xref: /openbmc/linux/arch/arm/plat-orion/gpio.c (revision e2ad626f) 
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/driver.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/leds.h>
24 #include <linux/of.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_address.h>
27 #include <plat/orion-gpio.h>
28 
29 /*
30  * GPIO unit register offsets.
31  */
32 #define GPIO_OUT_OFF		0x0000
33 #define GPIO_IO_CONF_OFF	0x0004
34 #define GPIO_BLINK_EN_OFF	0x0008
35 #define GPIO_IN_POL_OFF		0x000c
36 #define GPIO_DATA_IN_OFF	0x0010
37 #define GPIO_EDGE_CAUSE_OFF	0x0014
38 #define GPIO_EDGE_MASK_OFF	0x0018
39 #define GPIO_LEVEL_MASK_OFF	0x001c
40 
41 struct orion_gpio_chip {
42 	struct gpio_chip	chip;
43 	spinlock_t		lock;
44 	void __iomem		*base;
45 	unsigned long		valid_input;
46 	unsigned long		valid_output;
47 	int			mask_offset;
48 	int			secondary_irq_base;
49 	struct irq_domain       *domain;
50 };
51 
52 static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
53 {
54 	return ochip->base + GPIO_OUT_OFF;
55 }
56 
57 static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
58 {
59 	return ochip->base + GPIO_IO_CONF_OFF;
60 }
61 
62 static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
63 {
64 	return ochip->base + GPIO_BLINK_EN_OFF;
65 }
66 
67 static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
68 {
69 	return ochip->base + GPIO_IN_POL_OFF;
70 }
71 
72 static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
73 {
74 	return ochip->base + GPIO_DATA_IN_OFF;
75 }
76 
77 static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
78 {
79 	return ochip->base + GPIO_EDGE_CAUSE_OFF;
80 }
81 
82 static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
83 {
84 	return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
85 }
86 
87 static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
88 {
89 	return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
90 }
91 
92 
93 static struct orion_gpio_chip orion_gpio_chips[2];
94 static int orion_gpio_chip_count;
95 
96 static inline void
97 __set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
98 {
99 	u32 u;
100 
101 	u = readl(GPIO_IO_CONF(ochip));
102 	if (input)
103 		u |= 1 << pin;
104 	else
105 		u &= ~(1 << pin);
106 	writel(u, GPIO_IO_CONF(ochip));
107 }
108 
109 static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
110 {
111 	u32 u;
112 
113 	u = readl(GPIO_OUT(ochip));
114 	if (high)
115 		u |= 1 << pin;
116 	else
117 		u &= ~(1 << pin);
118 	writel(u, GPIO_OUT(ochip));
119 }
120 
121 static inline void
122 __set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
123 {
124 	u32 u;
125 
126 	u = readl(GPIO_BLINK_EN(ochip));
127 	if (blink)
128 		u |= 1 << pin;
129 	else
130 		u &= ~(1 << pin);
131 	writel(u, GPIO_BLINK_EN(ochip));
132 }
133 
134 static inline int
135 orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
136 {
137 	if (pin >= ochip->chip.ngpio)
138 		goto err_out;
139 
140 	if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
141 		goto err_out;
142 
143 	if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
144 		goto err_out;
145 
146 	return 1;
147 
148 err_out:
149 	pr_debug("%s: invalid GPIO %d\n", __func__, pin);
150 	return false;
151 }
152 
153 /*
154  * GPIO primitives.
155  */
156 static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
157 {
158 	struct orion_gpio_chip *ochip = gpiochip_get_data(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 = gpiochip_get_data(chip);
170 	unsigned long flags;
171 
172 	if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
173 		return -EINVAL;
174 
175 	spin_lock_irqsave(&ochip->lock, flags);
176 	__set_direction(ochip, pin, 1);
177 	spin_unlock_irqrestore(&ochip->lock, flags);
178 
179 	return 0;
180 }
181 
182 static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
183 {
184 	struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
185 	int val;
186 
187 	if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
188 		val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
189 	} else {
190 		val = readl(GPIO_OUT(ochip));
191 	}
192 
193 	return (val >> pin) & 1;
194 }
195 
196 static int
197 orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
198 {
199 	struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
200 	unsigned long flags;
201 
202 	if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
203 		return -EINVAL;
204 
205 	spin_lock_irqsave(&ochip->lock, flags);
206 	__set_blinking(ochip, pin, 0);
207 	__set_level(ochip, pin, value);
208 	__set_direction(ochip, pin, 0);
209 	spin_unlock_irqrestore(&ochip->lock, flags);
210 
211 	return 0;
212 }
213 
214 static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
215 {
216 	struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
217 	unsigned long flags;
218 
219 	spin_lock_irqsave(&ochip->lock, flags);
220 	__set_level(ochip, pin, value);
221 	spin_unlock_irqrestore(&ochip->lock, flags);
222 }
223 
224 static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
225 {
226 	struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
227 
228 	return irq_create_mapping(ochip->domain,
229 				  ochip->secondary_irq_base + pin);
230 }
231 
232 /*
233  * Orion-specific GPIO API extensions.
234  */
235 static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
236 {
237 	int i;
238 
239 	for (i = 0; i < orion_gpio_chip_count; i++) {
240 		struct orion_gpio_chip *ochip = orion_gpio_chips + i;
241 		struct gpio_chip *chip = &ochip->chip;
242 
243 		if (pin >= chip->base && pin < chip->base + chip->ngpio)
244 			return ochip;
245 	}
246 
247 	return NULL;
248 }
249 
250 void __init orion_gpio_set_unused(unsigned pin)
251 {
252 	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
253 
254 	if (ochip == NULL)
255 		return;
256 
257 	pin -= ochip->chip.base;
258 
259 	/* Configure as output, drive low. */
260 	__set_level(ochip, pin, 0);
261 	__set_direction(ochip, pin, 0);
262 }
263 
264 void __init orion_gpio_set_valid(unsigned pin, int mode)
265 {
266 	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
267 
268 	if (ochip == NULL)
269 		return;
270 
271 	pin -= ochip->chip.base;
272 
273 	if (mode == 1)
274 		mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
275 
276 	if (mode & GPIO_INPUT_OK)
277 		__set_bit(pin, &ochip->valid_input);
278 	else
279 		__clear_bit(pin, &ochip->valid_input);
280 
281 	if (mode & GPIO_OUTPUT_OK)
282 		__set_bit(pin, &ochip->valid_output);
283 	else
284 		__clear_bit(pin, &ochip->valid_output);
285 }
286 
287 void orion_gpio_set_blink(unsigned pin, int blink)
288 {
289 	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
290 	unsigned long flags;
291 
292 	if (ochip == NULL)
293 		return;
294 
295 	spin_lock_irqsave(&ochip->lock, flags);
296 	__set_level(ochip, pin & 31, 0);
297 	__set_blinking(ochip, pin & 31, blink);
298 	spin_unlock_irqrestore(&ochip->lock, flags);
299 }
300 EXPORT_SYMBOL(orion_gpio_set_blink);
301 
302 #define ORION_BLINK_HALF_PERIOD 100 /* ms */
303 
304 int orion_gpio_led_blink_set(struct gpio_desc *desc, int state,
305 	unsigned long *delay_on, unsigned long *delay_off)
306 {
307 	unsigned gpio = desc_to_gpio(desc);
308 
309 	if (delay_on && delay_off && !*delay_on && !*delay_off)
310 		*delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
311 
312 	switch (state) {
313 	case GPIO_LED_NO_BLINK_LOW:
314 	case GPIO_LED_NO_BLINK_HIGH:
315 		orion_gpio_set_blink(gpio, 0);
316 		gpiod_set_raw_value(desc, state);
317 		break;
318 	case GPIO_LED_BLINK:
319 		orion_gpio_set_blink(gpio, 1);
320 	}
321 	return 0;
322 }
323 EXPORT_SYMBOL_GPL(orion_gpio_led_blink_set);
324 
325 
326 /*****************************************************************************
327  * Orion GPIO IRQ
328  *
329  * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
330  * value of the line or the opposite value.
331  *
332  * Level IRQ handlers: DATA_IN is used directly as cause register.
333  *                     Interrupt are masked by LEVEL_MASK registers.
334  * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
335  *                     Interrupt are masked by EDGE_MASK registers.
336  * Both-edge handlers: Similar to regular Edge handlers, but also swaps
337  *                     the polarity to catch the next line transaction.
338  *                     This is a race condition that might not perfectly
339  *                     work on some use cases.
340  *
341  * Every eight GPIO lines are grouped (OR'ed) before going up to main
342  * cause register.
343  *
344  *                    EDGE  cause    mask
345  *        data-in   /--------| |-----| |----\
346  *     -----| |-----                         ---- to main cause reg
347  *           X      \----------------| |----/
348  *        polarity    LEVEL          mask
349  *
350  ****************************************************************************/
351 
352 static int gpio_irq_set_type(struct irq_data *d, u32 type)
353 {
354 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
355 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
356 	struct orion_gpio_chip *ochip = gc->private;
357 	int pin;
358 	u32 u;
359 
360 	pin = d->hwirq - ochip->secondary_irq_base;
361 
362 	u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
363 	if (!u) {
364 		return -EINVAL;
365 	}
366 
367 	type &= IRQ_TYPE_SENSE_MASK;
368 	if (type == IRQ_TYPE_NONE)
369 		return -EINVAL;
370 
371 	/* Check if we need to change chip and handler */
372 	if (!(ct->type & type))
373 		if (irq_setup_alt_chip(d, type))
374 			return -EINVAL;
375 
376 	/*
377 	 * Configure interrupt polarity.
378 	 */
379 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
380 		u = readl(GPIO_IN_POL(ochip));
381 		u &= ~(1 << pin);
382 		writel(u, GPIO_IN_POL(ochip));
383 	} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
384 		u = readl(GPIO_IN_POL(ochip));
385 		u |= 1 << pin;
386 		writel(u, GPIO_IN_POL(ochip));
387 	} else if (type == IRQ_TYPE_EDGE_BOTH) {
388 		u32 v;
389 
390 		v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
391 
392 		/*
393 		 * set initial polarity based on current input level
394 		 */
395 		u = readl(GPIO_IN_POL(ochip));
396 		if (v & (1 << pin))
397 			u |= 1 << pin;		/* falling */
398 		else
399 			u &= ~(1 << pin);	/* rising */
400 		writel(u, GPIO_IN_POL(ochip));
401 	}
402 	return 0;
403 }
404 
405 static void gpio_irq_handler(struct irq_desc *desc)
406 {
407 	struct orion_gpio_chip *ochip = irq_desc_get_handler_data(desc);
408 	u32 cause, type;
409 	int i;
410 
411 	if (ochip == NULL)
412 		return;
413 
414 	cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
415 	cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
416 
417 	for (i = 0; i < ochip->chip.ngpio; i++) {
418 		int irq;
419 
420 		irq = ochip->secondary_irq_base + i;
421 
422 		if (!(cause & (1 << i)))
423 			continue;
424 
425 		type = irq_get_trigger_type(irq);
426 		if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
427 			/* Swap polarity (race with GPIO line) */
428 			u32 polarity;
429 
430 			polarity = readl(GPIO_IN_POL(ochip));
431 			polarity ^= 1 << i;
432 			writel(polarity, GPIO_IN_POL(ochip));
433 		}
434 		generic_handle_irq(irq);
435 	}
436 }
437 
438 #ifdef CONFIG_DEBUG_FS
439 #include <linux/seq_file.h>
440 
441 static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
442 {
443 
444 	struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
445 	u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
446 	const char *label;
447 	int i;
448 
449 	out	= readl_relaxed(GPIO_OUT(ochip));
450 	io_conf	= readl_relaxed(GPIO_IO_CONF(ochip));
451 	blink	= readl_relaxed(GPIO_BLINK_EN(ochip));
452 	in_pol	= readl_relaxed(GPIO_IN_POL(ochip));
453 	data_in	= readl_relaxed(GPIO_DATA_IN(ochip));
454 	cause	= readl_relaxed(GPIO_EDGE_CAUSE(ochip));
455 	edg_msk	= readl_relaxed(GPIO_EDGE_MASK(ochip));
456 	lvl_msk	= readl_relaxed(GPIO_LEVEL_MASK(ochip));
457 
458 	for_each_requested_gpio(chip, i, label) {
459 		u32 msk;
460 		bool is_out;
461 
462 		msk = 1 << i;
463 		is_out = !(io_conf & msk);
464 
465 		seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
466 
467 		if (is_out) {
468 			seq_printf(s, " out %s %s\n",
469 				   out & msk ? "hi" : "lo",
470 				   blink & msk ? "(blink )" : "");
471 			continue;
472 		}
473 
474 		seq_printf(s, " in  %s (act %s) - IRQ",
475 			   (data_in ^ in_pol) & msk  ? "hi" : "lo",
476 			   in_pol & msk ? "lo" : "hi");
477 		if (!((edg_msk | lvl_msk) & msk)) {
478 			seq_puts(s, " disabled\n");
479 			continue;
480 		}
481 		if (edg_msk & msk)
482 			seq_puts(s, " edge ");
483 		if (lvl_msk & msk)
484 			seq_puts(s, " level");
485 		seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear  ");
486 	}
487 }
488 #else
489 #define orion_gpio_dbg_show NULL
490 #endif
491 
492 static void orion_gpio_unmask_irq(struct irq_data *d)
493 {
494 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
495 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
496 	u32 reg_val;
497 	u32 mask = d->mask;
498 
499 	irq_gc_lock(gc);
500 	reg_val = irq_reg_readl(gc, ct->regs.mask);
501 	reg_val |= mask;
502 	irq_reg_writel(gc, reg_val, ct->regs.mask);
503 	irq_gc_unlock(gc);
504 }
505 
506 static void orion_gpio_mask_irq(struct irq_data *d)
507 {
508 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
509 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
510 	u32 mask = d->mask;
511 	u32 reg_val;
512 
513 	irq_gc_lock(gc);
514 	reg_val = irq_reg_readl(gc, ct->regs.mask);
515 	reg_val &= ~mask;
516 	irq_reg_writel(gc, reg_val, ct->regs.mask);
517 	irq_gc_unlock(gc);
518 }
519 
520 void __init orion_gpio_init(int gpio_base, int ngpio,
521 			    void __iomem *base, int mask_offset,
522 			    int secondary_irq_base,
523 			    int irqs[4])
524 {
525 	struct orion_gpio_chip *ochip;
526 	struct irq_chip_generic *gc;
527 	struct irq_chip_type *ct;
528 	char gc_label[16];
529 	int i;
530 
531 	if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
532 		return;
533 
534 	snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
535 		orion_gpio_chip_count);
536 
537 	ochip = orion_gpio_chips + orion_gpio_chip_count;
538 	ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
539 	ochip->chip.request = orion_gpio_request;
540 	ochip->chip.direction_input = orion_gpio_direction_input;
541 	ochip->chip.get = orion_gpio_get;
542 	ochip->chip.direction_output = orion_gpio_direction_output;
543 	ochip->chip.set = orion_gpio_set;
544 	ochip->chip.to_irq = orion_gpio_to_irq;
545 	ochip->chip.base = gpio_base;
546 	ochip->chip.ngpio = ngpio;
547 	ochip->chip.can_sleep = 0;
548 	ochip->chip.dbg_show = orion_gpio_dbg_show;
549 
550 	spin_lock_init(&ochip->lock);
551 	ochip->base = (void __iomem *)base;
552 	ochip->valid_input = 0;
553 	ochip->valid_output = 0;
554 	ochip->mask_offset = mask_offset;
555 	ochip->secondary_irq_base = secondary_irq_base;
556 
557 	gpiochip_add_data(&ochip->chip, ochip);
558 
559 	/*
560 	 * Mask and clear GPIO interrupts.
561 	 */
562 	writel(0, GPIO_EDGE_CAUSE(ochip));
563 	writel(0, GPIO_EDGE_MASK(ochip));
564 	writel(0, GPIO_LEVEL_MASK(ochip));
565 
566 	/* Setup the interrupt handlers. Each chip can have up to 4
567 	 * interrupt handlers, with each handler dealing with 8 GPIO
568 	 * pins. */
569 
570 	for (i = 0; i < 4; i++) {
571 		if (irqs[i]) {
572 			irq_set_chained_handler_and_data(irqs[i],
573 							 gpio_irq_handler,
574 							 ochip);
575 		}
576 	}
577 
578 	gc = irq_alloc_generic_chip("orion_gpio_irq", 2,
579 				    secondary_irq_base,
580 				    ochip->base, handle_level_irq);
581 	gc->private = ochip;
582 	ct = gc->chip_types;
583 	ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
584 	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
585 	ct->chip.irq_mask = orion_gpio_mask_irq;
586 	ct->chip.irq_unmask = orion_gpio_unmask_irq;
587 	ct->chip.irq_set_type = gpio_irq_set_type;
588 	ct->chip.name = ochip->chip.label;
589 
590 	ct++;
591 	ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
592 	ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
593 	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
594 	ct->chip.irq_ack = irq_gc_ack_clr_bit;
595 	ct->chip.irq_mask = orion_gpio_mask_irq;
596 	ct->chip.irq_unmask = orion_gpio_unmask_irq;
597 	ct->chip.irq_set_type = gpio_irq_set_type;
598 	ct->handler = handle_edge_irq;
599 	ct->chip.name = ochip->chip.label;
600 
601 	irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
602 			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
603 
604 	/* Setup irq domain on top of the generic chip. */
605 	ochip->domain = irq_domain_add_legacy(NULL,
606 					      ochip->chip.ngpio,
607 					      ochip->secondary_irq_base,
608 					      ochip->secondary_irq_base,
609 					      &irq_domain_simple_ops,
610 					      ochip);
611 	if (!ochip->domain)
612 		panic("%s: couldn't allocate irq domain (DT).\n",
613 		      ochip->chip.label);
614 
615 	orion_gpio_chip_count++;
616 }
617