xref: /openbmc/linux/drivers/gpio/gpio-rcar.c (revision 62e7ca52)
1 /*
2  * Renesas R-Car GPIO Support
3  *
4  *  Copyright (C) 2013 Magnus Damm
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/ioport.h>
22 #include <linux/irq.h>
23 #include <linux/irqdomain.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/pinctrl/consumer.h>
27 #include <linux/platform_data/gpio-rcar.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 gpio_rcar_config config;
37 	struct platform_device *pdev;
38 	struct gpio_chip gpio_chip;
39 	struct irq_chip irq_chip;
40 	struct irq_domain *irq_domain;
41 };
42 
43 #define IOINTSEL 0x00
44 #define INOUTSEL 0x04
45 #define OUTDT 0x08
46 #define INDT 0x0c
47 #define INTDT 0x10
48 #define INTCLR 0x14
49 #define INTMSK 0x18
50 #define MSKCLR 0x1c
51 #define POSNEG 0x20
52 #define EDGLEVEL 0x24
53 #define FILONOFF 0x28
54 #define BOTHEDGE 0x4c
55 
56 #define RCAR_MAX_GPIO_PER_BANK		32
57 
58 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
59 {
60 	return ioread32(p->base + offs);
61 }
62 
63 static inline void gpio_rcar_write(struct gpio_rcar_priv *p, int offs,
64 				   u32 value)
65 {
66 	iowrite32(value, p->base + offs);
67 }
68 
69 static void gpio_rcar_modify_bit(struct gpio_rcar_priv *p, int offs,
70 				 int bit, bool value)
71 {
72 	u32 tmp = gpio_rcar_read(p, offs);
73 
74 	if (value)
75 		tmp |= BIT(bit);
76 	else
77 		tmp &= ~BIT(bit);
78 
79 	gpio_rcar_write(p, offs, tmp);
80 }
81 
82 static void gpio_rcar_irq_disable(struct irq_data *d)
83 {
84 	struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
85 
86 	gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
87 }
88 
89 static void gpio_rcar_irq_enable(struct irq_data *d)
90 {
91 	struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
92 
93 	gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
94 }
95 
96 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
97 						  unsigned int hwirq,
98 						  bool active_high_rising_edge,
99 						  bool level_trigger,
100 						  bool both)
101 {
102 	unsigned long flags;
103 
104 	/* follow steps in the GPIO documentation for
105 	 * "Setting Edge-Sensitive Interrupt Input Mode" and
106 	 * "Setting Level-Sensitive Interrupt Input Mode"
107 	 */
108 
109 	spin_lock_irqsave(&p->lock, flags);
110 
111 	/* Configure postive or negative logic in POSNEG */
112 	gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
113 
114 	/* Configure edge or level trigger in EDGLEVEL */
115 	gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
116 
117 	/* Select one edge or both edges in BOTHEDGE */
118 	if (p->config.has_both_edge_trigger)
119 		gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
120 
121 	/* Select "Interrupt Input Mode" in IOINTSEL */
122 	gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
123 
124 	/* Write INTCLR in case of edge trigger */
125 	if (!level_trigger)
126 		gpio_rcar_write(p, INTCLR, BIT(hwirq));
127 
128 	spin_unlock_irqrestore(&p->lock, flags);
129 }
130 
131 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
132 {
133 	struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
134 	unsigned int hwirq = irqd_to_hwirq(d);
135 
136 	dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
137 
138 	switch (type & IRQ_TYPE_SENSE_MASK) {
139 	case IRQ_TYPE_LEVEL_HIGH:
140 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true,
141 						      false);
142 		break;
143 	case IRQ_TYPE_LEVEL_LOW:
144 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true,
145 						      false);
146 		break;
147 	case IRQ_TYPE_EDGE_RISING:
148 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
149 						      false);
150 		break;
151 	case IRQ_TYPE_EDGE_FALLING:
152 		gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false,
153 						      false);
154 		break;
155 	case IRQ_TYPE_EDGE_BOTH:
156 		if (!p->config.has_both_edge_trigger)
157 			return -EINVAL;
158 		gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
159 						      true);
160 		break;
161 	default:
162 		return -EINVAL;
163 	}
164 	return 0;
165 }
166 
167 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
168 {
169 	struct gpio_rcar_priv *p = dev_id;
170 	u32 pending;
171 	unsigned int offset, irqs_handled = 0;
172 
173 	while ((pending = gpio_rcar_read(p, INTDT) &
174 			  gpio_rcar_read(p, INTMSK))) {
175 		offset = __ffs(pending);
176 		gpio_rcar_write(p, INTCLR, BIT(offset));
177 		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
178 		irqs_handled++;
179 	}
180 
181 	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
182 }
183 
184 static inline struct gpio_rcar_priv *gpio_to_priv(struct gpio_chip *chip)
185 {
186 	return container_of(chip, struct gpio_rcar_priv, gpio_chip);
187 }
188 
189 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
190 						       unsigned int gpio,
191 						       bool output)
192 {
193 	struct gpio_rcar_priv *p = gpio_to_priv(chip);
194 	unsigned long flags;
195 
196 	/* follow steps in the GPIO documentation for
197 	 * "Setting General Output Mode" and
198 	 * "Setting General Input Mode"
199 	 */
200 
201 	spin_lock_irqsave(&p->lock, flags);
202 
203 	/* Configure postive logic in POSNEG */
204 	gpio_rcar_modify_bit(p, POSNEG, gpio, false);
205 
206 	/* Select "General Input/Output Mode" in IOINTSEL */
207 	gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
208 
209 	/* Select Input Mode or Output Mode in INOUTSEL */
210 	gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
211 
212 	spin_unlock_irqrestore(&p->lock, flags);
213 }
214 
215 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
216 {
217 	return pinctrl_request_gpio(chip->base + offset);
218 }
219 
220 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
221 {
222 	pinctrl_free_gpio(chip->base + offset);
223 
224 	/* Set the GPIO as an input to ensure that the next GPIO request won't
225 	 * drive the GPIO pin as an output.
226 	 */
227 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
228 }
229 
230 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
231 {
232 	gpio_rcar_config_general_input_output_mode(chip, offset, false);
233 	return 0;
234 }
235 
236 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
237 {
238 	u32 bit = BIT(offset);
239 
240 	/* testing on r8a7790 shows that INDT does not show correct pin state
241 	 * when configured as output, so use OUTDT in case of output pins */
242 	if (gpio_rcar_read(gpio_to_priv(chip), INOUTSEL) & bit)
243 		return (int)(gpio_rcar_read(gpio_to_priv(chip), OUTDT) & bit);
244 	else
245 		return (int)(gpio_rcar_read(gpio_to_priv(chip), INDT) & bit);
246 }
247 
248 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
249 {
250 	struct gpio_rcar_priv *p = gpio_to_priv(chip);
251 	unsigned long flags;
252 
253 	spin_lock_irqsave(&p->lock, flags);
254 	gpio_rcar_modify_bit(p, OUTDT, offset, value);
255 	spin_unlock_irqrestore(&p->lock, flags);
256 }
257 
258 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
259 				      int value)
260 {
261 	/* write GPIO value to output before selecting output mode of pin */
262 	gpio_rcar_set(chip, offset, value);
263 	gpio_rcar_config_general_input_output_mode(chip, offset, true);
264 	return 0;
265 }
266 
267 static int gpio_rcar_to_irq(struct gpio_chip *chip, unsigned offset)
268 {
269 	return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
270 }
271 
272 static int gpio_rcar_irq_domain_map(struct irq_domain *h, unsigned int irq,
273 				 irq_hw_number_t hwirq)
274 {
275 	struct gpio_rcar_priv *p = h->host_data;
276 
277 	dev_dbg(&p->pdev->dev, "map hw irq = %d, irq = %d\n", (int)hwirq, irq);
278 
279 	irq_set_chip_data(irq, h->host_data);
280 	irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
281 	set_irq_flags(irq, IRQF_VALID); /* kill me now */
282 	return 0;
283 }
284 
285 static struct irq_domain_ops gpio_rcar_irq_domain_ops = {
286 	.map	= gpio_rcar_irq_domain_map,
287 	.xlate	= irq_domain_xlate_twocell,
288 };
289 
290 struct gpio_rcar_info {
291 	bool has_both_edge_trigger;
292 };
293 
294 static const struct of_device_id gpio_rcar_of_table[] = {
295 	{
296 		.compatible = "renesas,gpio-r8a7790",
297 		.data = (void *)&(const struct gpio_rcar_info) {
298 			.has_both_edge_trigger = true,
299 		},
300 	}, {
301 		.compatible = "renesas,gpio-r8a7791",
302 		.data = (void *)&(const struct gpio_rcar_info) {
303 			.has_both_edge_trigger = true,
304 		},
305 	}, {
306 		.compatible = "renesas,gpio-rcar",
307 		.data = (void *)&(const struct gpio_rcar_info) {
308 			.has_both_edge_trigger = false,
309 		},
310 	}, {
311 		/* Terminator */
312 	},
313 };
314 
315 MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
316 
317 static int gpio_rcar_parse_pdata(struct gpio_rcar_priv *p)
318 {
319 	struct gpio_rcar_config *pdata = dev_get_platdata(&p->pdev->dev);
320 	struct device_node *np = p->pdev->dev.of_node;
321 	struct of_phandle_args args;
322 	int ret;
323 
324 	if (pdata) {
325 		p->config = *pdata;
326 	} else if (IS_ENABLED(CONFIG_OF) && np) {
327 		const struct of_device_id *match;
328 		const struct gpio_rcar_info *info;
329 
330 		match = of_match_node(gpio_rcar_of_table, np);
331 		if (!match)
332 			return -EINVAL;
333 
334 		info = match->data;
335 
336 		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0,
337 						       &args);
338 		p->config.number_of_pins = ret == 0 ? args.args[2]
339 					 : RCAR_MAX_GPIO_PER_BANK;
340 		p->config.gpio_base = -1;
341 		p->config.has_both_edge_trigger = info->has_both_edge_trigger;
342 	}
343 
344 	if (p->config.number_of_pins == 0 ||
345 	    p->config.number_of_pins > RCAR_MAX_GPIO_PER_BANK) {
346 		dev_warn(&p->pdev->dev,
347 			 "Invalid number of gpio lines %u, using %u\n",
348 			 p->config.number_of_pins, RCAR_MAX_GPIO_PER_BANK);
349 		p->config.number_of_pins = RCAR_MAX_GPIO_PER_BANK;
350 	}
351 
352 	return 0;
353 }
354 
355 static int gpio_rcar_probe(struct platform_device *pdev)
356 {
357 	struct gpio_rcar_priv *p;
358 	struct resource *io, *irq;
359 	struct gpio_chip *gpio_chip;
360 	struct irq_chip *irq_chip;
361 	struct device *dev = &pdev->dev;
362 	const char *name = dev_name(dev);
363 	int ret;
364 
365 	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
366 	if (!p) {
367 		ret = -ENOMEM;
368 		goto err0;
369 	}
370 
371 	p->pdev = pdev;
372 	spin_lock_init(&p->lock);
373 
374 	/* Get device configuration from DT node or platform data. */
375 	ret = gpio_rcar_parse_pdata(p);
376 	if (ret < 0)
377 		return ret;
378 
379 	platform_set_drvdata(pdev, p);
380 
381 	pm_runtime_enable(dev);
382 	pm_runtime_get_sync(dev);
383 
384 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
385 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
386 
387 	if (!io || !irq) {
388 		dev_err(dev, "missing IRQ or IOMEM\n");
389 		ret = -EINVAL;
390 		goto err0;
391 	}
392 
393 	p->base = devm_ioremap_nocache(dev, io->start, resource_size(io));
394 	if (!p->base) {
395 		dev_err(dev, "failed to remap I/O memory\n");
396 		ret = -ENXIO;
397 		goto err0;
398 	}
399 
400 	gpio_chip = &p->gpio_chip;
401 	gpio_chip->request = gpio_rcar_request;
402 	gpio_chip->free = gpio_rcar_free;
403 	gpio_chip->direction_input = gpio_rcar_direction_input;
404 	gpio_chip->get = gpio_rcar_get;
405 	gpio_chip->direction_output = gpio_rcar_direction_output;
406 	gpio_chip->set = gpio_rcar_set;
407 	gpio_chip->to_irq = gpio_rcar_to_irq;
408 	gpio_chip->label = name;
409 	gpio_chip->dev = dev;
410 	gpio_chip->owner = THIS_MODULE;
411 	gpio_chip->base = p->config.gpio_base;
412 	gpio_chip->ngpio = p->config.number_of_pins;
413 
414 	irq_chip = &p->irq_chip;
415 	irq_chip->name = name;
416 	irq_chip->irq_mask = gpio_rcar_irq_disable;
417 	irq_chip->irq_unmask = gpio_rcar_irq_enable;
418 	irq_chip->irq_set_type = gpio_rcar_irq_set_type;
419 	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_SET_TYPE_MASKED
420 			 | IRQCHIP_MASK_ON_SUSPEND;
421 
422 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
423 					      p->config.number_of_pins,
424 					      p->config.irq_base,
425 					      &gpio_rcar_irq_domain_ops, p);
426 	if (!p->irq_domain) {
427 		ret = -ENXIO;
428 		dev_err(dev, "cannot initialize irq domain\n");
429 		goto err0;
430 	}
431 
432 	if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
433 			     IRQF_SHARED, name, p)) {
434 		dev_err(dev, "failed to request IRQ\n");
435 		ret = -ENOENT;
436 		goto err1;
437 	}
438 
439 	ret = gpiochip_add(gpio_chip);
440 	if (ret) {
441 		dev_err(dev, "failed to add GPIO controller\n");
442 		goto err1;
443 	}
444 
445 	dev_info(dev, "driving %d GPIOs\n", p->config.number_of_pins);
446 
447 	/* warn in case of mismatch if irq base is specified */
448 	if (p->config.irq_base) {
449 		ret = irq_find_mapping(p->irq_domain, 0);
450 		if (p->config.irq_base != ret)
451 			dev_warn(dev, "irq base mismatch (%u/%u)\n",
452 				 p->config.irq_base, ret);
453 	}
454 
455 	if (p->config.pctl_name) {
456 		ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
457 					     gpio_chip->base, gpio_chip->ngpio);
458 		if (ret < 0)
459 			dev_warn(dev, "failed to add pin range\n");
460 	}
461 
462 	return 0;
463 
464 err1:
465 	irq_domain_remove(p->irq_domain);
466 err0:
467 	pm_runtime_put(dev);
468 	pm_runtime_disable(dev);
469 	return ret;
470 }
471 
472 static int gpio_rcar_remove(struct platform_device *pdev)
473 {
474 	struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
475 	int ret;
476 
477 	ret = gpiochip_remove(&p->gpio_chip);
478 	if (ret)
479 		return ret;
480 
481 	irq_domain_remove(p->irq_domain);
482 	pm_runtime_put(&pdev->dev);
483 	pm_runtime_disable(&pdev->dev);
484 	return 0;
485 }
486 
487 static struct platform_driver gpio_rcar_device_driver = {
488 	.probe		= gpio_rcar_probe,
489 	.remove		= gpio_rcar_remove,
490 	.driver		= {
491 		.name	= "gpio_rcar",
492 		.of_match_table = of_match_ptr(gpio_rcar_of_table),
493 	}
494 };
495 
496 module_platform_driver(gpio_rcar_device_driver);
497 
498 MODULE_AUTHOR("Magnus Damm");
499 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
500 MODULE_LICENSE("GPL v2");
501