2 * drivers/irqchip/irq-crossbar.c
4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5 * Author: Sricharan R <r.sricharan@ti.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/err.h>
14 #include <linux/of_address.h>
15 #include <linux/of_irq.h>
16 #include <linux/slab.h>
17 #include <linux/irqchip/arm-gic.h>
20 #define IRQ_RESERVED -2
21 #define GIC_IRQ_START 32
24 * @int_max: maximum number of supported interrupts
25 * @irq_map: array of interrupts to crossbar number mapping
26 * @crossbar_base: crossbar base address
27 * @register_offsets: offsets for each irq number
29 struct crossbar_device {
32 void __iomem *crossbar_base;
33 int *register_offsets;
34 void (*write) (int, int);
37 static struct crossbar_device *cb;
39 static inline void crossbar_writel(int irq_no, int cb_no)
41 writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
44 static inline void crossbar_writew(int irq_no, int cb_no)
46 writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
49 static inline void crossbar_writeb(int irq_no, int cb_no)
51 writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
54 static inline int allocate_free_irq(int cb_no)
58 for (i = 0; i < cb->int_max; i++) {
59 if (cb->irq_map[i] == IRQ_FREE) {
60 cb->irq_map[i] = cb_no;
68 static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
71 cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
75 static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
77 irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
79 if (hw > GIC_IRQ_START)
80 cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
83 static int crossbar_domain_xlate(struct irq_domain *d,
84 struct device_node *controller,
85 const u32 *intspec, unsigned int intsize,
86 unsigned long *out_hwirq,
87 unsigned int *out_type)
91 ret = allocate_free_irq(intspec[1]);
93 if (IS_ERR_VALUE(ret))
96 *out_hwirq = ret + GIC_IRQ_START;
100 const struct irq_domain_ops routable_irq_domain_ops = {
101 .map = crossbar_domain_map,
102 .unmap = crossbar_domain_unmap,
103 .xlate = crossbar_domain_xlate
106 static int __init crossbar_of_init(struct device_node *node)
108 int i, size, max, reserved = 0, entry;
111 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
116 cb->crossbar_base = of_iomap(node, 0);
117 if (!cb->crossbar_base)
120 of_property_read_u32(node, "ti,max-irqs", &max);
121 cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL);
127 for (i = 0; i < max; i++)
128 cb->irq_map[i] = IRQ_FREE;
130 /* Get and mark reserved irqs */
131 irqsr = of_get_property(node, "ti,irqs-reserved", &size);
133 size /= sizeof(__be32);
135 for (i = 0; i < size; i++) {
136 of_property_read_u32_index(node,
140 pr_err("Invalid reserved entry\n");
143 cb->irq_map[entry] = IRQ_RESERVED;
147 cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL);
148 if (!cb->register_offsets)
151 of_property_read_u32(node, "ti,reg-size", &size);
155 cb->write = crossbar_writeb;
158 cb->write = crossbar_writew;
161 cb->write = crossbar_writel;
164 pr_err("Invalid reg-size property\n");
170 * Register offsets are not linear because of the
171 * reserved irqs. so find and store the offsets once.
173 for (i = 0; i < max; i++) {
174 if (cb->irq_map[i] == IRQ_RESERVED)
177 cb->register_offsets[i] = reserved;
181 register_routable_domain_ops(&routable_irq_domain_ops);
185 kfree(cb->register_offsets);
189 iounmap(cb->crossbar_base);
195 static const struct of_device_id crossbar_match[] __initconst = {
196 { .compatible = "ti,irq-crossbar" },
200 int __init irqcrossbar_init(void)
202 struct device_node *np;
203 np = of_find_matching_node(NULL, crossbar_match);
207 crossbar_of_init(np);