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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> | |
4dbf45e3 | 18 | #include <linux/irqchip/irq-crossbar.h> |
96ca848e S |
19 | |
20 | #define IRQ_FREE -1 | |
1d50d2ce | 21 | #define IRQ_RESERVED -2 |
64e0f8ba | 22 | #define IRQ_SKIP -3 |
96ca848e S |
23 | #define GIC_IRQ_START 32 |
24 | ||
e30ef8ab NM |
25 | /** |
26 | * struct crossbar_device - crossbar device description | |
96ca848e | 27 | * @int_max: maximum number of supported interrupts |
a35057d1 | 28 | * @safe_map: safe default value to initialize the crossbar |
96ca848e S |
29 | * @irq_map: array of interrupts to crossbar number mapping |
30 | * @crossbar_base: crossbar base address | |
31 | * @register_offsets: offsets for each irq number | |
e30ef8ab | 32 | * @write: register write function pointer |
96ca848e S |
33 | */ |
34 | struct crossbar_device { | |
35 | uint int_max; | |
a35057d1 | 36 | uint safe_map; |
96ca848e S |
37 | uint *irq_map; |
38 | void __iomem *crossbar_base; | |
39 | int *register_offsets; | |
a35057d1 | 40 | void (*write)(int, int); |
96ca848e S |
41 | }; |
42 | ||
43 | static struct crossbar_device *cb; | |
44 | ||
45 | static inline void crossbar_writel(int irq_no, int cb_no) | |
46 | { | |
47 | writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
48 | } | |
49 | ||
50 | static inline void crossbar_writew(int irq_no, int cb_no) | |
51 | { | |
52 | writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
53 | } | |
54 | ||
55 | static inline void crossbar_writeb(int irq_no, int cb_no) | |
56 | { | |
57 | writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]); | |
58 | } | |
59 | ||
6f16fc87 NM |
60 | static inline int get_prev_map_irq(int cb_no) |
61 | { | |
62 | int i; | |
63 | ||
ddee0fb4 | 64 | for (i = cb->int_max - 1; i >= 0; i--) |
6f16fc87 NM |
65 | if (cb->irq_map[i] == cb_no) |
66 | return i; | |
67 | ||
68 | return -ENODEV; | |
69 | } | |
70 | ||
96ca848e S |
71 | static inline int allocate_free_irq(int cb_no) |
72 | { | |
73 | int i; | |
74 | ||
ddee0fb4 | 75 | for (i = cb->int_max - 1; i >= 0; i--) { |
96ca848e S |
76 | if (cb->irq_map[i] == IRQ_FREE) { |
77 | cb->irq_map[i] = cb_no; | |
78 | return i; | |
79 | } | |
80 | } | |
81 | ||
82 | return -ENODEV; | |
83 | } | |
84 | ||
85 | static int crossbar_domain_map(struct irq_domain *d, unsigned int irq, | |
86 | irq_hw_number_t hw) | |
87 | { | |
88 | cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]); | |
89 | return 0; | |
90 | } | |
91 | ||
8b09a45d S |
92 | /** |
93 | * crossbar_domain_unmap - unmap a crossbar<->irq connection | |
94 | * @d: domain of irq to unmap | |
95 | * @irq: virq number | |
96 | * | |
97 | * We do not maintain a use count of total number of map/unmap | |
98 | * calls for a particular irq to find out if a irq can be really | |
99 | * unmapped. This is because unmap is called during irq_dispose_mapping(irq), | |
100 | * after which irq is anyways unusable. So an explicit map has to be called | |
101 | * after that. | |
102 | */ | |
96ca848e S |
103 | static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq) |
104 | { | |
105 | irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq; | |
106 | ||
a35057d1 | 107 | if (hw > GIC_IRQ_START) { |
96ca848e | 108 | cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE; |
a35057d1 NM |
109 | cb->write(hw - GIC_IRQ_START, cb->safe_map); |
110 | } | |
96ca848e S |
111 | } |
112 | ||
113 | static int crossbar_domain_xlate(struct irq_domain *d, | |
114 | struct device_node *controller, | |
115 | const u32 *intspec, unsigned int intsize, | |
116 | unsigned long *out_hwirq, | |
117 | unsigned int *out_type) | |
118 | { | |
d4922a95 | 119 | int ret; |
96ca848e | 120 | |
6f16fc87 | 121 | ret = get_prev_map_irq(intspec[1]); |
d4922a95 | 122 | if (ret >= 0) |
6f16fc87 NM |
123 | goto found; |
124 | ||
96ca848e S |
125 | ret = allocate_free_irq(intspec[1]); |
126 | ||
d4922a95 | 127 | if (ret < 0) |
96ca848e S |
128 | return ret; |
129 | ||
6f16fc87 | 130 | found: |
96ca848e S |
131 | *out_hwirq = ret + GIC_IRQ_START; |
132 | return 0; | |
133 | } | |
134 | ||
4dbf45e3 | 135 | static const struct irq_domain_ops routable_irq_domain_ops = { |
96ca848e S |
136 | .map = crossbar_domain_map, |
137 | .unmap = crossbar_domain_unmap, | |
138 | .xlate = crossbar_domain_xlate | |
139 | }; | |
140 | ||
141 | static int __init crossbar_of_init(struct device_node *node) | |
142 | { | |
edb442de | 143 | int i, size, max = 0, reserved = 0, entry; |
96ca848e | 144 | const __be32 *irqsr; |
edb442de | 145 | int ret = -ENOMEM; |
96ca848e | 146 | |
3894e9e8 | 147 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
96ca848e S |
148 | |
149 | if (!cb) | |
edb442de | 150 | return ret; |
96ca848e S |
151 | |
152 | cb->crossbar_base = of_iomap(node, 0); | |
153 | if (!cb->crossbar_base) | |
3c44d515 | 154 | goto err_cb; |
96ca848e S |
155 | |
156 | of_property_read_u32(node, "ti,max-irqs", &max); | |
edb442de NM |
157 | if (!max) { |
158 | pr_err("missing 'ti,max-irqs' property\n"); | |
159 | ret = -EINVAL; | |
3c44d515 | 160 | goto err_base; |
edb442de | 161 | } |
4dbf45e3 | 162 | cb->irq_map = kcalloc(max, sizeof(int), GFP_KERNEL); |
96ca848e | 163 | if (!cb->irq_map) |
3c44d515 | 164 | goto err_base; |
96ca848e S |
165 | |
166 | cb->int_max = max; | |
167 | ||
168 | for (i = 0; i < max; i++) | |
169 | cb->irq_map[i] = IRQ_FREE; | |
170 | ||
171 | /* Get and mark reserved irqs */ | |
172 | irqsr = of_get_property(node, "ti,irqs-reserved", &size); | |
173 | if (irqsr) { | |
174 | size /= sizeof(__be32); | |
175 | ||
176 | for (i = 0; i < size; i++) { | |
177 | of_property_read_u32_index(node, | |
178 | "ti,irqs-reserved", | |
179 | i, &entry); | |
180 | if (entry > max) { | |
181 | pr_err("Invalid reserved entry\n"); | |
edb442de | 182 | ret = -EINVAL; |
3c44d515 | 183 | goto err_irq_map; |
96ca848e | 184 | } |
1d50d2ce | 185 | cb->irq_map[entry] = IRQ_RESERVED; |
96ca848e S |
186 | } |
187 | } | |
188 | ||
64e0f8ba NM |
189 | /* Skip irqs hardwired to bypass the crossbar */ |
190 | irqsr = of_get_property(node, "ti,irqs-skip", &size); | |
191 | if (irqsr) { | |
192 | size /= sizeof(__be32); | |
193 | ||
194 | for (i = 0; i < size; i++) { | |
195 | of_property_read_u32_index(node, | |
196 | "ti,irqs-skip", | |
197 | i, &entry); | |
198 | if (entry > max) { | |
199 | pr_err("Invalid skip entry\n"); | |
200 | ret = -EINVAL; | |
3c44d515 | 201 | goto err_irq_map; |
64e0f8ba NM |
202 | } |
203 | cb->irq_map[entry] = IRQ_SKIP; | |
204 | } | |
205 | } | |
206 | ||
207 | ||
4dbf45e3 | 208 | cb->register_offsets = kcalloc(max, sizeof(int), GFP_KERNEL); |
96ca848e | 209 | if (!cb->register_offsets) |
3c44d515 | 210 | goto err_irq_map; |
96ca848e S |
211 | |
212 | of_property_read_u32(node, "ti,reg-size", &size); | |
213 | ||
214 | switch (size) { | |
215 | case 1: | |
216 | cb->write = crossbar_writeb; | |
217 | break; | |
218 | case 2: | |
219 | cb->write = crossbar_writew; | |
220 | break; | |
221 | case 4: | |
222 | cb->write = crossbar_writel; | |
223 | break; | |
224 | default: | |
225 | pr_err("Invalid reg-size property\n"); | |
edb442de | 226 | ret = -EINVAL; |
3c44d515 | 227 | goto err_reg_offset; |
96ca848e S |
228 | break; |
229 | } | |
230 | ||
231 | /* | |
232 | * Register offsets are not linear because of the | |
233 | * reserved irqs. so find and store the offsets once. | |
234 | */ | |
235 | for (i = 0; i < max; i++) { | |
1d50d2ce | 236 | if (cb->irq_map[i] == IRQ_RESERVED) |
96ca848e S |
237 | continue; |
238 | ||
239 | cb->register_offsets[i] = reserved; | |
240 | reserved += size; | |
241 | } | |
242 | ||
a35057d1 | 243 | of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map); |
a35057d1 NM |
244 | /* Initialize the crossbar with safe map to start with */ |
245 | for (i = 0; i < max; i++) { | |
246 | if (cb->irq_map[i] == IRQ_RESERVED || | |
247 | cb->irq_map[i] == IRQ_SKIP) | |
248 | continue; | |
249 | ||
250 | cb->write(i, cb->safe_map); | |
251 | } | |
252 | ||
96ca848e S |
253 | register_routable_domain_ops(&routable_irq_domain_ops); |
254 | return 0; | |
255 | ||
3c44d515 | 256 | err_reg_offset: |
96ca848e | 257 | kfree(cb->register_offsets); |
3c44d515 | 258 | err_irq_map: |
96ca848e | 259 | kfree(cb->irq_map); |
3c44d515 | 260 | err_base: |
96ca848e | 261 | iounmap(cb->crossbar_base); |
3c44d515 | 262 | err_cb: |
96ca848e | 263 | kfree(cb); |
99e37d0e S |
264 | |
265 | cb = NULL; | |
edb442de | 266 | return ret; |
96ca848e S |
267 | } |
268 | ||
269 | static const struct of_device_id crossbar_match[] __initconst = { | |
270 | { .compatible = "ti,irq-crossbar" }, | |
271 | {} | |
272 | }; | |
273 | ||
274 | int __init irqcrossbar_init(void) | |
275 | { | |
276 | struct device_node *np; | |
277 | np = of_find_matching_node(NULL, crossbar_match); | |
278 | if (!np) | |
279 | return -ENODEV; | |
280 | ||
281 | crossbar_of_init(np); | |
282 | return 0; | |
283 | } |