1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas RZ/A1 IRQC Driver
4  *
5  * Copyright (C) 2019 Glider bvba
6  */
7 
8 #include <linux/err.h>
9 #include <linux/init.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/irqdomain.h>
13 #include <linux/irq.h>
14 #include <linux/module.h>
15 #include <linux/of_irq.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 
19 #include <dt-bindings/interrupt-controller/arm-gic.h>
20 
21 #define IRQC_NUM_IRQ		8
22 
23 #define ICR0			0	/* Interrupt Control Register 0 */
24 
25 #define ICR0_NMIL		BIT(15)	/* NMI Input Level (0=low, 1=high) */
26 #define ICR0_NMIE		BIT(8)	/* Edge Select (0=falling, 1=rising) */
27 #define ICR0_NMIF		BIT(1)	/* NMI Interrupt Request */
28 
29 #define ICR1			2	/* Interrupt Control Register 1 */
30 
31 #define ICR1_IRQS(n, sense)	((sense) << ((n) * 2))	/* IRQ Sense Select */
32 #define ICR1_IRQS_LEVEL_LOW	0
33 #define ICR1_IRQS_EDGE_FALLING	1
34 #define ICR1_IRQS_EDGE_RISING	2
35 #define ICR1_IRQS_EDGE_BOTH	3
36 #define ICR1_IRQS_MASK(n)	ICR1_IRQS((n), 3)
37 
38 #define IRQRR			4	/* IRQ Interrupt Request Register */
39 
40 
41 struct rza1_irqc_priv {
42 	struct device *dev;
43 	void __iomem *base;
44 	struct irq_chip chip;
45 	struct irq_domain *irq_domain;
46 	struct of_phandle_args map[IRQC_NUM_IRQ];
47 };
48 
49 static struct rza1_irqc_priv *irq_data_to_priv(struct irq_data *data)
50 {
51 	return data->domain->host_data;
52 }
53 
54 static void rza1_irqc_eoi(struct irq_data *d)
55 {
56 	struct rza1_irqc_priv *priv = irq_data_to_priv(d);
57 	u16 bit = BIT(irqd_to_hwirq(d));
58 	u16 tmp;
59 
60 	tmp = readw_relaxed(priv->base + IRQRR);
61 	if (tmp & bit)
62 		writew_relaxed(GENMASK(IRQC_NUM_IRQ - 1, 0) & ~bit,
63 			       priv->base + IRQRR);
64 
65 	irq_chip_eoi_parent(d);
66 }
67 
68 static int rza1_irqc_set_type(struct irq_data *d, unsigned int type)
69 {
70 	struct rza1_irqc_priv *priv = irq_data_to_priv(d);
71 	unsigned int hw_irq = irqd_to_hwirq(d);
72 	u16 sense, tmp;
73 
74 	switch (type & IRQ_TYPE_SENSE_MASK) {
75 	case IRQ_TYPE_LEVEL_LOW:
76 		sense = ICR1_IRQS_LEVEL_LOW;
77 		break;
78 
79 	case IRQ_TYPE_EDGE_FALLING:
80 		sense = ICR1_IRQS_EDGE_FALLING;
81 		break;
82 
83 	case IRQ_TYPE_EDGE_RISING:
84 		sense = ICR1_IRQS_EDGE_RISING;
85 		break;
86 
87 	case IRQ_TYPE_EDGE_BOTH:
88 		sense = ICR1_IRQS_EDGE_BOTH;
89 		break;
90 
91 	default:
92 		return -EINVAL;
93 	}
94 
95 	tmp = readw_relaxed(priv->base + ICR1);
96 	tmp &= ~ICR1_IRQS_MASK(hw_irq);
97 	tmp |= ICR1_IRQS(hw_irq, sense);
98 	writew_relaxed(tmp, priv->base + ICR1);
99 	return 0;
100 }
101 
102 static int rza1_irqc_alloc(struct irq_domain *domain, unsigned int virq,
103 			   unsigned int nr_irqs, void *arg)
104 {
105 	struct rza1_irqc_priv *priv = domain->host_data;
106 	struct irq_fwspec *fwspec = arg;
107 	unsigned int hwirq = fwspec->param[0];
108 	struct irq_fwspec spec;
109 	unsigned int i;
110 	int ret;
111 
112 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &priv->chip,
113 					    priv);
114 	if (ret)
115 		return ret;
116 
117 	spec.fwnode = &priv->dev->of_node->fwnode;
118 	spec.param_count = priv->map[hwirq].args_count;
119 	for (i = 0; i < spec.param_count; i++)
120 		spec.param[i] = priv->map[hwirq].args[i];
121 
122 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &spec);
123 }
124 
125 static int rza1_irqc_translate(struct irq_domain *domain,
126 			       struct irq_fwspec *fwspec, unsigned long *hwirq,
127 			       unsigned int *type)
128 {
129 	if (fwspec->param_count != 2 || fwspec->param[0] >= IRQC_NUM_IRQ)
130 		return -EINVAL;
131 
132 	*hwirq = fwspec->param[0];
133 	*type = fwspec->param[1];
134 	return 0;
135 }
136 
137 static const struct irq_domain_ops rza1_irqc_domain_ops = {
138 	.alloc = rza1_irqc_alloc,
139 	.translate = rza1_irqc_translate,
140 };
141 
142 static int rza1_irqc_parse_map(struct rza1_irqc_priv *priv,
143 			       struct device_node *gic_node)
144 {
145 	unsigned int imaplen, i, j, ret;
146 	struct device *dev = priv->dev;
147 	struct device_node *ipar;
148 	const __be32 *imap;
149 	u32 intsize;
150 
151 	imap = of_get_property(dev->of_node, "interrupt-map", &imaplen);
152 	if (!imap)
153 		return -EINVAL;
154 
155 	for (i = 0; i < IRQC_NUM_IRQ; i++) {
156 		if (imaplen < 3)
157 			return -EINVAL;
158 
159 		/* Check interrupt number, ignore sense */
160 		if (be32_to_cpup(imap) != i)
161 			return -EINVAL;
162 
163 		ipar = of_find_node_by_phandle(be32_to_cpup(imap + 2));
164 		if (ipar != gic_node) {
165 			of_node_put(ipar);
166 			return -EINVAL;
167 		}
168 
169 		imap += 3;
170 		imaplen -= 3;
171 
172 		ret = of_property_read_u32(ipar, "#interrupt-cells", &intsize);
173 		of_node_put(ipar);
174 		if (ret)
175 			return ret;
176 
177 		if (imaplen < intsize)
178 			return -EINVAL;
179 
180 		priv->map[i].args_count = intsize;
181 		for (j = 0; j < intsize; j++)
182 			priv->map[i].args[j] = be32_to_cpup(imap++);
183 
184 		imaplen -= intsize;
185 	}
186 
187 	return 0;
188 }
189 
190 static int rza1_irqc_probe(struct platform_device *pdev)
191 {
192 	struct device *dev = &pdev->dev;
193 	struct device_node *np = dev->of_node;
194 	struct irq_domain *parent = NULL;
195 	struct device_node *gic_node;
196 	struct rza1_irqc_priv *priv;
197 	int ret;
198 
199 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
200 	if (!priv)
201 		return -ENOMEM;
202 
203 	platform_set_drvdata(pdev, priv);
204 	priv->dev = dev;
205 
206 	priv->base = devm_platform_ioremap_resource(pdev, 0);
207 	if (IS_ERR(priv->base))
208 		return PTR_ERR(priv->base);
209 
210 	gic_node = of_irq_find_parent(np);
211 	if (gic_node)
212 		parent = irq_find_host(gic_node);
213 
214 	if (!parent) {
215 		dev_err(dev, "cannot find parent domain\n");
216 		ret = -ENODEV;
217 		goto out_put_node;
218 	}
219 
220 	ret = rza1_irqc_parse_map(priv, gic_node);
221 	if (ret) {
222 		dev_err(dev, "cannot parse %s: %d\n", "interrupt-map", ret);
223 		goto out_put_node;
224 	}
225 
226 	priv->chip.name = "rza1-irqc";
227 	priv->chip.irq_mask = irq_chip_mask_parent;
228 	priv->chip.irq_unmask = irq_chip_unmask_parent;
229 	priv->chip.irq_eoi = rza1_irqc_eoi;
230 	priv->chip.irq_retrigger = irq_chip_retrigger_hierarchy;
231 	priv->chip.irq_set_type = rza1_irqc_set_type;
232 	priv->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
233 
234 	priv->irq_domain = irq_domain_add_hierarchy(parent, 0, IRQC_NUM_IRQ,
235 						    np, &rza1_irqc_domain_ops,
236 						    priv);
237 	if (!priv->irq_domain) {
238 		dev_err(dev, "cannot initialize irq domain\n");
239 		ret = -ENOMEM;
240 	}
241 
242 out_put_node:
243 	of_node_put(gic_node);
244 	return ret;
245 }
246 
247 static int rza1_irqc_remove(struct platform_device *pdev)
248 {
249 	struct rza1_irqc_priv *priv = platform_get_drvdata(pdev);
250 
251 	irq_domain_remove(priv->irq_domain);
252 	return 0;
253 }
254 
255 static const struct of_device_id rza1_irqc_dt_ids[] = {
256 	{ .compatible = "renesas,rza1-irqc" },
257 	{},
258 };
259 MODULE_DEVICE_TABLE(of, rza1_irqc_dt_ids);
260 
261 static struct platform_driver rza1_irqc_device_driver = {
262 	.probe		= rza1_irqc_probe,
263 	.remove		= rza1_irqc_remove,
264 	.driver		= {
265 		.name	= "renesas_rza1_irqc",
266 		.of_match_table	= rza1_irqc_dt_ids,
267 	}
268 };
269 
270 static int __init rza1_irqc_init(void)
271 {
272 	return platform_driver_register(&rza1_irqc_device_driver);
273 }
274 postcore_initcall(rza1_irqc_init);
275 
276 static void __exit rza1_irqc_exit(void)
277 {
278 	platform_driver_unregister(&rza1_irqc_device_driver);
279 }
280 module_exit(rza1_irqc_exit);
281 
282 MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
283 MODULE_DESCRIPTION("Renesas RZ/A1 IRQC Driver");
284