1/*
2 * Synopsys DW APB ICTL irqchip driver.
3 *
4 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
5 *
6 * based on GPL'ed 2.6 kernel sources
7 * (c) Marvell International Ltd.
8 *
9 * This file is licensed under the terms of the GNU General Public
10 * License version 2. This program is licensed "as is" without any
11 * warranty of any kind, whether express or implied.
12 */
13
14#include <linux/io.h>
15#include <linux/irq.h>
16#include <linux/irqchip.h>
17#include <linux/irqchip/chained_irq.h>
18#include <linux/of_address.h>
19#include <linux/of_irq.h>
20#include <linux/interrupt.h>
21
22#define APB_INT_ENABLE_L 0x00
23#define APB_INT_ENABLE_H 0x04
24#define APB_INT_MASK_L 0x08
25#define APB_INT_MASK_H 0x0c
26#define APB_INT_FINALSTATUS_L 0x30
27#define APB_INT_FINALSTATUS_H 0x34
28#define APB_INT_BASE_OFFSET 0x04
29
30/* irq domain of the primary interrupt controller. */
31static struct irq_domain *dw_apb_ictl_irq_domain;
32
33static void __irq_entry dw_apb_ictl_handle_irq(struct pt_regs *regs)
34{
35 struct irq_domain *d = dw_apb_ictl_irq_domain;
36 int n;
37
38 for (n = 0; n < d->revmap_size; n += 32) {
39 struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n);
40 u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
41
42 while (stat) {
43 u32 hwirq = ffs(stat) - 1;
44
45 generic_handle_domain_irq(d, hwirq);
46 stat &= ~BIT(hwirq);
47 }
48 }
49}
50
51static void dw_apb_ictl_handle_irq_cascaded(struct irq_desc *desc)
52{
53 struct irq_domain *d = irq_desc_get_handler_data(desc);
54 struct irq_chip *chip = irq_desc_get_chip(desc);
55 int n;
56
57 chained_irq_enter(chip, desc);
58
59 for (n = 0; n < d->revmap_size; n += 32) {
60 struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, hw_irq: n);
61 u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
62
63 while (stat) {
64 u32 hwirq = ffs(stat) - 1;
65 generic_handle_domain_irq(domain: d, hwirq: gc->irq_base + hwirq);
66
67 stat &= ~BIT(hwirq);
68 }
69 }
70
71 chained_irq_exit(chip, desc);
72}
73
74static int dw_apb_ictl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
75 unsigned int nr_irqs, void *arg)
76{
77 int i, ret;
78 irq_hw_number_t hwirq;
79 unsigned int type = IRQ_TYPE_NONE;
80 struct irq_fwspec *fwspec = arg;
81
82 ret = irq_domain_translate_onecell(d: domain, fwspec, out_hwirq: &hwirq, out_type: &type);
83 if (ret)
84 return ret;
85
86 for (i = 0; i < nr_irqs; i++)
87 irq_map_generic_chip(d: domain, virq: virq + i, hw_irq: hwirq + i);
88
89 return 0;
90}
91
92static const struct irq_domain_ops dw_apb_ictl_irq_domain_ops = {
93 .translate = irq_domain_translate_onecell,
94 .alloc = dw_apb_ictl_irq_domain_alloc,
95 .free = irq_domain_free_irqs_top,
96};
97
98#ifdef CONFIG_PM
99static void dw_apb_ictl_resume(struct irq_data *d)
100{
101 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
102 struct irq_chip_type *ct = irq_data_get_chip_type(d);
103
104 irq_gc_lock(gc);
105 writel_relaxed(~0, gc->reg_base + ct->regs.enable);
106 writel_relaxed(*ct->mask_cache, gc->reg_base + ct->regs.mask);
107 irq_gc_unlock(gc);
108}
109#else
110#define dw_apb_ictl_resume NULL
111#endif /* CONFIG_PM */
112
113static int __init dw_apb_ictl_init(struct device_node *np,
114 struct device_node *parent)
115{
116 const struct irq_domain_ops *domain_ops;
117 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
118 struct resource r;
119 struct irq_domain *domain;
120 struct irq_chip_generic *gc;
121 void __iomem *iobase;
122 int ret, nrirqs, parent_irq, i;
123 u32 reg;
124
125 if (!parent) {
126 /* Used as the primary interrupt controller */
127 parent_irq = 0;
128 domain_ops = &dw_apb_ictl_irq_domain_ops;
129 } else {
130 /* Map the parent interrupt for the chained handler */
131 parent_irq = irq_of_parse_and_map(node: np, index: 0);
132 if (parent_irq <= 0) {
133 pr_err("%pOF: unable to parse irq\n", np);
134 return -EINVAL;
135 }
136 domain_ops = &irq_generic_chip_ops;
137 }
138
139 ret = of_address_to_resource(dev: np, index: 0, r: &r);
140 if (ret) {
141 pr_err("%pOF: unable to get resource\n", np);
142 return ret;
143 }
144
145 if (!request_mem_region(r.start, resource_size(&r), np->full_name)) {
146 pr_err("%pOF: unable to request mem region\n", np);
147 return -ENOMEM;
148 }
149
150 iobase = ioremap(offset: r.start, size: resource_size(res: &r));
151 if (!iobase) {
152 pr_err("%pOF: unable to map resource\n", np);
153 ret = -ENOMEM;
154 goto err_release;
155 }
156
157 /*
158 * DW IP can be configured to allow 2-64 irqs. We can determine
159 * the number of irqs supported by writing into enable register
160 * and look for bits not set, as corresponding flip-flops will
161 * have been removed by synthesis tool.
162 */
163
164 /* mask and enable all interrupts */
165 writel_relaxed(~0, iobase + APB_INT_MASK_L);
166 writel_relaxed(~0, iobase + APB_INT_MASK_H);
167 writel_relaxed(~0, iobase + APB_INT_ENABLE_L);
168 writel_relaxed(~0, iobase + APB_INT_ENABLE_H);
169
170 reg = readl_relaxed(iobase + APB_INT_ENABLE_H);
171 if (reg)
172 nrirqs = 32 + fls(x: reg);
173 else
174 nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L));
175
176 domain = irq_domain_add_linear(of_node: np, size: nrirqs, ops: domain_ops, NULL);
177 if (!domain) {
178 pr_err("%pOF: unable to add irq domain\n", np);
179 ret = -ENOMEM;
180 goto err_unmap;
181 }
182
183 ret = irq_alloc_domain_generic_chips(domain, 32, 1, np->name,
184 handle_level_irq, clr, 0,
185 IRQ_GC_INIT_MASK_CACHE);
186 if (ret) {
187 pr_err("%pOF: unable to alloc irq domain gc\n", np);
188 goto err_unmap;
189 }
190
191 for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) {
192 gc = irq_get_domain_generic_chip(d: domain, hw_irq: i * 32);
193 gc->reg_base = iobase + i * APB_INT_BASE_OFFSET;
194 gc->chip_types[0].regs.mask = APB_INT_MASK_L;
195 gc->chip_types[0].regs.enable = APB_INT_ENABLE_L;
196 gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
197 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
198 gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume;
199 }
200
201 if (parent_irq) {
202 irq_set_chained_handler_and_data(irq: parent_irq,
203 handle: dw_apb_ictl_handle_irq_cascaded, data: domain);
204 } else {
205 dw_apb_ictl_irq_domain = domain;
206 set_handle_irq(dw_apb_ictl_handle_irq);
207 }
208
209 return 0;
210
211err_unmap:
212 iounmap(addr: iobase);
213err_release:
214 release_mem_region(r.start, resource_size(&r));
215 return ret;
216}
217IRQCHIP_DECLARE(dw_apb_ictl,
218 "snps,dw-apb-ictl", dw_apb_ictl_init);
219

source code of linux/drivers/irqchip/irq-dw-apb-ictl.c