xref: /openbmc/linux/drivers/gpio/gpio-uniphier.c (revision 6d99a79c)
1 /*
2  * Copyright (C) 2017 Socionext Inc.
3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/bits.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/irq.h>
18 #include <linux/irqdomain.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/of_irq.h>
23 #include <linux/platform_device.h>
24 #include <linux/spinlock.h>
25 #include <dt-bindings/gpio/uniphier-gpio.h>
26 
27 #define UNIPHIER_GPIO_BANK_MASK		\
28 				GENMASK((UNIPHIER_GPIO_LINES_PER_BANK) - 1, 0)
29 
30 #define UNIPHIER_GPIO_IRQ_MAX_NUM	24
31 
32 #define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
33 #define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
34 #define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
35 #define UNIPHIER_GPIO_IRQ_MODE		0x94	/* irq mode (1: both edge) */
36 #define UNIPHIER_GPIO_IRQ_FLT_EN	0x98	/* noise filter enable */
37 #define UNIPHIER_GPIO_IRQ_FLT_CYC	0x9c	/* noise filter clock cycle */
38 
39 struct uniphier_gpio_priv {
40 	struct gpio_chip chip;
41 	struct irq_chip irq_chip;
42 	struct irq_domain *domain;
43 	void __iomem *regs;
44 	spinlock_t lock;
45 	u32 saved_vals[0];
46 };
47 
48 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
49 {
50 	unsigned int reg;
51 
52 	reg = (bank + 1) * 8;
53 
54 	/*
55 	 * Unfortunately, the GPIO port registers are not contiguous because
56 	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
57 	 */
58 	if (reg >= UNIPHIER_GPIO_IRQ_EN)
59 		reg += 0x10;
60 
61 	return reg;
62 }
63 
64 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
65 					    unsigned int *bank, u32 *mask)
66 {
67 	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
68 	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
69 }
70 
71 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
72 				     unsigned int reg, u32 mask, u32 val)
73 {
74 	unsigned long flags;
75 	u32 tmp;
76 
77 	spin_lock_irqsave(&priv->lock, flags);
78 	tmp = readl(priv->regs + reg);
79 	tmp &= ~mask;
80 	tmp |= mask & val;
81 	writel(tmp, priv->regs + reg);
82 	spin_unlock_irqrestore(&priv->lock, flags);
83 }
84 
85 static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
86 				     unsigned int reg, u32 mask, u32 val)
87 {
88 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
89 
90 	if (!mask)
91 		return;
92 
93 	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
94 				 mask, val);
95 }
96 
97 static void uniphier_gpio_offset_write(struct gpio_chip *chip,
98 				       unsigned int offset, unsigned int reg,
99 				       int val)
100 {
101 	unsigned int bank;
102 	u32 mask;
103 
104 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
105 
106 	uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
107 }
108 
109 static int uniphier_gpio_offset_read(struct gpio_chip *chip,
110 				     unsigned int offset, unsigned int reg)
111 {
112 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
113 	unsigned int bank, reg_offset;
114 	u32 mask;
115 
116 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
117 	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
118 
119 	return !!(readl(priv->regs + reg_offset) & mask);
120 }
121 
122 static int uniphier_gpio_get_direction(struct gpio_chip *chip,
123 				       unsigned int offset)
124 {
125 	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR);
126 }
127 
128 static int uniphier_gpio_direction_input(struct gpio_chip *chip,
129 					 unsigned int offset)
130 {
131 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
132 
133 	return 0;
134 }
135 
136 static int uniphier_gpio_direction_output(struct gpio_chip *chip,
137 					  unsigned int offset, int val)
138 {
139 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
140 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
141 
142 	return 0;
143 }
144 
145 static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
146 {
147 	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
148 }
149 
150 static void uniphier_gpio_set(struct gpio_chip *chip,
151 			      unsigned int offset, int val)
152 {
153 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
154 }
155 
156 static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
157 				       unsigned long *mask, unsigned long *bits)
158 {
159 	unsigned int bank, shift, bank_mask, bank_bits;
160 	int i;
161 
162 	for (i = 0; i < chip->ngpio; i += UNIPHIER_GPIO_LINES_PER_BANK) {
163 		bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
164 		shift = i % BITS_PER_LONG;
165 		bank_mask = (mask[BIT_WORD(i)] >> shift) &
166 						UNIPHIER_GPIO_BANK_MASK;
167 		bank_bits = bits[BIT_WORD(i)] >> shift;
168 
169 		uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
170 					 bank_mask, bank_bits);
171 	}
172 }
173 
174 static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
175 {
176 	struct irq_fwspec fwspec;
177 
178 	if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
179 		return -ENXIO;
180 
181 	fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
182 	fwspec.param_count = 2;
183 	fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
184 	/*
185 	 * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
186 	 * temporarily. Anyway, ->irq_set_type() will override it later.
187 	 */
188 	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
189 
190 	return irq_create_fwspec_mapping(&fwspec);
191 }
192 
193 static void uniphier_gpio_irq_mask(struct irq_data *data)
194 {
195 	struct uniphier_gpio_priv *priv = data->chip_data;
196 	u32 mask = BIT(data->hwirq);
197 
198 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
199 
200 	return irq_chip_mask_parent(data);
201 }
202 
203 static void uniphier_gpio_irq_unmask(struct irq_data *data)
204 {
205 	struct uniphier_gpio_priv *priv = data->chip_data;
206 	u32 mask = BIT(data->hwirq);
207 
208 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
209 
210 	return irq_chip_unmask_parent(data);
211 }
212 
213 static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
214 {
215 	struct uniphier_gpio_priv *priv = data->chip_data;
216 	u32 mask = BIT(data->hwirq);
217 	u32 val = 0;
218 
219 	if (type == IRQ_TYPE_EDGE_BOTH) {
220 		val = mask;
221 		type = IRQ_TYPE_EDGE_FALLING;
222 	}
223 
224 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
225 	/* To enable both edge detection, the noise filter must be enabled. */
226 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
227 
228 	return irq_chip_set_type_parent(data, type);
229 }
230 
231 static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
232 					      unsigned int hwirq)
233 {
234 	struct device_node *np = priv->chip.parent->of_node;
235 	const __be32 *range;
236 	u32 base, parent_base, size;
237 	int len;
238 
239 	range = of_get_property(np, "socionext,interrupt-ranges", &len);
240 	if (!range)
241 		return -EINVAL;
242 
243 	len /= sizeof(*range);
244 
245 	for (; len >= 3; len -= 3) {
246 		base = be32_to_cpu(*range++);
247 		parent_base = be32_to_cpu(*range++);
248 		size = be32_to_cpu(*range++);
249 
250 		if (base <= hwirq && hwirq < base + size)
251 			return hwirq - base + parent_base;
252 	}
253 
254 	return -ENOENT;
255 }
256 
257 static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
258 					      struct irq_fwspec *fwspec,
259 					      unsigned long *out_hwirq,
260 					      unsigned int *out_type)
261 {
262 	if (WARN_ON(fwspec->param_count < 2))
263 		return -EINVAL;
264 
265 	*out_hwirq = fwspec->param[0];
266 	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
267 
268 	return 0;
269 }
270 
271 static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
272 					  unsigned int virq,
273 					  unsigned int nr_irqs, void *arg)
274 {
275 	struct uniphier_gpio_priv *priv = domain->host_data;
276 	struct irq_fwspec parent_fwspec;
277 	irq_hw_number_t hwirq;
278 	unsigned int type;
279 	int ret;
280 
281 	if (WARN_ON(nr_irqs != 1))
282 		return -EINVAL;
283 
284 	ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
285 	if (ret)
286 		return ret;
287 
288 	ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
289 	if (ret < 0)
290 		return ret;
291 
292 	/* parent is UniPhier AIDET */
293 	parent_fwspec.fwnode = domain->parent->fwnode;
294 	parent_fwspec.param_count = 2;
295 	parent_fwspec.param[0] = ret;
296 	parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
297 						IRQ_TYPE_EDGE_FALLING : type;
298 
299 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
300 					    &priv->irq_chip, priv);
301 	if (ret)
302 		return ret;
303 
304 	return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
305 }
306 
307 static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
308 					     struct irq_data *data, bool early)
309 {
310 	struct uniphier_gpio_priv *priv = domain->host_data;
311 	struct gpio_chip *chip = &priv->chip;
312 
313 	return gpiochip_lock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
314 }
315 
316 static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
317 						struct irq_data *data)
318 {
319 	struct uniphier_gpio_priv *priv = domain->host_data;
320 	struct gpio_chip *chip = &priv->chip;
321 
322 	gpiochip_unlock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
323 }
324 
325 static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
326 	.alloc = uniphier_gpio_irq_domain_alloc,
327 	.free = irq_domain_free_irqs_common,
328 	.activate = uniphier_gpio_irq_domain_activate,
329 	.deactivate = uniphier_gpio_irq_domain_deactivate,
330 	.translate = uniphier_gpio_irq_domain_translate,
331 };
332 
333 static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
334 {
335 	/*
336 	 * Due to the hardware design, the noise filter must be enabled to
337 	 * detect both edge interrupts.  This filter is intended to remove the
338 	 * noise from the irq lines.  It does not work for GPIO input, so GPIO
339 	 * debounce is not supported.  Unfortunately, the filter period is
340 	 * shared among all irq lines.  Just choose a sensible period here.
341 	 */
342 	writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
343 }
344 
345 static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
346 {
347 	return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
348 }
349 
350 static int uniphier_gpio_probe(struct platform_device *pdev)
351 {
352 	struct device *dev = &pdev->dev;
353 	struct device_node *parent_np;
354 	struct irq_domain *parent_domain;
355 	struct uniphier_gpio_priv *priv;
356 	struct gpio_chip *chip;
357 	struct irq_chip *irq_chip;
358 	struct resource *regs;
359 	unsigned int nregs;
360 	u32 ngpios;
361 	int ret;
362 
363 	parent_np = of_irq_find_parent(dev->of_node);
364 	if (!parent_np)
365 		return -ENXIO;
366 
367 	parent_domain = irq_find_host(parent_np);
368 	of_node_put(parent_np);
369 	if (!parent_domain)
370 		return -EPROBE_DEFER;
371 
372 	ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
373 	if (ret)
374 		return ret;
375 
376 	nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
377 	priv = devm_kzalloc(dev, struct_size(priv, saved_vals, nregs),
378 			    GFP_KERNEL);
379 	if (!priv)
380 		return -ENOMEM;
381 
382 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
383 	priv->regs = devm_ioremap_resource(dev, regs);
384 	if (IS_ERR(priv->regs))
385 		return PTR_ERR(priv->regs);
386 
387 	spin_lock_init(&priv->lock);
388 
389 	chip = &priv->chip;
390 	chip->label = dev_name(dev);
391 	chip->parent = dev;
392 	chip->request = gpiochip_generic_request;
393 	chip->free = gpiochip_generic_free;
394 	chip->get_direction = uniphier_gpio_get_direction;
395 	chip->direction_input = uniphier_gpio_direction_input;
396 	chip->direction_output = uniphier_gpio_direction_output;
397 	chip->get = uniphier_gpio_get;
398 	chip->set = uniphier_gpio_set;
399 	chip->set_multiple = uniphier_gpio_set_multiple;
400 	chip->to_irq = uniphier_gpio_to_irq;
401 	chip->base = -1;
402 	chip->ngpio = ngpios;
403 
404 	irq_chip = &priv->irq_chip;
405 	irq_chip->name = dev_name(dev);
406 	irq_chip->irq_mask = uniphier_gpio_irq_mask;
407 	irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
408 	irq_chip->irq_eoi = irq_chip_eoi_parent;
409 	irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
410 	irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
411 
412 	uniphier_gpio_hw_init(priv);
413 
414 	ret = devm_gpiochip_add_data(dev, chip, priv);
415 	if (ret)
416 		return ret;
417 
418 	priv->domain = irq_domain_create_hierarchy(
419 					parent_domain, 0,
420 					UNIPHIER_GPIO_IRQ_MAX_NUM,
421 					of_node_to_fwnode(dev->of_node),
422 					&uniphier_gpio_irq_domain_ops, priv);
423 	if (!priv->domain)
424 		return -ENOMEM;
425 
426 	platform_set_drvdata(pdev, priv);
427 
428 	return 0;
429 }
430 
431 static int uniphier_gpio_remove(struct platform_device *pdev)
432 {
433 	struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
434 
435 	irq_domain_remove(priv->domain);
436 
437 	return 0;
438 }
439 
440 static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
441 {
442 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
443 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
444 	u32 *val = priv->saved_vals;
445 	unsigned int reg;
446 	int i;
447 
448 	for (i = 0; i < nbanks; i++) {
449 		reg = uniphier_gpio_bank_to_reg(i);
450 
451 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
452 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
453 	}
454 
455 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
456 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
457 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
458 
459 	return 0;
460 }
461 
462 static int __maybe_unused uniphier_gpio_resume(struct device *dev)
463 {
464 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
465 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
466 	const u32 *val = priv->saved_vals;
467 	unsigned int reg;
468 	int i;
469 
470 	for (i = 0; i < nbanks; i++) {
471 		reg = uniphier_gpio_bank_to_reg(i);
472 
473 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
474 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
475 	}
476 
477 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
478 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
479 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
480 
481 	uniphier_gpio_hw_init(priv);
482 
483 	return 0;
484 }
485 
486 static const struct dev_pm_ops uniphier_gpio_pm_ops = {
487 	SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
488 				     uniphier_gpio_resume)
489 };
490 
491 static const struct of_device_id uniphier_gpio_match[] = {
492 	{ .compatible = "socionext,uniphier-gpio" },
493 	{ /* sentinel */ }
494 };
495 MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
496 
497 static struct platform_driver uniphier_gpio_driver = {
498 	.probe = uniphier_gpio_probe,
499 	.remove = uniphier_gpio_remove,
500 	.driver = {
501 		.name = "uniphier-gpio",
502 		.of_match_table = uniphier_gpio_match,
503 		.pm = &uniphier_gpio_pm_ops,
504 	},
505 };
506 module_platform_driver(uniphier_gpio_driver);
507 
508 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
509 MODULE_DESCRIPTION("UniPhier GPIO driver");
510 MODULE_LICENSE("GPL v2");
511