xref: /openbmc/linux/drivers/gpio/gpio-thunderx.c (revision 3dc4b6fb)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2016, 2017 Cavium Inc.
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/pci.h>
17 #include <linux/spinlock.h>
18 
19 
20 #define GPIO_RX_DAT	0x0
21 #define GPIO_TX_SET	0x8
22 #define GPIO_TX_CLR	0x10
23 #define GPIO_CONST	0x90
24 #define  GPIO_CONST_GPIOS_MASK 0xff
25 #define GPIO_BIT_CFG	0x400
26 #define  GPIO_BIT_CFG_TX_OE		BIT(0)
27 #define  GPIO_BIT_CFG_PIN_XOR		BIT(1)
28 #define  GPIO_BIT_CFG_INT_EN		BIT(2)
29 #define  GPIO_BIT_CFG_INT_TYPE		BIT(3)
30 #define  GPIO_BIT_CFG_FIL_MASK		GENMASK(11, 4)
31 #define  GPIO_BIT_CFG_FIL_CNT_SHIFT	4
32 #define  GPIO_BIT_CFG_FIL_SEL_SHIFT	8
33 #define  GPIO_BIT_CFG_TX_OD		BIT(12)
34 #define  GPIO_BIT_CFG_PIN_SEL_MASK	GENMASK(25, 16)
35 #define GPIO_INTR	0x800
36 #define  GPIO_INTR_INTR			BIT(0)
37 #define  GPIO_INTR_INTR_W1S		BIT(1)
38 #define  GPIO_INTR_ENA_W1C		BIT(2)
39 #define  GPIO_INTR_ENA_W1S		BIT(3)
40 #define GPIO_2ND_BANK	0x1400
41 
42 #define GLITCH_FILTER_400NS ((4u << GPIO_BIT_CFG_FIL_SEL_SHIFT) | \
43 			     (9u << GPIO_BIT_CFG_FIL_CNT_SHIFT))
44 
45 struct thunderx_gpio;
46 
47 struct thunderx_line {
48 	struct thunderx_gpio	*txgpio;
49 	unsigned int		line;
50 	unsigned int		fil_bits;
51 };
52 
53 struct thunderx_gpio {
54 	struct gpio_chip	chip;
55 	u8 __iomem		*register_base;
56 	struct msix_entry	*msix_entries;	/* per line MSI-X */
57 	struct thunderx_line	*line_entries;	/* per line irq info */
58 	raw_spinlock_t		lock;
59 	unsigned long		invert_mask[2];
60 	unsigned long		od_mask[2];
61 	int			base_msi;
62 };
63 
64 static unsigned int bit_cfg_reg(unsigned int line)
65 {
66 	return 8 * line + GPIO_BIT_CFG;
67 }
68 
69 static unsigned int intr_reg(unsigned int line)
70 {
71 	return 8 * line + GPIO_INTR;
72 }
73 
74 static bool thunderx_gpio_is_gpio_nowarn(struct thunderx_gpio *txgpio,
75 					 unsigned int line)
76 {
77 	u64 bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
78 
79 	return (bit_cfg & GPIO_BIT_CFG_PIN_SEL_MASK) == 0;
80 }
81 
82 /*
83  * Check (and WARN) that the pin is available for GPIO.  We will not
84  * allow modification of the state of non-GPIO pins from this driver.
85  */
86 static bool thunderx_gpio_is_gpio(struct thunderx_gpio *txgpio,
87 				  unsigned int line)
88 {
89 	bool rv = thunderx_gpio_is_gpio_nowarn(txgpio, line);
90 
91 	WARN_RATELIMIT(!rv, "Pin %d not available for GPIO\n", line);
92 
93 	return rv;
94 }
95 
96 static int thunderx_gpio_request(struct gpio_chip *chip, unsigned int line)
97 {
98 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
99 
100 	return thunderx_gpio_is_gpio(txgpio, line) ? 0 : -EIO;
101 }
102 
103 static int thunderx_gpio_dir_in(struct gpio_chip *chip, unsigned int line)
104 {
105 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
106 
107 	if (!thunderx_gpio_is_gpio(txgpio, line))
108 		return -EIO;
109 
110 	raw_spin_lock(&txgpio->lock);
111 	clear_bit(line, txgpio->invert_mask);
112 	clear_bit(line, txgpio->od_mask);
113 	writeq(txgpio->line_entries[line].fil_bits,
114 	       txgpio->register_base + bit_cfg_reg(line));
115 	raw_spin_unlock(&txgpio->lock);
116 	return 0;
117 }
118 
119 static void thunderx_gpio_set(struct gpio_chip *chip, unsigned int line,
120 			      int value)
121 {
122 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
123 	int bank = line / 64;
124 	int bank_bit = line % 64;
125 
126 	void __iomem *reg = txgpio->register_base +
127 		(bank * GPIO_2ND_BANK) + (value ? GPIO_TX_SET : GPIO_TX_CLR);
128 
129 	writeq(BIT_ULL(bank_bit), reg);
130 }
131 
132 static int thunderx_gpio_dir_out(struct gpio_chip *chip, unsigned int line,
133 				 int value)
134 {
135 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
136 	u64 bit_cfg = txgpio->line_entries[line].fil_bits | GPIO_BIT_CFG_TX_OE;
137 
138 	if (!thunderx_gpio_is_gpio(txgpio, line))
139 		return -EIO;
140 
141 	raw_spin_lock(&txgpio->lock);
142 
143 	thunderx_gpio_set(chip, line, value);
144 
145 	if (test_bit(line, txgpio->invert_mask))
146 		bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
147 
148 	if (test_bit(line, txgpio->od_mask))
149 		bit_cfg |= GPIO_BIT_CFG_TX_OD;
150 
151 	writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(line));
152 
153 	raw_spin_unlock(&txgpio->lock);
154 	return 0;
155 }
156 
157 static int thunderx_gpio_get_direction(struct gpio_chip *chip, unsigned int line)
158 {
159 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
160 	u64 bit_cfg;
161 
162 	if (!thunderx_gpio_is_gpio_nowarn(txgpio, line))
163 		/*
164 		 * Say it is input for now to avoid WARNing on
165 		 * gpiochip_add_data().  We will WARN if someone
166 		 * requests it or tries to use it.
167 		 */
168 		return 1;
169 
170 	bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
171 
172 	return !(bit_cfg & GPIO_BIT_CFG_TX_OE);
173 }
174 
175 static int thunderx_gpio_set_config(struct gpio_chip *chip,
176 				    unsigned int line,
177 				    unsigned long cfg)
178 {
179 	bool orig_invert, orig_od, orig_dat, new_invert, new_od;
180 	u32 arg, sel;
181 	u64 bit_cfg;
182 	int bank = line / 64;
183 	int bank_bit = line % 64;
184 	int ret = -ENOTSUPP;
185 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
186 	void __iomem *reg = txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET;
187 
188 	if (!thunderx_gpio_is_gpio(txgpio, line))
189 		return -EIO;
190 
191 	raw_spin_lock(&txgpio->lock);
192 	orig_invert = test_bit(line, txgpio->invert_mask);
193 	new_invert  = orig_invert;
194 	orig_od = test_bit(line, txgpio->od_mask);
195 	new_od = orig_od;
196 	orig_dat = ((readq(reg) >> bank_bit) & 1) ^ orig_invert;
197 	bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
198 	switch (pinconf_to_config_param(cfg)) {
199 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
200 		/*
201 		 * Weird, setting open-drain mode causes signal
202 		 * inversion.  Note this so we can compensate in the
203 		 * dir_out function.
204 		 */
205 		set_bit(line, txgpio->invert_mask);
206 		new_invert  = true;
207 		set_bit(line, txgpio->od_mask);
208 		new_od = true;
209 		ret = 0;
210 		break;
211 	case PIN_CONFIG_DRIVE_PUSH_PULL:
212 		clear_bit(line, txgpio->invert_mask);
213 		new_invert  = false;
214 		clear_bit(line, txgpio->od_mask);
215 		new_od  = false;
216 		ret = 0;
217 		break;
218 	case PIN_CONFIG_INPUT_DEBOUNCE:
219 		arg = pinconf_to_config_argument(cfg);
220 		if (arg > 1228) { /* 15 * 2^15 * 2.5nS maximum */
221 			ret = -EINVAL;
222 			break;
223 		}
224 		arg *= 400; /* scale to 2.5nS clocks. */
225 		sel = 0;
226 		while (arg > 15) {
227 			sel++;
228 			arg++; /* always round up */
229 			arg >>= 1;
230 		}
231 		txgpio->line_entries[line].fil_bits =
232 			(sel << GPIO_BIT_CFG_FIL_SEL_SHIFT) |
233 			(arg << GPIO_BIT_CFG_FIL_CNT_SHIFT);
234 		bit_cfg &= ~GPIO_BIT_CFG_FIL_MASK;
235 		bit_cfg |= txgpio->line_entries[line].fil_bits;
236 		writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(line));
237 		ret = 0;
238 		break;
239 	default:
240 		break;
241 	}
242 	raw_spin_unlock(&txgpio->lock);
243 
244 	/*
245 	 * If currently output and OPEN_DRAIN changed, install the new
246 	 * settings
247 	 */
248 	if ((new_invert != orig_invert || new_od != orig_od) &&
249 	    (bit_cfg & GPIO_BIT_CFG_TX_OE))
250 		ret = thunderx_gpio_dir_out(chip, line, orig_dat ^ new_invert);
251 
252 	return ret;
253 }
254 
255 static int thunderx_gpio_get(struct gpio_chip *chip, unsigned int line)
256 {
257 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
258 	int bank = line / 64;
259 	int bank_bit = line % 64;
260 	u64 read_bits = readq(txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_RX_DAT);
261 	u64 masked_bits = read_bits & BIT_ULL(bank_bit);
262 
263 	if (test_bit(line, txgpio->invert_mask))
264 		return masked_bits == 0;
265 	else
266 		return masked_bits != 0;
267 }
268 
269 static void thunderx_gpio_set_multiple(struct gpio_chip *chip,
270 				       unsigned long *mask,
271 				       unsigned long *bits)
272 {
273 	int bank;
274 	u64 set_bits, clear_bits;
275 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
276 
277 	for (bank = 0; bank <= chip->ngpio / 64; bank++) {
278 		set_bits = bits[bank] & mask[bank];
279 		clear_bits = ~bits[bank] & mask[bank];
280 		writeq(set_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET);
281 		writeq(clear_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_CLR);
282 	}
283 }
284 
285 static void thunderx_gpio_irq_ack(struct irq_data *d)
286 {
287 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
288 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
289 
290 	writeq(GPIO_INTR_INTR,
291 	       txgpio->register_base + intr_reg(irqd_to_hwirq(d)));
292 }
293 
294 static void thunderx_gpio_irq_mask(struct irq_data *d)
295 {
296 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
297 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
298 
299 	writeq(GPIO_INTR_ENA_W1C,
300 	       txgpio->register_base + intr_reg(irqd_to_hwirq(d)));
301 }
302 
303 static void thunderx_gpio_irq_mask_ack(struct irq_data *d)
304 {
305 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
306 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
307 
308 	writeq(GPIO_INTR_ENA_W1C | GPIO_INTR_INTR,
309 	       txgpio->register_base + intr_reg(irqd_to_hwirq(d)));
310 }
311 
312 static void thunderx_gpio_irq_unmask(struct irq_data *d)
313 {
314 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
315 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
316 
317 	writeq(GPIO_INTR_ENA_W1S,
318 	       txgpio->register_base + intr_reg(irqd_to_hwirq(d)));
319 }
320 
321 static int thunderx_gpio_irq_set_type(struct irq_data *d,
322 				      unsigned int flow_type)
323 {
324 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
325 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
326 	struct thunderx_line *txline =
327 		&txgpio->line_entries[irqd_to_hwirq(d)];
328 	u64 bit_cfg;
329 
330 	irqd_set_trigger_type(d, flow_type);
331 
332 	bit_cfg = txline->fil_bits | GPIO_BIT_CFG_INT_EN;
333 
334 	if (flow_type & IRQ_TYPE_EDGE_BOTH) {
335 		irq_set_handler_locked(d, handle_fasteoi_ack_irq);
336 		bit_cfg |= GPIO_BIT_CFG_INT_TYPE;
337 	} else {
338 		irq_set_handler_locked(d, handle_fasteoi_mask_irq);
339 	}
340 
341 	raw_spin_lock(&txgpio->lock);
342 	if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_LEVEL_LOW)) {
343 		bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
344 		set_bit(txline->line, txgpio->invert_mask);
345 	} else {
346 		clear_bit(txline->line, txgpio->invert_mask);
347 	}
348 	clear_bit(txline->line, txgpio->od_mask);
349 	writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(txline->line));
350 	raw_spin_unlock(&txgpio->lock);
351 
352 	return IRQ_SET_MASK_OK;
353 }
354 
355 static void thunderx_gpio_irq_enable(struct irq_data *data)
356 {
357 	irq_chip_enable_parent(data);
358 	thunderx_gpio_irq_unmask(data);
359 }
360 
361 static void thunderx_gpio_irq_disable(struct irq_data *data)
362 {
363 	thunderx_gpio_irq_mask(data);
364 	irq_chip_disable_parent(data);
365 }
366 
367 /*
368  * Interrupts are chained from underlying MSI-X vectors.  We have
369  * these irq_chip functions to be able to handle level triggering
370  * semantics and other acknowledgment tasks associated with the GPIO
371  * mechanism.
372  */
373 static struct irq_chip thunderx_gpio_irq_chip = {
374 	.name			= "GPIO",
375 	.irq_enable		= thunderx_gpio_irq_enable,
376 	.irq_disable		= thunderx_gpio_irq_disable,
377 	.irq_ack		= thunderx_gpio_irq_ack,
378 	.irq_mask		= thunderx_gpio_irq_mask,
379 	.irq_mask_ack		= thunderx_gpio_irq_mask_ack,
380 	.irq_unmask		= thunderx_gpio_irq_unmask,
381 	.irq_eoi		= irq_chip_eoi_parent,
382 	.irq_set_affinity	= irq_chip_set_affinity_parent,
383 	.irq_set_type		= thunderx_gpio_irq_set_type,
384 
385 	.flags			= IRQCHIP_SET_TYPE_MASKED
386 };
387 
388 static int thunderx_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
389 					       unsigned int child,
390 					       unsigned int child_type,
391 					       unsigned int *parent,
392 					       unsigned int *parent_type)
393 {
394 	struct thunderx_gpio *txgpio = gpiochip_get_data(gc);
395 
396 	*parent = txgpio->base_msi + (2 * child);
397 	*parent_type = IRQ_TYPE_LEVEL_HIGH;
398 	return 0;
399 }
400 
401 static int thunderx_gpio_probe(struct pci_dev *pdev,
402 			       const struct pci_device_id *id)
403 {
404 	void __iomem * const *tbl;
405 	struct device *dev = &pdev->dev;
406 	struct thunderx_gpio *txgpio;
407 	struct gpio_chip *chip;
408 	struct gpio_irq_chip *girq;
409 	int ngpio, i;
410 	int err = 0;
411 
412 	txgpio = devm_kzalloc(dev, sizeof(*txgpio), GFP_KERNEL);
413 	if (!txgpio)
414 		return -ENOMEM;
415 
416 	raw_spin_lock_init(&txgpio->lock);
417 	chip = &txgpio->chip;
418 
419 	pci_set_drvdata(pdev, txgpio);
420 
421 	err = pcim_enable_device(pdev);
422 	if (err) {
423 		dev_err(dev, "Failed to enable PCI device: err %d\n", err);
424 		goto out;
425 	}
426 
427 	err = pcim_iomap_regions(pdev, 1 << 0, KBUILD_MODNAME);
428 	if (err) {
429 		dev_err(dev, "Failed to iomap PCI device: err %d\n", err);
430 		goto out;
431 	}
432 
433 	tbl = pcim_iomap_table(pdev);
434 	txgpio->register_base = tbl[0];
435 	if (!txgpio->register_base) {
436 		dev_err(dev, "Cannot map PCI resource\n");
437 		err = -ENOMEM;
438 		goto out;
439 	}
440 
441 	if (pdev->subsystem_device == 0xa10a) {
442 		/* CN88XX has no GPIO_CONST register*/
443 		ngpio = 50;
444 		txgpio->base_msi = 48;
445 	} else {
446 		u64 c = readq(txgpio->register_base + GPIO_CONST);
447 
448 		ngpio = c & GPIO_CONST_GPIOS_MASK;
449 		txgpio->base_msi = (c >> 8) & 0xff;
450 	}
451 
452 	txgpio->msix_entries = devm_kcalloc(dev,
453 					    ngpio, sizeof(struct msix_entry),
454 					    GFP_KERNEL);
455 	if (!txgpio->msix_entries) {
456 		err = -ENOMEM;
457 		goto out;
458 	}
459 
460 	txgpio->line_entries = devm_kcalloc(dev,
461 					    ngpio,
462 					    sizeof(struct thunderx_line),
463 					    GFP_KERNEL);
464 	if (!txgpio->line_entries) {
465 		err = -ENOMEM;
466 		goto out;
467 	}
468 
469 	for (i = 0; i < ngpio; i++) {
470 		u64 bit_cfg = readq(txgpio->register_base + bit_cfg_reg(i));
471 
472 		txgpio->msix_entries[i].entry = txgpio->base_msi + (2 * i);
473 		txgpio->line_entries[i].line = i;
474 		txgpio->line_entries[i].txgpio = txgpio;
475 		/*
476 		 * If something has already programmed the pin, use
477 		 * the existing glitch filter settings, otherwise go
478 		 * to 400nS.
479 		 */
480 		txgpio->line_entries[i].fil_bits = bit_cfg ?
481 			(bit_cfg & GPIO_BIT_CFG_FIL_MASK) : GLITCH_FILTER_400NS;
482 
483 		if ((bit_cfg & GPIO_BIT_CFG_TX_OE) && (bit_cfg & GPIO_BIT_CFG_TX_OD))
484 			set_bit(i, txgpio->od_mask);
485 		if (bit_cfg & GPIO_BIT_CFG_PIN_XOR)
486 			set_bit(i, txgpio->invert_mask);
487 	}
488 
489 
490 	/* Enable all MSI-X for interrupts on all possible lines. */
491 	err = pci_enable_msix_range(pdev, txgpio->msix_entries, ngpio, ngpio);
492 	if (err < 0)
493 		goto out;
494 
495 	chip->label = KBUILD_MODNAME;
496 	chip->parent = dev;
497 	chip->owner = THIS_MODULE;
498 	chip->request = thunderx_gpio_request;
499 	chip->base = -1; /* System allocated */
500 	chip->can_sleep = false;
501 	chip->ngpio = ngpio;
502 	chip->get_direction = thunderx_gpio_get_direction;
503 	chip->direction_input = thunderx_gpio_dir_in;
504 	chip->get = thunderx_gpio_get;
505 	chip->direction_output = thunderx_gpio_dir_out;
506 	chip->set = thunderx_gpio_set;
507 	chip->set_multiple = thunderx_gpio_set_multiple;
508 	chip->set_config = thunderx_gpio_set_config;
509 	girq = &chip->irq;
510 	girq->chip = &thunderx_gpio_irq_chip;
511 	girq->fwnode = of_node_to_fwnode(dev->of_node);
512 	girq->parent_domain =
513 		irq_get_irq_data(txgpio->msix_entries[0].vector)->domain;
514 	girq->child_to_parent_hwirq = thunderx_gpio_child_to_parent_hwirq;
515 	girq->handler = handle_bad_irq;
516 	girq->default_type = IRQ_TYPE_NONE;
517 
518 	err = devm_gpiochip_add_data(dev, chip, txgpio);
519 	if (err)
520 		goto out;
521 
522 	/* Push on irq_data and the domain for each line. */
523 	for (i = 0; i < ngpio; i++) {
524 		err = irq_domain_push_irq(chip->irq.domain,
525 					  txgpio->msix_entries[i].vector,
526 					  chip);
527 		if (err < 0)
528 			dev_err(dev, "irq_domain_push_irq: %d\n", err);
529 	}
530 
531 	dev_info(dev, "ThunderX GPIO: %d lines with base %d.\n",
532 		 ngpio, chip->base);
533 	return 0;
534 out:
535 	pci_set_drvdata(pdev, NULL);
536 	return err;
537 }
538 
539 static void thunderx_gpio_remove(struct pci_dev *pdev)
540 {
541 	int i;
542 	struct thunderx_gpio *txgpio = pci_get_drvdata(pdev);
543 
544 	for (i = 0; i < txgpio->chip.ngpio; i++)
545 		irq_domain_pop_irq(txgpio->chip.irq.domain,
546 				   txgpio->msix_entries[i].vector);
547 
548 	irq_domain_remove(txgpio->chip.irq.domain);
549 
550 	pci_set_drvdata(pdev, NULL);
551 }
552 
553 static const struct pci_device_id thunderx_gpio_id_table[] = {
554 	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xA00A) },
555 	{ 0, }	/* end of table */
556 };
557 
558 MODULE_DEVICE_TABLE(pci, thunderx_gpio_id_table);
559 
560 static struct pci_driver thunderx_gpio_driver = {
561 	.name = KBUILD_MODNAME,
562 	.id_table = thunderx_gpio_id_table,
563 	.probe = thunderx_gpio_probe,
564 	.remove = thunderx_gpio_remove,
565 };
566 
567 module_pci_driver(thunderx_gpio_driver);
568 
569 MODULE_DESCRIPTION("Cavium Inc. ThunderX/OCTEON-TX GPIO Driver");
570 MODULE_LICENSE("GPL");
571