
246 		return error;
247 
248 	error = pinctrl_gpio_request(chip->base + offset);
249 	if (error)
250 		pm_runtime_put(&p->pdev->dev);
251 
252 	return error;
253 }
254 
255 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
256 {
257 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
258 
259 	pinctrl_gpio_free(chip->base + offset);
260 
261 	/*
262 	 * Set the GPIO as an input to ensure that the next GPIO request won't
263 	 * drive the GPIO pin as an output.
264 	 */
265 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
266 
267 	pm_runtime_put(&p->pdev->dev);
268 }
269 
270 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
271 {
272 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
273 	return 0;
274 }
275 
276 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
277 {
278 	u32 bit = BIT(offset);
279 
280 	/* testing on r8a7790 shows that INDT does not show correct pin state
281 	 * when configured as output, so use OUTDT in case of output pins */
282 	if (gpio_rcar_read(gpiochip_get_data(chip), INOUTSEL) & bit)
283 		return !!(gpio_rcar_read(gpiochip_get_data(chip), OUTDT) & bit);
284 	else
285 		return !!(gpio_rcar_read(gpiochip_get_data(chip), INDT) & bit);
286 }
287 
288 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
289 {
290 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
291 	unsigned long flags;
292 
293 	spin_lock_irqsave(&p->lock, flags);
294 	gpio_rcar_modify_bit(p, OUTDT, offset, value);
295 	spin_unlock_irqrestore(&p->lock, flags);
296 }
297 
298 static void gpio_rcar_set_multiple(struct gpio_chip *chip, unsigned long *mask,
299 				   unsigned long *bits)
300 {
301 	struct gpio_rcar_priv *p = gpiochip_get_data(chip);
302 	unsigned long flags;
303 	u32 val, bankmask;
304 
305 	bankmask = mask[0] & GENMASK(chip->ngpio - 1, 0);
306 	if (!bankmask)
307 		return;
308 
309 	spin_lock_irqsave(&p->lock, flags);
310 	val = gpio_rcar_read(p, OUTDT);
311 	val &= ~bankmask;
312 	val |= (bankmask & bits[0]);
313 	gpio_rcar_write(p, OUTDT, val);
314 	spin_unlock_irqrestore(&p->lock, flags);
315 }
316 
317 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
318 				      int value)
319 {
320 	/* write GPIO value to output before selecting output mode of pin */
321 	gpio_rcar_set(chip, offset, value);
322 	gpio_rcar_config_general_input_output_mode(chip, offset, true);
323 	return 0;
324 }
325 
326 struct gpio_rcar_info {
327 	bool has_both_edge_trigger;
328 };
329 
330 static const struct gpio_rcar_info gpio_rcar_info_gen1 = {
331 	.has_both_edge_trigger = false,
332 };
333 
334 static const struct gpio_rcar_info gpio_rcar_info_gen2 = {
335 	.has_both_edge_trigger = true,
336 };
337 
338 static const struct of_device_id gpio_rcar_of_table[] = {
339 	{
340 		.compatible = "renesas,gpio-r8a7743",
341 		/* RZ/G1 GPIO is identical to R-Car Gen2. */
342 		.data = &gpio_rcar_info_gen2,
343 	}, {
344 		.compatible = "renesas,gpio-r8a7790",
345 		.data = &gpio_rcar_info_gen2,
346 	}, {
347 		.compatible = "renesas,gpio-r8a7791",
348 		.data = &gpio_rcar_info_gen2,
349 	}, {
350 		.compatible = "renesas,gpio-r8a7792",
351 		.data = &gpio_rcar_info_gen2,
352 	}, {
353 		.compatible = "renesas,gpio-r8a7793",
354 		.data = &gpio_rcar_info_gen2,
355 	}, {
356 		.compatible = "renesas,gpio-r8a7794",
357 		.data = &gpio_rcar_info_gen2,
358 	}, {
359 		.compatible = "renesas,gpio-r8a7795",
360 		/* Gen3 GPIO is identical to Gen2. */
361 		.data = &gpio_rcar_info_gen2,
362 	}, {
363 		.compatible = "renesas,gpio-r8a7796",
364 		/* Gen3 GPIO is identical to Gen2. */
365 		.data = &gpio_rcar_info_gen2,
366 	}, {
367 		.compatible = "renesas,rcar-gen1-gpio",
368 		.data = &gpio_rcar_info_gen1,
369 	}, {
370 		.compatible = "renesas,rcar-gen2-gpio",
371 		.data = &gpio_rcar_info_gen2,
372 	}, {
373 		.compatible = "renesas,rcar-gen3-gpio",
374 		/* Gen3 GPIO is identical to Gen2. */
375 		.data = &gpio_rcar_info_gen2,
376 	}, {
377 		.compatible = "renesas,gpio-rcar",
378 		.data = &gpio_rcar_info_gen1,
379 	}, {
380 		/* Terminator */
381 	},
382 };
383 
384 MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
385 
386 static int gpio_rcar_parse_dt(struct gpio_rcar_priv *p, unsigned int *npins)
387 {
388 	struct device_node *np = p->pdev->dev.of_node;
389 	const struct gpio_rcar_info *info;
390 	struct of_phandle_args args;
391 	int ret;
392 
393 	info = of_device_get_match_data(&p->pdev->dev);
394 
395 	ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &args);
396 	*npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK;
397 	p->has_both_edge_trigger = info->has_both_edge_trigger;
398 
399 	if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) {
400 		dev_warn(&p->pdev->dev,
401 			 "Invalid number of gpio lines %u, using %u\n", *npins,
402 			 RCAR_MAX_GPIO_PER_BANK);
403 		*npins = RCAR_MAX_GPIO_PER_BANK;
404 	}
405 
406 	return 0;
407 }
408 
409 static int gpio_rcar_probe(struct platform_device *pdev)
410 {
411 	struct gpio_rcar_priv *p;
412 	struct resource *io, *irq;
413 	struct gpio_chip *gpio_chip;
414 	struct irq_chip *irq_chip;
415 	struct device *dev = &pdev->dev;
416 	const char *name = dev_name(dev);
417 	unsigned int npins;
418 	int ret;
419 
420 	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
421 	if (!p)
422 		return -ENOMEM;
423 
424 	p->pdev = pdev;
425 	spin_lock_init(&p->lock);
426 
427 	/* Get device configuration from DT node */
428 	ret = gpio_rcar_parse_dt(p, &npins);
429 	if (ret < 0)
430 		return ret;
431 
432 	platform_set_drvdata(pdev, p);
433 
434 	pm_runtime_enable(dev);
435 
436 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
437 	if (!irq) {
438 		dev_err(dev, "missing IRQ\n");
439 		ret = -EINVAL;
440 		goto err0;
441 	}
442 
443 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
444 	p->base = devm_ioremap_resource(dev, io);
445 	if (IS_ERR(p->base)) {
446 		ret = PTR_ERR(p->base);
447 		goto err0;
448 	}
449 
450 	gpio_chip = &p->gpio_chip;
451 	gpio_chip->request = gpio_rcar_request;
452 	gpio_chip->free = gpio_rcar_free;
453 	gpio_chip->direction_input = gpio_rcar_direction_input;
454 	gpio_chip->get = gpio_rcar_get;
455 	gpio_chip->direction_output = gpio_rcar_direction_output;
456 	gpio_chip->set = gpio_rcar_set;
457 	gpio_chip->set_multiple = gpio_rcar_set_multiple;
458 	gpio_chip->label = name;
459 	gpio_chip->parent = dev;
460 	gpio_chip->owner = THIS_MODULE;
461 	gpio_chip->base = -1;
462 	gpio_chip->ngpio = npins;
463 
464 	irq_chip = &p->irq_chip;
465 	irq_chip->name = name;
466 	irq_chip->parent_device = dev;
467 	irq_chip->irq_mask = gpio_rcar_irq_disable;
468 	irq_chip->irq_unmask = gpio_rcar_irq_enable;
469 	irq_chip->irq_set_type = gpio_rcar_irq_set_type;
470 	irq_chip->irq_set_wake = gpio_rcar_irq_set_wake;
471 	irq_chip->flags	= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
472 
473 	ret = gpiochip_add_data(gpio_chip, p);
474 	if (ret) {
475 		dev_err(dev, "failed to add GPIO controller\n");
476 		goto err0;
477 	}
478 
479 	ret = gpiochip_irqchip_add(gpio_chip, irq_chip, 0, handle_level_irq,
480 				   IRQ_TYPE_NONE);
481 	if (ret) {
482 		dev_err(dev, "cannot add irqchip\n");
483 		goto err1;
484 	}
485 
486 	p->irq_parent = irq->start;
487 	if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
488 			     IRQF_SHARED, name, p)) {
489 		dev_err(dev, "failed to request IRQ\n");
490 		ret = -ENOENT;
491 		goto err1;
492 	}
493 
494 	dev_info(dev, "driving %d GPIOs\n", npins);
495 
496 	return 0;
497 
498 err1:
499 	gpiochip_remove(gpio_chip);
500 err0:
501 	pm_runtime_disable(dev);
502 	return ret;
503 }
504 
505 static int gpio_rcar_remove(struct platform_device *pdev)
506 {
507 	struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
508 
509 	gpiochip_remove(&p->gpio_chip);
510 
511 	pm_runtime_disable(&pdev->dev);
512 	return 0;
513 }
514 
515 static int __maybe_unused gpio_rcar_suspend(struct device *dev)
516 {
517 	struct gpio_rcar_priv *p = dev_get_drvdata(dev);
518 
519 	if (atomic_read(&p->wakeup_path))
520 		device_set_wakeup_path(dev);
521 
522 	return 0;
523 }
524 
525 static SIMPLE_DEV_PM_OPS(gpio_rcar_pm_ops, gpio_rcar_suspend, NULL);
526 
527 static struct platform_driver gpio_rcar_device_driver = {
528 	.probe		= gpio_rcar_probe,
529 	.remove		= gpio_rcar_remove,
530 	.driver		= {
531 		.name	= "gpio_rcar",
532 		.pm     = &gpio_rcar_pm_ops,
533 		.of_match_table = of_match_ptr(gpio_rcar_of_table),
534 	}
535 };
536 
537 module_platform_driver(gpio_rcar_device_driver);
538 
539 MODULE_AUTHOR("Magnus Damm");
540 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
541 MODULE_LICENSE("GPL v2");
542