1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for NEC VR4100 series General-purpose I/O Unit.
4 *
5 * Copyright (C) 2002 MontaVista Software Inc.
6 * Author: Yoichi Yuasa <source@mvista.com>
7 * Copyright (C) 2003-2009 Yoichi Yuasa <yuasa@linux-mips.org>
8 */
9 #include <linux/errno.h>
10 #include <linux/fs.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/spinlock.h>
20 #include <linux/types.h>
21
22 #include <asm/vr41xx/giu.h>
23 #include <asm/vr41xx/irq.h>
24 #include <asm/vr41xx/vr41xx.h>
25
26 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
27 MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
28 MODULE_LICENSE("GPL");
29
30 #define GIUIOSELL 0x00
31 #define GIUIOSELH 0x02
32 #define GIUPIODL 0x04
33 #define GIUPIODH 0x06
34 #define GIUINTSTATL 0x08
35 #define GIUINTSTATH 0x0a
36 #define GIUINTENL 0x0c
37 #define GIUINTENH 0x0e
38 #define GIUINTTYPL 0x10
39 #define GIUINTTYPH 0x12
40 #define GIUINTALSELL 0x14
41 #define GIUINTALSELH 0x16
42 #define GIUINTHTSELL 0x18
43 #define GIUINTHTSELH 0x1a
44 #define GIUPODATL 0x1c
45 #define GIUPODATEN 0x1c
46 #define GIUPODATH 0x1e
47 #define PIOEN0 0x0100
48 #define PIOEN1 0x0200
49 #define GIUPODAT 0x1e
50 #define GIUFEDGEINHL 0x20
51 #define GIUFEDGEINHH 0x22
52 #define GIUREDGEINHL 0x24
53 #define GIUREDGEINHH 0x26
54
55 #define GIUUSEUPDN 0x1e0
56 #define GIUTERMUPDN 0x1e2
57
58 #define GPIO_HAS_PULLUPDOWN_IO 0x0001
59 #define GPIO_HAS_OUTPUT_ENABLE 0x0002
60 #define GPIO_HAS_INTERRUPT_EDGE_SELECT 0x0100
61
62 enum {
63 GPIO_INPUT,
64 GPIO_OUTPUT,
65 };
66
67 static DEFINE_SPINLOCK(giu_lock);
68 static unsigned long giu_flags;
69
70 static void __iomem *giu_base;
71 static struct gpio_chip vr41xx_gpio_chip;
72
73 #define giu_read(offset) readw(giu_base + (offset))
74 #define giu_write(offset, value) writew((value), giu_base + (offset))
75
76 #define GPIO_PIN_OF_IRQ(irq) ((irq) - GIU_IRQ_BASE)
77 #define GIUINT_HIGH_OFFSET 16
78 #define GIUINT_HIGH_MAX 32
79
giu_set(u16 offset,u16 set)80 static inline u16 giu_set(u16 offset, u16 set)
81 {
82 u16 data;
83
84 data = giu_read(offset);
85 data |= set;
86 giu_write(offset, data);
87
88 return data;
89 }
90
giu_clear(u16 offset,u16 clear)91 static inline u16 giu_clear(u16 offset, u16 clear)
92 {
93 u16 data;
94
95 data = giu_read(offset);
96 data &= ~clear;
97 giu_write(offset, data);
98
99 return data;
100 }
101
ack_giuint_low(struct irq_data * d)102 static void ack_giuint_low(struct irq_data *d)
103 {
104 giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(d->irq));
105 }
106
mask_giuint_low(struct irq_data * d)107 static void mask_giuint_low(struct irq_data *d)
108 {
109 giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
110 }
111
mask_ack_giuint_low(struct irq_data * d)112 static void mask_ack_giuint_low(struct irq_data *d)
113 {
114 unsigned int pin;
115
116 pin = GPIO_PIN_OF_IRQ(d->irq);
117 giu_clear(GIUINTENL, 1 << pin);
118 giu_write(GIUINTSTATL, 1 << pin);
119 }
120
unmask_giuint_low(struct irq_data * d)121 static void unmask_giuint_low(struct irq_data *d)
122 {
123 giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
124 }
125
startup_giuint(struct irq_data * data)126 static unsigned int startup_giuint(struct irq_data *data)
127 {
128 int ret;
129
130 ret = gpiochip_lock_as_irq(&vr41xx_gpio_chip, irqd_to_hwirq(data));
131 if (ret) {
132 dev_err(vr41xx_gpio_chip.parent,
133 "unable to lock HW IRQ %lu for IRQ\n",
134 data->hwirq);
135 return ret;
136 }
137
138 /* Satisfy the .enable semantics by unmasking the line */
139 unmask_giuint_low(data);
140 return 0;
141 }
142
shutdown_giuint(struct irq_data * data)143 static void shutdown_giuint(struct irq_data *data)
144 {
145 mask_giuint_low(data);
146 gpiochip_unlock_as_irq(&vr41xx_gpio_chip, data->hwirq);
147 }
148
149 static struct irq_chip giuint_low_irq_chip = {
150 .name = "GIUINTL",
151 .irq_ack = ack_giuint_low,
152 .irq_mask = mask_giuint_low,
153 .irq_mask_ack = mask_ack_giuint_low,
154 .irq_unmask = unmask_giuint_low,
155 .irq_startup = startup_giuint,
156 .irq_shutdown = shutdown_giuint,
157 };
158
ack_giuint_high(struct irq_data * d)159 static void ack_giuint_high(struct irq_data *d)
160 {
161 giu_write(GIUINTSTATH,
162 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
163 }
164
mask_giuint_high(struct irq_data * d)165 static void mask_giuint_high(struct irq_data *d)
166 {
167 giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
168 }
169
mask_ack_giuint_high(struct irq_data * d)170 static void mask_ack_giuint_high(struct irq_data *d)
171 {
172 unsigned int pin;
173
174 pin = GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET;
175 giu_clear(GIUINTENH, 1 << pin);
176 giu_write(GIUINTSTATH, 1 << pin);
177 }
178
unmask_giuint_high(struct irq_data * d)179 static void unmask_giuint_high(struct irq_data *d)
180 {
181 giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
182 }
183
184 static struct irq_chip giuint_high_irq_chip = {
185 .name = "GIUINTH",
186 .irq_ack = ack_giuint_high,
187 .irq_mask = mask_giuint_high,
188 .irq_mask_ack = mask_ack_giuint_high,
189 .irq_unmask = unmask_giuint_high,
190 };
191
giu_get_irq(unsigned int irq)192 static int giu_get_irq(unsigned int irq)
193 {
194 u16 pendl, pendh, maskl, maskh;
195 int i;
196
197 pendl = giu_read(GIUINTSTATL);
198 pendh = giu_read(GIUINTSTATH);
199 maskl = giu_read(GIUINTENL);
200 maskh = giu_read(GIUINTENH);
201
202 maskl &= pendl;
203 maskh &= pendh;
204
205 if (maskl) {
206 for (i = 0; i < 16; i++) {
207 if (maskl & (1 << i))
208 return GIU_IRQ(i);
209 }
210 } else if (maskh) {
211 for (i = 0; i < 16; i++) {
212 if (maskh & (1 << i))
213 return GIU_IRQ(i + GIUINT_HIGH_OFFSET);
214 }
215 }
216
217 printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
218 maskl, pendl, maskh, pendh);
219
220 return -EINVAL;
221 }
222
vr41xx_set_irq_trigger(unsigned int pin,irq_trigger_t trigger,irq_signal_t signal)223 void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger,
224 irq_signal_t signal)
225 {
226 u16 mask;
227
228 if (pin < GIUINT_HIGH_OFFSET) {
229 mask = 1 << pin;
230 if (trigger != IRQ_TRIGGER_LEVEL) {
231 giu_set(GIUINTTYPL, mask);
232 if (signal == IRQ_SIGNAL_HOLD)
233 giu_set(GIUINTHTSELL, mask);
234 else
235 giu_clear(GIUINTHTSELL, mask);
236 if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
237 switch (trigger) {
238 case IRQ_TRIGGER_EDGE_FALLING:
239 giu_set(GIUFEDGEINHL, mask);
240 giu_clear(GIUREDGEINHL, mask);
241 break;
242 case IRQ_TRIGGER_EDGE_RISING:
243 giu_clear(GIUFEDGEINHL, mask);
244 giu_set(GIUREDGEINHL, mask);
245 break;
246 default:
247 giu_set(GIUFEDGEINHL, mask);
248 giu_set(GIUREDGEINHL, mask);
249 break;
250 }
251 }
252 irq_set_chip_and_handler(GIU_IRQ(pin),
253 &giuint_low_irq_chip,
254 handle_edge_irq);
255 } else {
256 giu_clear(GIUINTTYPL, mask);
257 giu_clear(GIUINTHTSELL, mask);
258 irq_set_chip_and_handler(GIU_IRQ(pin),
259 &giuint_low_irq_chip,
260 handle_level_irq);
261 }
262 giu_write(GIUINTSTATL, mask);
263 } else if (pin < GIUINT_HIGH_MAX) {
264 mask = 1 << (pin - GIUINT_HIGH_OFFSET);
265 if (trigger != IRQ_TRIGGER_LEVEL) {
266 giu_set(GIUINTTYPH, mask);
267 if (signal == IRQ_SIGNAL_HOLD)
268 giu_set(GIUINTHTSELH, mask);
269 else
270 giu_clear(GIUINTHTSELH, mask);
271 if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
272 switch (trigger) {
273 case IRQ_TRIGGER_EDGE_FALLING:
274 giu_set(GIUFEDGEINHH, mask);
275 giu_clear(GIUREDGEINHH, mask);
276 break;
277 case IRQ_TRIGGER_EDGE_RISING:
278 giu_clear(GIUFEDGEINHH, mask);
279 giu_set(GIUREDGEINHH, mask);
280 break;
281 default:
282 giu_set(GIUFEDGEINHH, mask);
283 giu_set(GIUREDGEINHH, mask);
284 break;
285 }
286 }
287 irq_set_chip_and_handler(GIU_IRQ(pin),
288 &giuint_high_irq_chip,
289 handle_edge_irq);
290 } else {
291 giu_clear(GIUINTTYPH, mask);
292 giu_clear(GIUINTHTSELH, mask);
293 irq_set_chip_and_handler(GIU_IRQ(pin),
294 &giuint_high_irq_chip,
295 handle_level_irq);
296 }
297 giu_write(GIUINTSTATH, mask);
298 }
299 }
300 EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);
301
vr41xx_set_irq_level(unsigned int pin,irq_level_t level)302 void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
303 {
304 u16 mask;
305
306 if (pin < GIUINT_HIGH_OFFSET) {
307 mask = 1 << pin;
308 if (level == IRQ_LEVEL_HIGH)
309 giu_set(GIUINTALSELL, mask);
310 else
311 giu_clear(GIUINTALSELL, mask);
312 giu_write(GIUINTSTATL, mask);
313 } else if (pin < GIUINT_HIGH_MAX) {
314 mask = 1 << (pin - GIUINT_HIGH_OFFSET);
315 if (level == IRQ_LEVEL_HIGH)
316 giu_set(GIUINTALSELH, mask);
317 else
318 giu_clear(GIUINTALSELH, mask);
319 giu_write(GIUINTSTATH, mask);
320 }
321 }
322 EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);
323
giu_set_direction(struct gpio_chip * chip,unsigned pin,int dir)324 static int giu_set_direction(struct gpio_chip *chip, unsigned pin, int dir)
325 {
326 u16 offset, mask, reg;
327 unsigned long flags;
328
329 if (pin >= chip->ngpio)
330 return -EINVAL;
331
332 if (pin < 16) {
333 offset = GIUIOSELL;
334 mask = 1 << pin;
335 } else if (pin < 32) {
336 offset = GIUIOSELH;
337 mask = 1 << (pin - 16);
338 } else {
339 if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
340 offset = GIUPODATEN;
341 mask = 1 << (pin - 32);
342 } else {
343 switch (pin) {
344 case 48:
345 offset = GIUPODATH;
346 mask = PIOEN0;
347 break;
348 case 49:
349 offset = GIUPODATH;
350 mask = PIOEN1;
351 break;
352 default:
353 return -EINVAL;
354 }
355 }
356 }
357
358 spin_lock_irqsave(&giu_lock, flags);
359
360 reg = giu_read(offset);
361 if (dir == GPIO_OUTPUT)
362 reg |= mask;
363 else
364 reg &= ~mask;
365 giu_write(offset, reg);
366
367 spin_unlock_irqrestore(&giu_lock, flags);
368
369 return 0;
370 }
371
vr41xx_gpio_get(struct gpio_chip * chip,unsigned pin)372 static int vr41xx_gpio_get(struct gpio_chip *chip, unsigned pin)
373 {
374 u16 reg, mask;
375
376 if (pin >= chip->ngpio)
377 return -EINVAL;
378
379 if (pin < 16) {
380 reg = giu_read(GIUPIODL);
381 mask = 1 << pin;
382 } else if (pin < 32) {
383 reg = giu_read(GIUPIODH);
384 mask = 1 << (pin - 16);
385 } else if (pin < 48) {
386 reg = giu_read(GIUPODATL);
387 mask = 1 << (pin - 32);
388 } else {
389 reg = giu_read(GIUPODATH);
390 mask = 1 << (pin - 48);
391 }
392
393 if (reg & mask)
394 return 1;
395
396 return 0;
397 }
398
vr41xx_gpio_set(struct gpio_chip * chip,unsigned pin,int value)399 static void vr41xx_gpio_set(struct gpio_chip *chip, unsigned pin,
400 int value)
401 {
402 u16 offset, mask, reg;
403 unsigned long flags;
404
405 if (pin >= chip->ngpio)
406 return;
407
408 if (pin < 16) {
409 offset = GIUPIODL;
410 mask = 1 << pin;
411 } else if (pin < 32) {
412 offset = GIUPIODH;
413 mask = 1 << (pin - 16);
414 } else if (pin < 48) {
415 offset = GIUPODATL;
416 mask = 1 << (pin - 32);
417 } else {
418 offset = GIUPODATH;
419 mask = 1 << (pin - 48);
420 }
421
422 spin_lock_irqsave(&giu_lock, flags);
423
424 reg = giu_read(offset);
425 if (value)
426 reg |= mask;
427 else
428 reg &= ~mask;
429 giu_write(offset, reg);
430
431 spin_unlock_irqrestore(&giu_lock, flags);
432 }
433
434
vr41xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)435 static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
436 {
437 return giu_set_direction(chip, offset, GPIO_INPUT);
438 }
439
vr41xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)440 static int vr41xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
441 int value)
442 {
443 vr41xx_gpio_set(chip, offset, value);
444
445 return giu_set_direction(chip, offset, GPIO_OUTPUT);
446 }
447
vr41xx_gpio_to_irq(struct gpio_chip * chip,unsigned offset)448 static int vr41xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
449 {
450 if (offset >= chip->ngpio)
451 return -EINVAL;
452
453 return GIU_IRQ_BASE + offset;
454 }
455
456 static struct gpio_chip vr41xx_gpio_chip = {
457 .label = "vr41xx",
458 .owner = THIS_MODULE,
459 .direction_input = vr41xx_gpio_direction_input,
460 .get = vr41xx_gpio_get,
461 .direction_output = vr41xx_gpio_direction_output,
462 .set = vr41xx_gpio_set,
463 .to_irq = vr41xx_gpio_to_irq,
464 };
465
giu_probe(struct platform_device * pdev)466 static int giu_probe(struct platform_device *pdev)
467 {
468 unsigned int trigger, i, pin;
469 struct irq_chip *chip;
470 int irq;
471
472 switch (pdev->id) {
473 case GPIO_50PINS_PULLUPDOWN:
474 giu_flags = GPIO_HAS_PULLUPDOWN_IO;
475 vr41xx_gpio_chip.ngpio = 50;
476 break;
477 case GPIO_36PINS:
478 vr41xx_gpio_chip.ngpio = 36;
479 break;
480 case GPIO_48PINS_EDGE_SELECT:
481 giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
482 vr41xx_gpio_chip.ngpio = 48;
483 break;
484 default:
485 dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
486 return -ENODEV;
487 }
488
489 giu_base = devm_platform_ioremap_resource(pdev, 0);
490 if (IS_ERR(giu_base))
491 return PTR_ERR(giu_base);
492
493 vr41xx_gpio_chip.parent = &pdev->dev;
494
495 if (gpiochip_add_data(&vr41xx_gpio_chip, NULL))
496 return -ENODEV;
497
498 giu_write(GIUINTENL, 0);
499 giu_write(GIUINTENH, 0);
500
501 trigger = giu_read(GIUINTTYPH) << 16;
502 trigger |= giu_read(GIUINTTYPL);
503 for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
504 pin = GPIO_PIN_OF_IRQ(i);
505 if (pin < GIUINT_HIGH_OFFSET)
506 chip = &giuint_low_irq_chip;
507 else
508 chip = &giuint_high_irq_chip;
509
510 if (trigger & (1 << pin))
511 irq_set_chip_and_handler(i, chip, handle_edge_irq);
512 else
513 irq_set_chip_and_handler(i, chip, handle_level_irq);
514
515 }
516
517 irq = platform_get_irq(pdev, 0);
518 if (irq < 0 || irq >= nr_irqs)
519 return -EBUSY;
520
521 return cascade_irq(irq, giu_get_irq);
522 }
523
giu_remove(struct platform_device * pdev)524 static int giu_remove(struct platform_device *pdev)
525 {
526 if (giu_base) {
527 giu_base = NULL;
528 }
529
530 return 0;
531 }
532
533 static struct platform_driver giu_device_driver = {
534 .probe = giu_probe,
535 .remove = giu_remove,
536 .driver = {
537 .name = "GIU",
538 },
539 };
540
541 module_platform_driver(giu_device_driver);
542