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 <asm/mach/irq.h>
21 #include <linux/irqdomain.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 
25 #include <mach/hardware.h>
26 
27 #include "iomap.h"
28 
29 /* selected INTC register offsets */
30 
31 #define INTC_REVISION		0x0000
32 #define INTC_SYSCONFIG		0x0010
33 #define INTC_SYSSTATUS		0x0014
34 #define INTC_SIR		0x0040
35 #define INTC_CONTROL		0x0048
36 #define INTC_PROTECTION		0x004C
37 #define INTC_IDLE		0x0050
38 #define INTC_THRESHOLD		0x0068
39 #define INTC_MIR0		0x0084
40 #define INTC_MIR_CLEAR0		0x0088
41 #define INTC_MIR_SET0		0x008c
42 #define INTC_PENDING_IRQ0	0x0098
43 /* Number of IRQ state bits in each MIR register */
44 #define IRQ_BITS_PER_REG	32
45 
46 #define OMAP2_IRQ_BASE		OMAP2_L4_IO_ADDRESS(OMAP24XX_IC_BASE)
47 #define OMAP3_IRQ_BASE		OMAP2_L4_IO_ADDRESS(OMAP34XX_IC_BASE)
48 #define INTCPS_SIR_IRQ_OFFSET	0x0040	/* omap2/3 active interrupt offset */
49 #define ACTIVEIRQ_MASK		0x7f	/* omap2/3 active interrupt bits */
50 
51 /*
52  * OMAP2 has a number of different interrupt controllers, each interrupt
53  * controller is identified as its own "bank". Register definitions are
54  * fairly consistent for each bank, but not all registers are implemented
55  * for each bank.. when in doubt, consult the TRM.
56  */
57 static struct omap_irq_bank {
58 	void __iomem *base_reg;
59 	unsigned int nr_irqs;
60 } __attribute__ ((aligned(4))) irq_banks[] = {
61 	{
62 		/* MPU INTC */
63 		.nr_irqs	= 96,
64 	},
65 };
66 
67 static struct irq_domain *domain;
68 
69 /* Structure to save interrupt controller context */
70 struct omap3_intc_regs {
71 	u32 sysconfig;
72 	u32 protection;
73 	u32 idle;
74 	u32 threshold;
75 	u32 ilr[INTCPS_NR_IRQS];
76 	u32 mir[INTCPS_NR_MIR_REGS];
77 };
78 
79 /* INTC bank register get/set */
80 
intc_bank_write_reg(u32 val,struct omap_irq_bank * bank,u16 reg)81 static void intc_bank_write_reg(u32 val, struct omap_irq_bank *bank, u16 reg)
82 {
83 	__raw_writel(val, bank->base_reg + reg);
84 }
85 
intc_bank_read_reg(struct omap_irq_bank * bank,u16 reg)86 static u32 intc_bank_read_reg(struct omap_irq_bank *bank, u16 reg)
87 {
88 	return __raw_readl(bank->base_reg + reg);
89 }
90 
91 /* XXX: FIQ and additional INTC support (only MPU at the moment) */
omap_ack_irq(struct irq_data * d)92 static void omap_ack_irq(struct irq_data *d)
93 {
94 	intc_bank_write_reg(0x1, &irq_banks[0], INTC_CONTROL);
95 }
96 
omap_mask_ack_irq(struct irq_data * d)97 static void omap_mask_ack_irq(struct irq_data *d)
98 {
99 	irq_gc_mask_disable_reg(d);
100 	omap_ack_irq(d);
101 }
102 
omap_irq_bank_init_one(struct omap_irq_bank * bank)103 static void __init omap_irq_bank_init_one(struct omap_irq_bank *bank)
104 {
105 	unsigned long tmp;
106 
107 	tmp = intc_bank_read_reg(bank, INTC_REVISION) & 0xff;
108 	printk(KERN_INFO "IRQ: Found an INTC at 0x%p "
109 			 "(revision %ld.%ld) with %d interrupts\n",
110 			 bank->base_reg, tmp >> 4, tmp & 0xf, bank->nr_irqs);
111 
112 	tmp = intc_bank_read_reg(bank, INTC_SYSCONFIG);
113 	tmp |= 1 << 1;	/* soft reset */
114 	intc_bank_write_reg(tmp, bank, INTC_SYSCONFIG);
115 
116 	while (!(intc_bank_read_reg(bank, INTC_SYSSTATUS) & 0x1))
117 		/* Wait for reset to complete */;
118 
119 	/* Enable autoidle */
120 	intc_bank_write_reg(1 << 0, bank, INTC_SYSCONFIG);
121 }
122 
omap_irq_pending(void)123 int omap_irq_pending(void)
124 {
125 	int i;
126 
127 	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
128 		struct omap_irq_bank *bank = irq_banks + i;
129 		int irq;
130 
131 		for (irq = 0; irq < bank->nr_irqs; irq += 32)
132 			if (intc_bank_read_reg(bank, INTC_PENDING_IRQ0 +
133 					       ((irq >> 5) << 5)))
134 				return 1;
135 	}
136 	return 0;
137 }
138 
139 static __init void
omap_alloc_gc(void __iomem * base,unsigned int irq_start,unsigned int num)140 omap_alloc_gc(void __iomem *base, unsigned int irq_start, unsigned int num)
141 {
142 	struct irq_chip_generic *gc;
143 	struct irq_chip_type *ct;
144 
145 	gc = irq_alloc_generic_chip("INTC", 1, irq_start, base,
146 					handle_level_irq);
147 	ct = gc->chip_types;
148 	ct->chip.irq_ack = omap_mask_ack_irq;
149 	ct->chip.irq_mask = irq_gc_mask_disable_reg;
150 	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
151 
152 	ct->regs.ack = INTC_CONTROL;
153 	ct->regs.enable = INTC_MIR_CLEAR0;
154 	ct->regs.disable = INTC_MIR_SET0;
155 	irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
156 				IRQ_NOREQUEST | IRQ_NOPROBE, 0);
157 }
158 
omap_init_irq(u32 base,int nr_irqs,struct device_node * node)159 static void __init omap_init_irq(u32 base, int nr_irqs,
160 				 struct device_node *node)
161 {
162 	void __iomem *omap_irq_base;
163 	unsigned long nr_of_irqs = 0;
164 	unsigned int nr_banks = 0;
165 	int i, j, irq_base;
166 
167 	omap_irq_base = ioremap(base, SZ_4K);
168 	if (WARN_ON(!omap_irq_base))
169 		return;
170 
171 	irq_base = irq_alloc_descs(-1, 0, nr_irqs, 0);
172 	if (irq_base < 0) {
173 		pr_warn("Couldn't allocate IRQ numbers\n");
174 		irq_base = 0;
175 	}
176 
177 	domain = irq_domain_add_legacy(node, nr_irqs, irq_base, 0,
178 				       &irq_domain_simple_ops, NULL);
179 
180 	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
181 		struct omap_irq_bank *bank = irq_banks + i;
182 
183 		bank->nr_irqs = nr_irqs;
184 
185 		/* Static mapping, never released */
186 		bank->base_reg = ioremap(base, SZ_4K);
187 		if (!bank->base_reg) {
188 			pr_err("Could not ioremap irq bank%i\n", i);
189 			continue;
190 		}
191 
192 		omap_irq_bank_init_one(bank);
193 
194 		for (j = 0; j < bank->nr_irqs; j += 32)
195 			omap_alloc_gc(bank->base_reg + j, j + irq_base, 32);
196 
197 		nr_of_irqs += bank->nr_irqs;
198 		nr_banks++;
199 	}
200 
201 	pr_info("Total of %ld interrupts on %d active controller%s\n",
202 		nr_of_irqs, nr_banks, nr_banks > 1 ? "s" : "");
203 }
204 
omap2_init_irq(void)205 void __init omap2_init_irq(void)
206 {
207 	omap_init_irq(OMAP24XX_IC_BASE, 96, NULL);
208 }
209 
omap3_init_irq(void)210 void __init omap3_init_irq(void)
211 {
212 	omap_init_irq(OMAP34XX_IC_BASE, 96, NULL);
213 }
214 
ti81xx_init_irq(void)215 void __init ti81xx_init_irq(void)
216 {
217 	omap_init_irq(OMAP34XX_IC_BASE, 128, NULL);
218 }
219 
omap_intc_handle_irq(void __iomem * base_addr,struct pt_regs * regs)220 static inline void omap_intc_handle_irq(void __iomem *base_addr, struct pt_regs *regs)
221 {
222 	u32 irqnr;
223 	int handled_irq = 0;
224 
225 	do {
226 		irqnr = readl_relaxed(base_addr + 0x98);
227 		if (irqnr)
228 			goto out;
229 
230 		irqnr = readl_relaxed(base_addr + 0xb8);
231 		if (irqnr)
232 			goto out;
233 
234 		irqnr = readl_relaxed(base_addr + 0xd8);
235 #ifdef CONFIG_SOC_OMAPTI816X
236 		if (irqnr)
237 			goto out;
238 		irqnr = readl_relaxed(base_addr + 0xf8);
239 #endif
240 
241 out:
242 		if (!irqnr)
243 			break;
244 
245 		irqnr = readl_relaxed(base_addr + INTCPS_SIR_IRQ_OFFSET);
246 		irqnr &= ACTIVEIRQ_MASK;
247 
248 		if (irqnr) {
249 			irqnr = irq_find_mapping(domain, irqnr);
250 			handle_IRQ(irqnr, regs);
251 			handled_irq = 1;
252 		}
253 	} while (irqnr);
254 
255 	/* If an irq is masked or deasserted while active, we will
256 	 * keep ending up here with no irq handled. So remove it from
257 	 * the INTC with an ack.*/
258 	if (!handled_irq)
259 		omap_ack_irq(NULL);
260 }
261 
omap2_intc_handle_irq(struct pt_regs * regs)262 asmlinkage void __exception_irq_entry omap2_intc_handle_irq(struct pt_regs *regs)
263 {
264 	void __iomem *base_addr = OMAP2_IRQ_BASE;
265 	omap_intc_handle_irq(base_addr, regs);
266 }
267 
omap_intc_of_init(struct device_node * node,struct device_node * parent)268 int __init omap_intc_of_init(struct device_node *node,
269 			     struct device_node *parent)
270 {
271 	struct resource res;
272 	u32 nr_irqs = 96;
273 
274 	if (WARN_ON(!node))
275 		return -ENODEV;
276 
277 	if (of_address_to_resource(node, 0, &res)) {
278 		WARN(1, "unable to get intc registers\n");
279 		return -EINVAL;
280 	}
281 
282 	if (of_property_read_u32(node, "ti,intc-size", &nr_irqs))
283 		pr_warn("unable to get intc-size, default to %d\n", nr_irqs);
284 
285 	omap_init_irq(res.start, nr_irqs, of_node_get(node));
286 
287 	return 0;
288 }
289 
290 #ifdef CONFIG_ARCH_OMAP3
291 static struct omap3_intc_regs intc_context[ARRAY_SIZE(irq_banks)];
292 
omap_intc_save_context(void)293 void omap_intc_save_context(void)
294 {
295 	int ind = 0, i = 0;
296 	for (ind = 0; ind < ARRAY_SIZE(irq_banks); ind++) {
297 		struct omap_irq_bank *bank = irq_banks + ind;
298 		intc_context[ind].sysconfig =
299 			intc_bank_read_reg(bank, INTC_SYSCONFIG);
300 		intc_context[ind].protection =
301 			intc_bank_read_reg(bank, INTC_PROTECTION);
302 		intc_context[ind].idle =
303 			intc_bank_read_reg(bank, INTC_IDLE);
304 		intc_context[ind].threshold =
305 			intc_bank_read_reg(bank, INTC_THRESHOLD);
306 		for (i = 0; i < INTCPS_NR_IRQS; i++)
307 			intc_context[ind].ilr[i] =
308 				intc_bank_read_reg(bank, (0x100 + 0x4*i));
309 		for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
310 			intc_context[ind].mir[i] =
311 				intc_bank_read_reg(&irq_banks[0], INTC_MIR0 +
312 				(0x20 * i));
313 	}
314 }
315 
omap_intc_restore_context(void)316 void omap_intc_restore_context(void)
317 {
318 	int ind = 0, i = 0;
319 
320 	for (ind = 0; ind < ARRAY_SIZE(irq_banks); ind++) {
321 		struct omap_irq_bank *bank = irq_banks + ind;
322 		intc_bank_write_reg(intc_context[ind].sysconfig,
323 					bank, INTC_SYSCONFIG);
324 		intc_bank_write_reg(intc_context[ind].sysconfig,
325 					bank, INTC_SYSCONFIG);
326 		intc_bank_write_reg(intc_context[ind].protection,
327 					bank, INTC_PROTECTION);
328 		intc_bank_write_reg(intc_context[ind].idle,
329 					bank, INTC_IDLE);
330 		intc_bank_write_reg(intc_context[ind].threshold,
331 					bank, INTC_THRESHOLD);
332 		for (i = 0; i < INTCPS_NR_IRQS; i++)
333 			intc_bank_write_reg(intc_context[ind].ilr[i],
334 				bank, (0x100 + 0x4*i));
335 		for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
336 			intc_bank_write_reg(intc_context[ind].mir[i],
337 				 &irq_banks[0], INTC_MIR0 + (0x20 * i));
338 	}
339 	/* MIRs are saved and restore with other PRCM registers */
340 }
341 
omap3_intc_suspend(void)342 void omap3_intc_suspend(void)
343 {
344 	/* A pending interrupt would prevent OMAP from entering suspend */
345 	omap_ack_irq(0);
346 }
347 
omap3_intc_prepare_idle(void)348 void omap3_intc_prepare_idle(void)
349 {
350 	/*
351 	 * Disable autoidle as it can stall interrupt controller,
352 	 * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
353 	 */
354 	intc_bank_write_reg(0, &irq_banks[0], INTC_SYSCONFIG);
355 }
356 
omap3_intc_resume_idle(void)357 void omap3_intc_resume_idle(void)
358 {
359 	/* Re-enable autoidle */
360 	intc_bank_write_reg(1, &irq_banks[0], INTC_SYSCONFIG);
361 }
362 
omap3_intc_handle_irq(struct pt_regs * regs)363 asmlinkage void __exception_irq_entry omap3_intc_handle_irq(struct pt_regs *regs)
364 {
365 	void __iomem *base_addr = OMAP3_IRQ_BASE;
366 	omap_intc_handle_irq(base_addr, regs);
367 }
368 #endif /* CONFIG_ARCH_OMAP3 */
369