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/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqdomain.h>
16 #include <linux/of_address.h>
17 #include <linux/of_platform.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/reset.h>
20 #include <linux/spinlock.h>
21 
22 #define IRQC_IRQ_START			1
23 #define IRQC_IRQ_COUNT			8
24 #define IRQC_TINT_START			(IRQC_IRQ_START + IRQC_IRQ_COUNT)
25 #define IRQC_TINT_COUNT			32
26 #define IRQC_NUM_IRQ			(IRQC_TINT_START + IRQC_TINT_COUNT)
27 
28 #define ISCR				0x10
29 #define IITSR				0x14
30 #define TSCR				0x20
31 #define TITSR0				0x24
32 #define TITSR1				0x28
33 #define TITSR0_MAX_INT			16
34 #define TITSEL_WIDTH			0x2
35 #define TSSR(n)				(0x30 + ((n) * 4))
36 #define TIEN				BIT(7)
37 #define TSSEL_SHIFT(n)			(8 * (n))
38 #define TSSEL_MASK			GENMASK(7, 0)
39 #define IRQ_MASK			0x3
40 
41 #define TSSR_OFFSET(n)			((n) % 4)
42 #define TSSR_INDEX(n)			((n) / 4)
43 
44 #define TITSR_TITSEL_EDGE_RISING	0
45 #define TITSR_TITSEL_EDGE_FALLING	1
46 #define TITSR_TITSEL_LEVEL_HIGH		2
47 #define TITSR_TITSEL_LEVEL_LOW		3
48 
49 #define IITSR_IITSEL(n, sense)		((sense) << ((n) * 2))
50 #define IITSR_IITSEL_LEVEL_LOW		0
51 #define IITSR_IITSEL_EDGE_FALLING	1
52 #define IITSR_IITSEL_EDGE_RISING	2
53 #define IITSR_IITSEL_EDGE_BOTH		3
54 #define IITSR_IITSEL_MASK(n)		IITSR_IITSEL((n), 3)
55 
56 #define TINT_EXTRACT_HWIRQ(x)           FIELD_GET(GENMASK(15, 0), (x))
57 #define TINT_EXTRACT_GPIOINT(x)         FIELD_GET(GENMASK(31, 16), (x))
58 
59 struct rzg2l_irqc_priv {
60 	void __iomem *base;
61 	struct irq_fwspec fwspec[IRQC_NUM_IRQ];
62 	raw_spinlock_t lock;
63 };
64 
65 static struct rzg2l_irqc_priv *irq_data_to_priv(struct irq_data *data)
66 {
67 	return data->domain->host_data;
68 }
69 
70 static void rzg2l_irq_eoi(struct irq_data *d)
71 {
72 	unsigned int hw_irq = irqd_to_hwirq(d) - IRQC_IRQ_START;
73 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
74 	u32 bit = BIT(hw_irq);
75 	u32 reg;
76 
77 	reg = readl_relaxed(priv->base + ISCR);
78 	if (reg & bit)
79 		writel_relaxed(reg & ~bit, priv->base + ISCR);
80 }
81 
82 static void rzg2l_tint_eoi(struct irq_data *d)
83 {
84 	unsigned int hw_irq = irqd_to_hwirq(d) - IRQC_TINT_START;
85 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
86 	u32 bit = BIT(hw_irq);
87 	u32 reg;
88 
89 	reg = readl_relaxed(priv->base + TSCR);
90 	if (reg & bit)
91 		writel_relaxed(reg & ~bit, priv->base + TSCR);
92 }
93 
94 static void rzg2l_irqc_eoi(struct irq_data *d)
95 {
96 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
97 	unsigned int hw_irq = irqd_to_hwirq(d);
98 
99 	raw_spin_lock(&priv->lock);
100 	if (hw_irq >= IRQC_IRQ_START && hw_irq <= IRQC_IRQ_COUNT)
101 		rzg2l_irq_eoi(d);
102 	else if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ)
103 		rzg2l_tint_eoi(d);
104 	raw_spin_unlock(&priv->lock);
105 	irq_chip_eoi_parent(d);
106 }
107 
108 static void rzg2l_irqc_irq_disable(struct irq_data *d)
109 {
110 	unsigned int hw_irq = irqd_to_hwirq(d);
111 
112 	if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ) {
113 		struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
114 		u32 offset = hw_irq - IRQC_TINT_START;
115 		u32 tssr_offset = TSSR_OFFSET(offset);
116 		u8 tssr_index = TSSR_INDEX(offset);
117 		u32 reg;
118 
119 		raw_spin_lock(&priv->lock);
120 		reg = readl_relaxed(priv->base + TSSR(tssr_index));
121 		reg &= ~(TSSEL_MASK << TSSEL_SHIFT(tssr_offset));
122 		writel_relaxed(reg, priv->base + TSSR(tssr_index));
123 		raw_spin_unlock(&priv->lock);
124 	}
125 	irq_chip_disable_parent(d);
126 }
127 
128 static void rzg2l_irqc_irq_enable(struct irq_data *d)
129 {
130 	unsigned int hw_irq = irqd_to_hwirq(d);
131 
132 	if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ) {
133 		unsigned long tint = (uintptr_t)irq_data_get_irq_chip_data(d);
134 		struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
135 		u32 offset = hw_irq - IRQC_TINT_START;
136 		u32 tssr_offset = TSSR_OFFSET(offset);
137 		u8 tssr_index = TSSR_INDEX(offset);
138 		u32 reg;
139 
140 		raw_spin_lock(&priv->lock);
141 		reg = readl_relaxed(priv->base + TSSR(tssr_index));
142 		reg |= (TIEN | tint) << TSSEL_SHIFT(tssr_offset);
143 		writel_relaxed(reg, priv->base + TSSR(tssr_index));
144 		raw_spin_unlock(&priv->lock);
145 	}
146 	irq_chip_enable_parent(d);
147 }
148 
149 static int rzg2l_irq_set_type(struct irq_data *d, unsigned int type)
150 {
151 	unsigned int hw_irq = irqd_to_hwirq(d) - IRQC_IRQ_START;
152 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
153 	u16 sense, tmp;
154 
155 	switch (type & IRQ_TYPE_SENSE_MASK) {
156 	case IRQ_TYPE_LEVEL_LOW:
157 		sense = IITSR_IITSEL_LEVEL_LOW;
158 		break;
159 
160 	case IRQ_TYPE_EDGE_FALLING:
161 		sense = IITSR_IITSEL_EDGE_FALLING;
162 		break;
163 
164 	case IRQ_TYPE_EDGE_RISING:
165 		sense = IITSR_IITSEL_EDGE_RISING;
166 		break;
167 
168 	case IRQ_TYPE_EDGE_BOTH:
169 		sense = IITSR_IITSEL_EDGE_BOTH;
170 		break;
171 
172 	default:
173 		return -EINVAL;
174 	}
175 
176 	raw_spin_lock(&priv->lock);
177 	tmp = readl_relaxed(priv->base + IITSR);
178 	tmp &= ~IITSR_IITSEL_MASK(hw_irq);
179 	tmp |= IITSR_IITSEL(hw_irq, sense);
180 	writel_relaxed(tmp, priv->base + IITSR);
181 	raw_spin_unlock(&priv->lock);
182 
183 	return 0;
184 }
185 
186 static int rzg2l_tint_set_edge(struct irq_data *d, unsigned int type)
187 {
188 	struct rzg2l_irqc_priv *priv = irq_data_to_priv(d);
189 	unsigned int hwirq = irqd_to_hwirq(d);
190 	u32 titseln = hwirq - IRQC_TINT_START;
191 	u32 offset;
192 	u8 sense;
193 	u32 reg;
194 
195 	switch (type & IRQ_TYPE_SENSE_MASK) {
196 	case IRQ_TYPE_EDGE_RISING:
197 		sense = TITSR_TITSEL_EDGE_RISING;
198 		break;
199 
200 	case IRQ_TYPE_EDGE_FALLING:
201 		sense = TITSR_TITSEL_EDGE_FALLING;
202 		break;
203 
204 	default:
205 		return -EINVAL;
206 	}
207 
208 	offset = TITSR0;
209 	if (titseln >= TITSR0_MAX_INT) {
210 		titseln -= TITSR0_MAX_INT;
211 		offset = TITSR1;
212 	}
213 
214 	raw_spin_lock(&priv->lock);
215 	reg = readl_relaxed(priv->base + offset);
216 	reg &= ~(IRQ_MASK << (titseln * TITSEL_WIDTH));
217 	reg |= sense << (titseln * TITSEL_WIDTH);
218 	writel_relaxed(reg, priv->base + offset);
219 	raw_spin_unlock(&priv->lock);
220 
221 	return 0;
222 }
223 
224 static int rzg2l_irqc_set_type(struct irq_data *d, unsigned int type)
225 {
226 	unsigned int hw_irq = irqd_to_hwirq(d);
227 	int ret = -EINVAL;
228 
229 	if (hw_irq >= IRQC_IRQ_START && hw_irq <= IRQC_IRQ_COUNT)
230 		ret = rzg2l_irq_set_type(d, type);
231 	else if (hw_irq >= IRQC_TINT_START && hw_irq < IRQC_NUM_IRQ)
232 		ret = rzg2l_tint_set_edge(d, type);
233 	if (ret)
234 		return ret;
235 
236 	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
237 }
238 
239 static const struct irq_chip irqc_chip = {
240 	.name			= "rzg2l-irqc",
241 	.irq_eoi		= rzg2l_irqc_eoi,
242 	.irq_mask		= irq_chip_mask_parent,
243 	.irq_unmask		= irq_chip_unmask_parent,
244 	.irq_disable		= rzg2l_irqc_irq_disable,
245 	.irq_enable		= rzg2l_irqc_irq_enable,
246 	.irq_get_irqchip_state	= irq_chip_get_parent_state,
247 	.irq_set_irqchip_state	= irq_chip_set_parent_state,
248 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
249 	.irq_set_type		= rzg2l_irqc_set_type,
250 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
251 				  IRQCHIP_SET_TYPE_MASKED |
252 				  IRQCHIP_SKIP_SET_WAKE,
253 };
254 
255 static int rzg2l_irqc_alloc(struct irq_domain *domain, unsigned int virq,
256 			    unsigned int nr_irqs, void *arg)
257 {
258 	struct rzg2l_irqc_priv *priv = domain->host_data;
259 	unsigned long tint = 0;
260 	irq_hw_number_t hwirq;
261 	unsigned int type;
262 	int ret;
263 
264 	ret = irq_domain_translate_twocell(domain, arg, &hwirq, &type);
265 	if (ret)
266 		return ret;
267 
268 	/*
269 	 * For TINT interrupts ie where pinctrl driver is child of irqc domain
270 	 * the hwirq and TINT are encoded in fwspec->param[0].
271 	 * hwirq for TINT range from 9-40, hwirq is embedded 0-15 bits and TINT
272 	 * from 16-31 bits. TINT from the pinctrl driver needs to be programmed
273 	 * in IRQC registers to enable a given gpio pin as interrupt.
274 	 */
275 	if (hwirq > IRQC_IRQ_COUNT) {
276 		tint = TINT_EXTRACT_GPIOINT(hwirq);
277 		hwirq = TINT_EXTRACT_HWIRQ(hwirq);
278 
279 		if (hwirq < IRQC_TINT_START)
280 			return -EINVAL;
281 	}
282 
283 	if (hwirq > (IRQC_NUM_IRQ - 1))
284 		return -EINVAL;
285 
286 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &irqc_chip,
287 					    (void *)(uintptr_t)tint);
288 	if (ret)
289 		return ret;
290 
291 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &priv->fwspec[hwirq]);
292 }
293 
294 static const struct irq_domain_ops rzg2l_irqc_domain_ops = {
295 	.alloc = rzg2l_irqc_alloc,
296 	.free = irq_domain_free_irqs_common,
297 	.translate = irq_domain_translate_twocell,
298 };
299 
300 static int rzg2l_irqc_parse_interrupts(struct rzg2l_irqc_priv *priv,
301 				       struct device_node *np)
302 {
303 	struct of_phandle_args map;
304 	unsigned int i;
305 	int ret;
306 
307 	for (i = 0; i < IRQC_NUM_IRQ; i++) {
308 		ret = of_irq_parse_one(np, i, &map);
309 		if (ret)
310 			return ret;
311 		of_phandle_args_to_fwspec(np, map.args, map.args_count,
312 					  &priv->fwspec[i]);
313 	}
314 
315 	return 0;
316 }
317 
318 static int rzg2l_irqc_init(struct device_node *node, struct device_node *parent)
319 {
320 	struct irq_domain *irq_domain, *parent_domain;
321 	struct platform_device *pdev;
322 	struct reset_control *resetn;
323 	struct rzg2l_irqc_priv *priv;
324 	int ret;
325 
326 	pdev = of_find_device_by_node(node);
327 	if (!pdev)
328 		return -ENODEV;
329 
330 	parent_domain = irq_find_host(parent);
331 	if (!parent_domain) {
332 		dev_err(&pdev->dev, "cannot find parent domain\n");
333 		return -ENODEV;
334 	}
335 
336 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
337 	if (!priv)
338 		return -ENOMEM;
339 
340 	priv->base = devm_of_iomap(&pdev->dev, pdev->dev.of_node, 0, NULL);
341 	if (IS_ERR(priv->base))
342 		return PTR_ERR(priv->base);
343 
344 	ret = rzg2l_irqc_parse_interrupts(priv, node);
345 	if (ret) {
346 		dev_err(&pdev->dev, "cannot parse interrupts: %d\n", ret);
347 		return ret;
348 	}
349 
350 	resetn = devm_reset_control_get_exclusive(&pdev->dev, NULL);
351 	if (IS_ERR(resetn))
352 		return PTR_ERR(resetn);
353 
354 	ret = reset_control_deassert(resetn);
355 	if (ret) {
356 		dev_err(&pdev->dev, "failed to deassert resetn pin, %d\n", ret);
357 		return ret;
358 	}
359 
360 	pm_runtime_enable(&pdev->dev);
361 	ret = pm_runtime_resume_and_get(&pdev->dev);
362 	if (ret < 0) {
363 		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed: %d\n", ret);
364 		goto pm_disable;
365 	}
366 
367 	raw_spin_lock_init(&priv->lock);
368 
369 	irq_domain = irq_domain_add_hierarchy(parent_domain, 0, IRQC_NUM_IRQ,
370 					      node, &rzg2l_irqc_domain_ops,
371 					      priv);
372 	if (!irq_domain) {
373 		dev_err(&pdev->dev, "failed to add irq domain\n");
374 		ret = -ENOMEM;
375 		goto pm_put;
376 	}
377 
378 	return 0;
379 
380 pm_put:
381 	pm_runtime_put(&pdev->dev);
382 pm_disable:
383 	pm_runtime_disable(&pdev->dev);
384 	reset_control_assert(resetn);
385 	return ret;
386 }
387 
388 IRQCHIP_PLATFORM_DRIVER_BEGIN(rzg2l_irqc)
389 IRQCHIP_MATCH("renesas,rzg2l-irqc", rzg2l_irqc_init)
390 IRQCHIP_PLATFORM_DRIVER_END(rzg2l_irqc)
391 MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
392 MODULE_DESCRIPTION("Renesas RZ/G2L IRQC Driver");
393