1 /*
2 * Driver for Socionext External Interrupt Unit (EXIU)
3 *
4 * Copyright (c) 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
5 *
6 * Based on irq-tegra.c:
7 * Copyright (C) 2011 Google, Inc.
8 * Copyright (C) 2010,2013, NVIDIA Corporation
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/irqchip.h>
19 #include <linux/irqdomain.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23
24 #include <dt-bindings/interrupt-controller/arm-gic.h>
25
26 #define NUM_IRQS 32
27
28 #define EIMASK 0x00
29 #define EISRCSEL 0x04
30 #define EIREQSTA 0x08
31 #define EIRAWREQSTA 0x0C
32 #define EIREQCLR 0x10
33 #define EILVL 0x14
34 #define EIEDG 0x18
35 #define EISIR 0x1C
36
37 struct exiu_irq_data {
38 void __iomem *base;
39 u32 spi_base;
40 };
41
exiu_irq_eoi(struct irq_data * d)42 static void exiu_irq_eoi(struct irq_data *d)
43 {
44 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
45
46 writel(BIT(d->hwirq), data->base + EIREQCLR);
47 irq_chip_eoi_parent(d);
48 }
49
exiu_irq_mask(struct irq_data * d)50 static void exiu_irq_mask(struct irq_data *d)
51 {
52 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
53 u32 val;
54
55 val = readl_relaxed(data->base + EIMASK) | BIT(d->hwirq);
56 writel_relaxed(val, data->base + EIMASK);
57 irq_chip_mask_parent(d);
58 }
59
exiu_irq_unmask(struct irq_data * d)60 static void exiu_irq_unmask(struct irq_data *d)
61 {
62 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
63 u32 val;
64
65 val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
66 writel_relaxed(val, data->base + EIMASK);
67 irq_chip_unmask_parent(d);
68 }
69
exiu_irq_enable(struct irq_data * d)70 static void exiu_irq_enable(struct irq_data *d)
71 {
72 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
73 u32 val;
74
75 /* clear interrupts that were latched while disabled */
76 writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
77
78 val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
79 writel_relaxed(val, data->base + EIMASK);
80 irq_chip_enable_parent(d);
81 }
82
exiu_irq_set_type(struct irq_data * d,unsigned int type)83 static int exiu_irq_set_type(struct irq_data *d, unsigned int type)
84 {
85 struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
86 u32 val;
87
88 val = readl_relaxed(data->base + EILVL);
89 if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
90 val |= BIT(d->hwirq);
91 else
92 val &= ~BIT(d->hwirq);
93 writel_relaxed(val, data->base + EILVL);
94
95 val = readl_relaxed(data->base + EIEDG);
96 if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
97 val &= ~BIT(d->hwirq);
98 else
99 val |= BIT(d->hwirq);
100 writel_relaxed(val, data->base + EIEDG);
101
102 writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
103
104 return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
105 }
106
107 static struct irq_chip exiu_irq_chip = {
108 .name = "EXIU",
109 .irq_eoi = exiu_irq_eoi,
110 .irq_enable = exiu_irq_enable,
111 .irq_mask = exiu_irq_mask,
112 .irq_unmask = exiu_irq_unmask,
113 .irq_set_type = exiu_irq_set_type,
114 .irq_set_affinity = irq_chip_set_affinity_parent,
115 .flags = IRQCHIP_SET_TYPE_MASKED |
116 IRQCHIP_SKIP_SET_WAKE |
117 IRQCHIP_EOI_THREADED |
118 IRQCHIP_MASK_ON_SUSPEND,
119 };
120
exiu_domain_translate(struct irq_domain * domain,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)121 static int exiu_domain_translate(struct irq_domain *domain,
122 struct irq_fwspec *fwspec,
123 unsigned long *hwirq,
124 unsigned int *type)
125 {
126 struct exiu_irq_data *info = domain->host_data;
127
128 if (is_of_node(fwspec->fwnode)) {
129 if (fwspec->param_count != 3)
130 return -EINVAL;
131
132 if (fwspec->param[0] != GIC_SPI)
133 return -EINVAL; /* No PPI should point to this domain */
134
135 *hwirq = fwspec->param[1] - info->spi_base;
136 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
137 return 0;
138 }
139 return -EINVAL;
140 }
141
exiu_domain_alloc(struct irq_domain * dom,unsigned int virq,unsigned int nr_irqs,void * data)142 static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
143 unsigned int nr_irqs, void *data)
144 {
145 struct irq_fwspec *fwspec = data;
146 struct irq_fwspec parent_fwspec;
147 struct exiu_irq_data *info = dom->host_data;
148 irq_hw_number_t hwirq;
149
150 if (fwspec->param_count != 3)
151 return -EINVAL; /* Not GIC compliant */
152 if (fwspec->param[0] != GIC_SPI)
153 return -EINVAL; /* No PPI should point to this domain */
154
155 WARN_ON(nr_irqs != 1);
156 hwirq = fwspec->param[1] - info->spi_base;
157 irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
158
159 parent_fwspec = *fwspec;
160 parent_fwspec.fwnode = dom->parent->fwnode;
161 return irq_domain_alloc_irqs_parent(dom, virq, nr_irqs, &parent_fwspec);
162 }
163
164 static const struct irq_domain_ops exiu_domain_ops = {
165 .translate = exiu_domain_translate,
166 .alloc = exiu_domain_alloc,
167 .free = irq_domain_free_irqs_common,
168 };
169
exiu_init(struct device_node * node,struct device_node * parent)170 static int __init exiu_init(struct device_node *node,
171 struct device_node *parent)
172 {
173 struct irq_domain *parent_domain, *domain;
174 struct exiu_irq_data *data;
175 int err;
176
177 if (!parent) {
178 pr_err("%pOF: no parent, giving up\n", node);
179 return -ENODEV;
180 }
181
182 parent_domain = irq_find_host(parent);
183 if (!parent_domain) {
184 pr_err("%pOF: unable to obtain parent domain\n", node);
185 return -ENXIO;
186 }
187
188 data = kzalloc(sizeof(*data), GFP_KERNEL);
189 if (!data)
190 return -ENOMEM;
191
192 if (of_property_read_u32(node, "socionext,spi-base", &data->spi_base)) {
193 pr_err("%pOF: failed to parse 'spi-base' property\n", node);
194 err = -ENODEV;
195 goto out_free;
196 }
197
198 data->base = of_iomap(node, 0);
199 if (!data->base) {
200 err = -ENODEV;
201 goto out_free;
202 }
203
204 /* clear and mask all interrupts */
205 writel_relaxed(0xFFFFFFFF, data->base + EIREQCLR);
206 writel_relaxed(0xFFFFFFFF, data->base + EIMASK);
207
208 domain = irq_domain_add_hierarchy(parent_domain, 0, NUM_IRQS, node,
209 &exiu_domain_ops, data);
210 if (!domain) {
211 pr_err("%pOF: failed to allocate domain\n", node);
212 err = -ENOMEM;
213 goto out_unmap;
214 }
215
216 pr_info("%pOF: %d interrupts forwarded to %pOF\n", node, NUM_IRQS,
217 parent);
218
219 return 0;
220
221 out_unmap:
222 iounmap(data->base);
223 out_free:
224 kfree(data);
225 return err;
226 }
227 IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_init);
228