blob: 31e231e1f566f4426720039676ec634a2a245bd4 [file] [log] [blame]
Sebastian Hesselbarth350d71b92013-09-09 14:01:20 +02001/*
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/chained_irq.h>
17#include <linux/of_address.h>
18#include <linux/of_irq.h>
19
20#include "irqchip.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
29static void dw_apb_ictl_handler(unsigned int irq, struct irq_desc *desc)
30{
31 struct irq_chip *chip = irq_get_chip(irq);
32 struct irq_chip_generic *gc = irq_get_handler_data(irq);
33 struct irq_domain *d = gc->private;
34 u32 stat;
35 int n;
36
37 chained_irq_enter(chip, desc);
38
39 for (n = 0; n < gc->num_ct; n++) {
40 stat = readl_relaxed(gc->reg_base +
41 APB_INT_FINALSTATUS_L + 4 * n);
42 while (stat) {
43 u32 hwirq = ffs(stat) - 1;
44 generic_handle_irq(irq_find_mapping(d,
45 gc->irq_base + hwirq + 32 * n));
46 stat &= ~(1 << hwirq);
47 }
48 }
49
50 chained_irq_exit(chip, desc);
51}
52
53static int __init dw_apb_ictl_init(struct device_node *np,
54 struct device_node *parent)
55{
56 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
57 struct resource r;
58 struct irq_domain *domain;
59 struct irq_chip_generic *gc;
60 void __iomem *iobase;
61 int ret, nrirqs, irq;
62 u32 reg;
63
64 /* Map the parent interrupt for the chained handler */
65 irq = irq_of_parse_and_map(np, 0);
66 if (irq <= 0) {
67 pr_err("%s: unable to parse irq\n", np->full_name);
68 return -EINVAL;
69 }
70
71 ret = of_address_to_resource(np, 0, &r);
72 if (ret) {
73 pr_err("%s: unable to get resource\n", np->full_name);
74 return ret;
75 }
76
77 if (!request_mem_region(r.start, resource_size(&r), np->full_name)) {
78 pr_err("%s: unable to request mem region\n", np->full_name);
79 return -ENOMEM;
80 }
81
82 iobase = ioremap(r.start, resource_size(&r));
83 if (!iobase) {
84 pr_err("%s: unable to map resource\n", np->full_name);
85 ret = -ENOMEM;
86 goto err_release;
87 }
88
89 /*
90 * DW IP can be configured to allow 2-64 irqs. We can determine
91 * the number of irqs supported by writing into enable register
92 * and look for bits not set, as corresponding flip-flops will
93 * have been removed by sythesis tool.
94 */
95
96 /* mask and enable all interrupts */
97 writel(~0, iobase + APB_INT_MASK_L);
98 writel(~0, iobase + APB_INT_MASK_H);
99 writel(~0, iobase + APB_INT_ENABLE_L);
100 writel(~0, iobase + APB_INT_ENABLE_H);
101
102 reg = readl(iobase + APB_INT_ENABLE_H);
103 if (reg)
104 nrirqs = 32 + fls(reg);
105 else
106 nrirqs = fls(readl(iobase + APB_INT_ENABLE_L));
107
108 domain = irq_domain_add_linear(np, nrirqs,
109 &irq_generic_chip_ops, NULL);
110 if (!domain) {
111 pr_err("%s: unable to add irq domain\n", np->full_name);
112 ret = -ENOMEM;
113 goto err_unmap;
114 }
115
116 ret = irq_alloc_domain_generic_chips(domain, 32, (nrirqs > 32) ? 2 : 1,
117 np->name, handle_level_irq, clr, 0,
118 IRQ_GC_INIT_MASK_CACHE);
119 if (ret) {
120 pr_err("%s: unable to alloc irq domain gc\n", np->full_name);
121 goto err_unmap;
122 }
123
124 gc = irq_get_domain_generic_chip(domain, 0);
125 gc->private = domain;
126 gc->reg_base = iobase;
127
128 gc->chip_types[0].regs.mask = APB_INT_MASK_L;
129 gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
130 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
131
132 if (nrirqs > 32) {
133 gc->chip_types[1].regs.mask = APB_INT_MASK_H;
134 gc->chip_types[1].chip.irq_mask = irq_gc_mask_set_bit;
135 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_clr_bit;
136 }
137
138 irq_set_handler_data(irq, gc);
139 irq_set_chained_handler(irq, dw_apb_ictl_handler);
140
141 return 0;
142
143err_unmap:
144 iounmap(iobase);
145err_release:
146 release_mem_region(r.start, resource_size(&r));
147 return ret;
148}
149IRQCHIP_DECLARE(dw_apb_ictl,
150 "snps,dw-apb-ictl", dw_apb_ictl_init);