xref: /openbmc/linux/drivers/gpio/gpio-uniphier.c (revision 9470114d)
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_irq.h>
13 #include <linux/platform_device.h>
14 #include <linux/spinlock.h>
15 #include <dt-bindings/gpio/uniphier-gpio.h>
16 
17 #define UNIPHIER_GPIO_IRQ_MAX_NUM	24
18 
19 #define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
20 #define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
21 #define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
22 #define UNIPHIER_GPIO_IRQ_MODE		0x94	/* irq mode (1: both edge) */
23 #define UNIPHIER_GPIO_IRQ_FLT_EN	0x98	/* noise filter enable */
24 #define UNIPHIER_GPIO_IRQ_FLT_CYC	0x9c	/* noise filter clock cycle */
25 
26 struct uniphier_gpio_priv {
27 	struct gpio_chip chip;
28 	struct irq_chip irq_chip;
29 	struct irq_domain *domain;
30 	void __iomem *regs;
31 	spinlock_t lock;
32 	u32 saved_vals[];
33 };
34 
35 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
36 {
37 	unsigned int reg;
38 
39 	reg = (bank + 1) * 8;
40 
41 	/*
42 	 * Unfortunately, the GPIO port registers are not contiguous because
43 	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
44 	 */
45 	if (reg >= UNIPHIER_GPIO_IRQ_EN)
46 		reg += 0x10;
47 
48 	return reg;
49 }
50 
51 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
52 					    unsigned int *bank, u32 *mask)
53 {
54 	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
55 	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
56 }
57 
58 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
59 				     unsigned int reg, u32 mask, u32 val)
60 {
61 	unsigned long flags;
62 	u32 tmp;
63 
64 	spin_lock_irqsave(&priv->lock, flags);
65 	tmp = readl(priv->regs + reg);
66 	tmp &= ~mask;
67 	tmp |= mask & val;
68 	writel(tmp, priv->regs + reg);
69 	spin_unlock_irqrestore(&priv->lock, flags);
70 }
71 
72 static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
73 				     unsigned int reg, u32 mask, u32 val)
74 {
75 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
76 
77 	if (!mask)
78 		return;
79 
80 	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
81 				 mask, val);
82 }
83 
84 static void uniphier_gpio_offset_write(struct gpio_chip *chip,
85 				       unsigned int offset, unsigned int reg,
86 				       int val)
87 {
88 	unsigned int bank;
89 	u32 mask;
90 
91 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
92 
93 	uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
94 }
95 
96 static int uniphier_gpio_offset_read(struct gpio_chip *chip,
97 				     unsigned int offset, unsigned int reg)
98 {
99 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
100 	unsigned int bank, reg_offset;
101 	u32 mask;
102 
103 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
104 	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
105 
106 	return !!(readl(priv->regs + reg_offset) & mask);
107 }
108 
109 static int uniphier_gpio_get_direction(struct gpio_chip *chip,
110 				       unsigned int offset)
111 {
112 	if (uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR))
113 		return GPIO_LINE_DIRECTION_IN;
114 
115 	return GPIO_LINE_DIRECTION_OUT;
116 }
117 
118 static int uniphier_gpio_direction_input(struct gpio_chip *chip,
119 					 unsigned int offset)
120 {
121 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
122 
123 	return 0;
124 }
125 
126 static int uniphier_gpio_direction_output(struct gpio_chip *chip,
127 					  unsigned int offset, int val)
128 {
129 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
130 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
131 
132 	return 0;
133 }
134 
135 static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
136 {
137 	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
138 }
139 
140 static void uniphier_gpio_set(struct gpio_chip *chip,
141 			      unsigned int offset, int val)
142 {
143 	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
144 }
145 
146 static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
147 				       unsigned long *mask, unsigned long *bits)
148 {
149 	unsigned long i, bank, bank_mask, bank_bits;
150 
151 	for_each_set_clump8(i, bank_mask, mask, chip->ngpio) {
152 		bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
153 		bank_bits = bitmap_get_value8(bits, i);
154 
155 		uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
156 					 bank_mask, bank_bits);
157 	}
158 }
159 
160 static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
161 {
162 	struct irq_fwspec fwspec;
163 
164 	if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
165 		return -ENXIO;
166 
167 	fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
168 	fwspec.param_count = 2;
169 	fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
170 	/*
171 	 * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
172 	 * temporarily. Anyway, ->irq_set_type() will override it later.
173 	 */
174 	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
175 
176 	return irq_create_fwspec_mapping(&fwspec);
177 }
178 
179 static void uniphier_gpio_irq_mask(struct irq_data *data)
180 {
181 	struct uniphier_gpio_priv *priv = irq_data_get_irq_chip_data(data);
182 	u32 mask = BIT(irqd_to_hwirq(data));
183 
184 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
185 
186 	irq_chip_mask_parent(data);
187 }
188 
189 static void uniphier_gpio_irq_unmask(struct irq_data *data)
190 {
191 	struct uniphier_gpio_priv *priv = irq_data_get_irq_chip_data(data);
192 	u32 mask = BIT(irqd_to_hwirq(data));
193 
194 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
195 
196 	irq_chip_unmask_parent(data);
197 }
198 
199 static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
200 {
201 	struct uniphier_gpio_priv *priv = irq_data_get_irq_chip_data(data);
202 	u32 mask = BIT(irqd_to_hwirq(data));
203 	u32 val = 0;
204 
205 	if (type == IRQ_TYPE_EDGE_BOTH) {
206 		val = mask;
207 		type = IRQ_TYPE_EDGE_FALLING;
208 	}
209 
210 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
211 	/* To enable both edge detection, the noise filter must be enabled. */
212 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
213 
214 	return irq_chip_set_type_parent(data, type);
215 }
216 
217 static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
218 					      unsigned int hwirq)
219 {
220 	struct device_node *np = priv->chip.parent->of_node;
221 	const __be32 *range;
222 	u32 base, parent_base, size;
223 	int len;
224 
225 	range = of_get_property(np, "socionext,interrupt-ranges", &len);
226 	if (!range)
227 		return -EINVAL;
228 
229 	len /= sizeof(*range);
230 
231 	for (; len >= 3; len -= 3) {
232 		base = be32_to_cpu(*range++);
233 		parent_base = be32_to_cpu(*range++);
234 		size = be32_to_cpu(*range++);
235 
236 		if (base <= hwirq && hwirq < base + size)
237 			return hwirq - base + parent_base;
238 	}
239 
240 	return -ENOENT;
241 }
242 
243 static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
244 					      struct irq_fwspec *fwspec,
245 					      unsigned long *out_hwirq,
246 					      unsigned int *out_type)
247 {
248 	if (WARN_ON(fwspec->param_count < 2))
249 		return -EINVAL;
250 
251 	*out_hwirq = fwspec->param[0];
252 	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
253 
254 	return 0;
255 }
256 
257 static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
258 					  unsigned int virq,
259 					  unsigned int nr_irqs, void *arg)
260 {
261 	struct uniphier_gpio_priv *priv = domain->host_data;
262 	struct irq_fwspec parent_fwspec;
263 	irq_hw_number_t hwirq;
264 	unsigned int type;
265 	int ret;
266 
267 	if (WARN_ON(nr_irqs != 1))
268 		return -EINVAL;
269 
270 	ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
271 	if (ret)
272 		return ret;
273 
274 	ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
275 	if (ret < 0)
276 		return ret;
277 
278 	/* parent is UniPhier AIDET */
279 	parent_fwspec.fwnode = domain->parent->fwnode;
280 	parent_fwspec.param_count = 2;
281 	parent_fwspec.param[0] = ret;
282 	parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
283 						IRQ_TYPE_EDGE_FALLING : type;
284 
285 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
286 					    &priv->irq_chip, priv);
287 	if (ret)
288 		return ret;
289 
290 	return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
291 }
292 
293 static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
294 					     struct irq_data *data, bool early)
295 {
296 	struct uniphier_gpio_priv *priv = domain->host_data;
297 	struct gpio_chip *chip = &priv->chip;
298 
299 	return gpiochip_lock_as_irq(chip,
300 			irqd_to_hwirq(data) + UNIPHIER_GPIO_IRQ_OFFSET);
301 }
302 
303 static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
304 						struct irq_data *data)
305 {
306 	struct uniphier_gpio_priv *priv = domain->host_data;
307 	struct gpio_chip *chip = &priv->chip;
308 
309 	gpiochip_unlock_as_irq(chip,
310 			irqd_to_hwirq(data) + UNIPHIER_GPIO_IRQ_OFFSET);
311 }
312 
313 static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
314 	.alloc = uniphier_gpio_irq_domain_alloc,
315 	.free = irq_domain_free_irqs_common,
316 	.activate = uniphier_gpio_irq_domain_activate,
317 	.deactivate = uniphier_gpio_irq_domain_deactivate,
318 	.translate = uniphier_gpio_irq_domain_translate,
319 };
320 
321 static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
322 {
323 	/*
324 	 * Due to the hardware design, the noise filter must be enabled to
325 	 * detect both edge interrupts.  This filter is intended to remove the
326 	 * noise from the irq lines.  It does not work for GPIO input, so GPIO
327 	 * debounce is not supported.  Unfortunately, the filter period is
328 	 * shared among all irq lines.  Just choose a sensible period here.
329 	 */
330 	writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
331 }
332 
333 static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
334 {
335 	return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
336 }
337 
338 static int uniphier_gpio_probe(struct platform_device *pdev)
339 {
340 	struct device *dev = &pdev->dev;
341 	struct device_node *parent_np;
342 	struct irq_domain *parent_domain;
343 	struct uniphier_gpio_priv *priv;
344 	struct gpio_chip *chip;
345 	struct irq_chip *irq_chip;
346 	unsigned int nregs;
347 	u32 ngpios;
348 	int ret;
349 
350 	parent_np = of_irq_find_parent(dev->of_node);
351 	if (!parent_np)
352 		return -ENXIO;
353 
354 	parent_domain = irq_find_host(parent_np);
355 	of_node_put(parent_np);
356 	if (!parent_domain)
357 		return -EPROBE_DEFER;
358 
359 	ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
360 	if (ret)
361 		return ret;
362 
363 	nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
364 	priv = devm_kzalloc(dev, struct_size(priv, saved_vals, nregs),
365 			    GFP_KERNEL);
366 	if (!priv)
367 		return -ENOMEM;
368 
369 	priv->regs = devm_platform_ioremap_resource(pdev, 0);
370 	if (IS_ERR(priv->regs))
371 		return PTR_ERR(priv->regs);
372 
373 	spin_lock_init(&priv->lock);
374 
375 	chip = &priv->chip;
376 	chip->label = dev_name(dev);
377 	chip->parent = dev;
378 	chip->request = gpiochip_generic_request;
379 	chip->free = gpiochip_generic_free;
380 	chip->get_direction = uniphier_gpio_get_direction;
381 	chip->direction_input = uniphier_gpio_direction_input;
382 	chip->direction_output = uniphier_gpio_direction_output;
383 	chip->get = uniphier_gpio_get;
384 	chip->set = uniphier_gpio_set;
385 	chip->set_multiple = uniphier_gpio_set_multiple;
386 	chip->to_irq = uniphier_gpio_to_irq;
387 	chip->base = -1;
388 	chip->ngpio = ngpios;
389 
390 	irq_chip = &priv->irq_chip;
391 	irq_chip->name = dev_name(dev);
392 	irq_chip->irq_mask = uniphier_gpio_irq_mask;
393 	irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
394 	irq_chip->irq_eoi = irq_chip_eoi_parent;
395 	irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
396 	irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
397 
398 	uniphier_gpio_hw_init(priv);
399 
400 	ret = devm_gpiochip_add_data(dev, chip, priv);
401 	if (ret)
402 		return ret;
403 
404 	priv->domain = irq_domain_create_hierarchy(
405 					parent_domain, 0,
406 					UNIPHIER_GPIO_IRQ_MAX_NUM,
407 					of_node_to_fwnode(dev->of_node),
408 					&uniphier_gpio_irq_domain_ops, priv);
409 	if (!priv->domain)
410 		return -ENOMEM;
411 
412 	platform_set_drvdata(pdev, priv);
413 
414 	return 0;
415 }
416 
417 static int uniphier_gpio_remove(struct platform_device *pdev)
418 {
419 	struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
420 
421 	irq_domain_remove(priv->domain);
422 
423 	return 0;
424 }
425 
426 static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
427 {
428 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
429 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
430 	u32 *val = priv->saved_vals;
431 	unsigned int reg;
432 	int i;
433 
434 	for (i = 0; i < nbanks; i++) {
435 		reg = uniphier_gpio_bank_to_reg(i);
436 
437 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
438 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
439 	}
440 
441 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
442 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
443 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
444 
445 	return 0;
446 }
447 
448 static int __maybe_unused uniphier_gpio_resume(struct device *dev)
449 {
450 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
451 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
452 	const u32 *val = priv->saved_vals;
453 	unsigned int reg;
454 	int i;
455 
456 	for (i = 0; i < nbanks; i++) {
457 		reg = uniphier_gpio_bank_to_reg(i);
458 
459 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
460 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
461 	}
462 
463 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
464 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
465 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
466 
467 	uniphier_gpio_hw_init(priv);
468 
469 	return 0;
470 }
471 
472 static const struct dev_pm_ops uniphier_gpio_pm_ops = {
473 	SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
474 				     uniphier_gpio_resume)
475 };
476 
477 static const struct of_device_id uniphier_gpio_match[] = {
478 	{ .compatible = "socionext,uniphier-gpio" },
479 	{ /* sentinel */ }
480 };
481 MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
482 
483 static struct platform_driver uniphier_gpio_driver = {
484 	.probe = uniphier_gpio_probe,
485 	.remove = uniphier_gpio_remove,
486 	.driver = {
487 		.name = "uniphier-gpio",
488 		.of_match_table = uniphier_gpio_match,
489 		.pm = &uniphier_gpio_pm_ops,
490 	},
491 };
492 module_platform_driver(uniphier_gpio_driver);
493 
494 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
495 MODULE_DESCRIPTION("UniPhier GPIO driver");
496 MODULE_LICENSE("GPL v2");
497