xref: /openbmc/linux/arch/arm/plat-orion/gpio.c (revision a8da474e) 
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(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 }
630