xref: /openbmc/linux/drivers/gpio/gpio-uniphier.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2017 Socionext Inc.
4 //   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
5 
6 #include <linux/bits.h>
7 #include <linux/gpio/driver.h>
8 #include <linux/irq.h>
9 #include <linux/irqdomain.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/of_irq.h>
14 #include <linux/platform_device.h>
15 #include <linux/spinlock.h>
16 #include <dt-bindings/gpio/uniphier-gpio.h>
17 
18 #define UNIPHIER_GPIO_BANK_MASK		\
19 				GENMASK((UNIPHIER_GPIO_LINES_PER_BANK) - 1, 0)
20 
21 #define UNIPHIER_GPIO_IRQ_MAX_NUM	24
22 
23 #define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
24 #define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
25 #define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
26 #define UNIPHIER_GPIO_IRQ_MODE		0x94	/* irq mode (1: both edge) */
27 #define UNIPHIER_GPIO_IRQ_FLT_EN	0x98	/* noise filter enable */
28 #define UNIPHIER_GPIO_IRQ_FLT_CYC	0x9c	/* noise filter clock cycle */
29 
30 struct uniphier_gpio_priv {
31 	struct gpio_chip chip;
32 	struct irq_chip irq_chip;
33 	struct irq_domain *domain;
34 	void __iomem *regs;
35 	spinlock_t lock;
36 	u32 saved_vals[0];
37 };
38 
39 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
40 {
41 	unsigned int reg;
42 
43 	reg = (bank + 1) * 8;
44 
45 	/*
46 	 * Unfortunately, the GPIO port registers are not contiguous because
47 	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
48 	 */
49 	if (reg >= UNIPHIER_GPIO_IRQ_EN)
50 		reg += 0x10;
51 
52 	return reg;
53 }
54 
55 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
56 					    unsigned int *bank, u32 *mask)
57 {
58 	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
59 	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
60 }
61 
62 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
63 				     unsigned int reg, u32 mask, u32 val)
64 {
65 	unsigned long flags;
66 	u32 tmp;
67 
68 	spin_lock_irqsave(&priv->lock, flags);
69 	tmp = readl(priv->regs + reg);
70 	tmp &= ~mask;
71 	tmp |= mask & val;
72 	writel(tmp, priv->regs + reg);
73 	spin_unlock_irqrestore(&priv->lock, flags);
74 }
75 
76 static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
77 				     unsigned int reg, u32 mask, u32 val)
78 {
79 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
80 
81 	if (!mask)
82 		return;
83 
84 	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
85 				 mask, val);
86 }
87 
88 static void uniphier_gpio_offset_write(struct gpio_chip *chip,
89 				       unsigned int offset, unsigned int reg,
90 				       int val)
91 {
92 	unsigned int bank;
93 	u32 mask;
94 
95 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
96 
97 	uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
98 }
99 
100 static int uniphier_gpio_offset_read(struct gpio_chip *chip,
101 				     unsigned int offset, unsigned int reg)
102 {
103 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
104 	unsigned int bank, reg_offset;
105 	u32 mask;
106 
107 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
108 	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
109 
110 	return !!(readl(priv->regs + reg_offset) & mask);
111 }
112 
113 static int uniphier_gpio_get_direction(struct gpio_chip *chip,
114 				       unsigned int offset)
115 {
116 	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR);
117 }
118 
119 static int uniphier_gpio_direction_input(struct gpio_chip *chip,
120 					 unsigned int offset)
121 {
122 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
123 
124 	return 0;
125 }
126 
127 static int uniphier_gpio_direction_output(struct gpio_chip *chip,
128 					  unsigned int offset, int val)
129 {
130 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
131 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
132 
133 	return 0;
134 }
135 
136 static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
137 {
138 	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
139 }
140 
141 static void uniphier_gpio_set(struct gpio_chip *chip,
142 			      unsigned int offset, int val)
143 {
144 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
145 }
146 
147 static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
148 				       unsigned long *mask, unsigned long *bits)
149 {
150 	unsigned int bank, shift, bank_mask, bank_bits;
151 	int i;
152 
153 	for (i = 0; i < chip->ngpio; i += UNIPHIER_GPIO_LINES_PER_BANK) {
154 		bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
155 		shift = i % BITS_PER_LONG;
156 		bank_mask = (mask[BIT_WORD(i)] >> shift) &
157 						UNIPHIER_GPIO_BANK_MASK;
158 		bank_bits = bits[BIT_WORD(i)] >> shift;
159 
160 		uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
161 					 bank_mask, bank_bits);
162 	}
163 }
164 
165 static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
166 {
167 	struct irq_fwspec fwspec;
168 
169 	if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
170 		return -ENXIO;
171 
172 	fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
173 	fwspec.param_count = 2;
174 	fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
175 	/*
176 	 * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
177 	 * temporarily. Anyway, ->irq_set_type() will override it later.
178 	 */
179 	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
180 
181 	return irq_create_fwspec_mapping(&fwspec);
182 }
183 
184 static void uniphier_gpio_irq_mask(struct irq_data *data)
185 {
186 	struct uniphier_gpio_priv *priv = data->chip_data;
187 	u32 mask = BIT(data->hwirq);
188 
189 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
190 
191 	return irq_chip_mask_parent(data);
192 }
193 
194 static void uniphier_gpio_irq_unmask(struct irq_data *data)
195 {
196 	struct uniphier_gpio_priv *priv = data->chip_data;
197 	u32 mask = BIT(data->hwirq);
198 
199 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
200 
201 	return irq_chip_unmask_parent(data);
202 }
203 
204 static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
205 {
206 	struct uniphier_gpio_priv *priv = data->chip_data;
207 	u32 mask = BIT(data->hwirq);
208 	u32 val = 0;
209 
210 	if (type == IRQ_TYPE_EDGE_BOTH) {
211 		val = mask;
212 		type = IRQ_TYPE_EDGE_FALLING;
213 	}
214 
215 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
216 	/* To enable both edge detection, the noise filter must be enabled. */
217 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
218 
219 	return irq_chip_set_type_parent(data, type);
220 }
221 
222 static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
223 					      unsigned int hwirq)
224 {
225 	struct device_node *np = priv->chip.parent->of_node;
226 	const __be32 *range;
227 	u32 base, parent_base, size;
228 	int len;
229 
230 	range = of_get_property(np, "socionext,interrupt-ranges", &len);
231 	if (!range)
232 		return -EINVAL;
233 
234 	len /= sizeof(*range);
235 
236 	for (; len >= 3; len -= 3) {
237 		base = be32_to_cpu(*range++);
238 		parent_base = be32_to_cpu(*range++);
239 		size = be32_to_cpu(*range++);
240 
241 		if (base <= hwirq && hwirq < base + size)
242 			return hwirq - base + parent_base;
243 	}
244 
245 	return -ENOENT;
246 }
247 
248 static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
249 					      struct irq_fwspec *fwspec,
250 					      unsigned long *out_hwirq,
251 					      unsigned int *out_type)
252 {
253 	if (WARN_ON(fwspec->param_count < 2))
254 		return -EINVAL;
255 
256 	*out_hwirq = fwspec->param[0];
257 	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
258 
259 	return 0;
260 }
261 
262 static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
263 					  unsigned int virq,
264 					  unsigned int nr_irqs, void *arg)
265 {
266 	struct uniphier_gpio_priv *priv = domain->host_data;
267 	struct irq_fwspec parent_fwspec;
268 	irq_hw_number_t hwirq;
269 	unsigned int type;
270 	int ret;
271 
272 	if (WARN_ON(nr_irqs != 1))
273 		return -EINVAL;
274 
275 	ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
276 	if (ret)
277 		return ret;
278 
279 	ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
280 	if (ret < 0)
281 		return ret;
282 
283 	/* parent is UniPhier AIDET */
284 	parent_fwspec.fwnode = domain->parent->fwnode;
285 	parent_fwspec.param_count = 2;
286 	parent_fwspec.param[0] = ret;
287 	parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
288 						IRQ_TYPE_EDGE_FALLING : type;
289 
290 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
291 					    &priv->irq_chip, priv);
292 	if (ret)
293 		return ret;
294 
295 	return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
296 }
297 
298 static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
299 					     struct irq_data *data, bool early)
300 {
301 	struct uniphier_gpio_priv *priv = domain->host_data;
302 	struct gpio_chip *chip = &priv->chip;
303 
304 	return gpiochip_lock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
305 }
306 
307 static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
308 						struct irq_data *data)
309 {
310 	struct uniphier_gpio_priv *priv = domain->host_data;
311 	struct gpio_chip *chip = &priv->chip;
312 
313 	gpiochip_unlock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
314 }
315 
316 static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
317 	.alloc = uniphier_gpio_irq_domain_alloc,
318 	.free = irq_domain_free_irqs_common,
319 	.activate = uniphier_gpio_irq_domain_activate,
320 	.deactivate = uniphier_gpio_irq_domain_deactivate,
321 	.translate = uniphier_gpio_irq_domain_translate,
322 };
323 
324 static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
325 {
326 	/*
327 	 * Due to the hardware design, the noise filter must be enabled to
328 	 * detect both edge interrupts.  This filter is intended to remove the
329 	 * noise from the irq lines.  It does not work for GPIO input, so GPIO
330 	 * debounce is not supported.  Unfortunately, the filter period is
331 	 * shared among all irq lines.  Just choose a sensible period here.
332 	 */
333 	writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
334 }
335 
336 static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
337 {
338 	return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
339 }
340 
341 static int uniphier_gpio_probe(struct platform_device *pdev)
342 {
343 	struct device *dev = &pdev->dev;
344 	struct device_node *parent_np;
345 	struct irq_domain *parent_domain;
346 	struct uniphier_gpio_priv *priv;
347 	struct gpio_chip *chip;
348 	struct irq_chip *irq_chip;
349 	unsigned int nregs;
350 	u32 ngpios;
351 	int ret;
352 
353 	parent_np = of_irq_find_parent(dev->of_node);
354 	if (!parent_np)
355 		return -ENXIO;
356 
357 	parent_domain = irq_find_host(parent_np);
358 	of_node_put(parent_np);
359 	if (!parent_domain)
360 		return -EPROBE_DEFER;
361 
362 	ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
363 	if (ret)
364 		return ret;
365 
366 	nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
367 	priv = devm_kzalloc(dev, struct_size(priv, saved_vals, nregs),
368 			    GFP_KERNEL);
369 	if (!priv)
370 		return -ENOMEM;
371 
372 	priv->regs = devm_platform_ioremap_resource(pdev, 0);
373 	if (IS_ERR(priv->regs))
374 		return PTR_ERR(priv->regs);
375 
376 	spin_lock_init(&priv->lock);
377 
378 	chip = &priv->chip;
379 	chip->label = dev_name(dev);
380 	chip->parent = dev;
381 	chip->request = gpiochip_generic_request;
382 	chip->free = gpiochip_generic_free;
383 	chip->get_direction = uniphier_gpio_get_direction;
384 	chip->direction_input = uniphier_gpio_direction_input;
385 	chip->direction_output = uniphier_gpio_direction_output;
386 	chip->get = uniphier_gpio_get;
387 	chip->set = uniphier_gpio_set;
388 	chip->set_multiple = uniphier_gpio_set_multiple;
389 	chip->to_irq = uniphier_gpio_to_irq;
390 	chip->base = -1;
391 	chip->ngpio = ngpios;
392 
393 	irq_chip = &priv->irq_chip;
394 	irq_chip->name = dev_name(dev);
395 	irq_chip->irq_mask = uniphier_gpio_irq_mask;
396 	irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
397 	irq_chip->irq_eoi = irq_chip_eoi_parent;
398 	irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
399 	irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
400 
401 	uniphier_gpio_hw_init(priv);
402 
403 	ret = devm_gpiochip_add_data(dev, chip, priv);
404 	if (ret)
405 		return ret;
406 
407 	priv->domain = irq_domain_create_hierarchy(
408 					parent_domain, 0,
409 					UNIPHIER_GPIO_IRQ_MAX_NUM,
410 					of_node_to_fwnode(dev->of_node),
411 					&uniphier_gpio_irq_domain_ops, priv);
412 	if (!priv->domain)
413 		return -ENOMEM;
414 
415 	platform_set_drvdata(pdev, priv);
416 
417 	return 0;
418 }
419 
420 static int uniphier_gpio_remove(struct platform_device *pdev)
421 {
422 	struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
423 
424 	irq_domain_remove(priv->domain);
425 
426 	return 0;
427 }
428 
429 static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
430 {
431 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
432 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
433 	u32 *val = priv->saved_vals;
434 	unsigned int reg;
435 	int i;
436 
437 	for (i = 0; i < nbanks; i++) {
438 		reg = uniphier_gpio_bank_to_reg(i);
439 
440 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
441 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
442 	}
443 
444 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
445 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
446 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
447 
448 	return 0;
449 }
450 
451 static int __maybe_unused uniphier_gpio_resume(struct device *dev)
452 {
453 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
454 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
455 	const u32 *val = priv->saved_vals;
456 	unsigned int reg;
457 	int i;
458 
459 	for (i = 0; i < nbanks; i++) {
460 		reg = uniphier_gpio_bank_to_reg(i);
461 
462 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
463 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
464 	}
465 
466 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
467 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
468 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
469 
470 	uniphier_gpio_hw_init(priv);
471 
472 	return 0;
473 }
474 
475 static const struct dev_pm_ops uniphier_gpio_pm_ops = {
476 	SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
477 				     uniphier_gpio_resume)
478 };
479 
480 static const struct of_device_id uniphier_gpio_match[] = {
481 	{ .compatible = "socionext,uniphier-gpio" },
482 	{ /* sentinel */ }
483 };
484 MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
485 
486 static struct platform_driver uniphier_gpio_driver = {
487 	.probe = uniphier_gpio_probe,
488 	.remove = uniphier_gpio_remove,
489 	.driver = {
490 		.name = "uniphier-gpio",
491 		.of_match_table = uniphier_gpio_match,
492 		.pm = &uniphier_gpio_pm_ops,
493 	},
494 };
495 module_platform_driver(uniphier_gpio_driver);
496 
497 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
498 MODULE_DESCRIPTION("UniPhier GPIO driver");
499 MODULE_LICENSE("GPL v2");
500