tjh.dev
Linux kernel mirror (for testing)
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linux
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
26MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
27MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
28MODULE_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
62enum {
63 GPIO_INPUT,
64 GPIO_OUTPUT,
65};
66
67static DEFINE_SPINLOCK(giu_lock);
68static unsigned long giu_flags;
69
70static void __iomem *giu_base;
71static 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
80static 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
91static 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
102static void ack_giuint_low(struct irq_data *d)
103{
104 giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(d->irq));
105}
106
107static void mask_giuint_low(struct irq_data *d)
108{
109 giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
110}
111
112static 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
121static void unmask_giuint_low(struct irq_data *d)
122{
123 giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
124}
125
126static 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
143static 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
149static 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
159static 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
165static 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
170static 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
179static 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
184static 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
192static 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
225void 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}
302EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);
303
304void 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}
324EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);
325
326static 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
374static 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
401static 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
437static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
438{
439 return giu_set_direction(chip, offset, GPIO_INPUT);
440}
441
442static 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
450static 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
458static 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
468static int giu_probe(struct platform_device *pdev)
469{
470 struct resource *res;
471 unsigned int trigger, i, pin;
472 struct irq_chip *chip;
473 int irq, ret;
474
475 switch (pdev->id) {
476 case GPIO_50PINS_PULLUPDOWN:
477 giu_flags = GPIO_HAS_PULLUPDOWN_IO;
478 vr41xx_gpio_chip.ngpio = 50;
479 break;
480 case GPIO_36PINS:
481 vr41xx_gpio_chip.ngpio = 36;
482 break;
483 case GPIO_48PINS_EDGE_SELECT:
484 giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
485 vr41xx_gpio_chip.ngpio = 48;
486 break;
487 default:
488 dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
489 return -ENODEV;
490 }
491
492 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
493 if (!res)
494 return -EBUSY;
495
496 giu_base = ioremap(res->start, resource_size(res));
497 if (!giu_base)
498 return -ENOMEM;
499
500 vr41xx_gpio_chip.parent = &pdev->dev;
501
502 ret = gpiochip_add_data(&vr41xx_gpio_chip, NULL);
503 if (!ret) {
504 iounmap(giu_base);
505 return -ENODEV;
506 }
507
508 giu_write(GIUINTENL, 0);
509 giu_write(GIUINTENH, 0);
510
511 trigger = giu_read(GIUINTTYPH) << 16;
512 trigger |= giu_read(GIUINTTYPL);
513 for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
514 pin = GPIO_PIN_OF_IRQ(i);
515 if (pin < GIUINT_HIGH_OFFSET)
516 chip = &giuint_low_irq_chip;
517 else
518 chip = &giuint_high_irq_chip;
519
520 if (trigger & (1 << pin))
521 irq_set_chip_and_handler(i, chip, handle_edge_irq);
522 else
523 irq_set_chip_and_handler(i, chip, handle_level_irq);
524
525 }
526
527 irq = platform_get_irq(pdev, 0);
528 if (irq < 0 || irq >= nr_irqs)
529 return -EBUSY;
530
531 return cascade_irq(irq, giu_get_irq);
532}
533
534static int giu_remove(struct platform_device *pdev)
535{
536 if (giu_base) {
537 iounmap(giu_base);
538 giu_base = NULL;
539 }
540
541 return 0;
542}
543
544static struct platform_driver giu_device_driver = {
545 .probe = giu_probe,
546 .remove = giu_remove,
547 .driver = {
548 .name = "GIU",
549 },
550};
551
552module_platform_driver(giu_device_driver);