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1 /*
2 * arch/arm/plat-orion/gpio.c
3 *
4 * Marvell Orion SoC GPIO handling.
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10
11 #define DEBUG
12
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/module.h>
18 #include <linux/spinlock.h>
19 #include <linux/bitops.h>
20 #include <linux/io.h>
21 #include <linux/gpio.h>
22 #include <linux/leds.h>
23 #include <linux/of.h>
24 #include <linux/of_irq.h>
25 #include <linux/of_address.h>
26 #include <plat/orion-gpio.h>
27
28 /*
29 * GPIO unit register offsets.
30 */
31 #define GPIO_OUT_OFF 0x0000
32 #define GPIO_IO_CONF_OFF 0x0004
33 #define GPIO_BLINK_EN_OFF 0x0008
34 #define GPIO_IN_POL_OFF 0x000c
35 #define GPIO_DATA_IN_OFF 0x0010
36 #define GPIO_EDGE_CAUSE_OFF 0x0014
37 #define GPIO_EDGE_MASK_OFF 0x0018
38 #define GPIO_LEVEL_MASK_OFF 0x001c
39
40 struct orion_gpio_chip {
41 struct gpio_chip chip;
42 spinlock_t lock;
43 void __iomem *base;
44 unsigned long valid_input;
45 unsigned long valid_output;
46 int mask_offset;
47 int secondary_irq_base;
48 struct irq_domain *domain;
49 };
50
51 static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
52 {
53 return ochip->base + GPIO_OUT_OFF;
54 }
55
56 static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
57 {
58 return ochip->base + GPIO_IO_CONF_OFF;
59 }
60
61 static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
62 {
63 return ochip->base + GPIO_BLINK_EN_OFF;
64 }
65
66 static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
67 {
68 return ochip->base + GPIO_IN_POL_OFF;
69 }
70
71 static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
72 {
73 return ochip->base + GPIO_DATA_IN_OFF;
74 }
75
76 static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
77 {
78 return ochip->base + GPIO_EDGE_CAUSE_OFF;
79 }
80
81 static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
82 {
83 return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
84 }
85
86 static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
87 {
88 return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
89 }
90
91
92 static struct orion_gpio_chip orion_gpio_chips[2];
93 static int orion_gpio_chip_count;
94
95 static inline void
96 __set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
97 {
98 u32 u;
99
100 u = readl(GPIO_IO_CONF(ochip));
101 if (input)
102 u |= 1 << pin;
103 else
104 u &= ~(1 << pin);
105 writel(u, GPIO_IO_CONF(ochip));
106 }
107
108 static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
109 {
110 u32 u;
111
112 u = readl(GPIO_OUT(ochip));
113 if (high)
114 u |= 1 << pin;
115 else
116 u &= ~(1 << pin);
117 writel(u, GPIO_OUT(ochip));
118 }
119
120 static inline void
121 __set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
122 {
123 u32 u;
124
125 u = readl(GPIO_BLINK_EN(ochip));
126 if (blink)
127 u |= 1 << pin;
128 else
129 u &= ~(1 << pin);
130 writel(u, GPIO_BLINK_EN(ochip));
131 }
132
133 static inline int
134 orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
135 {
136 if (pin >= ochip->chip.ngpio)
137 goto err_out;
138
139 if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
140 goto err_out;
141
142 if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
143 goto err_out;
144
145 return 1;
146
147 err_out:
148 pr_debug("%s: invalid GPIO %d\n", __func__, pin);
149 return false;
150 }
151
152 /*
153 * GPIO primitives.
154 */
155 static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
156 {
157 struct orion_gpio_chip *ochip =
158 container_of(chip, struct orion_gpio_chip, chip);
159
160 if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
161 orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
162 return 0;
163
164 return -EINVAL;
165 }
166
167 static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
168 {
169 struct orion_gpio_chip *ochip =
170 container_of(chip, struct orion_gpio_chip, chip);
171 unsigned long flags;
172
173 if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
174 return -EINVAL;
175
176 spin_lock_irqsave(&ochip->lock, flags);
177 __set_direction(ochip, pin, 1);
178 spin_unlock_irqrestore(&ochip->lock, flags);
179
180 return 0;
181 }
182
183 static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
184 {
185 struct orion_gpio_chip *ochip =
186 container_of(chip, struct orion_gpio_chip, chip);
187 int val;
188
189 if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
190 val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
191 } else {
192 val = readl(GPIO_OUT(ochip));
193 }
194
195 return (val >> pin) & 1;
196 }
197
198 static int
199 orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
200 {
201 struct orion_gpio_chip *ochip =
202 container_of(chip, struct orion_gpio_chip, chip);
203 unsigned long flags;
204
205 if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
206 return -EINVAL;
207
208 spin_lock_irqsave(&ochip->lock, flags);
209 __set_blinking(ochip, pin, 0);
210 __set_level(ochip, pin, value);
211 __set_direction(ochip, pin, 0);
212 spin_unlock_irqrestore(&ochip->lock, flags);
213
214 return 0;
215 }
216
217 static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
218 {
219 struct orion_gpio_chip *ochip =
220 container_of(chip, struct orion_gpio_chip, chip);
221 unsigned long flags;
222
223 spin_lock_irqsave(&ochip->lock, flags);
224 __set_level(ochip, pin, value);
225 spin_unlock_irqrestore(&ochip->lock, flags);
226 }
227
228 static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
229 {
230 struct orion_gpio_chip *ochip =
231 container_of(chip, struct orion_gpio_chip, chip);
232
233 return irq_create_mapping(ochip->domain,
234 ochip->secondary_irq_base + pin);
235 }
236
237 /*
238 * Orion-specific GPIO API extensions.
239 */
240 static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
241 {
242 int i;
243
244 for (i = 0; i < orion_gpio_chip_count; i++) {
245 struct orion_gpio_chip *ochip = orion_gpio_chips + i;
246 struct gpio_chip *chip = &ochip->chip;
247
248 if (pin >= chip->base && pin < chip->base + chip->ngpio)
249 return ochip;
250 }
251
252 return NULL;
253 }
254
255 void __init orion_gpio_set_unused(unsigned pin)
256 {
257 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
258
259 if (ochip == NULL)
260 return;
261
262 pin -= ochip->chip.base;
263
264 /* Configure as output, drive low. */
265 __set_level(ochip, pin, 0);
266 __set_direction(ochip, pin, 0);
267 }
268
269 void __init orion_gpio_set_valid(unsigned pin, int mode)
270 {
271 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
272
273 if (ochip == NULL)
274 return;
275
276 pin -= ochip->chip.base;
277
278 if (mode == 1)
279 mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
280
281 if (mode & GPIO_INPUT_OK)
282 __set_bit(pin, &ochip->valid_input);
283 else
284 __clear_bit(pin, &ochip->valid_input);
285
286 if (mode & GPIO_OUTPUT_OK)
287 __set_bit(pin, &ochip->valid_output);
288 else
289 __clear_bit(pin, &ochip->valid_output);
290 }
291
292 void orion_gpio_set_blink(unsigned pin, int blink)
293 {
294 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
295 unsigned long flags;
296
297 if (ochip == NULL)
298 return;
299
300 spin_lock_irqsave(&ochip->lock, flags);
301 __set_level(ochip, pin & 31, 0);
302 __set_blinking(ochip, pin & 31, blink);
303 spin_unlock_irqrestore(&ochip->lock, flags);
304 }
305 EXPORT_SYMBOL(orion_gpio_set_blink);
306
307 #define ORION_BLINK_HALF_PERIOD 100 /* ms */
308
309 int orion_gpio_led_blink_set(struct gpio_desc *desc, int state,
310 unsigned long *delay_on, unsigned long *delay_off)
311 {
312 unsigned gpio = desc_to_gpio(desc);
313
314 if (delay_on && delay_off && !*delay_on && !*delay_off)
315 *delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
316
317 switch (state) {
318 case GPIO_LED_NO_BLINK_LOW:
319 case GPIO_LED_NO_BLINK_HIGH:
320 orion_gpio_set_blink(gpio, 0);
321 gpio_set_value(gpio, state);
322 break;
323 case GPIO_LED_BLINK:
324 orion_gpio_set_blink(gpio, 1);
325 }
326 return 0;
327 }
328 EXPORT_SYMBOL_GPL(orion_gpio_led_blink_set);
329
330
331 /*****************************************************************************
332 * Orion GPIO IRQ
333 *
334 * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
335 * value of the line or the opposite value.
336 *
337 * Level IRQ handlers: DATA_IN is used directly as cause register.
338 * Interrupt are masked by LEVEL_MASK registers.
339 * Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
340 * Interrupt are masked by EDGE_MASK registers.
341 * Both-edge handlers: Similar to regular Edge handlers, but also swaps
342 * the polarity to catch the next line transaction.
343 * This is a race condition that might not perfectly
344 * work on some use cases.
345 *
346 * Every eight GPIO lines are grouped (OR'ed) before going up to main
347 * cause register.
348 *
349 * EDGE cause mask
350 * data-in /--------| |-----| |----\
351 * -----| |----- ---- to main cause reg
352 * X \----------------| |----/
353 * polarity LEVEL mask
354 *
355 ****************************************************************************/
356
357 static int gpio_irq_set_type(struct irq_data *d, u32 type)
358 {
359 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
360 struct irq_chip_type *ct = irq_data_get_chip_type(d);
361 struct orion_gpio_chip *ochip = gc->private;
362 int pin;
363 u32 u;
364
365 pin = d->hwirq - ochip->secondary_irq_base;
366
367 u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
368 if (!u) {
369 return -EINVAL;
370 }
371
372 type &= IRQ_TYPE_SENSE_MASK;
373 if (type == IRQ_TYPE_NONE)
374 return -EINVAL;
375
376 /* Check if we need to change chip and handler */
377 if (!(ct->type & type))
378 if (irq_setup_alt_chip(d, type))
379 return -EINVAL;
380
381 /*
382 * Configure interrupt polarity.
383 */
384 if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
385 u = readl(GPIO_IN_POL(ochip));
386 u &= ~(1 << pin);
387 writel(u, GPIO_IN_POL(ochip));
388 } else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
389 u = readl(GPIO_IN_POL(ochip));
390 u |= 1 << pin;
391 writel(u, GPIO_IN_POL(ochip));
392 } else if (type == IRQ_TYPE_EDGE_BOTH) {
393 u32 v;
394
395 v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
396
397 /*
398 * set initial polarity based on current input level
399 */
400 u = readl(GPIO_IN_POL(ochip));
401 if (v & (1 << pin))
402 u |= 1 << pin; /* falling */
403 else
404 u &= ~(1 << pin); /* rising */
405 writel(u, GPIO_IN_POL(ochip));
406 }
407 return 0;
408 }
409
410 static void gpio_irq_handler(unsigned __irq, struct irq_desc *desc)
411 {
412 struct orion_gpio_chip *ochip = irq_desc_get_handler_data(desc);
413 u32 cause, type;
414 int i;
415
416 if (ochip == NULL)
417 return;
418
419 cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
420 cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
421
422 for (i = 0; i < ochip->chip.ngpio; i++) {
423 int irq;
424
425 irq = ochip->secondary_irq_base + i;
426
427 if (!(cause & (1 << i)))
428 continue;
429
430 type = irq_get_trigger_type(irq);
431 if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
432 /* Swap polarity (race with GPIO line) */
433 u32 polarity;
434
435 polarity = readl(GPIO_IN_POL(ochip));
436 polarity ^= 1 << i;
437 writel(polarity, GPIO_IN_POL(ochip));
438 }
439 generic_handle_irq(irq);
440 }
441 }
442
443 #ifdef CONFIG_DEBUG_FS
444 #include <linux/seq_file.h>
445
446 static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
447 {
448 struct orion_gpio_chip *ochip =
449 container_of(chip, struct orion_gpio_chip, chip);
450 u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
451 int i;
452
453 out = readl_relaxed(GPIO_OUT(ochip));
454 io_conf = readl_relaxed(GPIO_IO_CONF(ochip));
455 blink = readl_relaxed(GPIO_BLINK_EN(ochip));
456 in_pol = readl_relaxed(GPIO_IN_POL(ochip));
457 data_in = readl_relaxed(GPIO_DATA_IN(ochip));
458 cause = readl_relaxed(GPIO_EDGE_CAUSE(ochip));
459 edg_msk = readl_relaxed(GPIO_EDGE_MASK(ochip));
460 lvl_msk = readl_relaxed(GPIO_LEVEL_MASK(ochip));
461
462 for (i = 0; i < chip->ngpio; i++) {
463 const char *label;
464 u32 msk;
465 bool is_out;
466
467 label = gpiochip_is_requested(chip, i);
468 if (!label)
469 continue;
470
471 msk = 1 << i;
472 is_out = !(io_conf & msk);
473
474 seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
475
476 if (is_out) {
477 seq_printf(s, " out %s %s\n",
478 out & msk ? "hi" : "lo",
479 blink & msk ? "(blink )" : "");
480 continue;
481 }
482
483 seq_printf(s, " in %s (act %s) - IRQ",
484 (data_in ^ in_pol) & msk ? "hi" : "lo",
485 in_pol & msk ? "lo" : "hi");
486 if (!((edg_msk | lvl_msk) & msk)) {
487 seq_printf(s, " disabled\n");
488 continue;
489 }
490 if (edg_msk & msk)
491 seq_printf(s, " edge ");
492 if (lvl_msk & msk)
493 seq_printf(s, " level");
494 seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear ");
495 }
496 }
497 #else
498 #define orion_gpio_dbg_show NULL
499 #endif
500
501 static void orion_gpio_unmask_irq(struct irq_data *d)
502 {
503 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
504 struct irq_chip_type *ct = irq_data_get_chip_type(d);
505 u32 reg_val;
506 u32 mask = d->mask;
507
508 irq_gc_lock(gc);
509 reg_val = irq_reg_readl(gc, ct->regs.mask);
510 reg_val |= mask;
511 irq_reg_writel(gc, reg_val, ct->regs.mask);
512 irq_gc_unlock(gc);
513 }
514
515 static void orion_gpio_mask_irq(struct irq_data *d)
516 {
517 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
518 struct irq_chip_type *ct = irq_data_get_chip_type(d);
519 u32 mask = d->mask;
520 u32 reg_val;
521
522 irq_gc_lock(gc);
523 reg_val = irq_reg_readl(gc, ct->regs.mask);
524 reg_val &= ~mask;
525 irq_reg_writel(gc, reg_val, ct->regs.mask);
526 irq_gc_unlock(gc);
527 }
528
529 void __init orion_gpio_init(struct device_node *np,
530 int gpio_base, int ngpio,
531 void __iomem *base, int mask_offset,
532 int secondary_irq_base,
533 int irqs[4])
534 {
535 struct orion_gpio_chip *ochip;
536 struct irq_chip_generic *gc;
537 struct irq_chip_type *ct;
538 char gc_label[16];
539 int i;
540
541 if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
542 return;
543
544 snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
545 orion_gpio_chip_count);
546
547 ochip = orion_gpio_chips + orion_gpio_chip_count;
548 ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
549 ochip->chip.request = orion_gpio_request;
550 ochip->chip.direction_input = orion_gpio_direction_input;
551 ochip->chip.get = orion_gpio_get;
552 ochip->chip.direction_output = orion_gpio_direction_output;
553 ochip->chip.set = orion_gpio_set;
554 ochip->chip.to_irq = orion_gpio_to_irq;
555 ochip->chip.base = gpio_base;
556 ochip->chip.ngpio = ngpio;
557 ochip->chip.can_sleep = 0;
558 #ifdef CONFIG_OF
559 ochip->chip.of_node = np;
560 #endif
561 ochip->chip.dbg_show = orion_gpio_dbg_show;
562
563 spin_lock_init(&ochip->lock);
564 ochip->base = (void __iomem *)base;
565 ochip->valid_input = 0;
566 ochip->valid_output = 0;
567 ochip->mask_offset = mask_offset;
568 ochip->secondary_irq_base = secondary_irq_base;
569
570 gpiochip_add(&ochip->chip);
571
572 /*
573 * Mask and clear GPIO interrupts.
574 */
575 writel(0, GPIO_EDGE_CAUSE(ochip));
576 writel(0, GPIO_EDGE_MASK(ochip));
577 writel(0, GPIO_LEVEL_MASK(ochip));
578
579 /* Setup the interrupt handlers. Each chip can have up to 4
580 * interrupt handlers, with each handler dealing with 8 GPIO
581 * pins. */
582
583 for (i = 0; i < 4; i++) {
584 if (irqs[i]) {
585 irq_set_chained_handler_and_data(irqs[i],
586 gpio_irq_handler,
587 ochip);
588 }
589 }
590
591 gc = irq_alloc_generic_chip("orion_gpio_irq", 2,
592 secondary_irq_base,
593 ochip->base, handle_level_irq);
594 gc->private = ochip;
595 ct = gc->chip_types;
596 ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
597 ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
598 ct->chip.irq_mask = orion_gpio_mask_irq;
599 ct->chip.irq_unmask = orion_gpio_unmask_irq;
600 ct->chip.irq_set_type = gpio_irq_set_type;
601 ct->chip.name = ochip->chip.label;
602
603 ct++;
604 ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
605 ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
606 ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
607 ct->chip.irq_ack = irq_gc_ack_clr_bit;
608 ct->chip.irq_mask = orion_gpio_mask_irq;
609 ct->chip.irq_unmask = orion_gpio_unmask_irq;
610 ct->chip.irq_set_type = gpio_irq_set_type;
611 ct->handler = handle_edge_irq;
612 ct->chip.name = ochip->chip.label;
613
614 irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
615 IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
616
617 /* Setup irq domain on top of the generic chip. */
618 ochip->domain = irq_domain_add_legacy(np,
619 ochip->chip.ngpio,
620 ochip->secondary_irq_base,
621 ochip->secondary_irq_base,
622 &irq_domain_simple_ops,
623 ochip);
624 if (!ochip->domain)
625 panic("%s: couldn't allocate irq domain (DT).\n",
626 ochip->chip.label);
627
628 orion_gpio_chip_count++;
629 }