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 atomic_inc(&irq_err_count);
221
222 return -EINVAL;
223 }
224
vr41xx_set_irq_trigger(unsigned int pin,irq_trigger_t trigger,irq_signal_t signal)225 void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger,
226 irq_signal_t signal)
227 {
228 u16 mask;
229
230 if (pin < GIUINT_HIGH_OFFSET) {
231 mask = 1 << pin;
232 if (trigger != IRQ_TRIGGER_LEVEL) {
233 giu_set(GIUINTTYPL, mask);
234 if (signal == IRQ_SIGNAL_HOLD)
235 giu_set(GIUINTHTSELL, mask);
236 else
237 giu_clear(GIUINTHTSELL, mask);
238 if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
239 switch (trigger) {
240 case IRQ_TRIGGER_EDGE_FALLING:
241 giu_set(GIUFEDGEINHL, mask);
242 giu_clear(GIUREDGEINHL, mask);
243 break;
244 case IRQ_TRIGGER_EDGE_RISING:
245 giu_clear(GIUFEDGEINHL, mask);
246 giu_set(GIUREDGEINHL, mask);
247 break;
248 default:
249 giu_set(GIUFEDGEINHL, mask);
250 giu_set(GIUREDGEINHL, mask);
251 break;
252 }
253 }
254 irq_set_chip_and_handler(GIU_IRQ(pin),
255 &giuint_low_irq_chip,
256 handle_edge_irq);
257 } else {
258 giu_clear(GIUINTTYPL, mask);
259 giu_clear(GIUINTHTSELL, mask);
260 irq_set_chip_and_handler(GIU_IRQ(pin),
261 &giuint_low_irq_chip,
262 handle_level_irq);
263 }
264 giu_write(GIUINTSTATL, mask);
265 } else if (pin < GIUINT_HIGH_MAX) {
266 mask = 1 << (pin - GIUINT_HIGH_OFFSET);
267 if (trigger != IRQ_TRIGGER_LEVEL) {
268 giu_set(GIUINTTYPH, mask);
269 if (signal == IRQ_SIGNAL_HOLD)
270 giu_set(GIUINTHTSELH, mask);
271 else
272 giu_clear(GIUINTHTSELH, mask);
273 if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
274 switch (trigger) {
275 case IRQ_TRIGGER_EDGE_FALLING:
276 giu_set(GIUFEDGEINHH, mask);
277 giu_clear(GIUREDGEINHH, mask);
278 break;
279 case IRQ_TRIGGER_EDGE_RISING:
280 giu_clear(GIUFEDGEINHH, mask);
281 giu_set(GIUREDGEINHH, mask);
282 break;
283 default:
284 giu_set(GIUFEDGEINHH, mask);
285 giu_set(GIUREDGEINHH, mask);
286 break;
287 }
288 }
289 irq_set_chip_and_handler(GIU_IRQ(pin),
290 &giuint_high_irq_chip,
291 handle_edge_irq);
292 } else {
293 giu_clear(GIUINTTYPH, mask);
294 giu_clear(GIUINTHTSELH, mask);
295 irq_set_chip_and_handler(GIU_IRQ(pin),
296 &giuint_high_irq_chip,
297 handle_level_irq);
298 }
299 giu_write(GIUINTSTATH, mask);
300 }
301 }
302 EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);
303
vr41xx_set_irq_level(unsigned int pin,irq_level_t level)304 void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
305 {
306 u16 mask;
307
308 if (pin < GIUINT_HIGH_OFFSET) {
309 mask = 1 << pin;
310 if (level == IRQ_LEVEL_HIGH)
311 giu_set(GIUINTALSELL, mask);
312 else
313 giu_clear(GIUINTALSELL, mask);
314 giu_write(GIUINTSTATL, mask);
315 } else if (pin < GIUINT_HIGH_MAX) {
316 mask = 1 << (pin - GIUINT_HIGH_OFFSET);
317 if (level == IRQ_LEVEL_HIGH)
318 giu_set(GIUINTALSELH, mask);
319 else
320 giu_clear(GIUINTALSELH, mask);
321 giu_write(GIUINTSTATH, mask);
322 }
323 }
324 EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);
325
giu_set_direction(struct gpio_chip * chip,unsigned pin,int dir)326 static int giu_set_direction(struct gpio_chip *chip, unsigned pin, int dir)
327 {
328 u16 offset, mask, reg;
329 unsigned long flags;
330
331 if (pin >= chip->ngpio)
332 return -EINVAL;
333
334 if (pin < 16) {
335 offset = GIUIOSELL;
336 mask = 1 << pin;
337 } else if (pin < 32) {
338 offset = GIUIOSELH;
339 mask = 1 << (pin - 16);
340 } else {
341 if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
342 offset = GIUPODATEN;
343 mask = 1 << (pin - 32);
344 } else {
345 switch (pin) {
346 case 48:
347 offset = GIUPODATH;
348 mask = PIOEN0;
349 break;
350 case 49:
351 offset = GIUPODATH;
352 mask = PIOEN1;
353 break;
354 default:
355 return -EINVAL;
356 }
357 }
358 }
359
360 spin_lock_irqsave(&giu_lock, flags);
361
362 reg = giu_read(offset);
363 if (dir == GPIO_OUTPUT)
364 reg |= mask;
365 else
366 reg &= ~mask;
367 giu_write(offset, reg);
368
369 spin_unlock_irqrestore(&giu_lock, flags);
370
371 return 0;
372 }
373
vr41xx_gpio_get(struct gpio_chip * chip,unsigned pin)374 static int vr41xx_gpio_get(struct gpio_chip *chip, unsigned pin)
375 {
376 u16 reg, mask;
377
378 if (pin >= chip->ngpio)
379 return -EINVAL;
380
381 if (pin < 16) {
382 reg = giu_read(GIUPIODL);
383 mask = 1 << pin;
384 } else if (pin < 32) {
385 reg = giu_read(GIUPIODH);
386 mask = 1 << (pin - 16);
387 } else if (pin < 48) {
388 reg = giu_read(GIUPODATL);
389 mask = 1 << (pin - 32);
390 } else {
391 reg = giu_read(GIUPODATH);
392 mask = 1 << (pin - 48);
393 }
394
395 if (reg & mask)
396 return 1;
397
398 return 0;
399 }
400
vr41xx_gpio_set(struct gpio_chip * chip,unsigned pin,int value)401 static void vr41xx_gpio_set(struct gpio_chip *chip, unsigned pin,
402 int value)
403 {
404 u16 offset, mask, reg;
405 unsigned long flags;
406
407 if (pin >= chip->ngpio)
408 return;
409
410 if (pin < 16) {
411 offset = GIUPIODL;
412 mask = 1 << pin;
413 } else if (pin < 32) {
414 offset = GIUPIODH;
415 mask = 1 << (pin - 16);
416 } else if (pin < 48) {
417 offset = GIUPODATL;
418 mask = 1 << (pin - 32);
419 } else {
420 offset = GIUPODATH;
421 mask = 1 << (pin - 48);
422 }
423
424 spin_lock_irqsave(&giu_lock, flags);
425
426 reg = giu_read(offset);
427 if (value)
428 reg |= mask;
429 else
430 reg &= ~mask;
431 giu_write(offset, reg);
432
433 spin_unlock_irqrestore(&giu_lock, flags);
434 }
435
436
vr41xx_gpio_direction_input(struct gpio_chip * chip,unsigned offset)437 static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
438 {
439 return giu_set_direction(chip, offset, GPIO_INPUT);
440 }
441
vr41xx_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)442 static int vr41xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
443 int value)
444 {
445 vr41xx_gpio_set(chip, offset, value);
446
447 return giu_set_direction(chip, offset, GPIO_OUTPUT);
448 }
449
vr41xx_gpio_to_irq(struct gpio_chip * chip,unsigned offset)450 static int vr41xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
451 {
452 if (offset >= chip->ngpio)
453 return -EINVAL;
454
455 return GIU_IRQ_BASE + offset;
456 }
457
458 static struct gpio_chip vr41xx_gpio_chip = {
459 .label = "vr41xx",
460 .owner = THIS_MODULE,
461 .direction_input = vr41xx_gpio_direction_input,
462 .get = vr41xx_gpio_get,
463 .direction_output = vr41xx_gpio_direction_output,
464 .set = vr41xx_gpio_set,
465 .to_irq = vr41xx_gpio_to_irq,
466 };
467
giu_probe(struct platform_device * pdev)468 static int giu_probe(struct platform_device *pdev)
469 {
470 unsigned int trigger, i, pin;
471 struct irq_chip *chip;
472 int irq;
473
474 switch (pdev->id) {
475 case GPIO_50PINS_PULLUPDOWN:
476 giu_flags = GPIO_HAS_PULLUPDOWN_IO;
477 vr41xx_gpio_chip.ngpio = 50;
478 break;
479 case GPIO_36PINS:
480 vr41xx_gpio_chip.ngpio = 36;
481 break;
482 case GPIO_48PINS_EDGE_SELECT:
483 giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
484 vr41xx_gpio_chip.ngpio = 48;
485 break;
486 default:
487 dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
488 return -ENODEV;
489 }
490
491 giu_base = devm_platform_ioremap_resource(pdev, 0);
492 if (IS_ERR(giu_base))
493 return PTR_ERR(giu_base);
494
495 vr41xx_gpio_chip.parent = &pdev->dev;
496
497 if (gpiochip_add_data(&vr41xx_gpio_chip, NULL))
498 return -ENODEV;
499
500 giu_write(GIUINTENL, 0);
501 giu_write(GIUINTENH, 0);
502
503 trigger = giu_read(GIUINTTYPH) << 16;
504 trigger |= giu_read(GIUINTTYPL);
505 for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
506 pin = GPIO_PIN_OF_IRQ(i);
507 if (pin < GIUINT_HIGH_OFFSET)
508 chip = &giuint_low_irq_chip;
509 else
510 chip = &giuint_high_irq_chip;
511
512 if (trigger & (1 << pin))
513 irq_set_chip_and_handler(i, chip, handle_edge_irq);
514 else
515 irq_set_chip_and_handler(i, chip, handle_level_irq);
516
517 }
518
519 irq = platform_get_irq(pdev, 0);
520 if (irq < 0 || irq >= nr_irqs)
521 return -EBUSY;
522
523 return cascade_irq(irq, giu_get_irq);
524 }
525
giu_remove(struct platform_device * pdev)526 static int giu_remove(struct platform_device *pdev)
527 {
528 if (giu_base) {
529 giu_base = NULL;
530 }
531
532 return 0;
533 }
534
535 static struct platform_driver giu_device_driver = {
536 .probe = giu_probe,
537 .remove = giu_remove,
538 .driver = {
539 .name = "GIU",
540 },
541 };
542
543 module_platform_driver(giu_device_driver);
544