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 /* Define these here for now until we drop all board-files */
27 #define OMAP24XX_IC_BASE	0x480fe000
28 #define OMAP34XX_IC_BASE	0x48200000
29 
30 /* selected INTC register offsets */
31 
32 #define INTC_REVISION		0x0000
33 #define INTC_SYSCONFIG		0x0010
34 #define INTC_SYSSTATUS		0x0014
35 #define INTC_SIR		0x0040
36 #define INTC_CONTROL		0x0048
37 #define INTC_PROTECTION		0x004C
38 #define INTC_IDLE		0x0050
39 #define INTC_THRESHOLD		0x0068
40 #define INTC_MIR0		0x0084
41 #define INTC_MIR_CLEAR0		0x0088
42 #define INTC_MIR_SET0		0x008c
43 #define INTC_PENDING_IRQ0	0x0098
44 #define INTC_PENDING_IRQ1	0x00b8
45 #define INTC_PENDING_IRQ2	0x00d8
46 #define INTC_PENDING_IRQ3	0x00f8
47 #define INTC_ILR0		0x0100
48 
49 #define ACTIVEIRQ_MASK		0x7f	/* omap2/3 active interrupt bits */
50 #define INTCPS_NR_ILR_REGS	128
51 #define INTCPS_NR_MIR_REGS	4
52 
53 #define INTC_IDLE_FUNCIDLE	(1 << 0)
54 #define INTC_IDLE_TURBO		(1 << 1)
55 
56 #define INTC_PROTECTION_ENABLE	(1 << 0)
57 
58 struct omap_intc_regs {
59 	u32 sysconfig;
60 	u32 protection;
61 	u32 idle;
62 	u32 threshold;
63 	u32 ilr[INTCPS_NR_ILR_REGS];
64 	u32 mir[INTCPS_NR_MIR_REGS];
65 };
66 static struct omap_intc_regs intc_context;
67 
68 static struct irq_domain *domain;
69 static void __iomem *omap_irq_base;
70 static int omap_nr_pending = 3;
71 static int omap_nr_irqs = 96;
72 
73 static void intc_writel(u32 reg, u32 val)
74 {
75 	writel_relaxed(val, omap_irq_base + reg);
76 }
77 
78 static u32 intc_readl(u32 reg)
79 {
80 	return readl_relaxed(omap_irq_base + reg);
81 }
82 
83 void omap_intc_save_context(void)
84 {
85 	int i;
86 
87 	intc_context.sysconfig =
88 		intc_readl(INTC_SYSCONFIG);
89 	intc_context.protection =
90 		intc_readl(INTC_PROTECTION);
91 	intc_context.idle =
92 		intc_readl(INTC_IDLE);
93 	intc_context.threshold =
94 		intc_readl(INTC_THRESHOLD);
95 
96 	for (i = 0; i < omap_nr_irqs; i++)
97 		intc_context.ilr[i] =
98 			intc_readl((INTC_ILR0 + 0x4 * i));
99 	for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
100 		intc_context.mir[i] =
101 			intc_readl(INTC_MIR0 + (0x20 * i));
102 }
103 
104 void omap_intc_restore_context(void)
105 {
106 	int i;
107 
108 	intc_writel(INTC_SYSCONFIG, intc_context.sysconfig);
109 	intc_writel(INTC_PROTECTION, intc_context.protection);
110 	intc_writel(INTC_IDLE, intc_context.idle);
111 	intc_writel(INTC_THRESHOLD, intc_context.threshold);
112 
113 	for (i = 0; i < omap_nr_irqs; i++)
114 		intc_writel(INTC_ILR0 + 0x4 * i,
115 				intc_context.ilr[i]);
116 
117 	for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
118 		intc_writel(INTC_MIR0 + 0x20 * i,
119 			intc_context.mir[i]);
120 	/* MIRs are saved and restore with other PRCM registers */
121 }
122 
123 void omap3_intc_prepare_idle(void)
124 {
125 	/*
126 	 * Disable autoidle as it can stall interrupt controller,
127 	 * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
128 	 */
129 	intc_writel(INTC_SYSCONFIG, 0);
130 	intc_writel(INTC_IDLE, INTC_IDLE_TURBO);
131 }
132 
133 void omap3_intc_resume_idle(void)
134 {
135 	/* Re-enable autoidle */
136 	intc_writel(INTC_SYSCONFIG, 1);
137 	intc_writel(INTC_IDLE, 0);
138 }
139 
140 /* XXX: FIQ and additional INTC support (only MPU at the moment) */
141 static void omap_ack_irq(struct irq_data *d)
142 {
143 	intc_writel(INTC_CONTROL, 0x1);
144 }
145 
146 static void omap_mask_ack_irq(struct irq_data *d)
147 {
148 	irq_gc_mask_disable_reg(d);
149 	omap_ack_irq(d);
150 }
151 
152 static void __init omap_irq_soft_reset(void)
153 {
154 	unsigned long tmp;
155 
156 	tmp = intc_readl(INTC_REVISION) & 0xff;
157 
158 	pr_info("IRQ: Found an INTC at 0x%p (revision %ld.%ld) with %d interrupts\n",
159 		omap_irq_base, tmp >> 4, tmp & 0xf, omap_nr_irqs);
160 
161 	tmp = intc_readl(INTC_SYSCONFIG);
162 	tmp |= 1 << 1;	/* soft reset */
163 	intc_writel(INTC_SYSCONFIG, tmp);
164 
165 	while (!(intc_readl(INTC_SYSSTATUS) & 0x1))
166 		/* Wait for reset to complete */;
167 
168 	/* Enable autoidle */
169 	intc_writel(INTC_SYSCONFIG, 1 << 0);
170 }
171 
172 int omap_irq_pending(void)
173 {
174 	int i;
175 
176 	for (i = 0; i < omap_nr_pending; i++)
177 		if (intc_readl(INTC_PENDING_IRQ0 + (0x20 * i)))
178 			return 1;
179 	return 0;
180 }
181 
182 void omap3_intc_suspend(void)
183 {
184 	/* A pending interrupt would prevent OMAP from entering suspend */
185 	omap_ack_irq(NULL);
186 }
187 
188 static int __init omap_alloc_gc_of(struct irq_domain *d, void __iomem *base)
189 {
190 	int ret;
191 	int i;
192 
193 	ret = irq_alloc_domain_generic_chips(d, 32, 1, "INTC",
194 			handle_level_irq, IRQ_NOREQUEST | IRQ_NOPROBE,
195 			IRQ_LEVEL, 0);
196 	if (ret) {
197 		pr_warn("Failed to allocate irq chips\n");
198 		return ret;
199 	}
200 
201 	for (i = 0; i < omap_nr_pending; i++) {
202 		struct irq_chip_generic *gc;
203 		struct irq_chip_type *ct;
204 
205 		gc = irq_get_domain_generic_chip(d, 32 * i);
206 		gc->reg_base = base;
207 		ct = gc->chip_types;
208 
209 		ct->type = IRQ_TYPE_LEVEL_MASK;
210 		ct->handler = handle_level_irq;
211 
212 		ct->chip.irq_ack = omap_mask_ack_irq;
213 		ct->chip.irq_mask = irq_gc_mask_disable_reg;
214 		ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
215 
216 		ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
217 
218 		ct->regs.enable = INTC_MIR_CLEAR0 + 32 * i;
219 		ct->regs.disable = INTC_MIR_SET0 + 32 * i;
220 	}
221 
222 	return 0;
223 }
224 
225 static void __init omap_alloc_gc_legacy(void __iomem *base,
226 		unsigned int irq_start, unsigned int num)
227 {
228 	struct irq_chip_generic *gc;
229 	struct irq_chip_type *ct;
230 
231 	gc = irq_alloc_generic_chip("INTC", 1, irq_start, base,
232 			handle_level_irq);
233 	ct = gc->chip_types;
234 	ct->chip.irq_ack = omap_mask_ack_irq;
235 	ct->chip.irq_mask = irq_gc_mask_disable_reg;
236 	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
237 	ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
238 
239 	ct->regs.enable = INTC_MIR_CLEAR0;
240 	ct->regs.disable = INTC_MIR_SET0;
241 	irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
242 			IRQ_NOREQUEST | IRQ_NOPROBE, 0);
243 }
244 
245 static int __init omap_init_irq_of(struct device_node *node)
246 {
247 	int ret;
248 
249 	omap_irq_base = of_iomap(node, 0);
250 	if (WARN_ON(!omap_irq_base))
251 		return -ENOMEM;
252 
253 	domain = irq_domain_add_linear(node, omap_nr_irqs,
254 			&irq_generic_chip_ops, NULL);
255 
256 	omap_irq_soft_reset();
257 
258 	ret = omap_alloc_gc_of(domain, omap_irq_base);
259 	if (ret < 0)
260 		irq_domain_remove(domain);
261 
262 	return ret;
263 }
264 
265 static int __init omap_init_irq_legacy(u32 base, struct device_node *node)
266 {
267 	int j, irq_base;
268 
269 	omap_irq_base = ioremap(base, SZ_4K);
270 	if (WARN_ON(!omap_irq_base))
271 		return -ENOMEM;
272 
273 	irq_base = irq_alloc_descs(-1, 0, omap_nr_irqs, 0);
274 	if (irq_base < 0) {
275 		pr_warn("Couldn't allocate IRQ numbers\n");
276 		irq_base = 0;
277 	}
278 
279 	domain = irq_domain_add_legacy(node, omap_nr_irqs, irq_base, 0,
280 			&irq_domain_simple_ops, NULL);
281 
282 	omap_irq_soft_reset();
283 
284 	for (j = 0; j < omap_nr_irqs; j += 32)
285 		omap_alloc_gc_legacy(omap_irq_base + j, j + irq_base, 32);
286 
287 	return 0;
288 }
289 
290 static void __init omap_irq_enable_protection(void)
291 {
292 	u32 reg;
293 
294 	reg = intc_readl(INTC_PROTECTION);
295 	reg |= INTC_PROTECTION_ENABLE;
296 	intc_writel(INTC_PROTECTION, reg);
297 }
298 
299 static int __init omap_init_irq(u32 base, struct device_node *node)
300 {
301 	int ret;
302 
303 	/*
304 	 * FIXME legacy OMAP DMA driver sitting under arch/arm/plat-omap/dma.c
305 	 * depends is still not ready for linear IRQ domains; because of that
306 	 * we need to temporarily "blacklist" OMAP2 and OMAP3 devices from using
307 	 * linear IRQ Domain until that driver is finally fixed.
308 	 */
309 	if (of_device_is_compatible(node, "ti,omap2-intc") ||
310 			of_device_is_compatible(node, "ti,omap3-intc")) {
311 		struct resource res;
312 
313 		if (of_address_to_resource(node, 0, &res))
314 			return -ENOMEM;
315 
316 		base = res.start;
317 		ret = omap_init_irq_legacy(base, node);
318 	} else if (node) {
319 		ret = omap_init_irq_of(node);
320 	} else {
321 		ret = omap_init_irq_legacy(base, NULL);
322 	}
323 
324 	if (ret == 0)
325 		omap_irq_enable_protection();
326 
327 	return ret;
328 }
329 
330 static asmlinkage void __exception_irq_entry
331 omap_intc_handle_irq(struct pt_regs *regs)
332 {
333 	u32 irqnr;
334 
335 	irqnr = intc_readl(INTC_SIR);
336 	irqnr &= ACTIVEIRQ_MASK;
337 	WARN_ONCE(!irqnr, "Spurious IRQ ?\n");
338 	handle_domain_irq(domain, irqnr, regs);
339 }
340 
341 void __init omap3_init_irq(void)
342 {
343 	omap_nr_irqs = 96;
344 	omap_nr_pending = 3;
345 	omap_init_irq(OMAP34XX_IC_BASE, NULL);
346 	set_handle_irq(omap_intc_handle_irq);
347 }
348 
349 static int __init intc_of_init(struct device_node *node,
350 			     struct device_node *parent)
351 {
352 	int ret;
353 
354 	omap_nr_pending = 3;
355 	omap_nr_irqs = 96;
356 
357 	if (WARN_ON(!node))
358 		return -ENODEV;
359 
360 	if (of_device_is_compatible(node, "ti,dm814-intc") ||
361 	    of_device_is_compatible(node, "ti,dm816-intc") ||
362 	    of_device_is_compatible(node, "ti,am33xx-intc")) {
363 		omap_nr_irqs = 128;
364 		omap_nr_pending = 4;
365 	}
366 
367 	ret = omap_init_irq(-1, of_node_get(node));
368 	if (ret < 0)
369 		return ret;
370 
371 	set_handle_irq(omap_intc_handle_irq);
372 
373 	return 0;
374 }
375 
376 IRQCHIP_DECLARE(omap2_intc, "ti,omap2-intc", intc_of_init);
377 IRQCHIP_DECLARE(omap3_intc, "ti,omap3-intc", intc_of_init);
378 IRQCHIP_DECLARE(dm814x_intc, "ti,dm814-intc", intc_of_init);
379 IRQCHIP_DECLARE(dm816x_intc, "ti,dm816-intc", intc_of_init);
380 IRQCHIP_DECLARE(am33xx_intc, "ti,am33xx-intc", intc_of_init);
381