1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Socionext External Interrupt Unit (EXIU)
4 *
5 * Copyright (c) 2017-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
6 *
7 * Based on irq-tegra.c:
8 * Copyright (C) 2011 Google, Inc.
9 * Copyright (C) 2010,2013, NVIDIA Corporation
10 */
11
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/irq.h>
15 #include <linux/irqchip.h>
16 #include <linux/irqdomain.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/platform_device.h>
21
22 #include <dt-bindings/interrupt-controller/arm-gic.h>
23
24 #define NUM_IRQS 32
25
26 #define EIMASK 0x00
27 #define EISRCSEL 0x04
28 #define EIREQSTA 0x08
29 #define EIRAWREQSTA 0x0C
30 #define EIREQCLR 0x10
31 #define EILVL 0x14
32 #define EIEDG 0x18
33 #define EISIR 0x1C
34
35 struct exiu_irq_data {
36 void __iomem *base;
37 u32 spi_base;
38 };
39
exiu_irq_eoi(struct irq_data * d)40 static void exiu_irq_eoi(struct irq_data *d)
41 {
42 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
43
44 writel(BIT(d->hwirq), data->base + EIREQCLR);
45 irq_chip_eoi_parent(d);
46 }
47
exiu_irq_mask(struct irq_data * d)48 static void exiu_irq_mask(struct irq_data *d)
49 {
50 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
51 u32 val;
52
53 val = readl_relaxed(data->base + EIMASK) | BIT(d->hwirq);
54 writel_relaxed(val, data->base + EIMASK);
55 irq_chip_mask_parent(d);
56 }
57
exiu_irq_unmask(struct irq_data * d)58 static void exiu_irq_unmask(struct irq_data *d)
59 {
60 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
61 u32 val;
62
63 val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
64 writel_relaxed(val, data->base + EIMASK);
65 irq_chip_unmask_parent(d);
66 }
67
exiu_irq_enable(struct irq_data * d)68 static void exiu_irq_enable(struct irq_data *d)
69 {
70 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
71 u32 val;
72
73 /* clear interrupts that were latched while disabled */
74 writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
75
76 val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
77 writel_relaxed(val, data->base + EIMASK);
78 irq_chip_enable_parent(d);
79 }
80
exiu_irq_set_type(struct irq_data * d,unsigned int type)81 static int exiu_irq_set_type(struct irq_data *d, unsigned int type)
82 {
83 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
84 u32 val;
85
86 val = readl_relaxed(data->base + EILVL);
87 if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
88 val |= BIT(d->hwirq);
89 else
90 val &= ~BIT(d->hwirq);
91 writel_relaxed(val, data->base + EILVL);
92
93 val = readl_relaxed(data->base + EIEDG);
94 if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
95 val &= ~BIT(d->hwirq);
96 else
97 val |= BIT(d->hwirq);
98 writel_relaxed(val, data->base + EIEDG);
99
100 writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
101
102 return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
103 }
104
105 static struct irq_chip exiu_irq_chip = {
106 .name = "EXIU",
107 .irq_eoi = exiu_irq_eoi,
108 .irq_enable = exiu_irq_enable,
109 .irq_mask = exiu_irq_mask,
110 .irq_unmask = exiu_irq_unmask,
111 .irq_set_type = exiu_irq_set_type,
112 .irq_set_affinity = irq_chip_set_affinity_parent,
113 .flags = IRQCHIP_SET_TYPE_MASKED |
114 IRQCHIP_SKIP_SET_WAKE |
115 IRQCHIP_EOI_THREADED |
116 IRQCHIP_MASK_ON_SUSPEND,
117 };
118
exiu_domain_translate(struct irq_domain * domain,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)119 static int exiu_domain_translate(struct irq_domain *domain,
120 struct irq_fwspec *fwspec,
121 unsigned long *hwirq,
122 unsigned int *type)
123 {
124 struct exiu_irq_data *info = domain->host_data;
125
126 if (is_of_node(fwspec->fwnode)) {
127 if (fwspec->param_count != 3)
128 return -EINVAL;
129
130 if (fwspec->param[0] != GIC_SPI)
131 return -EINVAL; /* No PPI should point to this domain */
132
133 *hwirq = fwspec->param[1] - info->spi_base;
134 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
135 } else {
136 if (fwspec->param_count != 2)
137 return -EINVAL;
138 *hwirq = fwspec->param[0];
139 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
140 }
141 return 0;
142 }
143
exiu_domain_alloc(struct irq_domain * dom,unsigned int virq,unsigned int nr_irqs,void * data)144 static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
145 unsigned int nr_irqs, void *data)
146 {
147 struct irq_fwspec *fwspec = data;
148 struct irq_fwspec parent_fwspec;
149 struct exiu_irq_data *info = dom->host_data;
150 irq_hw_number_t hwirq;
151
152 parent_fwspec = *fwspec;
153 if (is_of_node(dom->parent->fwnode)) {
154 if (fwspec->param_count != 3)
155 return -EINVAL; /* Not GIC compliant */
156 if (fwspec->param[0] != GIC_SPI)
157 return -EINVAL; /* No PPI should point to this domain */
158
159 hwirq = fwspec->param[1] - info->spi_base;
160 } else {
161 hwirq = fwspec->param[0];
162 parent_fwspec.param[0] = hwirq + info->spi_base + 32;
163 }
164 WARN_ON(nr_irqs != 1);
165 irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
166
167 parent_fwspec.fwnode = dom->parent->fwnode;
168 return irq_domain_alloc_irqs_parent(dom, virq, nr_irqs, &parent_fwspec);
169 }
170
171 static const struct irq_domain_ops exiu_domain_ops = {
172 .translate = exiu_domain_translate,
173 .alloc = exiu_domain_alloc,
174 .free = irq_domain_free_irqs_common,
175 };
176
exiu_init(const struct fwnode_handle * fwnode,struct resource * res)177 static struct exiu_irq_data *exiu_init(const struct fwnode_handle *fwnode,
178 struct resource *res)
179 {
180 struct exiu_irq_data *data;
181 int err;
182
183 data = kzalloc(sizeof(*data), GFP_KERNEL);
184 if (!data)
185 return ERR_PTR(-ENOMEM);
186
187 if (fwnode_property_read_u32_array(fwnode, "socionext,spi-base",
188 &data->spi_base, 1)) {
189 err = -ENODEV;
190 goto out_free;
191 }
192
193 data->base = ioremap(res->start, resource_size(res));
194 if (!data->base) {
195 err = -ENODEV;
196 goto out_free;
197 }
198
199 /* clear and mask all interrupts */
200 writel_relaxed(0xFFFFFFFF, data->base + EIREQCLR);
201 writel_relaxed(0xFFFFFFFF, data->base + EIMASK);
202
203 return data;
204
205 out_free:
206 kfree(data);
207 return ERR_PTR(err);
208 }
209
exiu_dt_init(struct device_node * node,struct device_node * parent)210 static int __init exiu_dt_init(struct device_node *node,
211 struct device_node *parent)
212 {
213 struct irq_domain *parent_domain, *domain;
214 struct exiu_irq_data *data;
215 struct resource res;
216
217 if (!parent) {
218 pr_err("%pOF: no parent, giving up\n", node);
219 return -ENODEV;
220 }
221
222 parent_domain = irq_find_host(parent);
223 if (!parent_domain) {
224 pr_err("%pOF: unable to obtain parent domain\n", node);
225 return -ENXIO;
226 }
227
228 if (of_address_to_resource(node, 0, &res)) {
229 pr_err("%pOF: failed to parse memory resource\n", node);
230 return -ENXIO;
231 }
232
233 data = exiu_init(of_node_to_fwnode(node), &res);
234 if (IS_ERR(data))
235 return PTR_ERR(data);
236
237 domain = irq_domain_add_hierarchy(parent_domain, 0, NUM_IRQS, node,
238 &exiu_domain_ops, data);
239 if (!domain) {
240 pr_err("%pOF: failed to allocate domain\n", node);
241 goto out_unmap;
242 }
243
244 pr_info("%pOF: %d interrupts forwarded to %pOF\n", node, NUM_IRQS,
245 parent);
246
247 return 0;
248
249 out_unmap:
250 iounmap(data->base);
251 kfree(data);
252 return -ENOMEM;
253 }
254 IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_dt_init);
255
256 #ifdef CONFIG_ACPI
exiu_acpi_probe(struct platform_device * pdev)257 static int exiu_acpi_probe(struct platform_device *pdev)
258 {
259 struct irq_domain *domain;
260 struct exiu_irq_data *data;
261 struct resource *res;
262
263 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
264 if (!res) {
265 dev_err(&pdev->dev, "failed to parse memory resource\n");
266 return -ENXIO;
267 }
268
269 data = exiu_init(dev_fwnode(&pdev->dev), res);
270 if (IS_ERR(data))
271 return PTR_ERR(data);
272
273 domain = acpi_irq_create_hierarchy(0, NUM_IRQS, dev_fwnode(&pdev->dev),
274 &exiu_domain_ops, data);
275 if (!domain) {
276 dev_err(&pdev->dev, "failed to create IRQ domain\n");
277 goto out_unmap;
278 }
279
280 dev_info(&pdev->dev, "%d interrupts forwarded\n", NUM_IRQS);
281
282 return 0;
283
284 out_unmap:
285 iounmap(data->base);
286 kfree(data);
287 return -ENOMEM;
288 }
289
290 static const struct acpi_device_id exiu_acpi_ids[] = {
291 { "SCX0008" },
292 { /* sentinel */ }
293 };
294 MODULE_DEVICE_TABLE(acpi, exiu_acpi_ids);
295
296 static struct platform_driver exiu_driver = {
297 .driver = {
298 .name = "exiu",
299 .acpi_match_table = exiu_acpi_ids,
300 },
301 .probe = exiu_acpi_probe,
302 };
303 builtin_platform_driver(exiu_driver);
304 #endif
305
