1 /*
2  *  Driver for NEC VR4100 series General-purpose I/O Unit.
3  *
4  *  Copyright (C) 2002 MontaVista Software Inc.
5  *	Author: Yoichi Yuasa <source@mvista.com>
6  *  Copyright (C) 2003-2009  Yoichi Yuasa <yuasa@linux-mips.org>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 #include <linux/errno.h>
23 #include <linux/fs.h>
24 #include <linux/gpio.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/irq.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/platform_device.h>
32 #include <linux/spinlock.h>
33 #include <linux/types.h>
34 
35 #include <asm/vr41xx/giu.h>
36 #include <asm/vr41xx/irq.h>
37 #include <asm/vr41xx/vr41xx.h>
38 
39 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
40 MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
41 MODULE_LICENSE("GPL");
42 
43 #define GIUIOSELL	0x00
44 #define GIUIOSELH	0x02
45 #define GIUPIODL	0x04
46 #define GIUPIODH	0x06
47 #define GIUINTSTATL	0x08
48 #define GIUINTSTATH	0x0a
49 #define GIUINTENL	0x0c
50 #define GIUINTENH	0x0e
51 #define GIUINTTYPL	0x10
52 #define GIUINTTYPH	0x12
53 #define GIUINTALSELL	0x14
54 #define GIUINTALSELH	0x16
55 #define GIUINTHTSELL	0x18
56 #define GIUINTHTSELH	0x1a
57 #define GIUPODATL	0x1c
58 #define GIUPODATEN	0x1c
59 #define GIUPODATH	0x1e
60  #define PIOEN0		0x0100
61  #define PIOEN1		0x0200
62 #define GIUPODAT	0x1e
63 #define GIUFEDGEINHL	0x20
64 #define GIUFEDGEINHH	0x22
65 #define GIUREDGEINHL	0x24
66 #define GIUREDGEINHH	0x26
67 
68 #define GIUUSEUPDN	0x1e0
69 #define GIUTERMUPDN	0x1e2
70 
71 #define GPIO_HAS_PULLUPDOWN_IO		0x0001
72 #define GPIO_HAS_OUTPUT_ENABLE		0x0002
73 #define GPIO_HAS_INTERRUPT_EDGE_SELECT	0x0100
74 
75 enum {
76 	GPIO_INPUT,
77 	GPIO_OUTPUT,
78 };
79 
80 static DEFINE_SPINLOCK(giu_lock);
81 static unsigned long giu_flags;
82 
83 static void __iomem *giu_base;
84 
85 #define giu_read(offset)		readw(giu_base + (offset))
86 #define giu_write(offset, value)	writew((value), giu_base + (offset))
87 
88 #define GPIO_PIN_OF_IRQ(irq)	((irq) - GIU_IRQ_BASE)
89 #define GIUINT_HIGH_OFFSET	16
90 #define GIUINT_HIGH_MAX		32
91 
giu_set(u16 offset,u16 set)92 static inline u16 giu_set(u16 offset, u16 set)
93 {
94 	u16 data;
95 
96 	data = giu_read(offset);
97 	data |= set;
98 	giu_write(offset, data);
99 
100 	return data;
101 }
102 
giu_clear(u16 offset,u16 clear)103 static inline u16 giu_clear(u16 offset, u16 clear)
104 {
105 	u16 data;
106 
107 	data = giu_read(offset);
108 	data &= ~clear;
109 	giu_write(offset, data);
110 
111 	return data;
112 }
113 
ack_giuint_low(struct irq_data * d)114 static void ack_giuint_low(struct irq_data *d)
115 {
116 	giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(d->irq));
117 }
118 
mask_giuint_low(struct irq_data * d)119 static void mask_giuint_low(struct irq_data *d)
120 {
121 	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
122 }
123 
mask_ack_giuint_low(struct irq_data * d)124 static void mask_ack_giuint_low(struct irq_data *d)
125 {
126 	unsigned int pin;
127 
128 	pin = GPIO_PIN_OF_IRQ(d->irq);
129 	giu_clear(GIUINTENL, 1 << pin);
130 	giu_write(GIUINTSTATL, 1 << pin);
131 }
132 
unmask_giuint_low(struct irq_data * d)133 static void unmask_giuint_low(struct irq_data *d)
134 {
135 	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
136 }
137 
138 static struct irq_chip giuint_low_irq_chip = {
139 	.name		= "GIUINTL",
140 	.irq_ack	= ack_giuint_low,
141 	.irq_mask	= mask_giuint_low,
142 	.irq_mask_ack	= mask_ack_giuint_low,
143 	.irq_unmask	= unmask_giuint_low,
144 };
145 
ack_giuint_high(struct irq_data * d)146 static void ack_giuint_high(struct irq_data *d)
147 {
148 	giu_write(GIUINTSTATH,
149 		  1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
150 }
151 
mask_giuint_high(struct irq_data * d)152 static void mask_giuint_high(struct irq_data *d)
153 {
154 	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
155 }
156 
mask_ack_giuint_high(struct irq_data * d)157 static void mask_ack_giuint_high(struct irq_data *d)
158 {
159 	unsigned int pin;
160 
161 	pin = GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET;
162 	giu_clear(GIUINTENH, 1 << pin);
163 	giu_write(GIUINTSTATH, 1 << pin);
164 }
165 
unmask_giuint_high(struct irq_data * d)166 static void unmask_giuint_high(struct irq_data *d)
167 {
168 	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
169 }
170 
171 static struct irq_chip giuint_high_irq_chip = {
172 	.name		= "GIUINTH",
173 	.irq_ack	= ack_giuint_high,
174 	.irq_mask	= mask_giuint_high,
175 	.irq_mask_ack	= mask_ack_giuint_high,
176 	.irq_unmask	= unmask_giuint_high,
177 };
178 
giu_get_irq(unsigned int irq)179 static int giu_get_irq(unsigned int irq)
180 {
181 	u16 pendl, pendh, maskl, maskh;
182 	int i;
183 
184 	pendl = giu_read(GIUINTSTATL);
185 	pendh = giu_read(GIUINTSTATH);
186 	maskl = giu_read(GIUINTENL);
187 	maskh = giu_read(GIUINTENH);
188 
189 	maskl &= pendl;
190 	maskh &= pendh;
191 
192 	if (maskl) {
193 		for (i = 0; i < 16; i++) {
194 			if (maskl & (1 << i))
195 				return GIU_IRQ(i);
196 		}
197 	} else if (maskh) {
198 		for (i = 0; i < 16; i++) {
199 			if (maskh & (1 << i))
200 				return GIU_IRQ(i + GIUINT_HIGH_OFFSET);
201 		}
202 	}
203 
204 	printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
205 	       maskl, pendl, maskh, pendh);
206 
207 	atomic_inc(&irq_err_count);
208 
209 	return -EINVAL;
210 }
211 
vr41xx_set_irq_trigger(unsigned int pin,irq_trigger_t trigger,irq_signal_t signal)212 void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger,
213 			    irq_signal_t signal)
214 {
215 	u16 mask;
216 
217 	if (pin < GIUINT_HIGH_OFFSET) {
218 		mask = 1 << pin;
219 		if (trigger != IRQ_TRIGGER_LEVEL) {
220 			giu_set(GIUINTTYPL, mask);
221 			if (signal == IRQ_SIGNAL_HOLD)
222 				giu_set(GIUINTHTSELL, mask);
223 			else
224 				giu_clear(GIUINTHTSELL, mask);
225 			if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
226 				switch (trigger) {
227 				case IRQ_TRIGGER_EDGE_FALLING:
228 					giu_set(GIUFEDGEINHL, mask);
229 					giu_clear(GIUREDGEINHL, mask);
230 					break;
231 				case IRQ_TRIGGER_EDGE_RISING:
232 					giu_clear(GIUFEDGEINHL, mask);
233 					giu_set(GIUREDGEINHL, mask);
234 					break;
235 				default:
236 					giu_set(GIUFEDGEINHL, mask);
237 					giu_set(GIUREDGEINHL, mask);
238 					break;
239 				}
240 			}
241 			irq_set_chip_and_handler(GIU_IRQ(pin),
242 						 &giuint_low_irq_chip,
243 						 handle_edge_irq);
244 		} else {
245 			giu_clear(GIUINTTYPL, mask);
246 			giu_clear(GIUINTHTSELL, mask);
247 			irq_set_chip_and_handler(GIU_IRQ(pin),
248 						 &giuint_low_irq_chip,
249 						 handle_level_irq);
250 		}
251 		giu_write(GIUINTSTATL, mask);
252 	} else if (pin < GIUINT_HIGH_MAX) {
253 		mask = 1 << (pin - GIUINT_HIGH_OFFSET);
254 		if (trigger != IRQ_TRIGGER_LEVEL) {
255 			giu_set(GIUINTTYPH, mask);
256 			if (signal == IRQ_SIGNAL_HOLD)
257 				giu_set(GIUINTHTSELH, mask);
258 			else
259 				giu_clear(GIUINTHTSELH, mask);
260 			if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
261 				switch (trigger) {
262 				case IRQ_TRIGGER_EDGE_FALLING:
263 					giu_set(GIUFEDGEINHH, mask);
264 					giu_clear(GIUREDGEINHH, mask);
265 					break;
266 				case IRQ_TRIGGER_EDGE_RISING:
267 					giu_clear(GIUFEDGEINHH, mask);
268 					giu_set(GIUREDGEINHH, mask);
269 					break;
270 				default:
271 					giu_set(GIUFEDGEINHH, mask);
272 					giu_set(GIUREDGEINHH, mask);
273 					break;
274 				}
275 			}
276 			irq_set_chip_and_handler(GIU_IRQ(pin),
277 						 &giuint_high_irq_chip,
278 						 handle_edge_irq);
279 		} else {
280 			giu_clear(GIUINTTYPH, mask);
281 			giu_clear(GIUINTHTSELH, mask);
282 			irq_set_chip_and_handler(GIU_IRQ(pin),
283 						 &giuint_high_irq_chip,
284 						 handle_level_irq);
285 		}
286 		giu_write(GIUINTSTATH, mask);
287 	}
288 }
289 EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);
290 
vr41xx_set_irq_level(unsigned int pin,irq_level_t level)291 void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
292 {
293 	u16 mask;
294 
295 	if (pin < GIUINT_HIGH_OFFSET) {
296 		mask = 1 << pin;
297 		if (level == IRQ_LEVEL_HIGH)
298 			giu_set(GIUINTALSELL, mask);
299 		else
300 			giu_clear(GIUINTALSELL, mask);
301 		giu_write(GIUINTSTATL, mask);
302 	} else if (pin < GIUINT_HIGH_MAX) {
303 		mask = 1 << (pin - GIUINT_HIGH_OFFSET);
304 		if (level == IRQ_LEVEL_HIGH)
305 			giu_set(GIUINTALSELH, mask);
306 		else
307 			giu_clear(GIUINTALSELH, mask);
308 		giu_write(GIUINTSTATH, mask);
309 	}
310 }
311 EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);
312 
giu_set_direction(struct gpio_chip * chip,unsigned pin,int dir)313 static int giu_set_direction(struct gpio_chip *chip, unsigned pin, int dir)
314 {
315 	u16 offset, mask, reg;
316 	unsigned long flags;
317 
318 	if (pin >= chip->ngpio)
319 		return -EINVAL;
320 
321 	if (pin < 16) {
322 		offset = GIUIOSELL;
323 		mask = 1 << pin;
324 	} else if (pin < 32) {
325 		offset = GIUIOSELH;
326 		mask = 1 << (pin - 16);
327 	} else {
328 		if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
329 			offset = GIUPODATEN;
330 			mask = 1 << (pin - 32);
331 		} else {
332 			switch (pin) {
333 			case 48:
334 				offset = GIUPODATH;
335 				mask = PIOEN0;
336 				break;
337 			case 49:
338 				offset = GIUPODATH;
339 				mask = PIOEN1;
340 				break;
341 			default:
342 				return -EINVAL;
343 			}
344 		}
345 	}
346 
347 	spin_lock_irqsave(&giu_lock, flags);
348 
349 	reg = giu_read(offset);
350 	if (dir == GPIO_OUTPUT)
351 		reg |= mask;
352 	else
353 		reg &= ~mask;
354 	giu_write(offset, reg);
355 
356 	spin_unlock_irqrestore(&giu_lock, flags);
357 
358 	return 0;
359 }
360 
vr41xx_gpio_pullupdown(unsigned int pin,gpio_pull_t pull)361 int vr41xx_gpio_pullupdown(unsigned int pin, gpio_pull_t pull)
362 {
363 	u16 reg, mask;
364 	unsigned long flags;
365 
366 	if ((giu_flags & GPIO_HAS_PULLUPDOWN_IO) != GPIO_HAS_PULLUPDOWN_IO)
367 		return -EPERM;
368 
369 	if (pin >= 15)
370 		return -EINVAL;
371 
372 	mask = 1 << pin;
373 
374 	spin_lock_irqsave(&giu_lock, flags);
375 
376 	if (pull == GPIO_PULL_UP || pull == GPIO_PULL_DOWN) {
377 		reg = giu_read(GIUTERMUPDN);
378 		if (pull == GPIO_PULL_UP)
379 			reg |= mask;
380 		else
381 			reg &= ~mask;
382 		giu_write(GIUTERMUPDN, reg);
383 
384 		reg = giu_read(GIUUSEUPDN);
385 		reg |= mask;
386 		giu_write(GIUUSEUPDN, reg);
387 	} else {
388 		reg = giu_read(GIUUSEUPDN);
389 		reg &= ~mask;
390 		giu_write(GIUUSEUPDN, reg);
391 	}
392 
393 	spin_unlock_irqrestore(&giu_lock, flags);
394 
395 	return 0;
396 }
397 EXPORT_SYMBOL_GPL(vr41xx_gpio_pullupdown);
398 
vr41xx_gpio_get(struct gpio_chip * chip,unsigned pin)399 static int vr41xx_gpio_get(struct gpio_chip *chip, unsigned pin)
400 {
401 	u16 reg, mask;
402 
403 	if (pin >= chip->ngpio)
404 		return -EINVAL;
405 
406 	if (pin < 16) {
407 		reg = giu_read(GIUPIODL);
408 		mask = 1 << pin;
409 	} else if (pin < 32) {
410 		reg = giu_read(GIUPIODH);
411 		mask = 1 << (pin - 16);
412 	} else if (pin < 48) {
413 		reg = giu_read(GIUPODATL);
414 		mask = 1 << (pin - 32);
415 	} else {
416 		reg = giu_read(GIUPODATH);
417 		mask = 1 << (pin - 48);
418 	}
419 
420 	if (reg & mask)
421 		return 1;
422 
423 	return 0;
424 }
425 
vr41xx_gpio_set(struct gpio_chip * chip,unsigned pin,int value)426 static void vr41xx_gpio_set(struct gpio_chip *chip, unsigned pin,
427 			    int value)
428 {
429 	u16 offset, mask, reg;
430 	unsigned long flags;
431 
432 	if (pin >= chip->ngpio)
433 		return;
434 
435 	if (pin < 16) {
436 		offset = GIUPIODL;
437 		mask = 1 << pin;
438 	} else if (pin < 32) {
439 		offset = GIUPIODH;
440 		mask = 1 << (pin - 16);
441 	} else if (pin < 48) {
442 		offset = GIUPODATL;
443 		mask = 1 << (pin - 32);
444 	} else {
445 		offset = GIUPODATH;
446 		mask = 1 << (pin - 48);
447 	}
448 
449 	spin_lock_irqsave(&giu_lock, flags);
450 
451 	reg = giu_read(offset);
452 	if (value)
453 		reg |= mask;
454 	else
455 		reg &= ~mask;
456 	giu_write(offset, reg);
457 
458 	spin_unlock_irqrestore(&giu_lock, flags);
459 }
460 
461 
vr41xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)462 static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
463 {
464 	return giu_set_direction(chip, offset, GPIO_INPUT);
465 }
466 
vr41xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)467 static int vr41xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
468 				int value)
469 {
470 	vr41xx_gpio_set(chip, offset, value);
471 
472 	return giu_set_direction(chip, offset, GPIO_OUTPUT);
473 }
474 
vr41xx_gpio_to_irq(struct gpio_chip * chip,unsigned offset)475 static int vr41xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
476 {
477 	if (offset >= chip->ngpio)
478 		return -EINVAL;
479 
480 	return GIU_IRQ_BASE + offset;
481 }
482 
483 static struct gpio_chip vr41xx_gpio_chip = {
484 	.label			= "vr41xx",
485 	.owner			= THIS_MODULE,
486 	.direction_input	= vr41xx_gpio_direction_input,
487 	.get			= vr41xx_gpio_get,
488 	.direction_output	= vr41xx_gpio_direction_output,
489 	.set			= vr41xx_gpio_set,
490 	.to_irq			= vr41xx_gpio_to_irq,
491 };
492 
giu_probe(struct platform_device * pdev)493 static int __devinit giu_probe(struct platform_device *pdev)
494 {
495 	struct resource *res;
496 	unsigned int trigger, i, pin;
497 	struct irq_chip *chip;
498 	int irq, retval;
499 
500 	switch (pdev->id) {
501 	case GPIO_50PINS_PULLUPDOWN:
502 		giu_flags = GPIO_HAS_PULLUPDOWN_IO;
503 		vr41xx_gpio_chip.ngpio = 50;
504 		break;
505 	case GPIO_36PINS:
506 		vr41xx_gpio_chip.ngpio = 36;
507 		break;
508 	case GPIO_48PINS_EDGE_SELECT:
509 		giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
510 		vr41xx_gpio_chip.ngpio = 48;
511 		break;
512 	default:
513 		dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
514 		return -ENODEV;
515 	}
516 
517 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
518 	if (!res)
519 		return -EBUSY;
520 
521 	giu_base = ioremap(res->start, resource_size(res));
522 	if (!giu_base)
523 		return -ENOMEM;
524 
525 	vr41xx_gpio_chip.dev = &pdev->dev;
526 
527 	retval = gpiochip_add(&vr41xx_gpio_chip);
528 
529 	giu_write(GIUINTENL, 0);
530 	giu_write(GIUINTENH, 0);
531 
532 	trigger = giu_read(GIUINTTYPH) << 16;
533 	trigger |= giu_read(GIUINTTYPL);
534 	for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
535 		pin = GPIO_PIN_OF_IRQ(i);
536 		if (pin < GIUINT_HIGH_OFFSET)
537 			chip = &giuint_low_irq_chip;
538 		else
539 			chip = &giuint_high_irq_chip;
540 
541 		if (trigger & (1 << pin))
542 			irq_set_chip_and_handler(i, chip, handle_edge_irq);
543 		else
544 			irq_set_chip_and_handler(i, chip, handle_level_irq);
545 
546 	}
547 
548 	irq = platform_get_irq(pdev, 0);
549 	if (irq < 0 || irq >= nr_irqs)
550 		return -EBUSY;
551 
552 	return cascade_irq(irq, giu_get_irq);
553 }
554 
giu_remove(struct platform_device * pdev)555 static int __devexit giu_remove(struct platform_device *pdev)
556 {
557 	if (giu_base) {
558 		iounmap(giu_base);
559 		giu_base = NULL;
560 	}
561 
562 	return 0;
563 }
564 
565 static struct platform_driver giu_device_driver = {
566 	.probe		= giu_probe,
567 	.remove		= __devexit_p(giu_remove),
568 	.driver		= {
569 		.name	= "GIU",
570 		.owner	= THIS_MODULE,
571 	},
572 };
573 
574 module_platform_driver(giu_device_driver);
575