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96ca848e S |
1 | /* |
2 | * drivers/irqchip/irq-crossbar.c | |
3 | * | |
4 | * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com | |
5 | * Author: Sricharan R <r.sricharan@ti.com> | |
6 | * | |
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. | |
10 | * | |
11 | */ | |
12 | #include <linux/err.h> | |
13 | #include <linux/io.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> | |
18 | ||
19 | #define IRQ_FREE -1 | |
1d50d2ce | 20 | #define IRQ_RESERVED -2 |
96ca848e S |
21 | #define GIC_IRQ_START 32 |
22 | ||
23 | /* | |
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 | |
28 | */ | |
29 | struct crossbar_device { | |
30 | uint int_max; | |
31 | uint *irq_map; | |
32 | void __iomem *crossbar_base; | |
33 | int *register_offsets; | |
34 | void (*write) (int, int); | |
35 | }; | |
36 | ||
37 | static struct crossbar_device *cb; | |
38 | ||
39 | static inline void crossbar_writel(int irq_no, int cb_no) | |
40 | { | |
41 | writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
42 | } | |
43 | ||
44 | static inline void crossbar_writew(int irq_no, int cb_no) | |
45 | { | |
46 | writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
47 | } | |
48 | ||
49 | static inline void crossbar_writeb(int irq_no, int cb_no) | |
50 | { | |
51 | writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
52 | } | |
53 | ||
54 | static inline int allocate_free_irq(int cb_no) | |
55 | { | |
56 | int i; | |
57 | ||
58 | for (i = 0; i < cb->int_max; i++) { | |
59 | if (cb->irq_map[i] == IRQ_FREE) { | |
60 | cb->irq_map[i] = cb_no; | |
61 | return i; | |
62 | } | |
63 | } | |
64 | ||
65 | return -ENODEV; | |
66 | } | |
67 | ||
68 | static int crossbar_domain_map(struct irq_domain *d, unsigned int irq, | |
69 | irq_hw_number_t hw) | |
70 | { | |
71 | cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]); | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq) | |
76 | { | |
77 | irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq; | |
78 | ||
79 | if (hw > GIC_IRQ_START) | |
80 | cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE; | |
81 | } | |
82 | ||
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) | |
88 | { | |
89 | unsigned long ret; | |
90 | ||
91 | ret = allocate_free_irq(intspec[1]); | |
92 | ||
93 | if (IS_ERR_VALUE(ret)) | |
94 | return ret; | |
95 | ||
96 | *out_hwirq = ret + GIC_IRQ_START; | |
97 | return 0; | |
98 | } | |
99 | ||
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 | |
104 | }; | |
105 | ||
106 | static int __init crossbar_of_init(struct device_node *node) | |
107 | { | |
108 | int i, size, max, reserved = 0, entry; | |
109 | const __be32 *irqsr; | |
110 | ||
3894e9e8 | 111 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
96ca848e S |
112 | |
113 | if (!cb) | |
114 | return -ENOMEM; | |
115 | ||
116 | cb->crossbar_base = of_iomap(node, 0); | |
117 | if (!cb->crossbar_base) | |
118 | goto err1; | |
119 | ||
120 | of_property_read_u32(node, "ti,max-irqs", &max); | |
121 | cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL); | |
122 | if (!cb->irq_map) | |
123 | goto err2; | |
124 | ||
125 | cb->int_max = max; | |
126 | ||
127 | for (i = 0; i < max; i++) | |
128 | cb->irq_map[i] = IRQ_FREE; | |
129 | ||
130 | /* Get and mark reserved irqs */ | |
131 | irqsr = of_get_property(node, "ti,irqs-reserved", &size); | |
132 | if (irqsr) { | |
133 | size /= sizeof(__be32); | |
134 | ||
135 | for (i = 0; i < size; i++) { | |
136 | of_property_read_u32_index(node, | |
137 | "ti,irqs-reserved", | |
138 | i, &entry); | |
139 | if (entry > max) { | |
140 | pr_err("Invalid reserved entry\n"); | |
141 | goto err3; | |
142 | } | |
1d50d2ce | 143 | cb->irq_map[entry] = IRQ_RESERVED; |
96ca848e S |
144 | } |
145 | } | |
146 | ||
147 | cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL); | |
148 | if (!cb->register_offsets) | |
149 | goto err3; | |
150 | ||
151 | of_property_read_u32(node, "ti,reg-size", &size); | |
152 | ||
153 | switch (size) { | |
154 | case 1: | |
155 | cb->write = crossbar_writeb; | |
156 | break; | |
157 | case 2: | |
158 | cb->write = crossbar_writew; | |
159 | break; | |
160 | case 4: | |
161 | cb->write = crossbar_writel; | |
162 | break; | |
163 | default: | |
164 | pr_err("Invalid reg-size property\n"); | |
165 | goto err4; | |
166 | break; | |
167 | } | |
168 | ||
169 | /* | |
170 | * Register offsets are not linear because of the | |
171 | * reserved irqs. so find and store the offsets once. | |
172 | */ | |
173 | for (i = 0; i < max; i++) { | |
1d50d2ce | 174 | if (cb->irq_map[i] == IRQ_RESERVED) |
96ca848e S |
175 | continue; |
176 | ||
177 | cb->register_offsets[i] = reserved; | |
178 | reserved += size; | |
179 | } | |
180 | ||
181 | register_routable_domain_ops(&routable_irq_domain_ops); | |
182 | return 0; | |
183 | ||
184 | err4: | |
185 | kfree(cb->register_offsets); | |
186 | err3: | |
187 | kfree(cb->irq_map); | |
188 | err2: | |
189 | iounmap(cb->crossbar_base); | |
190 | err1: | |
191 | kfree(cb); | |
192 | return -ENOMEM; | |
193 | } | |
194 | ||
195 | static const struct of_device_id crossbar_match[] __initconst = { | |
196 | { .compatible = "ti,irq-crossbar" }, | |
197 | {} | |
198 | }; | |
199 | ||
200 | int __init irqcrossbar_init(void) | |
201 | { | |
202 | struct device_node *np; | |
203 | np = of_find_matching_node(NULL, crossbar_match); | |
204 | if (!np) | |
205 | return -ENODEV; | |
206 | ||
207 | crossbar_of_init(np); | |
208 | return 0; | |
209 | } |