1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Texas Instruments' K3 Interrupt Router irqchip driver
4  *
5  * Copyright (C) 2018-2019 Texas Instruments Incorporated - https://www.ti.com/
6  *	Lokesh Vutla <lokeshvutla@ti.com>
7  */
8 
9 #include <linux/err.h>
10 #include <linux/module.h>
11 #include <linux/moduleparam.h>
12 #include <linux/io.h>
13 #include <linux/irqchip.h>
14 #include <linux/irqdomain.h>
15 #include <linux/of.h>
16 #include <linux/of_irq.h>
17 #include <linux/platform_device.h>
18 #include <linux/soc/ti/ti_sci_protocol.h>
19 
20 /**
21  * struct ti_sci_intr_irq_domain - Structure representing a TISCI based
22  *				   Interrupt Router IRQ domain.
23  * @sci:	Pointer to TISCI handle
24  * @out_irqs:	TISCI resource pointer representing INTR irqs.
25  * @dev:	Struct device pointer.
26  * @ti_sci_id:	TI-SCI device identifier
27  * @type:	Specifies the trigger type supported by this Interrupt Router
28  */
29 struct ti_sci_intr_irq_domain {
30 	const struct ti_sci_handle *sci;
31 	struct ti_sci_resource *out_irqs;
32 	struct device *dev;
33 	u32 ti_sci_id;
34 	u32 type;
35 };
36 
37 static struct irq_chip ti_sci_intr_irq_chip = {
38 	.name			= "INTR",
39 	.irq_eoi		= irq_chip_eoi_parent,
40 	.irq_mask		= irq_chip_mask_parent,
41 	.irq_unmask		= irq_chip_unmask_parent,
42 	.irq_set_type		= irq_chip_set_type_parent,
43 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
44 	.irq_set_affinity	= irq_chip_set_affinity_parent,
45 };
46 
47 /**
48  * ti_sci_intr_irq_domain_translate() - Retrieve hwirq and type from
49  *					IRQ firmware specific handler.
50  * @domain:	Pointer to IRQ domain
51  * @fwspec:	Pointer to IRQ specific firmware structure
52  * @hwirq:	IRQ number identified by hardware
53  * @type:	IRQ type
54  *
55  * Return 0 if all went ok else appropriate error.
56  */
ti_sci_intr_irq_domain_translate(struct irq_domain * domain,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)57 static int ti_sci_intr_irq_domain_translate(struct irq_domain *domain,
58 					    struct irq_fwspec *fwspec,
59 					    unsigned long *hwirq,
60 					    unsigned int *type)
61 {
62 	struct ti_sci_intr_irq_domain *intr = domain->host_data;
63 
64 	if (fwspec->param_count != 1)
65 		return -EINVAL;
66 
67 	*hwirq = fwspec->param[0];
68 	*type = intr->type;
69 
70 	return 0;
71 }
72 
73 /**
74  * ti_sci_intr_xlate_irq() - Translate hwirq to parent's hwirq.
75  * @intr:	IRQ domain corresponding to Interrupt Router
76  * @irq:	Hardware irq corresponding to the above irq domain
77  *
78  * Return parent irq number if translation is available else -ENOENT.
79  */
ti_sci_intr_xlate_irq(struct ti_sci_intr_irq_domain * intr,u32 irq)80 static int ti_sci_intr_xlate_irq(struct ti_sci_intr_irq_domain *intr, u32 irq)
81 {
82 	struct device_node *np = dev_of_node(intr->dev);
83 	u32 base, pbase, size, len;
84 	const __be32 *range;
85 
86 	range = of_get_property(np, "ti,interrupt-ranges", &len);
87 	if (!range)
88 		return irq;
89 
90 	for (len /= sizeof(*range); len >= 3; len -= 3) {
91 		base = be32_to_cpu(*range++);
92 		pbase = be32_to_cpu(*range++);
93 		size = be32_to_cpu(*range++);
94 
95 		if (base <= irq && irq < base + size)
96 			return irq - base + pbase;
97 	}
98 
99 	return -ENOENT;
100 }
101 
102 /**
103  * ti_sci_intr_irq_domain_free() - Free the specified IRQs from the domain.
104  * @domain:	Domain to which the irqs belong
105  * @virq:	Linux virtual IRQ to be freed.
106  * @nr_irqs:	Number of continuous irqs to be freed
107  */
ti_sci_intr_irq_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)108 static void ti_sci_intr_irq_domain_free(struct irq_domain *domain,
109 					unsigned int virq, unsigned int nr_irqs)
110 {
111 	struct ti_sci_intr_irq_domain *intr = domain->host_data;
112 	struct irq_data *data;
113 	int out_irq;
114 
115 	data = irq_domain_get_irq_data(domain, virq);
116 	out_irq = (uintptr_t)data->chip_data;
117 
118 	intr->sci->ops.rm_irq_ops.free_irq(intr->sci,
119 					   intr->ti_sci_id, data->hwirq,
120 					   intr->ti_sci_id, out_irq);
121 	ti_sci_release_resource(intr->out_irqs, out_irq);
122 	irq_domain_free_irqs_parent(domain, virq, 1);
123 	irq_domain_reset_irq_data(data);
124 }
125 
126 /**
127  * ti_sci_intr_alloc_parent_irq() - Allocate parent IRQ
128  * @domain:	Pointer to the interrupt router IRQ domain
129  * @virq:	Corresponding Linux virtual IRQ number
130  * @hwirq:	Corresponding hwirq for the IRQ within this IRQ domain
131  *
132  * Returns intr output irq if all went well else appropriate error pointer.
133  */
ti_sci_intr_alloc_parent_irq(struct irq_domain * domain,unsigned int virq,u32 hwirq)134 static int ti_sci_intr_alloc_parent_irq(struct irq_domain *domain,
135 					unsigned int virq, u32 hwirq)
136 {
137 	struct ti_sci_intr_irq_domain *intr = domain->host_data;
138 	struct device_node *parent_node;
139 	struct irq_fwspec fwspec;
140 	int p_hwirq, err = 0;
141 	u16 out_irq;
142 
143 	out_irq = ti_sci_get_free_resource(intr->out_irqs);
144 	if (out_irq == TI_SCI_RESOURCE_NULL)
145 		return -EINVAL;
146 
147 	p_hwirq = ti_sci_intr_xlate_irq(intr, out_irq);
148 	if (p_hwirq < 0)
149 		goto err_irqs;
150 
151 	parent_node = of_irq_find_parent(dev_of_node(intr->dev));
152 	fwspec.fwnode = of_node_to_fwnode(parent_node);
153 
154 	if (of_device_is_compatible(parent_node, "arm,gic-v3")) {
155 		/* Parent is GIC */
156 		fwspec.param_count = 3;
157 		fwspec.param[0] = 0;	/* SPI */
158 		fwspec.param[1] = p_hwirq - 32; /* SPI offset */
159 		fwspec.param[2] = intr->type;
160 	} else {
161 		/* Parent is Interrupt Router */
162 		fwspec.param_count = 1;
163 		fwspec.param[0] = p_hwirq;
164 	}
165 
166 	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
167 	if (err)
168 		goto err_irqs;
169 
170 	err = intr->sci->ops.rm_irq_ops.set_irq(intr->sci,
171 						intr->ti_sci_id, hwirq,
172 						intr->ti_sci_id, out_irq);
173 	if (err)
174 		goto err_msg;
175 
176 	return out_irq;
177 
178 err_msg:
179 	irq_domain_free_irqs_parent(domain, virq, 1);
180 err_irqs:
181 	ti_sci_release_resource(intr->out_irqs, out_irq);
182 	return err;
183 }
184 
185 /**
186  * ti_sci_intr_irq_domain_alloc() - Allocate Interrupt router IRQs
187  * @domain:	Point to the interrupt router IRQ domain
188  * @virq:	Corresponding Linux virtual IRQ number
189  * @nr_irqs:	Continuous irqs to be allocated
190  * @data:	Pointer to firmware specifier
191  *
192  * Return 0 if all went well else appropriate error value.
193  */
ti_sci_intr_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * data)194 static int ti_sci_intr_irq_domain_alloc(struct irq_domain *domain,
195 					unsigned int virq, unsigned int nr_irqs,
196 					void *data)
197 {
198 	struct irq_fwspec *fwspec = data;
199 	unsigned long hwirq;
200 	unsigned int flags;
201 	int err, out_irq;
202 
203 	err = ti_sci_intr_irq_domain_translate(domain, fwspec, &hwirq, &flags);
204 	if (err)
205 		return err;
206 
207 	out_irq = ti_sci_intr_alloc_parent_irq(domain, virq, hwirq);
208 	if (out_irq < 0)
209 		return out_irq;
210 
211 	irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
212 				      &ti_sci_intr_irq_chip,
213 				      (void *)(uintptr_t)out_irq);
214 
215 	return 0;
216 }
217 
218 static const struct irq_domain_ops ti_sci_intr_irq_domain_ops = {
219 	.free		= ti_sci_intr_irq_domain_free,
220 	.alloc		= ti_sci_intr_irq_domain_alloc,
221 	.translate	= ti_sci_intr_irq_domain_translate,
222 };
223 
ti_sci_intr_irq_domain_probe(struct platform_device * pdev)224 static int ti_sci_intr_irq_domain_probe(struct platform_device *pdev)
225 {
226 	struct irq_domain *parent_domain, *domain;
227 	struct ti_sci_intr_irq_domain *intr;
228 	struct device_node *parent_node;
229 	struct device *dev = &pdev->dev;
230 	int ret;
231 
232 	parent_node = of_irq_find_parent(dev_of_node(dev));
233 	if (!parent_node) {
234 		dev_err(dev, "Failed to get IRQ parent node\n");
235 		return -ENODEV;
236 	}
237 
238 	parent_domain = irq_find_host(parent_node);
239 	of_node_put(parent_node);
240 	if (!parent_domain) {
241 		dev_err(dev, "Failed to find IRQ parent domain\n");
242 		return -ENODEV;
243 	}
244 
245 	intr = devm_kzalloc(dev, sizeof(*intr), GFP_KERNEL);
246 	if (!intr)
247 		return -ENOMEM;
248 
249 	intr->dev = dev;
250 	ret = of_property_read_u32(dev_of_node(dev), "ti,intr-trigger-type",
251 				   &intr->type);
252 	if (ret) {
253 		dev_err(dev, "missing ti,intr-trigger-type property\n");
254 		return -EINVAL;
255 	}
256 
257 	intr->sci = devm_ti_sci_get_by_phandle(dev, "ti,sci");
258 	if (IS_ERR(intr->sci))
259 		return dev_err_probe(dev, PTR_ERR(intr->sci),
260 				     "ti,sci read fail\n");
261 
262 	ret = of_property_read_u32(dev_of_node(dev), "ti,sci-dev-id",
263 				   &intr->ti_sci_id);
264 	if (ret) {
265 		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
266 		return -EINVAL;
267 	}
268 
269 	intr->out_irqs = devm_ti_sci_get_resource(intr->sci, dev,
270 						  intr->ti_sci_id,
271 						  TI_SCI_RESASG_SUBTYPE_IR_OUTPUT);
272 	if (IS_ERR(intr->out_irqs)) {
273 		dev_err(dev, "Destination irq resource allocation failed\n");
274 		return PTR_ERR(intr->out_irqs);
275 	}
276 
277 	domain = irq_domain_add_hierarchy(parent_domain, 0, 0, dev_of_node(dev),
278 					  &ti_sci_intr_irq_domain_ops, intr);
279 	if (!domain) {
280 		dev_err(dev, "Failed to allocate IRQ domain\n");
281 		return -ENOMEM;
282 	}
283 
284 	dev_info(dev, "Interrupt Router %d domain created\n", intr->ti_sci_id);
285 
286 	return 0;
287 }
288 
289 static const struct of_device_id ti_sci_intr_irq_domain_of_match[] = {
290 	{ .compatible = "ti,sci-intr", },
291 	{ /* sentinel */ },
292 };
293 MODULE_DEVICE_TABLE(of, ti_sci_intr_irq_domain_of_match);
294 
295 static struct platform_driver ti_sci_intr_irq_domain_driver = {
296 	.probe = ti_sci_intr_irq_domain_probe,
297 	.driver = {
298 		.name = "ti-sci-intr",
299 		.of_match_table = ti_sci_intr_irq_domain_of_match,
300 	},
301 };
302 module_platform_driver(ti_sci_intr_irq_domain_driver);
303 
304 MODULE_AUTHOR("Lokesh Vutla <lokeshvutla@ticom>");
305 MODULE_DESCRIPTION("K3 Interrupt Router driver over TI SCI protocol");
306