1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas RZ/G2L IRQC Driver
4  *
5  * Copyright (C) 2022 Renesas Electronics Corporation.
6  *
7  * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/cleanup.h>
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/io.h>
15 #include <linux/irqchip.h>
16 #include <linux/irqdomain.h>
17 #include <linux/of_address.h>
18 #include <linux/of_platform.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/reset.h>
21 #include <linux/spinlock.h>
22 #include <linux/syscore_ops.h>
23 
24 #define IRQC_IRQ_START			1
25 #define IRQC_IRQ_COUNT			8
26 #define IRQC_TINT_START			(IRQC_IRQ_START + IRQC_IRQ_COUNT)
27 #define IRQC_TINT_COUNT			32
28 #define IRQC_NUM_IRQ			(IRQC_TINT_START + IRQC_TINT_COUNT)
29 
30 #define ISCR				0x10
31 #define IITSR				0x14
32 #define TSCR				0x20
33 #define TITSR(n)			(0x24 + (n) * 4)
34 #define TITSR0_MAX_INT			16
35 #define TITSEL_WIDTH			0x2
36 #define TSSR(n)				(0x30 + ((n) * 4))
37 #define TIEN				BIT(7)
38 #define TSSEL_SHIFT(n)			(8 * (n))
39 #define TSSEL_MASK			GENMASK(7, 0)
40 #define IRQ_MASK			0x3
41 
42 #define TSSR_OFFSET(n)			((n) % 4)
43 #define TSSR_INDEX(n)			((n) / 4)
44 
45 #define TITSR_TITSEL_EDGE_RISING	0
46 #define TITSR_TITSEL_EDGE_FALLING	1
47 #define TITSR_TITSEL_LEVEL_HIGH		2
48 #define TITSR_TITSEL_LEVEL_LOW		3
49 
50 #define IITSR_IITSEL(n, sense)		((sense) << ((n) * 2))
51 #define IITSR_IITSEL_LEVEL_LOW		0
52 #define IITSR_IITSEL_EDGE_FALLING	1
53 #define IITSR_IITSEL_EDGE_RISING	2
54 #define IITSR_IITSEL_EDGE_BOTH		3
55 #define IITSR_IITSEL_MASK(n)		IITSR_IITSEL((n), 3)
56 
57 #define TINT_EXTRACT_HWIRQ(x)           FIELD_GET(GENMASK(15, 0), (x))
58 #define TINT_EXTRACT_GPIOINT(x)         FIELD_GET(GENMASK(31, 16), (x))
59 
60 /**
61  * struct rzg2l_irqc_reg_cache - registers cache (necessary for suspend/resume)
62  * @iitsr: IITSR register
63  * @titsr: TITSR registers
64  */
65 struct rzg2l_irqc_reg_cache {
66 	u32	iitsr;
67 	u32	titsr[2];
68 };
69 
70 /**
71  * struct rzg2l_irqc_priv - IRQ controller private data structure
72  * @base:	Controller's base address
73  * @fwspec:	IRQ firmware specific data
74  * @lock:	Lock to serialize access to hardware registers
75  * @cache:	Registers cache for suspend/resume
76  */
77 static struct rzg2l_irqc_priv {
78 	void __iomem			*base;
79 	struct irq_fwspec		fwspec[IRQC_NUM_IRQ];
80 	raw_spinlock_t			lock;
81 	struct rzg2l_irqc_reg_cache	cache;
82 } *rzg2l_irqc_data;
83 
84 static struct rzg2l_irqc_priv *irq_data_to_priv(struct irq_data *data)
85 {
86 	return data->domain->host_data;
87 }
88 
89 static void rzg2l_clear_irq_int(struct rzg2l_irqc_priv *priv, unsigned int hwirq)
90 {
91 	unsigned int hw_irq = hwirq - IRQC_IRQ_START;
92 	u32 bit = BIT(hw_irq);
93 	u32 iitsr, iscr;
94 
95 	iscr = readl_relaxed(priv->base + ISCR);
96 	iitsr = readl_relaxed(priv->base + IITSR);
97 
98 	/*
99 	 * ISCR can only be cleared if the type is falling-edge, rising-edge or
100 	 * falling/rising-edge.
101 	 */
102 	if ((iscr & bit) && (iitsr & IITSR_IITSEL_MASK(hw_irq))) {
103 		writel_relaxed(iscr & ~bit, priv->base + ISCR);
104 		/*
105 		 * Enforce that the posted write is flushed to prevent that the
106 		 * just handled interrupt is raised again.
107 		 */
108 		readl_relaxed(priv->base + ISCR);
109 	}
110 }
111 
112 static void rzg2l_clear_tint_int(struct rzg2l_irqc_priv *priv, unsigned int hwirq)
113 {
114 	u32 bit = BIT(hwirq - IRQC_TINT_START);
115 	u32 reg;
116 
117 	reg = readl_relaxed(priv->base + TSCR);
118 	if (reg & bit) {
119 		writel_relaxed(reg & ~bit, priv->base + TSCR);
120 		/*
121 		 * Enforce that the posted write is flushed to prevent that the
122 		 * just handled interrupt is raised again.
123 		 */
124 		readl_relaxed(priv->base + TSCR);
125 	}
126 }
127 
128 static void rzg2l_irqc_eoi(struct irq_data *d)
129 {
130 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
131 	unsigned int hw_irq = irqd_to_hwirq(d);
132 
133 	raw_spin_lock(&priv->lock);
134 	if (hw_irq >= IRQC_IRQ_START && hw_irq <= IRQC_IRQ_COUNT)
135 		rzg2l_clear_irq_int(priv, hw_irq);
136 	else if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ)
137 		rzg2l_clear_tint_int(priv, hw_irq);
138 	raw_spin_unlock(&priv->lock);
139 	irq_chip_eoi_parent(d);
140 }
141 
142 static void rzg2l_irqc_irq_disable(struct irq_data *d)
143 {
144 	unsigned int hw_irq = irqd_to_hwirq(d);
145 
146 	if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ) {
147 		struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
148 		u32 offset = hw_irq - IRQC_TINT_START;
149 		u32 tssr_offset = TSSR_OFFSET(offset);
150 		u8 tssr_index = TSSR_INDEX(offset);
151 		u32 reg;
152 
153 		raw_spin_lock(&priv->lock);
154 		reg = readl_relaxed(priv->base + TSSR(tssr_index));
155 		reg &= ~(TIEN << TSSEL_SHIFT(tssr_offset));
156 		writel_relaxed(reg, priv->base + TSSR(tssr_index));
157 		raw_spin_unlock(&priv->lock);
158 	}
159 	irq_chip_disable_parent(d);
160 }
161 
162 static void rzg2l_irqc_irq_enable(struct irq_data *d)
163 {
164 	unsigned int hw_irq = irqd_to_hwirq(d);
165 
166 	if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ) {
167 		struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
168 		u32 offset = hw_irq - IRQC_TINT_START;
169 		u32 tssr_offset = TSSR_OFFSET(offset);
170 		u8 tssr_index = TSSR_INDEX(offset);
171 		u32 reg;
172 
173 		raw_spin_lock(&priv->lock);
174 		reg = readl_relaxed(priv->base + TSSR(tssr_index));
175 		reg |= TIEN << TSSEL_SHIFT(tssr_offset);
176 		writel_relaxed(reg, priv->base + TSSR(tssr_index));
177 		raw_spin_unlock(&priv->lock);
178 	}
179 	irq_chip_enable_parent(d);
180 }
181 
182 static int rzg2l_irq_set_type(struct irq_data *d, unsigned int type)
183 {
184 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
185 	unsigned int hwirq = irqd_to_hwirq(d);
186 	u32 iitseln = hwirq - IRQC_IRQ_START;
187 	bool clear_irq_int = false;
188 	u16 sense, tmp;
189 
190 	switch (type & IRQ_TYPE_SENSE_MASK) {
191 	case IRQ_TYPE_LEVEL_LOW:
192 		sense = IITSR_IITSEL_LEVEL_LOW;
193 		break;
194 
195 	case IRQ_TYPE_EDGE_FALLING:
196 		sense = IITSR_IITSEL_EDGE_FALLING;
197 		clear_irq_int = true;
198 		break;
199 
200 	case IRQ_TYPE_EDGE_RISING:
201 		sense = IITSR_IITSEL_EDGE_RISING;
202 		clear_irq_int = true;
203 		break;
204 
205 	case IRQ_TYPE_EDGE_BOTH:
206 		sense = IITSR_IITSEL_EDGE_BOTH;
207 		clear_irq_int = true;
208 		break;
209 
210 	default:
211 		return -EINVAL;
212 	}
213 
214 	raw_spin_lock(&priv->lock);
215 	tmp = readl_relaxed(priv->base + IITSR);
216 	tmp &= ~IITSR_IITSEL_MASK(iitseln);
217 	tmp |= IITSR_IITSEL(iitseln, sense);
218 	if (clear_irq_int)
219 		rzg2l_clear_irq_int(priv, hwirq);
220 	writel_relaxed(tmp, priv->base + IITSR);
221 	raw_spin_unlock(&priv->lock);
222 
223 	return 0;
224 }
225 
226 static u32 rzg2l_disable_tint_and_set_tint_source(struct irq_data *d, struct rzg2l_irqc_priv *priv,
227 						  u32 reg, u32 tssr_offset, u8 tssr_index)
228 {
229 	u32 tint = (u32)(uintptr_t)irq_data_get_irq_chip_data(d);
230 	u32 tien = reg & (TIEN << TSSEL_SHIFT(tssr_offset));
231 
232 	/* Clear the relevant byte in reg */
233 	reg &= ~(TSSEL_MASK << TSSEL_SHIFT(tssr_offset));
234 	/* Set TINT and leave TIEN clear */
235 	reg |= tint << TSSEL_SHIFT(tssr_offset);
236 	writel_relaxed(reg, priv->base + TSSR(tssr_index));
237 
238 	return reg | tien;
239 }
240 
241 static int rzg2l_tint_set_edge(struct irq_data *d, unsigned int type)
242 {
243 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
244 	unsigned int hwirq = irqd_to_hwirq(d);
245 	u32 titseln = hwirq - IRQC_TINT_START;
246 	u32 tssr_offset = TSSR_OFFSET(titseln);
247 	u8 tssr_index = TSSR_INDEX(titseln);
248 	u8 index, sense;
249 	u32 reg, tssr;
250 
251 	switch (type & IRQ_TYPE_SENSE_MASK) {
252 	case IRQ_TYPE_EDGE_RISING:
253 		sense = TITSR_TITSEL_EDGE_RISING;
254 		break;
255 
256 	case IRQ_TYPE_EDGE_FALLING:
257 		sense = TITSR_TITSEL_EDGE_FALLING;
258 		break;
259 
260 	default:
261 		return -EINVAL;
262 	}
263 
264 	index = 0;
265 	if (titseln >= TITSR0_MAX_INT) {
266 		titseln -= TITSR0_MAX_INT;
267 		index = 1;
268 	}
269 
270 	raw_spin_lock(&priv->lock);
271 	tssr = readl_relaxed(priv->base + TSSR(tssr_index));
272 	tssr = rzg2l_disable_tint_and_set_tint_source(d, priv, tssr, tssr_offset, tssr_index);
273 	reg = readl_relaxed(priv->base + TITSR(index));
274 	reg &= ~(IRQ_MASK << (titseln * TITSEL_WIDTH));
275 	reg |= sense << (titseln * TITSEL_WIDTH);
276 	writel_relaxed(reg, priv->base + TITSR(index));
277 	rzg2l_clear_tint_int(priv, hwirq);
278 	writel_relaxed(tssr, priv->base + TSSR(tssr_index));
279 	raw_spin_unlock(&priv->lock);
280 
281 	return 0;
282 }
283 
284 static int rzg2l_irqc_set_type(struct irq_data *d, unsigned int type)
285 {
286 	unsigned int hw_irq = irqd_to_hwirq(d);
287 	int ret = -EINVAL;
288 
289 	if (hw_irq >= IRQC_IRQ_START && hw_irq <= IRQC_IRQ_COUNT)
290 		ret = rzg2l_irq_set_type(d, type);
291 	else if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ)
292 		ret = rzg2l_tint_set_edge(d, type);
293 	if (ret)
294 		return ret;
295 
296 	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
297 }
298 
299 static int rzg2l_irqc_irq_suspend(void)
300 {
301 	struct rzg2l_irqc_reg_cache *cache = &rzg2l_irqc_data->cache;
302 	void __iomem *base = rzg2l_irqc_data->base;
303 
304 	cache->iitsr = readl_relaxed(base + IITSR);
305 	for (u8 i = 0; i < 2; i++)
306 		cache->titsr[i] = readl_relaxed(base + TITSR(i));
307 
308 	return 0;
309 }
310 
311 static void rzg2l_irqc_irq_resume(void)
312 {
313 	struct rzg2l_irqc_reg_cache *cache = &rzg2l_irqc_data->cache;
314 	void __iomem *base = rzg2l_irqc_data->base;
315 
316 	/*
317 	 * Restore only interrupt type. TSSRx will be restored at the
318 	 * request of pin controller to avoid spurious interrupts due
319 	 * to invalid PIN states.
320 	 */
321 	for (u8 i = 0; i < 2; i++)
322 		writel_relaxed(cache->titsr[i], base + TITSR(i));
323 	writel_relaxed(cache->iitsr, base + IITSR);
324 }
325 
326 static struct syscore_ops rzg2l_irqc_syscore_ops = {
327 	.suspend	= rzg2l_irqc_irq_suspend,
328 	.resume		= rzg2l_irqc_irq_resume,
329 };
330 
331 static const struct irq_chip irqc_chip = {
332 	.name			= "rzg2l-irqc",
333 	.irq_eoi		= rzg2l_irqc_eoi,
334 	.irq_mask		= irq_chip_mask_parent,
335 	.irq_unmask		= irq_chip_unmask_parent,
336 	.irq_disable		= rzg2l_irqc_irq_disable,
337 	.irq_enable		= rzg2l_irqc_irq_enable,
338 	.irq_get_irqchip_state	= irq_chip_get_parent_state,
339 	.irq_set_irqchip_state	= irq_chip_set_parent_state,
340 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
341 	.irq_set_type		= rzg2l_irqc_set_type,
342 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
343 				  IRQCHIP_SET_TYPE_MASKED |
344 				  IRQCHIP_SKIP_SET_WAKE,
345 };
346 
347 static int rzg2l_irqc_alloc(struct irq_domain *domain, unsigned int virq,
348 			    unsigned int nr_irqs, void *arg)
349 {
350 	struct rzg2l_irqc_priv *priv = domain->host_data;
351 	unsigned long tint = 0;
352 	irq_hw_number_t hwirq;
353 	unsigned int type;
354 	int ret;
355 
356 	ret = irq_domain_translate_twocell(domain, arg, &hwirq, &type);
357 	if (ret)
358 		return ret;
359 
360 	/*
361 	 * For TINT interrupts ie where pinctrl driver is child of irqc domain
362 	 * the hwirq and TINT are encoded in fwspec->param[0].
363 	 * hwirq for TINT range from 9-40, hwirq is embedded 0-15 bits and TINT
364 	 * from 16-31 bits. TINT from the pinctrl driver needs to be programmed
365 	 * in IRQC registers to enable a given gpio pin as interrupt.
366 	 */
367 	if (hwirq > IRQC_IRQ_COUNT) {
368 		tint = TINT_EXTRACT_GPIOINT(hwirq);
369 		hwirq = TINT_EXTRACT_HWIRQ(hwirq);
370 
371 		if (hwirq < IRQC_TINT_START)
372 			return -EINVAL;
373 	}
374 
375 	if (hwirq > (IRQC_NUM_IRQ - 1))
376 		return -EINVAL;
377 
378 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &irqc_chip,
379 					    (void *)(uintptr_t)tint);
380 	if (ret)
381 		return ret;
382 
383 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &priv->fwspec[hwirq]);
384 }
385 
386 static const struct irq_domain_ops rzg2l_irqc_domain_ops = {
387 	.alloc = rzg2l_irqc_alloc,
388 	.free = irq_domain_free_irqs_common,
389 	.translate = irq_domain_translate_twocell,
390 };
391 
392 static int rzg2l_irqc_parse_interrupts(struct rzg2l_irqc_priv *priv,
393 				       struct device_node *np)
394 {
395 	struct of_phandle_args map;
396 	unsigned int i;
397 	int ret;
398 
399 	for (i = 0; i < IRQC_NUM_IRQ; i++) {
400 		ret = of_irq_parse_one(np, i, &map);
401 		if (ret)
402 			return ret;
403 		of_phandle_args_to_fwspec(np, map.args, map.args_count,
404 					  &priv->fwspec[i]);
405 	}
406 
407 	return 0;
408 }
409 
410 static int rzg2l_irqc_init(struct device_node *node, struct device_node *parent)
411 {
412 	struct platform_device *pdev = of_find_device_by_node(node);
413 	struct device *dev __free(put_device) = pdev ? &pdev->dev : NULL;
414 	struct irq_domain *irq_domain, *parent_domain;
415 	struct reset_control *resetn;
416 	int ret;
417 
418 	if (!pdev)
419 		return -ENODEV;
420 
421 	parent_domain = irq_find_host(parent);
422 	if (!parent_domain) {
423 		dev_err(&pdev->dev, "cannot find parent domain\n");
424 		return -ENODEV;
425 	}
426 
427 	rzg2l_irqc_data = devm_kzalloc(&pdev->dev, sizeof(*rzg2l_irqc_data), GFP_KERNEL);
428 	if (!rzg2l_irqc_data)
429 		return -ENOMEM;
430 
431 	rzg2l_irqc_data->base = devm_of_iomap(&pdev->dev, pdev->dev.of_node, 0, NULL);
432 	if (IS_ERR(rzg2l_irqc_data->base))
433 		return PTR_ERR(rzg2l_irqc_data->base);
434 
435 	ret = rzg2l_irqc_parse_interrupts(rzg2l_irqc_data, node);
436 	if (ret) {
437 		dev_err(&pdev->dev, "cannot parse interrupts: %d\n", ret);
438 		return ret;
439 	}
440 
441 	resetn = devm_reset_control_get_exclusive(&pdev->dev, NULL);
442 	if (IS_ERR(resetn))
443 		return PTR_ERR(resetn);
444 
445 	ret = reset_control_deassert(resetn);
446 	if (ret) {
447 		dev_err(&pdev->dev, "failed to deassert resetn pin, %d\n", ret);
448 		return ret;
449 	}
450 
451 	pm_runtime_enable(&pdev->dev);
452 	ret = pm_runtime_resume_and_get(&pdev->dev);
453 	if (ret < 0) {
454 		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed: %d\n", ret);
455 		goto pm_disable;
456 	}
457 
458 	raw_spin_lock_init(&rzg2l_irqc_data->lock);
459 
460 	irq_domain = irq_domain_add_hierarchy(parent_domain, 0, IRQC_NUM_IRQ,
461 					      node, &rzg2l_irqc_domain_ops,
462 					      rzg2l_irqc_data);
463 	if (!irq_domain) {
464 		dev_err(&pdev->dev, "failed to add irq domain\n");
465 		ret = -ENOMEM;
466 		goto pm_put;
467 	}
468 
469 	register_syscore_ops(&rzg2l_irqc_syscore_ops);
470 
471 	/*
472 	 * Prevent the cleanup function from invoking put_device by assigning
473 	 * NULL to dev.
474 	 *
475 	 * make coccicheck will complain about missing put_device calls, but
476 	 * those are false positives, as dev will be automatically "put" via
477 	 * __free_put_device on the failing path.
478 	 * On the successful path we don't actually want to "put" dev.
479 	 */
480 	dev = NULL;
481 
482 	return 0;
483 
484 pm_put:
485 	pm_runtime_put(&pdev->dev);
486 pm_disable:
487 	pm_runtime_disable(&pdev->dev);
488 	reset_control_assert(resetn);
489 	return ret;
490 }
491 
492 IRQCHIP_PLATFORM_DRIVER_BEGIN(rzg2l_irqc)
493 IRQCHIP_MATCH("renesas,rzg2l-irqc", rzg2l_irqc_init)
494 IRQCHIP_PLATFORM_DRIVER_END(rzg2l_irqc)
495 MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
496 MODULE_DESCRIPTION("Renesas RZ/G2L IRQC Driver");
497