1 /*
2 * linux/arch/arm/mach-at91/gpio.c
3 *
4 * Copyright (C) 2005 HP Labs
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, or
9 * (at your option) any later version.
10 */
11
12 #include <linux/clk.h>
13 #include <linux/errno.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/debugfs.h>
17 #include <linux/seq_file.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 #include <linux/io.h>
22
23 #include <mach/hardware.h>
24 #include <mach/at91_pio.h>
25 #include <mach/gpio.h>
26
27 #include <asm/gpio.h>
28
29 #include "generic.h"
30
31 struct at91_gpio_chip {
32 struct gpio_chip chip;
33 struct at91_gpio_chip *next; /* Bank sharing same clock */
34 struct at91_gpio_bank *bank; /* Bank definition */
35 void __iomem *regbase; /* Base of register bank */
36 };
37
38 #define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)
39
40 static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
41 static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
42 static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
43 static int at91_gpiolib_direction_output(struct gpio_chip *chip,
44 unsigned offset, int val);
45 static int at91_gpiolib_direction_input(struct gpio_chip *chip,
46 unsigned offset);
47
48 #define AT91_GPIO_CHIP(name, base_gpio, nr_gpio) \
49 { \
50 .chip = { \
51 .label = name, \
52 .direction_input = at91_gpiolib_direction_input, \
53 .direction_output = at91_gpiolib_direction_output, \
54 .get = at91_gpiolib_get, \
55 .set = at91_gpiolib_set, \
56 .dbg_show = at91_gpiolib_dbg_show, \
57 .base = base_gpio, \
58 .ngpio = nr_gpio, \
59 }, \
60 }
61
62 static struct at91_gpio_chip gpio_chip[] = {
63 AT91_GPIO_CHIP("A", 0x00 + PIN_BASE, 32),
64 AT91_GPIO_CHIP("B", 0x20 + PIN_BASE, 32),
65 AT91_GPIO_CHIP("C", 0x40 + PIN_BASE, 32),
66 AT91_GPIO_CHIP("D", 0x60 + PIN_BASE, 32),
67 AT91_GPIO_CHIP("E", 0x80 + PIN_BASE, 32),
68 };
69
70 static int gpio_banks;
71
pin_to_controller(unsigned pin)72 static inline void __iomem *pin_to_controller(unsigned pin)
73 {
74 pin -= PIN_BASE;
75 pin /= 32;
76 if (likely(pin < gpio_banks))
77 return gpio_chip[pin].regbase;
78
79 return NULL;
80 }
81
pin_to_mask(unsigned pin)82 static inline unsigned pin_to_mask(unsigned pin)
83 {
84 pin -= PIN_BASE;
85 return 1 << (pin % 32);
86 }
87
88
89 /*--------------------------------------------------------------------------*/
90
91 /* Not all hardware capabilities are exposed through these calls; they
92 * only encapsulate the most common features and modes. (So if you
93 * want to change signals in groups, do it directly.)
94 *
95 * Bootloaders will usually handle some of the pin multiplexing setup.
96 * The intent is certainly that by the time Linux is fully booted, all
97 * pins should have been fully initialized. These setup calls should
98 * only be used by board setup routines, or possibly in driver probe().
99 *
100 * For bootloaders doing all that setup, these calls could be inlined
101 * as NOPs so Linux won't duplicate any setup code
102 */
103
104
105 /*
106 * mux the pin to the "GPIO" peripheral role.
107 */
at91_set_GPIO_periph(unsigned pin,int use_pullup)108 int __init_or_module at91_set_GPIO_periph(unsigned pin, int use_pullup)
109 {
110 void __iomem *pio = pin_to_controller(pin);
111 unsigned mask = pin_to_mask(pin);
112
113 if (!pio)
114 return -EINVAL;
115 __raw_writel(mask, pio + PIO_IDR);
116 __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
117 __raw_writel(mask, pio + PIO_PER);
118 return 0;
119 }
120 EXPORT_SYMBOL(at91_set_GPIO_periph);
121
122
123 /*
124 * mux the pin to the "A" internal peripheral role.
125 */
at91_set_A_periph(unsigned pin,int use_pullup)126 int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup)
127 {
128 void __iomem *pio = pin_to_controller(pin);
129 unsigned mask = pin_to_mask(pin);
130
131 if (!pio)
132 return -EINVAL;
133
134 __raw_writel(mask, pio + PIO_IDR);
135 __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
136 __raw_writel(mask, pio + PIO_ASR);
137 __raw_writel(mask, pio + PIO_PDR);
138 return 0;
139 }
140 EXPORT_SYMBOL(at91_set_A_periph);
141
142
143 /*
144 * mux the pin to the "B" internal peripheral role.
145 */
at91_set_B_periph(unsigned pin,int use_pullup)146 int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup)
147 {
148 void __iomem *pio = pin_to_controller(pin);
149 unsigned mask = pin_to_mask(pin);
150
151 if (!pio)
152 return -EINVAL;
153
154 __raw_writel(mask, pio + PIO_IDR);
155 __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
156 __raw_writel(mask, pio + PIO_BSR);
157 __raw_writel(mask, pio + PIO_PDR);
158 return 0;
159 }
160 EXPORT_SYMBOL(at91_set_B_periph);
161
162
163 /*
164 * mux the pin to the gpio controller (instead of "A" or "B" peripheral), and
165 * configure it for an input.
166 */
at91_set_gpio_input(unsigned pin,int use_pullup)167 int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup)
168 {
169 void __iomem *pio = pin_to_controller(pin);
170 unsigned mask = pin_to_mask(pin);
171
172 if (!pio)
173 return -EINVAL;
174
175 __raw_writel(mask, pio + PIO_IDR);
176 __raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
177 __raw_writel(mask, pio + PIO_ODR);
178 __raw_writel(mask, pio + PIO_PER);
179 return 0;
180 }
181 EXPORT_SYMBOL(at91_set_gpio_input);
182
183
184 /*
185 * mux the pin to the gpio controller (instead of "A" or "B" peripheral),
186 * and configure it for an output.
187 */
at91_set_gpio_output(unsigned pin,int value)188 int __init_or_module at91_set_gpio_output(unsigned pin, int value)
189 {
190 void __iomem *pio = pin_to_controller(pin);
191 unsigned mask = pin_to_mask(pin);
192
193 if (!pio)
194 return -EINVAL;
195
196 __raw_writel(mask, pio + PIO_IDR);
197 __raw_writel(mask, pio + PIO_PUDR);
198 __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
199 __raw_writel(mask, pio + PIO_OER);
200 __raw_writel(mask, pio + PIO_PER);
201 return 0;
202 }
203 EXPORT_SYMBOL(at91_set_gpio_output);
204
205
206 /*
207 * enable/disable the glitch filter; mostly used with IRQ handling.
208 */
at91_set_deglitch(unsigned pin,int is_on)209 int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
210 {
211 void __iomem *pio = pin_to_controller(pin);
212 unsigned mask = pin_to_mask(pin);
213
214 if (!pio)
215 return -EINVAL;
216 __raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
217 return 0;
218 }
219 EXPORT_SYMBOL(at91_set_deglitch);
220
221 /*
222 * enable/disable the multi-driver; This is only valid for output and
223 * allows the output pin to run as an open collector output.
224 */
at91_set_multi_drive(unsigned pin,int is_on)225 int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
226 {
227 void __iomem *pio = pin_to_controller(pin);
228 unsigned mask = pin_to_mask(pin);
229
230 if (!pio)
231 return -EINVAL;
232
233 __raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
234 return 0;
235 }
236 EXPORT_SYMBOL(at91_set_multi_drive);
237
238 /*
239 * assuming the pin is muxed as a gpio output, set its value.
240 */
at91_set_gpio_value(unsigned pin,int value)241 int at91_set_gpio_value(unsigned pin, int value)
242 {
243 void __iomem *pio = pin_to_controller(pin);
244 unsigned mask = pin_to_mask(pin);
245
246 if (!pio)
247 return -EINVAL;
248 __raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
249 return 0;
250 }
251 EXPORT_SYMBOL(at91_set_gpio_value);
252
253
254 /*
255 * read the pin's value (works even if it's not muxed as a gpio).
256 */
at91_get_gpio_value(unsigned pin)257 int at91_get_gpio_value(unsigned pin)
258 {
259 void __iomem *pio = pin_to_controller(pin);
260 unsigned mask = pin_to_mask(pin);
261 u32 pdsr;
262
263 if (!pio)
264 return -EINVAL;
265 pdsr = __raw_readl(pio + PIO_PDSR);
266 return (pdsr & mask) != 0;
267 }
268 EXPORT_SYMBOL(at91_get_gpio_value);
269
270 /*--------------------------------------------------------------------------*/
271
272 #ifdef CONFIG_PM
273
274 static u32 wakeups[MAX_GPIO_BANKS];
275 static u32 backups[MAX_GPIO_BANKS];
276
gpio_irq_set_wake(struct irq_data * d,unsigned state)277 static int gpio_irq_set_wake(struct irq_data *d, unsigned state)
278 {
279 unsigned mask = pin_to_mask(d->irq);
280 unsigned bank = (d->irq - PIN_BASE) / 32;
281
282 if (unlikely(bank >= MAX_GPIO_BANKS))
283 return -EINVAL;
284
285 if (state)
286 wakeups[bank] |= mask;
287 else
288 wakeups[bank] &= ~mask;
289
290 irq_set_irq_wake(gpio_chip[bank].bank->id, state);
291
292 return 0;
293 }
294
at91_gpio_suspend(void)295 void at91_gpio_suspend(void)
296 {
297 int i;
298
299 for (i = 0; i < gpio_banks; i++) {
300 void __iomem *pio = gpio_chip[i].regbase;
301
302 backups[i] = __raw_readl(pio + PIO_IMR);
303 __raw_writel(backups[i], pio + PIO_IDR);
304 __raw_writel(wakeups[i], pio + PIO_IER);
305
306 if (!wakeups[i])
307 clk_disable(gpio_chip[i].bank->clock);
308 else {
309 #ifdef CONFIG_PM_DEBUG
310 printk(KERN_DEBUG "GPIO-%c may wake for %08x\n", 'A'+i, wakeups[i]);
311 #endif
312 }
313 }
314 }
315
at91_gpio_resume(void)316 void at91_gpio_resume(void)
317 {
318 int i;
319
320 for (i = 0; i < gpio_banks; i++) {
321 void __iomem *pio = gpio_chip[i].regbase;
322
323 if (!wakeups[i])
324 clk_enable(gpio_chip[i].bank->clock);
325
326 __raw_writel(wakeups[i], pio + PIO_IDR);
327 __raw_writel(backups[i], pio + PIO_IER);
328 }
329 }
330
331 #else
332 #define gpio_irq_set_wake NULL
333 #endif
334
335
336 /* Several AIC controller irqs are dispatched through this GPIO handler.
337 * To use any AT91_PIN_* as an externally triggered IRQ, first call
338 * at91_set_gpio_input() then maybe enable its glitch filter.
339 * Then just request_irq() with the pin ID; it works like any ARM IRQ
340 * handler, though it always triggers on rising and falling edges.
341 *
342 * Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
343 * configuring them with at91_set_a_periph() or at91_set_b_periph().
344 * IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering.
345 */
346
gpio_irq_mask(struct irq_data * d)347 static void gpio_irq_mask(struct irq_data *d)
348 {
349 void __iomem *pio = pin_to_controller(d->irq);
350 unsigned mask = pin_to_mask(d->irq);
351
352 if (pio)
353 __raw_writel(mask, pio + PIO_IDR);
354 }
355
gpio_irq_unmask(struct irq_data * d)356 static void gpio_irq_unmask(struct irq_data *d)
357 {
358 void __iomem *pio = pin_to_controller(d->irq);
359 unsigned mask = pin_to_mask(d->irq);
360
361 if (pio)
362 __raw_writel(mask, pio + PIO_IER);
363 }
364
gpio_irq_type(struct irq_data * d,unsigned type)365 static int gpio_irq_type(struct irq_data *d, unsigned type)
366 {
367 switch (type) {
368 case IRQ_TYPE_NONE:
369 case IRQ_TYPE_EDGE_BOTH:
370 return 0;
371 default:
372 return -EINVAL;
373 }
374 }
375
376 static struct irq_chip gpio_irqchip = {
377 .name = "GPIO",
378 .irq_disable = gpio_irq_mask,
379 .irq_mask = gpio_irq_mask,
380 .irq_unmask = gpio_irq_unmask,
381 .irq_set_type = gpio_irq_type,
382 .irq_set_wake = gpio_irq_set_wake,
383 };
384
gpio_irq_handler(unsigned irq,struct irq_desc * desc)385 static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
386 {
387 unsigned pin;
388 struct irq_data *idata = irq_desc_get_irq_data(desc);
389 struct irq_chip *chip = irq_data_get_irq_chip(idata);
390 struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(idata);
391 void __iomem *pio = at91_gpio->regbase;
392 u32 isr;
393
394 /* temporarily mask (level sensitive) parent IRQ */
395 chip->irq_ack(idata);
396 for (;;) {
397 /* Reading ISR acks pending (edge triggered) GPIO interrupts.
398 * When there none are pending, we're finished unless we need
399 * to process multiple banks (like ID_PIOCDE on sam9263).
400 */
401 isr = __raw_readl(pio + PIO_ISR) & __raw_readl(pio + PIO_IMR);
402 if (!isr) {
403 if (!at91_gpio->next)
404 break;
405 at91_gpio = at91_gpio->next;
406 pio = at91_gpio->regbase;
407 continue;
408 }
409
410 pin = at91_gpio->chip.base;
411
412 while (isr) {
413 if (isr & 1)
414 generic_handle_irq(pin);
415 pin++;
416 isr >>= 1;
417 }
418 }
419 chip->irq_unmask(idata);
420 /* now it may re-trigger */
421 }
422
423 /*--------------------------------------------------------------------------*/
424
425 #ifdef CONFIG_DEBUG_FS
426
at91_gpio_show(struct seq_file * s,void * unused)427 static int at91_gpio_show(struct seq_file *s, void *unused)
428 {
429 int bank, j;
430
431 /* print heading */
432 seq_printf(s, "Pin\t");
433 for (bank = 0; bank < gpio_banks; bank++) {
434 seq_printf(s, "PIO%c\t", 'A' + bank);
435 };
436 seq_printf(s, "\n\n");
437
438 /* print pin status */
439 for (j = 0; j < 32; j++) {
440 seq_printf(s, "%i:\t", j);
441
442 for (bank = 0; bank < gpio_banks; bank++) {
443 unsigned pin = PIN_BASE + (32 * bank) + j;
444 void __iomem *pio = pin_to_controller(pin);
445 unsigned mask = pin_to_mask(pin);
446
447 if (__raw_readl(pio + PIO_PSR) & mask)
448 seq_printf(s, "GPIO:%s", __raw_readl(pio + PIO_PDSR) & mask ? "1" : "0");
449 else
450 seq_printf(s, "%s", __raw_readl(pio + PIO_ABSR) & mask ? "B" : "A");
451
452 seq_printf(s, "\t");
453 }
454
455 seq_printf(s, "\n");
456 }
457
458 return 0;
459 }
460
at91_gpio_open(struct inode * inode,struct file * file)461 static int at91_gpio_open(struct inode *inode, struct file *file)
462 {
463 return single_open(file, at91_gpio_show, NULL);
464 }
465
466 static const struct file_operations at91_gpio_operations = {
467 .open = at91_gpio_open,
468 .read = seq_read,
469 .llseek = seq_lseek,
470 .release = single_release,
471 };
472
at91_gpio_debugfs_init(void)473 static int __init at91_gpio_debugfs_init(void)
474 {
475 /* /sys/kernel/debug/at91_gpio */
476 (void) debugfs_create_file("at91_gpio", S_IFREG | S_IRUGO, NULL, NULL, &at91_gpio_operations);
477 return 0;
478 }
479 postcore_initcall(at91_gpio_debugfs_init);
480
481 #endif
482
483 /*--------------------------------------------------------------------------*/
484
485 /*
486 * This lock class tells lockdep that GPIO irqs are in a different
487 * category than their parents, so it won't report false recursion.
488 */
489 static struct lock_class_key gpio_lock_class;
490
491 /*
492 * Called from the processor-specific init to enable GPIO interrupt support.
493 */
at91_gpio_irq_setup(void)494 void __init at91_gpio_irq_setup(void)
495 {
496 unsigned pioc, pin;
497 struct at91_gpio_chip *this, *prev;
498
499 for (pioc = 0, pin = PIN_BASE, this = gpio_chip, prev = NULL;
500 pioc++ < gpio_banks;
501 prev = this, this++) {
502 unsigned id = this->bank->id;
503 unsigned i;
504
505 __raw_writel(~0, this->regbase + PIO_IDR);
506
507 for (i = 0, pin = this->chip.base; i < 32; i++, pin++) {
508 irq_set_lockdep_class(pin, &gpio_lock_class);
509
510 /*
511 * Can use the "simple" and not "edge" handler since it's
512 * shorter, and the AIC handles interrupts sanely.
513 */
514 irq_set_chip_and_handler(pin, &gpio_irqchip,
515 handle_simple_irq);
516 set_irq_flags(pin, IRQF_VALID);
517 }
518
519 /* The toplevel handler handles one bank of GPIOs, except
520 * AT91SAM9263_ID_PIOCDE handles three... PIOC is first in
521 * the list, so we only set up that handler.
522 */
523 if (prev && prev->next == this)
524 continue;
525
526 irq_set_chip_data(id, this);
527 irq_set_chained_handler(id, gpio_irq_handler);
528 }
529 pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, gpio_banks);
530 }
531
532 /* gpiolib support */
at91_gpiolib_direction_input(struct gpio_chip * chip,unsigned offset)533 static int at91_gpiolib_direction_input(struct gpio_chip *chip,
534 unsigned offset)
535 {
536 struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
537 void __iomem *pio = at91_gpio->regbase;
538 unsigned mask = 1 << offset;
539
540 __raw_writel(mask, pio + PIO_ODR);
541 return 0;
542 }
543
at91_gpiolib_direction_output(struct gpio_chip * chip,unsigned offset,int val)544 static int at91_gpiolib_direction_output(struct gpio_chip *chip,
545 unsigned offset, int val)
546 {
547 struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
548 void __iomem *pio = at91_gpio->regbase;
549 unsigned mask = 1 << offset;
550
551 __raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR));
552 __raw_writel(mask, pio + PIO_OER);
553 return 0;
554 }
555
at91_gpiolib_get(struct gpio_chip * chip,unsigned offset)556 static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset)
557 {
558 struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
559 void __iomem *pio = at91_gpio->regbase;
560 unsigned mask = 1 << offset;
561 u32 pdsr;
562
563 pdsr = __raw_readl(pio + PIO_PDSR);
564 return (pdsr & mask) != 0;
565 }
566
at91_gpiolib_set(struct gpio_chip * chip,unsigned offset,int val)567 static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val)
568 {
569 struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
570 void __iomem *pio = at91_gpio->regbase;
571 unsigned mask = 1 << offset;
572
573 __raw_writel(mask, pio + (val ? PIO_SODR : PIO_CODR));
574 }
575
at91_gpiolib_dbg_show(struct seq_file * s,struct gpio_chip * chip)576 static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
577 {
578 int i;
579
580 for (i = 0; i < chip->ngpio; i++) {
581 unsigned pin = chip->base + i;
582 void __iomem *pio = pin_to_controller(pin);
583 unsigned mask = pin_to_mask(pin);
584 const char *gpio_label;
585
586 gpio_label = gpiochip_is_requested(chip, i);
587 if (gpio_label) {
588 seq_printf(s, "[%s] GPIO%s%d: ",
589 gpio_label, chip->label, i);
590 if (__raw_readl(pio + PIO_PSR) & mask)
591 seq_printf(s, "[gpio] %s\n",
592 at91_get_gpio_value(pin) ?
593 "set" : "clear");
594 else
595 seq_printf(s, "[periph %s]\n",
596 __raw_readl(pio + PIO_ABSR) &
597 mask ? "B" : "A");
598 }
599 }
600 }
601
602 /*
603 * Called from the processor-specific init to enable GPIO pin support.
604 */
at91_gpio_init(struct at91_gpio_bank * data,int nr_banks)605 void __init at91_gpio_init(struct at91_gpio_bank *data, int nr_banks)
606 {
607 unsigned i;
608 struct at91_gpio_chip *at91_gpio, *last = NULL;
609
610 BUG_ON(nr_banks > MAX_GPIO_BANKS);
611
612 gpio_banks = nr_banks;
613
614 for (i = 0; i < nr_banks; i++) {
615 at91_gpio = &gpio_chip[i];
616
617 at91_gpio->bank = &data[i];
618 at91_gpio->chip.base = PIN_BASE + i * 32;
619 at91_gpio->regbase = at91_gpio->bank->offset +
620 (void __iomem *)AT91_VA_BASE_SYS;
621
622 /* enable PIO controller's clock */
623 clk_enable(at91_gpio->bank->clock);
624
625 /* AT91SAM9263_ID_PIOCDE groups PIOC, PIOD, PIOE */
626 if (last && last->bank->id == at91_gpio->bank->id)
627 last->next = at91_gpio;
628 last = at91_gpio;
629
630 gpiochip_add(&at91_gpio->chip);
631 }
632 }
633