xref: /openbmc/linux/arch/arm/plat-orion/gpio.c (revision 78700c0a) 
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 }
624