1 /*
2 * linux/arch/arm/mach-omap2/irq.c
3 *
4 * Interrupt handler for OMAP2 boards.
5 *
6 * Copyright (C) 2005 Nokia Corporation
7 * Author: Paul Mundt <paul.mundt@nokia.com>
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18
19 #include <asm/exception.h>
20 #include <linux/irqchip.h>
21 #include <linux/irqdomain.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25
26 #include <linux/irqchip/irq-omap-intc.h>
27
28 /* selected INTC register offsets */
29
30 #define INTC_REVISION 0x0000
31 #define INTC_SYSCONFIG 0x0010
32 #define INTC_SYSSTATUS 0x0014
33 #define INTC_SIR 0x0040
34 #define INTC_CONTROL 0x0048
35 #define INTC_PROTECTION 0x004C
36 #define INTC_IDLE 0x0050
37 #define INTC_THRESHOLD 0x0068
38 #define INTC_MIR0 0x0084
39 #define INTC_MIR_CLEAR0 0x0088
40 #define INTC_MIR_SET0 0x008c
41 #define INTC_PENDING_IRQ0 0x0098
42 #define INTC_PENDING_IRQ1 0x00b8
43 #define INTC_PENDING_IRQ2 0x00d8
44 #define INTC_PENDING_IRQ3 0x00f8
45 #define INTC_ILR0 0x0100
46
47 #define ACTIVEIRQ_MASK 0x7f /* omap2/3 active interrupt bits */
48 #define SPURIOUSIRQ_MASK (0x1ffffff << 7)
49 #define INTCPS_NR_ILR_REGS 128
50 #define INTCPS_NR_MIR_REGS 4
51
52 #define INTC_IDLE_FUNCIDLE (1 << 0)
53 #define INTC_IDLE_TURBO (1 << 1)
54
55 #define INTC_PROTECTION_ENABLE (1 << 0)
56
57 struct omap_intc_regs {
58 u32 sysconfig;
59 u32 protection;
60 u32 idle;
61 u32 threshold;
62 u32 ilr[INTCPS_NR_ILR_REGS];
63 u32 mir[INTCPS_NR_MIR_REGS];
64 };
65 static struct omap_intc_regs intc_context;
66
67 static struct irq_domain *domain;
68 static void __iomem *omap_irq_base;
69 static int omap_nr_pending;
70 static int omap_nr_irqs;
71
intc_writel(u32 reg,u32 val)72 static void intc_writel(u32 reg, u32 val)
73 {
74 writel_relaxed(val, omap_irq_base + reg);
75 }
76
intc_readl(u32 reg)77 static u32 intc_readl(u32 reg)
78 {
79 return readl_relaxed(omap_irq_base + reg);
80 }
81
omap_intc_save_context(void)82 void omap_intc_save_context(void)
83 {
84 int i;
85
86 intc_context.sysconfig =
87 intc_readl(INTC_SYSCONFIG);
88 intc_context.protection =
89 intc_readl(INTC_PROTECTION);
90 intc_context.idle =
91 intc_readl(INTC_IDLE);
92 intc_context.threshold =
93 intc_readl(INTC_THRESHOLD);
94
95 for (i = 0; i < omap_nr_irqs; i++)
96 intc_context.ilr[i] =
97 intc_readl((INTC_ILR0 + 0x4 * i));
98 for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
99 intc_context.mir[i] =
100 intc_readl(INTC_MIR0 + (0x20 * i));
101 }
102
omap_intc_restore_context(void)103 void omap_intc_restore_context(void)
104 {
105 int i;
106
107 intc_writel(INTC_SYSCONFIG, intc_context.sysconfig);
108 intc_writel(INTC_PROTECTION, intc_context.protection);
109 intc_writel(INTC_IDLE, intc_context.idle);
110 intc_writel(INTC_THRESHOLD, intc_context.threshold);
111
112 for (i = 0; i < omap_nr_irqs; i++)
113 intc_writel(INTC_ILR0 + 0x4 * i,
114 intc_context.ilr[i]);
115
116 for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
117 intc_writel(INTC_MIR0 + 0x20 * i,
118 intc_context.mir[i]);
119 /* MIRs are saved and restore with other PRCM registers */
120 }
121
omap3_intc_prepare_idle(void)122 void omap3_intc_prepare_idle(void)
123 {
124 /*
125 * Disable autoidle as it can stall interrupt controller,
126 * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
127 */
128 intc_writel(INTC_SYSCONFIG, 0);
129 intc_writel(INTC_IDLE, INTC_IDLE_TURBO);
130 }
131
omap3_intc_resume_idle(void)132 void omap3_intc_resume_idle(void)
133 {
134 /* Re-enable autoidle */
135 intc_writel(INTC_SYSCONFIG, 1);
136 intc_writel(INTC_IDLE, 0);
137 }
138
139 /* XXX: FIQ and additional INTC support (only MPU at the moment) */
omap_ack_irq(struct irq_data * d)140 static void omap_ack_irq(struct irq_data *d)
141 {
142 intc_writel(INTC_CONTROL, 0x1);
143 }
144
omap_mask_ack_irq(struct irq_data * d)145 static void omap_mask_ack_irq(struct irq_data *d)
146 {
147 irq_gc_mask_disable_reg(d);
148 omap_ack_irq(d);
149 }
150
omap_irq_soft_reset(void)151 static void __init omap_irq_soft_reset(void)
152 {
153 unsigned long tmp;
154
155 tmp = intc_readl(INTC_REVISION) & 0xff;
156
157 pr_info("IRQ: Found an INTC at 0x%p (revision %ld.%ld) with %d interrupts\n",
158 omap_irq_base, tmp >> 4, tmp & 0xf, omap_nr_irqs);
159
160 tmp = intc_readl(INTC_SYSCONFIG);
161 tmp |= 1 << 1; /* soft reset */
162 intc_writel(INTC_SYSCONFIG, tmp);
163
164 while (!(intc_readl(INTC_SYSSTATUS) & 0x1))
165 /* Wait for reset to complete */;
166
167 /* Enable autoidle */
168 intc_writel(INTC_SYSCONFIG, 1 << 0);
169 }
170
omap_irq_pending(void)171 int omap_irq_pending(void)
172 {
173 int i;
174
175 for (i = 0; i < omap_nr_pending; i++)
176 if (intc_readl(INTC_PENDING_IRQ0 + (0x20 * i)))
177 return 1;
178 return 0;
179 }
180
omap3_intc_suspend(void)181 void omap3_intc_suspend(void)
182 {
183 /* A pending interrupt would prevent OMAP from entering suspend */
184 omap_ack_irq(NULL);
185 }
186
omap_alloc_gc_of(struct irq_domain * d,void __iomem * base)187 static int __init omap_alloc_gc_of(struct irq_domain *d, void __iomem *base)
188 {
189 int ret;
190 int i;
191
192 ret = irq_alloc_domain_generic_chips(d, 32, 1, "INTC",
193 handle_level_irq, IRQ_NOREQUEST | IRQ_NOPROBE,
194 IRQ_LEVEL, 0);
195 if (ret) {
196 pr_warn("Failed to allocate irq chips\n");
197 return ret;
198 }
199
200 for (i = 0; i < omap_nr_pending; i++) {
201 struct irq_chip_generic *gc;
202 struct irq_chip_type *ct;
203
204 gc = irq_get_domain_generic_chip(d, 32 * i);
205 gc->reg_base = base;
206 ct = gc->chip_types;
207
208 ct->type = IRQ_TYPE_LEVEL_MASK;
209
210 ct->chip.irq_ack = omap_mask_ack_irq;
211 ct->chip.irq_mask = irq_gc_mask_disable_reg;
212 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
213
214 ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
215
216 ct->regs.enable = INTC_MIR_CLEAR0 + 32 * i;
217 ct->regs.disable = INTC_MIR_SET0 + 32 * i;
218 }
219
220 return 0;
221 }
222
omap_alloc_gc_legacy(void __iomem * base,unsigned int irq_start,unsigned int num)223 static void __init omap_alloc_gc_legacy(void __iomem *base,
224 unsigned int irq_start, unsigned int num)
225 {
226 struct irq_chip_generic *gc;
227 struct irq_chip_type *ct;
228
229 gc = irq_alloc_generic_chip("INTC", 1, irq_start, base,
230 handle_level_irq);
231 ct = gc->chip_types;
232 ct->chip.irq_ack = omap_mask_ack_irq;
233 ct->chip.irq_mask = irq_gc_mask_disable_reg;
234 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
235 ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
236
237 ct->regs.enable = INTC_MIR_CLEAR0;
238 ct->regs.disable = INTC_MIR_SET0;
239 irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
240 IRQ_NOREQUEST | IRQ_NOPROBE, 0);
241 }
242
omap_init_irq_of(struct device_node * node)243 static int __init omap_init_irq_of(struct device_node *node)
244 {
245 int ret;
246
247 omap_irq_base = of_iomap(node, 0);
248 if (WARN_ON(!omap_irq_base))
249 return -ENOMEM;
250
251 domain = irq_domain_add_linear(node, omap_nr_irqs,
252 &irq_generic_chip_ops, NULL);
253
254 omap_irq_soft_reset();
255
256 ret = omap_alloc_gc_of(domain, omap_irq_base);
257 if (ret < 0)
258 irq_domain_remove(domain);
259
260 return ret;
261 }
262
omap_init_irq_legacy(u32 base,struct device_node * node)263 static int __init omap_init_irq_legacy(u32 base, struct device_node *node)
264 {
265 int j, irq_base;
266
267 omap_irq_base = ioremap(base, SZ_4K);
268 if (WARN_ON(!omap_irq_base))
269 return -ENOMEM;
270
271 irq_base = irq_alloc_descs(-1, 0, omap_nr_irqs, 0);
272 if (irq_base < 0) {
273 pr_warn("Couldn't allocate IRQ numbers\n");
274 irq_base = 0;
275 }
276
277 domain = irq_domain_add_legacy(node, omap_nr_irqs, irq_base, 0,
278 &irq_domain_simple_ops, NULL);
279
280 omap_irq_soft_reset();
281
282 for (j = 0; j < omap_nr_irqs; j += 32)
283 omap_alloc_gc_legacy(omap_irq_base + j, j + irq_base, 32);
284
285 return 0;
286 }
287
omap_irq_enable_protection(void)288 static void __init omap_irq_enable_protection(void)
289 {
290 u32 reg;
291
292 reg = intc_readl(INTC_PROTECTION);
293 reg |= INTC_PROTECTION_ENABLE;
294 intc_writel(INTC_PROTECTION, reg);
295 }
296
omap_init_irq(u32 base,struct device_node * node)297 static int __init omap_init_irq(u32 base, struct device_node *node)
298 {
299 int ret;
300
301 /*
302 * FIXME legacy OMAP DMA driver sitting under arch/arm/plat-omap/dma.c
303 * depends is still not ready for linear IRQ domains; because of that
304 * we need to temporarily "blacklist" OMAP2 and OMAP3 devices from using
305 * linear IRQ Domain until that driver is finally fixed.
306 */
307 if (of_device_is_compatible(node, "ti,omap2-intc") ||
308 of_device_is_compatible(node, "ti,omap3-intc")) {
309 struct resource res;
310
311 if (of_address_to_resource(node, 0, &res))
312 return -ENOMEM;
313
314 base = res.start;
315 ret = omap_init_irq_legacy(base, node);
316 } else if (node) {
317 ret = omap_init_irq_of(node);
318 } else {
319 ret = omap_init_irq_legacy(base, NULL);
320 }
321
322 if (ret == 0)
323 omap_irq_enable_protection();
324
325 return ret;
326 }
327
omap_intc_handle_irq(struct pt_regs * regs)328 static void __exception_irq_entry omap_intc_handle_irq(struct pt_regs *regs)
329 {
330 extern unsigned long irq_err_count;
331 u32 irqnr;
332
333 irqnr = intc_readl(INTC_SIR);
334
335 /*
336 * A spurious IRQ can result if interrupt that triggered the
337 * sorting is no longer active during the sorting (10 INTC
338 * functional clock cycles after interrupt assertion). Or a
339 * change in interrupt mask affected the result during sorting
340 * time. There is no special handling required except ignoring
341 * the SIR register value just read and retrying.
342 * See section 6.2.5 of AM335x TRM Literature Number: SPRUH73K
343 *
344 * Many a times, a spurious interrupt situation has been fixed
345 * by adding a flush for the posted write acking the IRQ in
346 * the device driver. Typically, this is going be the device
347 * driver whose interrupt was handled just before the spurious
348 * IRQ occurred. Pay attention to those device drivers if you
349 * run into hitting the spurious IRQ condition below.
350 */
351 if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) {
352 pr_err_once("%s: spurious irq!\n", __func__);
353 irq_err_count++;
354 omap_ack_irq(NULL);
355 return;
356 }
357
358 irqnr &= ACTIVEIRQ_MASK;
359 generic_handle_domain_irq(domain, irqnr);
360 }
361
intc_of_init(struct device_node * node,struct device_node * parent)362 static int __init intc_of_init(struct device_node *node,
363 struct device_node *parent)
364 {
365 int ret;
366
367 omap_nr_pending = 3;
368 omap_nr_irqs = 96;
369
370 if (WARN_ON(!node))
371 return -ENODEV;
372
373 if (of_device_is_compatible(node, "ti,dm814-intc") ||
374 of_device_is_compatible(node, "ti,dm816-intc") ||
375 of_device_is_compatible(node, "ti,am33xx-intc")) {
376 omap_nr_irqs = 128;
377 omap_nr_pending = 4;
378 }
379
380 ret = omap_init_irq(-1, of_node_get(node));
381 if (ret < 0)
382 return ret;
383
384 set_handle_irq(omap_intc_handle_irq);
385
386 return 0;
387 }
388
389 IRQCHIP_DECLARE(omap2_intc, "ti,omap2-intc", intc_of_init);
390 IRQCHIP_DECLARE(omap3_intc, "ti,omap3-intc", intc_of_init);
391 IRQCHIP_DECLARE(dm814x_intc, "ti,dm814-intc", intc_of_init);
392 IRQCHIP_DECLARE(dm816x_intc, "ti,dm816-intc", intc_of_init);
393 IRQCHIP_DECLARE(am33xx_intc, "ti,am33xx-intc", intc_of_init);
394