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[mirror_ubuntu-zesty-kernel.git] / arch / arm / plat-orion / gpio.c
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 = gpiochip_get_data(chip);
158
159 if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
160 orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
161 return 0;
162
163 return -EINVAL;
164 }
165
166 static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
167 {
168 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
169 unsigned long flags;
170
171 if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
172 return -EINVAL;
173
174 spin_lock_irqsave(&ochip->lock, flags);
175 __set_direction(ochip, pin, 1);
176 spin_unlock_irqrestore(&ochip->lock, flags);
177
178 return 0;
179 }
180
181 static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
182 {
183 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
184 int val;
185
186 if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
187 val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
188 } else {
189 val = readl(GPIO_OUT(ochip));
190 }
191
192 return (val >> pin) & 1;
193 }
194
195 static int
196 orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
197 {
198 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
199 unsigned long flags;
200
201 if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
202 return -EINVAL;
203
204 spin_lock_irqsave(&ochip->lock, flags);
205 __set_blinking(ochip, pin, 0);
206 __set_level(ochip, pin, value);
207 __set_direction(ochip, pin, 0);
208 spin_unlock_irqrestore(&ochip->lock, flags);
209
210 return 0;
211 }
212
213 static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
214 {
215 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
216 unsigned long flags;
217
218 spin_lock_irqsave(&ochip->lock, flags);
219 __set_level(ochip, pin, value);
220 spin_unlock_irqrestore(&ochip->lock, flags);
221 }
222
223 static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
224 {
225 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
226
227 return irq_create_mapping(ochip->domain,
228 ochip->secondary_irq_base + pin);
229 }
230
231 /*
232 * Orion-specific GPIO API extensions.
233 */
234 static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
235 {
236 int i;
237
238 for (i = 0; i < orion_gpio_chip_count; i++) {
239 struct orion_gpio_chip *ochip = orion_gpio_chips + i;
240 struct gpio_chip *chip = &ochip->chip;
241
242 if (pin >= chip->base && pin < chip->base + chip->ngpio)
243 return ochip;
244 }
245
246 return NULL;
247 }
248
249 void __init orion_gpio_set_unused(unsigned pin)
250 {
251 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
252
253 if (ochip == NULL)
254 return;
255
256 pin -= ochip->chip.base;
257
258 /* Configure as output, drive low. */
259 __set_level(ochip, pin, 0);
260 __set_direction(ochip, pin, 0);
261 }
262
263 void __init orion_gpio_set_valid(unsigned pin, int mode)
264 {
265 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
266
267 if (ochip == NULL)
268 return;
269
270 pin -= ochip->chip.base;
271
272 if (mode == 1)
273 mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
274
275 if (mode & GPIO_INPUT_OK)
276 __set_bit(pin, &ochip->valid_input);
277 else
278 __clear_bit(pin, &ochip->valid_input);
279
280 if (mode & GPIO_OUTPUT_OK)
281 __set_bit(pin, &ochip->valid_output);
282 else
283 __clear_bit(pin, &ochip->valid_output);
284 }
285
286 void orion_gpio_set_blink(unsigned pin, int blink)
287 {
288 struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
289 unsigned long flags;
290
291 if (ochip == NULL)
292 return;
293
294 spin_lock_irqsave(&ochip->lock, flags);
295 __set_level(ochip, pin & 31, 0);
296 __set_blinking(ochip, pin & 31, blink);
297 spin_unlock_irqrestore(&ochip->lock, flags);
298 }
299 EXPORT_SYMBOL(orion_gpio_set_blink);
300
301 #define ORION_BLINK_HALF_PERIOD 100 /* ms */
302
303 int orion_gpio_led_blink_set(struct gpio_desc *desc, int state,
304 unsigned long *delay_on, unsigned long *delay_off)
305 {
306 unsigned gpio = desc_to_gpio(desc);
307
308 if (delay_on && delay_off && !*delay_on && !*delay_off)
309 *delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
310
311 switch (state) {
312 case GPIO_LED_NO_BLINK_LOW:
313 case GPIO_LED_NO_BLINK_HIGH:
314 orion_gpio_set_blink(gpio, 0);
315 gpio_set_value(gpio, state);
316 break;
317 case GPIO_LED_BLINK:
318 orion_gpio_set_blink(gpio, 1);
319 }
320 return 0;
321 }
322 EXPORT_SYMBOL_GPL(orion_gpio_led_blink_set);
323
324
325 /*****************************************************************************
326 * Orion GPIO IRQ
327 *
328 * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
329 * value of the line or the opposite value.
330 *
331 * Level IRQ handlers: DATA_IN is used directly as cause register.
332 * Interrupt are masked by LEVEL_MASK registers.
333 * Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
334 * Interrupt are masked by EDGE_MASK registers.
335 * Both-edge handlers: Similar to regular Edge handlers, but also swaps
336 * the polarity to catch the next line transaction.
337 * This is a race condition that might not perfectly
338 * work on some use cases.
339 *
340 * Every eight GPIO lines are grouped (OR'ed) before going up to main
341 * cause register.
342 *
343 * EDGE cause mask
344 * data-in /--------| |-----| |----\
345 * -----| |----- ---- to main cause reg
346 * X \----------------| |----/
347 * polarity LEVEL mask
348 *
349 ****************************************************************************/
350
351 static int gpio_irq_set_type(struct irq_data *d, u32 type)
352 {
353 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
354 struct irq_chip_type *ct = irq_data_get_chip_type(d);
355 struct orion_gpio_chip *ochip = gc->private;
356 int pin;
357 u32 u;
358
359 pin = d->hwirq - ochip->secondary_irq_base;
360
361 u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
362 if (!u) {
363 return -EINVAL;
364 }
365
366 type &= IRQ_TYPE_SENSE_MASK;
367 if (type == IRQ_TYPE_NONE)
368 return -EINVAL;
369
370 /* Check if we need to change chip and handler */
371 if (!(ct->type & type))
372 if (irq_setup_alt_chip(d, type))
373 return -EINVAL;
374
375 /*
376 * Configure interrupt polarity.
377 */
378 if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
379 u = readl(GPIO_IN_POL(ochip));
380 u &= ~(1 << pin);
381 writel(u, GPIO_IN_POL(ochip));
382 } else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
383 u = readl(GPIO_IN_POL(ochip));
384 u |= 1 << pin;
385 writel(u, GPIO_IN_POL(ochip));
386 } else if (type == IRQ_TYPE_EDGE_BOTH) {
387 u32 v;
388
389 v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
390
391 /*
392 * set initial polarity based on current input level
393 */
394 u = readl(GPIO_IN_POL(ochip));
395 if (v & (1 << pin))
396 u |= 1 << pin; /* falling */
397 else
398 u &= ~(1 << pin); /* rising */
399 writel(u, GPIO_IN_POL(ochip));
400 }
401 return 0;
402 }
403
404 static void gpio_irq_handler(struct irq_desc *desc)
405 {
406 struct orion_gpio_chip *ochip = irq_desc_get_handler_data(desc);
407 u32 cause, type;
408 int i;
409
410 if (ochip == NULL)
411 return;
412
413 cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
414 cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
415
416 for (i = 0; i < ochip->chip.ngpio; i++) {
417 int irq;
418
419 irq = ochip->secondary_irq_base + i;
420
421 if (!(cause & (1 << i)))
422 continue;
423
424 type = irq_get_trigger_type(irq);
425 if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
426 /* Swap polarity (race with GPIO line) */
427 u32 polarity;
428
429 polarity = readl(GPIO_IN_POL(ochip));
430 polarity ^= 1 << i;
431 writel(polarity, GPIO_IN_POL(ochip));
432 }
433 generic_handle_irq(irq);
434 }
435 }
436
437 #ifdef CONFIG_DEBUG_FS
438 #include <linux/seq_file.h>
439
440 static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
441 {
442
443 struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
444 u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
445 int i;
446
447 out = readl_relaxed(GPIO_OUT(ochip));
448 io_conf = readl_relaxed(GPIO_IO_CONF(ochip));
449 blink = readl_relaxed(GPIO_BLINK_EN(ochip));
450 in_pol = readl_relaxed(GPIO_IN_POL(ochip));
451 data_in = readl_relaxed(GPIO_DATA_IN(ochip));
452 cause = readl_relaxed(GPIO_EDGE_CAUSE(ochip));
453 edg_msk = readl_relaxed(GPIO_EDGE_MASK(ochip));
454 lvl_msk = readl_relaxed(GPIO_LEVEL_MASK(ochip));
455
456 for (i = 0; i < chip->ngpio; i++) {
457 const char *label;
458 u32 msk;
459 bool is_out;
460
461 label = gpiochip_is_requested(chip, i);
462 if (!label)
463 continue;
464
465 msk = 1 << i;
466 is_out = !(io_conf & msk);
467
468 seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
469
470 if (is_out) {
471 seq_printf(s, " out %s %s\n",
472 out & msk ? "hi" : "lo",
473 blink & msk ? "(blink )" : "");
474 continue;
475 }
476
477 seq_printf(s, " in %s (act %s) - IRQ",
478 (data_in ^ in_pol) & msk ? "hi" : "lo",
479 in_pol & msk ? "lo" : "hi");
480 if (!((edg_msk | lvl_msk) & msk)) {
481 seq_printf(s, " disabled\n");
482 continue;
483 }
484 if (edg_msk & msk)
485 seq_printf(s, " edge ");
486 if (lvl_msk & msk)
487 seq_printf(s, " level");
488 seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear ");
489 }
490 }
491 #else
492 #define orion_gpio_dbg_show NULL
493 #endif
494
495 static void orion_gpio_unmask_irq(struct irq_data *d)
496 {
497 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
498 struct irq_chip_type *ct = irq_data_get_chip_type(d);
499 u32 reg_val;
500 u32 mask = d->mask;
501
502 irq_gc_lock(gc);
503 reg_val = irq_reg_readl(gc, ct->regs.mask);
504 reg_val |= mask;
505 irq_reg_writel(gc, reg_val, ct->regs.mask);
506 irq_gc_unlock(gc);
507 }
508
509 static void orion_gpio_mask_irq(struct irq_data *d)
510 {
511 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
512 struct irq_chip_type *ct = irq_data_get_chip_type(d);
513 u32 mask = d->mask;
514 u32 reg_val;
515
516 irq_gc_lock(gc);
517 reg_val = irq_reg_readl(gc, ct->regs.mask);
518 reg_val &= ~mask;
519 irq_reg_writel(gc, reg_val, ct->regs.mask);
520 irq_gc_unlock(gc);
521 }
522
523 void __init orion_gpio_init(struct device_node *np,
524 int gpio_base, int ngpio,
525 void __iomem *base, int mask_offset,
526 int secondary_irq_base,
527 int irqs[4])
528 {
529 struct orion_gpio_chip *ochip;
530 struct irq_chip_generic *gc;
531 struct irq_chip_type *ct;
532 char gc_label[16];
533 int i;
534
535 if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
536 return;
537
538 snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
539 orion_gpio_chip_count);
540
541 ochip = orion_gpio_chips + orion_gpio_chip_count;
542 ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
543 ochip->chip.request = orion_gpio_request;
544 ochip->chip.direction_input = orion_gpio_direction_input;
545 ochip->chip.get = orion_gpio_get;
546 ochip->chip.direction_output = orion_gpio_direction_output;
547 ochip->chip.set = orion_gpio_set;
548 ochip->chip.to_irq = orion_gpio_to_irq;
549 ochip->chip.base = gpio_base;
550 ochip->chip.ngpio = ngpio;
551 ochip->chip.can_sleep = 0;
552 #ifdef CONFIG_OF
553 ochip->chip.of_node = np;
554 #endif
555 ochip->chip.dbg_show = orion_gpio_dbg_show;
556
557 spin_lock_init(&ochip->lock);
558 ochip->base = (void __iomem *)base;
559 ochip->valid_input = 0;
560 ochip->valid_output = 0;
561 ochip->mask_offset = mask_offset;
562 ochip->secondary_irq_base = secondary_irq_base;
563
564 gpiochip_add_data(&ochip->chip, ochip);
565
566 /*
567 * Mask and clear GPIO interrupts.
568 */
569 writel(0, GPIO_EDGE_CAUSE(ochip));
570 writel(0, GPIO_EDGE_MASK(ochip));
571 writel(0, GPIO_LEVEL_MASK(ochip));
572
573 /* Setup the interrupt handlers. Each chip can have up to 4
574 * interrupt handlers, with each handler dealing with 8 GPIO
575 * pins. */
576
577 for (i = 0; i < 4; i++) {
578 if (irqs[i]) {
579 irq_set_chained_handler_and_data(irqs[i],
580 gpio_irq_handler,
581 ochip);
582 }
583 }
584
585 gc = irq_alloc_generic_chip("orion_gpio_irq", 2,
586 secondary_irq_base,
587 ochip->base, handle_level_irq);
588 gc->private = ochip;
589 ct = gc->chip_types;
590 ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
591 ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
592 ct->chip.irq_mask = orion_gpio_mask_irq;
593 ct->chip.irq_unmask = orion_gpio_unmask_irq;
594 ct->chip.irq_set_type = gpio_irq_set_type;
595 ct->chip.name = ochip->chip.label;
596
597 ct++;
598 ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
599 ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
600 ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
601 ct->chip.irq_ack = irq_gc_ack_clr_bit;
602 ct->chip.irq_mask = orion_gpio_mask_irq;
603 ct->chip.irq_unmask = orion_gpio_unmask_irq;
604 ct->chip.irq_set_type = gpio_irq_set_type;
605 ct->handler = handle_edge_irq;
606 ct->chip.name = ochip->chip.label;
607
608 irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
609 IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
610
611 /* Setup irq domain on top of the generic chip. */
612 ochip->domain = irq_domain_add_legacy(np,
613 ochip->chip.ngpio,
614 ochip->secondary_irq_base,
615 ochip->secondary_irq_base,
616 &irq_domain_simple_ops,
617 ochip);
618 if (!ochip->domain)
619 panic("%s: couldn't allocate irq domain (DT).\n",
620 ochip->chip.label);
621
622 orion_gpio_chip_count++;
623 }