xref: /openbmc/linux/drivers/gpio/gpio-uniphier.c (revision 842ed298)
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_IRQ_MAX_NUM	24
19 
20 #define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
21 #define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
22 #define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
23 #define UNIPHIER_GPIO_IRQ_MODE		0x94	/* irq mode (1: both edge) */
24 #define UNIPHIER_GPIO_IRQ_FLT_EN	0x98	/* noise filter enable */
25 #define UNIPHIER_GPIO_IRQ_FLT_CYC	0x9c	/* noise filter clock cycle */
26 
27 struct uniphier_gpio_priv {
28 	struct gpio_chip chip;
29 	struct irq_chip irq_chip;
30 	struct irq_domain *domain;
31 	void __iomem *regs;
32 	spinlock_t lock;
33 	u32 saved_vals[];
34 };
35 
36 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
37 {
38 	unsigned int reg;
39 
40 	reg = (bank + 1) * 8;
41 
42 	/*
43 	 * Unfortunately, the GPIO port registers are not contiguous because
44 	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
45 	 */
46 	if (reg >= UNIPHIER_GPIO_IRQ_EN)
47 		reg += 0x10;
48 
49 	return reg;
50 }
51 
52 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
53 					    unsigned int *bank, u32 *mask)
54 {
55 	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
56 	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
57 }
58 
59 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
60 				     unsigned int reg, u32 mask, u32 val)
61 {
62 	unsigned long flags;
63 	u32 tmp;
64 
65 	spin_lock_irqsave(&priv->lock, flags);
66 	tmp = readl(priv->regs + reg);
67 	tmp &= ~mask;
68 	tmp |= mask & val;
69 	writel(tmp, priv->regs + reg);
70 	spin_unlock_irqrestore(&priv->lock, flags);
71 }
72 
73 static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
74 				     unsigned int reg, u32 mask, u32 val)
75 {
76 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
77 
78 	if (!mask)
79 		return;
80 
81 	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
82 				 mask, val);
83 }
84 
85 static void uniphier_gpio_offset_write(struct gpio_chip *chip,
86 				       unsigned int offset, unsigned int reg,
87 				       int val)
88 {
89 	unsigned int bank;
90 	u32 mask;
91 
92 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
93 
94 	uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
95 }
96 
97 static int uniphier_gpio_offset_read(struct gpio_chip *chip,
98 				     unsigned int offset, unsigned int reg)
99 {
100 	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
101 	unsigned int bank, reg_offset;
102 	u32 mask;
103 
104 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
105 	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
106 
107 	return !!(readl(priv->regs + reg_offset) & mask);
108 }
109 
110 static int uniphier_gpio_get_direction(struct gpio_chip *chip,
111 				       unsigned int offset)
112 {
113 	if (uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR))
114 		return GPIO_LINE_DIRECTION_IN;
115 
116 	return GPIO_LINE_DIRECTION_OUT;
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 long i, bank, bank_mask, bank_bits;
151 
152 	for_each_set_clump8(i, bank_mask, mask, chip->ngpio) {
153 		bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
154 		bank_bits = bitmap_get_value8(bits, i);
155 
156 		uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
157 					 bank_mask, bank_bits);
158 	}
159 }
160 
161 static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
162 {
163 	struct irq_fwspec fwspec;
164 
165 	if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
166 		return -ENXIO;
167 
168 	fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
169 	fwspec.param_count = 2;
170 	fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
171 	/*
172 	 * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
173 	 * temporarily. Anyway, ->irq_set_type() will override it later.
174 	 */
175 	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
176 
177 	return irq_create_fwspec_mapping(&fwspec);
178 }
179 
180 static void uniphier_gpio_irq_mask(struct irq_data *data)
181 {
182 	struct uniphier_gpio_priv *priv = data->chip_data;
183 	u32 mask = BIT(data->hwirq);
184 
185 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
186 
187 	return irq_chip_mask_parent(data);
188 }
189 
190 static void uniphier_gpio_irq_unmask(struct irq_data *data)
191 {
192 	struct uniphier_gpio_priv *priv = data->chip_data;
193 	u32 mask = BIT(data->hwirq);
194 
195 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
196 
197 	return irq_chip_unmask_parent(data);
198 }
199 
200 static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
201 {
202 	struct uniphier_gpio_priv *priv = data->chip_data;
203 	u32 mask = BIT(data->hwirq);
204 	u32 val = 0;
205 
206 	if (type == IRQ_TYPE_EDGE_BOTH) {
207 		val = mask;
208 		type = IRQ_TYPE_EDGE_FALLING;
209 	}
210 
211 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
212 	/* To enable both edge detection, the noise filter must be enabled. */
213 	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
214 
215 	return irq_chip_set_type_parent(data, type);
216 }
217 
218 static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
219 					      unsigned int hwirq)
220 {
221 	struct device_node *np = priv->chip.parent->of_node;
222 	const __be32 *range;
223 	u32 base, parent_base, size;
224 	int len;
225 
226 	range = of_get_property(np, "socionext,interrupt-ranges", &len);
227 	if (!range)
228 		return -EINVAL;
229 
230 	len /= sizeof(*range);
231 
232 	for (; len >= 3; len -= 3) {
233 		base = be32_to_cpu(*range++);
234 		parent_base = be32_to_cpu(*range++);
235 		size = be32_to_cpu(*range++);
236 
237 		if (base <= hwirq && hwirq < base + size)
238 			return hwirq - base + parent_base;
239 	}
240 
241 	return -ENOENT;
242 }
243 
244 static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
245 					      struct irq_fwspec *fwspec,
246 					      unsigned long *out_hwirq,
247 					      unsigned int *out_type)
248 {
249 	if (WARN_ON(fwspec->param_count < 2))
250 		return -EINVAL;
251 
252 	*out_hwirq = fwspec->param[0];
253 	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
254 
255 	return 0;
256 }
257 
258 static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
259 					  unsigned int virq,
260 					  unsigned int nr_irqs, void *arg)
261 {
262 	struct uniphier_gpio_priv *priv = domain->host_data;
263 	struct irq_fwspec parent_fwspec;
264 	irq_hw_number_t hwirq;
265 	unsigned int type;
266 	int ret;
267 
268 	if (WARN_ON(nr_irqs != 1))
269 		return -EINVAL;
270 
271 	ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
272 	if (ret)
273 		return ret;
274 
275 	ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
276 	if (ret < 0)
277 		return ret;
278 
279 	/* parent is UniPhier AIDET */
280 	parent_fwspec.fwnode = domain->parent->fwnode;
281 	parent_fwspec.param_count = 2;
282 	parent_fwspec.param[0] = ret;
283 	parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
284 						IRQ_TYPE_EDGE_FALLING : type;
285 
286 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
287 					    &priv->irq_chip, priv);
288 	if (ret)
289 		return ret;
290 
291 	return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
292 }
293 
294 static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
295 					     struct irq_data *data, bool early)
296 {
297 	struct uniphier_gpio_priv *priv = domain->host_data;
298 	struct gpio_chip *chip = &priv->chip;
299 
300 	return gpiochip_lock_as_irq(chip, data->hwirq + 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, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
310 }
311 
312 static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
313 	.alloc = uniphier_gpio_irq_domain_alloc,
314 	.free = irq_domain_free_irqs_common,
315 	.activate = uniphier_gpio_irq_domain_activate,
316 	.deactivate = uniphier_gpio_irq_domain_deactivate,
317 	.translate = uniphier_gpio_irq_domain_translate,
318 };
319 
320 static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
321 {
322 	/*
323 	 * Due to the hardware design, the noise filter must be enabled to
324 	 * detect both edge interrupts.  This filter is intended to remove the
325 	 * noise from the irq lines.  It does not work for GPIO input, so GPIO
326 	 * debounce is not supported.  Unfortunately, the filter period is
327 	 * shared among all irq lines.  Just choose a sensible period here.
328 	 */
329 	writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
330 }
331 
332 static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
333 {
334 	return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
335 }
336 
337 static int uniphier_gpio_probe(struct platform_device *pdev)
338 {
339 	struct device *dev = &pdev->dev;
340 	struct device_node *parent_np;
341 	struct irq_domain *parent_domain;
342 	struct uniphier_gpio_priv *priv;
343 	struct gpio_chip *chip;
344 	struct irq_chip *irq_chip;
345 	unsigned int nregs;
346 	u32 ngpios;
347 	int ret;
348 
349 	parent_np = of_irq_find_parent(dev->of_node);
350 	if (!parent_np)
351 		return -ENXIO;
352 
353 	parent_domain = irq_find_host(parent_np);
354 	of_node_put(parent_np);
355 	if (!parent_domain)
356 		return -EPROBE_DEFER;
357 
358 	ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
359 	if (ret)
360 		return ret;
361 
362 	nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
363 	priv = devm_kzalloc(dev, struct_size(priv, saved_vals, nregs),
364 			    GFP_KERNEL);
365 	if (!priv)
366 		return -ENOMEM;
367 
368 	priv->regs = devm_platform_ioremap_resource(pdev, 0);
369 	if (IS_ERR(priv->regs))
370 		return PTR_ERR(priv->regs);
371 
372 	spin_lock_init(&priv->lock);
373 
374 	chip = &priv->chip;
375 	chip->label = dev_name(dev);
376 	chip->parent = dev;
377 	chip->request = gpiochip_generic_request;
378 	chip->free = gpiochip_generic_free;
379 	chip->get_direction = uniphier_gpio_get_direction;
380 	chip->direction_input = uniphier_gpio_direction_input;
381 	chip->direction_output = uniphier_gpio_direction_output;
382 	chip->get = uniphier_gpio_get;
383 	chip->set = uniphier_gpio_set;
384 	chip->set_multiple = uniphier_gpio_set_multiple;
385 	chip->to_irq = uniphier_gpio_to_irq;
386 	chip->base = -1;
387 	chip->ngpio = ngpios;
388 
389 	irq_chip = &priv->irq_chip;
390 	irq_chip->name = dev_name(dev);
391 	irq_chip->irq_mask = uniphier_gpio_irq_mask;
392 	irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
393 	irq_chip->irq_eoi = irq_chip_eoi_parent;
394 	irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
395 	irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
396 
397 	uniphier_gpio_hw_init(priv);
398 
399 	ret = devm_gpiochip_add_data(dev, chip, priv);
400 	if (ret)
401 		return ret;
402 
403 	priv->domain = irq_domain_create_hierarchy(
404 					parent_domain, 0,
405 					UNIPHIER_GPIO_IRQ_MAX_NUM,
406 					of_node_to_fwnode(dev->of_node),
407 					&uniphier_gpio_irq_domain_ops, priv);
408 	if (!priv->domain)
409 		return -ENOMEM;
410 
411 	platform_set_drvdata(pdev, priv);
412 
413 	return 0;
414 }
415 
416 static int uniphier_gpio_remove(struct platform_device *pdev)
417 {
418 	struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
419 
420 	irq_domain_remove(priv->domain);
421 
422 	return 0;
423 }
424 
425 static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
426 {
427 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
428 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
429 	u32 *val = priv->saved_vals;
430 	unsigned int reg;
431 	int i;
432 
433 	for (i = 0; i < nbanks; i++) {
434 		reg = uniphier_gpio_bank_to_reg(i);
435 
436 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
437 		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
438 	}
439 
440 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
441 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
442 	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
443 
444 	return 0;
445 }
446 
447 static int __maybe_unused uniphier_gpio_resume(struct device *dev)
448 {
449 	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
450 	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
451 	const u32 *val = priv->saved_vals;
452 	unsigned int reg;
453 	int i;
454 
455 	for (i = 0; i < nbanks; i++) {
456 		reg = uniphier_gpio_bank_to_reg(i);
457 
458 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
459 		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
460 	}
461 
462 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
463 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
464 	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
465 
466 	uniphier_gpio_hw_init(priv);
467 
468 	return 0;
469 }
470 
471 static const struct dev_pm_ops uniphier_gpio_pm_ops = {
472 	SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
473 				     uniphier_gpio_resume)
474 };
475 
476 static const struct of_device_id uniphier_gpio_match[] = {
477 	{ .compatible = "socionext,uniphier-gpio" },
478 	{ /* sentinel */ }
479 };
480 MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
481 
482 static struct platform_driver uniphier_gpio_driver = {
483 	.probe = uniphier_gpio_probe,
484 	.remove = uniphier_gpio_remove,
485 	.driver = {
486 		.name = "uniphier-gpio",
487 		.of_match_table = uniphier_gpio_match,
488 		.pm = &uniphier_gpio_pm_ops,
489 	},
490 };
491 module_platform_driver(uniphier_gpio_driver);
492 
493 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
494 MODULE_DESCRIPTION("UniPhier GPIO driver");
495 MODULE_LICENSE("GPL v2");
496