xref: /openbmc/linux/drivers/gpio/gpio-rcar.c (revision 4161b450) 
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/irqdomain.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/platform_data/gpio-rcar.h>
29 #include <linux/platform_device.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/spinlock.h>
32 #include <linux/slab.h>
33 
34 struct gpio_rcar_priv {
35 	void __iomem *base;
36 	spinlock_t lock;
37 	struct gpio_rcar_config config;
38 	struct platform_device *pdev;
39 	struct gpio_chip gpio_chip;
40 	struct irq_chip irq_chip;
41 	struct irq_domain *irq_domain;
42 };
43 
44 #define IOINTSEL 0x00
45 #define INOUTSEL 0x04
46 #define OUTDT 0x08
47 #define INDT 0x0c
48 #define INTDT 0x10
49 #define INTCLR 0x14
50 #define INTMSK 0x18
51 #define MSKCLR 0x1c
52 #define POSNEG 0x20
53 #define EDGLEVEL 0x24
54 #define FILONOFF 0x28
55 #define BOTHEDGE 0x4c
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_rcar_priv *p = irq_data_get_irq_chip_data(d);
86 
87 	gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
88 }
89 
90 static void gpio_rcar_irq_enable(struct irq_data *d)
91 {
92 	struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
93 
94 	gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
95 }
96 
97 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
98 						  unsigned int hwirq,
99 						  bool active_high_rising_edge,
100 						  bool level_trigger,
101 						  bool both)
102 {
103 	unsigned long flags;
104 
105 	/* follow steps in the GPIO documentation for
106 	 * "Setting Edge-Sensitive Interrupt Input Mode" and
107 	 * "Setting Level-Sensitive Interrupt Input Mode"
108 	 */
109 
110 	spin_lock_irqsave(&p->lock, flags);
111 
112 	/* Configure postive or negative logic in POSNEG */
113 	gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
114 
115 	/* Configure edge or level trigger in EDGLEVEL */
116 	gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
117 
118 	/* Select one edge or both edges in BOTHEDGE */
119 	if (p->config.has_both_edge_trigger)
120 		gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
121 
122 	/* Select "Interrupt Input Mode" in IOINTSEL */
123 	gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
124 
125 	/* Write INTCLR in case of edge trigger */
126 	if (!level_trigger)
127 		gpio_rcar_write(p, INTCLR, BIT(hwirq));
128 
129 	spin_unlock_irqrestore(&p->lock, flags);
130 }
131 
132 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
133 {
134 	struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
135 	unsigned int hwirq = irqd_to_hwirq(d);
136 
137 	dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
138 
139 	switch (type & IRQ_TYPE_SENSE_MASK) {
140 	case IRQ_TYPE_LEVEL_HIGH:
141 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true,
142 						      false);
143 		break;
144 	case IRQ_TYPE_LEVEL_LOW:
145 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true,
146 						      false);
147 		break;
148 	case IRQ_TYPE_EDGE_RISING:
149 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
150 						      false);
151 		break;
152 	case IRQ_TYPE_EDGE_FALLING:
153 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false,
154 						      false);
155 		break;
156 	case IRQ_TYPE_EDGE_BOTH:
157 		if (!p->config.has_both_edge_trigger)
158 			return -EINVAL;
159 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
160 						      true);
161 		break;
162 	default:
163 		return -EINVAL;
164 	}
165 	return 0;
166 }
167 
168 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
169 {
170 	struct gpio_rcar_priv *p = dev_id;
171 	u32 pending;
172 	unsigned int offset, irqs_handled = 0;
173 
174 	while ((pending = gpio_rcar_read(p, INTDT) &
175 			  gpio_rcar_read(p, INTMSK))) {
176 		offset = __ffs(pending);
177 		gpio_rcar_write(p, INTCLR, BIT(offset));
178 		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
179 		irqs_handled++;
180 	}
181 
182 	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
183 }
184 
185 static inline struct gpio_rcar_priv *gpio_to_priv(struct gpio_chip *chip)
186 {
187 	return container_of(chip, struct gpio_rcar_priv, gpio_chip);
188 }
189 
190 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
191 						       unsigned int gpio,
192 						       bool output)
193 {
194 	struct gpio_rcar_priv *p = gpio_to_priv(chip);
195 	unsigned long flags;
196 
197 	/* follow steps in the GPIO documentation for
198 	 * "Setting General Output Mode" and
199 	 * "Setting General Input Mode"
200 	 */
201 
202 	spin_lock_irqsave(&p->lock, flags);
203 
204 	/* Configure postive logic in POSNEG */
205 	gpio_rcar_modify_bit(p, POSNEG, gpio, false);
206 
207 	/* Select "General Input/Output Mode" in IOINTSEL */
208 	gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
209 
210 	/* Select Input Mode or Output Mode in INOUTSEL */
211 	gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
212 
213 	spin_unlock_irqrestore(&p->lock, flags);
214 }
215 
216 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
217 {
218 	return pinctrl_request_gpio(chip->base + offset);
219 }
220 
221 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
222 {
223 	pinctrl_free_gpio(chip->base + offset);
224 
225 	/* Set the GPIO as an input to ensure that the next GPIO request won't
226 	 * drive the GPIO pin as an output.
227 	 */
228 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
229 }
230 
231 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
232 {
233 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
234 	return 0;
235 }
236 
237 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
238 {
239 	u32 bit = BIT(offset);
240 
241 	/* testing on r8a7790 shows that INDT does not show correct pin state
242 	 * when configured as output, so use OUTDT in case of output pins */
243 	if (gpio_rcar_read(gpio_to_priv(chip), INOUTSEL) & bit)
244 		return !!(gpio_rcar_read(gpio_to_priv(chip), OUTDT) & bit);
245 	else
246 		return !!(gpio_rcar_read(gpio_to_priv(chip), INDT) & bit);
247 }
248 
249 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
250 {
251 	struct gpio_rcar_priv *p = gpio_to_priv(chip);
252 	unsigned long flags;
253 
254 	spin_lock_irqsave(&p->lock, flags);
255 	gpio_rcar_modify_bit(p, OUTDT, offset, value);
256 	spin_unlock_irqrestore(&p->lock, flags);
257 }
258 
259 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
260 				      int value)
261 {
262 	/* write GPIO value to output before selecting output mode of pin */
263 	gpio_rcar_set(chip, offset, value);
264 	gpio_rcar_config_general_input_output_mode(chip, offset, true);
265 	return 0;
266 }
267 
268 static int gpio_rcar_to_irq(struct gpio_chip *chip, unsigned offset)
269 {
270 	return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
271 }
272 
273 static int gpio_rcar_irq_domain_map(struct irq_domain *h, unsigned int irq,
274 				 irq_hw_number_t hwirq)
275 {
276 	struct gpio_rcar_priv *p = h->host_data;
277 
278 	dev_dbg(&p->pdev->dev, "map hw irq = %d, irq = %d\n", (int)hwirq, irq);
279 
280 	irq_set_chip_data(irq, h->host_data);
281 	irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
282 	set_irq_flags(irq, IRQF_VALID); /* kill me now */
283 	return 0;
284 }
285 
286 static struct irq_domain_ops gpio_rcar_irq_domain_ops = {
287 	.map	= gpio_rcar_irq_domain_map,
288 	.xlate	= irq_domain_xlate_twocell,
289 };
290 
291 struct gpio_rcar_info {
292 	bool has_both_edge_trigger;
293 };
294 
295 static const struct gpio_rcar_info gpio_rcar_info_gen1 = {
296 	.has_both_edge_trigger = false,
297 };
298 
299 static const struct gpio_rcar_info gpio_rcar_info_gen2 = {
300 	.has_both_edge_trigger = true,
301 };
302 
303 static const struct of_device_id gpio_rcar_of_table[] = {
304 	{
305 		.compatible = "renesas,gpio-r8a7790",
306 		.data = &gpio_rcar_info_gen2,
307 	}, {
308 		.compatible = "renesas,gpio-r8a7791",
309 		.data = &gpio_rcar_info_gen2,
310 	}, {
311 		.compatible = "renesas,gpio-r8a7793",
312 		.data = &gpio_rcar_info_gen2,
313 	}, {
314 		.compatible = "renesas,gpio-r8a7794",
315 		.data = &gpio_rcar_info_gen2,
316 	}, {
317 		.compatible = "renesas,gpio-rcar",
318 		.data = &gpio_rcar_info_gen1,
319 	}, {
320 		/* Terminator */
321 	},
322 };
323 
324 MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
325 
326 static int gpio_rcar_parse_pdata(struct gpio_rcar_priv *p)
327 {
328 	struct gpio_rcar_config *pdata = dev_get_platdata(&p->pdev->dev);
329 	struct device_node *np = p->pdev->dev.of_node;
330 	struct of_phandle_args args;
331 	int ret;
332 
333 	if (pdata) {
334 		p->config = *pdata;
335 	} else if (IS_ENABLED(CONFIG_OF) && np) {
336 		const struct of_device_id *match;
337 		const struct gpio_rcar_info *info;
338 
339 		match = of_match_node(gpio_rcar_of_table, np);
340 		if (!match)
341 			return -EINVAL;
342 
343 		info = match->data;
344 
345 		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0,
346 						       &args);
347 		p->config.number_of_pins = ret == 0 ? args.args[2]
348 					 : RCAR_MAX_GPIO_PER_BANK;
349 		p->config.gpio_base = -1;
350 		p->config.has_both_edge_trigger = info->has_both_edge_trigger;
351 	}
352 
353 	if (p->config.number_of_pins == 0 ||
354 	    p->config.number_of_pins > RCAR_MAX_GPIO_PER_BANK) {
355 		dev_warn(&p->pdev->dev,
356 			 "Invalid number of gpio lines %u, using %u\n",
357 			 p->config.number_of_pins, RCAR_MAX_GPIO_PER_BANK);
358 		p->config.number_of_pins = RCAR_MAX_GPIO_PER_BANK;
359 	}
360 
361 	return 0;
362 }
363 
364 static int gpio_rcar_probe(struct platform_device *pdev)
365 {
366 	struct gpio_rcar_priv *p;
367 	struct resource *io, *irq;
368 	struct gpio_chip *gpio_chip;
369 	struct irq_chip *irq_chip;
370 	struct device *dev = &pdev->dev;
371 	const char *name = dev_name(dev);
372 	int ret;
373 
374 	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
375 	if (!p) {
376 		ret = -ENOMEM;
377 		goto err0;
378 	}
379 
380 	p->pdev = pdev;
381 	spin_lock_init(&p->lock);
382 
383 	/* Get device configuration from DT node or platform data. */
384 	ret = gpio_rcar_parse_pdata(p);
385 	if (ret < 0)
386 		return ret;
387 
388 	platform_set_drvdata(pdev, p);
389 
390 	pm_runtime_enable(dev);
391 	pm_runtime_get_sync(dev);
392 
393 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
394 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
395 
396 	if (!io || !irq) {
397 		dev_err(dev, "missing IRQ or IOMEM\n");
398 		ret = -EINVAL;
399 		goto err0;
400 	}
401 
402 	p->base = devm_ioremap_nocache(dev, io->start, resource_size(io));
403 	if (!p->base) {
404 		dev_err(dev, "failed to remap I/O memory\n");
405 		ret = -ENXIO;
406 		goto err0;
407 	}
408 
409 	gpio_chip = &p->gpio_chip;
410 	gpio_chip->request = gpio_rcar_request;
411 	gpio_chip->free = gpio_rcar_free;
412 	gpio_chip->direction_input = gpio_rcar_direction_input;
413 	gpio_chip->get = gpio_rcar_get;
414 	gpio_chip->direction_output = gpio_rcar_direction_output;
415 	gpio_chip->set = gpio_rcar_set;
416 	gpio_chip->to_irq = gpio_rcar_to_irq;
417 	gpio_chip->label = name;
418 	gpio_chip->dev = dev;
419 	gpio_chip->owner = THIS_MODULE;
420 	gpio_chip->base = p->config.gpio_base;
421 	gpio_chip->ngpio = p->config.number_of_pins;
422 
423 	irq_chip = &p->irq_chip;
424 	irq_chip->name = name;
425 	irq_chip->irq_mask = gpio_rcar_irq_disable;
426 	irq_chip->irq_unmask = gpio_rcar_irq_enable;
427 	irq_chip->irq_set_type = gpio_rcar_irq_set_type;
428 	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_SET_TYPE_MASKED
429 			 | IRQCHIP_MASK_ON_SUSPEND;
430 
431 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
432 					      p->config.number_of_pins,
433 					      p->config.irq_base,
434 					      &gpio_rcar_irq_domain_ops, p);
435 	if (!p->irq_domain) {
436 		ret = -ENXIO;
437 		dev_err(dev, "cannot initialize irq domain\n");
438 		goto err0;
439 	}
440 
441 	if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
442 			     IRQF_SHARED, name, p)) {
443 		dev_err(dev, "failed to request IRQ\n");
444 		ret = -ENOENT;
445 		goto err1;
446 	}
447 
448 	ret = gpiochip_add(gpio_chip);
449 	if (ret) {
450 		dev_err(dev, "failed to add GPIO controller\n");
451 		goto err1;
452 	}
453 
454 	dev_info(dev, "driving %d GPIOs\n", p->config.number_of_pins);
455 
456 	/* warn in case of mismatch if irq base is specified */
457 	if (p->config.irq_base) {
458 		ret = irq_find_mapping(p->irq_domain, 0);
459 		if (p->config.irq_base != ret)
460 			dev_warn(dev, "irq base mismatch (%u/%u)\n",
461 				 p->config.irq_base, ret);
462 	}
463 
464 	if (p->config.pctl_name) {
465 		ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
466 					     gpio_chip->base, gpio_chip->ngpio);
467 		if (ret < 0)
468 			dev_warn(dev, "failed to add pin range\n");
469 	}
470 
471 	return 0;
472 
473 err1:
474 	irq_domain_remove(p->irq_domain);
475 err0:
476 	pm_runtime_put(dev);
477 	pm_runtime_disable(dev);
478 	return ret;
479 }
480 
481 static int gpio_rcar_remove(struct platform_device *pdev)
482 {
483 	struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
484 
485 	gpiochip_remove(&p->gpio_chip);
486 
487 	irq_domain_remove(p->irq_domain);
488 	pm_runtime_put(&pdev->dev);
489 	pm_runtime_disable(&pdev->dev);
490 	return 0;
491 }
492 
493 static struct platform_driver gpio_rcar_device_driver = {
494 	.probe		= gpio_rcar_probe,
495 	.remove		= gpio_rcar_remove,
496 	.driver		= {
497 		.name	= "gpio_rcar",
498 		.of_match_table = of_match_ptr(gpio_rcar_of_table),
499 	}
500 };
501 
502 module_platform_driver(gpio_rcar_device_driver);
503 
504 MODULE_AUTHOR("Magnus Damm");
505 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
506 MODULE_LICENSE("GPL v2");
507