xref: /linux/arch/arm/mach-imx/avic.c (revision a4f174dee4ae842e07cab7eeec194a3e60925c8d)
1 /*
2  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
3  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version 2
8  * of the License, or (at your option) any later version.
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
17  * MA  02110-1301, USA.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/irq.h>
22 #include <linux/irqdomain.h>
23 #include <linux/io.h>
24 #include <linux/of.h>
25 #include <asm/mach/irq.h>
26 #include <asm/exception.h>
27 
28 #include "common.h"
29 #include "hardware.h"
30 #include "irq-common.h"
31 
32 #define AVIC_INTCNTL		0x00	/* int control reg */
33 #define AVIC_NIMASK		0x04	/* int mask reg */
34 #define AVIC_INTENNUM		0x08	/* int enable number reg */
35 #define AVIC_INTDISNUM		0x0C	/* int disable number reg */
36 #define AVIC_INTENABLEH		0x10	/* int enable reg high */
37 #define AVIC_INTENABLEL		0x14	/* int enable reg low */
38 #define AVIC_INTTYPEH		0x18	/* int type reg high */
39 #define AVIC_INTTYPEL		0x1C	/* int type reg low */
40 #define AVIC_NIPRIORITY(x)	(0x20 + 4 * (7 - (x))) /* int priority */
41 #define AVIC_NIVECSR		0x40	/* norm int vector/status */
42 #define AVIC_FIVECSR		0x44	/* fast int vector/status */
43 #define AVIC_INTSRCH		0x48	/* int source reg high */
44 #define AVIC_INTSRCL		0x4C	/* int source reg low */
45 #define AVIC_INTFRCH		0x50	/* int force reg high */
46 #define AVIC_INTFRCL		0x54	/* int force reg low */
47 #define AVIC_NIPNDH		0x58	/* norm int pending high */
48 #define AVIC_NIPNDL		0x5C	/* norm int pending low */
49 #define AVIC_FIPNDH		0x60	/* fast int pending high */
50 #define AVIC_FIPNDL		0x64	/* fast int pending low */
51 
52 #define AVIC_NUM_IRQS 64
53 
54 static void __iomem *avic_base;
55 static struct irq_domain *domain;
56 
57 #ifdef CONFIG_FIQ
58 static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
59 {
60 	struct irq_data *d = irq_get_irq_data(irq);
61 	unsigned int irqt;
62 
63 	irq = d->hwirq;
64 
65 	if (irq >= AVIC_NUM_IRQS)
66 		return -EINVAL;
67 
68 	if (irq < AVIC_NUM_IRQS / 2) {
69 		irqt = __raw_readl(avic_base + AVIC_INTTYPEL) & ~(1 << irq);
70 		__raw_writel(irqt | (!!type << irq), avic_base + AVIC_INTTYPEL);
71 	} else {
72 		irq -= AVIC_NUM_IRQS / 2;
73 		irqt = __raw_readl(avic_base + AVIC_INTTYPEH) & ~(1 << irq);
74 		__raw_writel(irqt | (!!type << irq), avic_base + AVIC_INTTYPEH);
75 	}
76 
77 	return 0;
78 }
79 #endif /* CONFIG_FIQ */
80 
81 
82 static struct mxc_extra_irq avic_extra_irq = {
83 #ifdef CONFIG_FIQ
84 	.set_irq_fiq = avic_set_irq_fiq,
85 #endif
86 };
87 
88 #ifdef CONFIG_PM
89 static u32 avic_saved_mask_reg[2];
90 
91 static void avic_irq_suspend(struct irq_data *d)
92 {
93 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
94 	struct irq_chip_type *ct = gc->chip_types;
95 	int idx = d->hwirq >> 5;
96 
97 	avic_saved_mask_reg[idx] = __raw_readl(avic_base + ct->regs.mask);
98 	__raw_writel(gc->wake_active, avic_base + ct->regs.mask);
99 }
100 
101 static void avic_irq_resume(struct irq_data *d)
102 {
103 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
104 	struct irq_chip_type *ct = gc->chip_types;
105 	int idx = d->hwirq >> 5;
106 
107 	__raw_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
108 }
109 
110 #else
111 #define avic_irq_suspend NULL
112 #define avic_irq_resume NULL
113 #endif
114 
115 static __init void avic_init_gc(int idx, unsigned int irq_start)
116 {
117 	struct irq_chip_generic *gc;
118 	struct irq_chip_type *ct;
119 
120 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
121 				    handle_level_irq);
122 	gc->private = &avic_extra_irq;
123 	gc->wake_enabled = IRQ_MSK(32);
124 
125 	ct = gc->chip_types;
126 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
127 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
128 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
129 	ct->chip.irq_set_wake = irq_gc_set_wake;
130 	ct->chip.irq_suspend = avic_irq_suspend;
131 	ct->chip.irq_resume = avic_irq_resume;
132 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
133 	ct->regs.ack = ct->regs.mask;
134 
135 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
136 }
137 
138 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
139 {
140 	u32 nivector;
141 
142 	do {
143 		nivector = __raw_readl(avic_base + AVIC_NIVECSR) >> 16;
144 		if (nivector == 0xffff)
145 			break;
146 
147 		handle_domain_irq(domain, nivector, regs);
148 	} while (1);
149 }
150 
151 /*
152  * This function initializes the AVIC hardware and disables all the
153  * interrupts. It registers the interrupt enable and disable functions
154  * to the kernel for each interrupt source.
155  */
156 void __init mxc_init_irq(void __iomem *irqbase)
157 {
158 	struct device_node *np;
159 	int irq_base;
160 	int i;
161 
162 	avic_base = irqbase;
163 
164 	/* put the AVIC into the reset value with
165 	 * all interrupts disabled
166 	 */
167 	__raw_writel(0, avic_base + AVIC_INTCNTL);
168 	__raw_writel(0x1f, avic_base + AVIC_NIMASK);
169 
170 	/* disable all interrupts */
171 	__raw_writel(0, avic_base + AVIC_INTENABLEH);
172 	__raw_writel(0, avic_base + AVIC_INTENABLEL);
173 
174 	/* all IRQ no FIQ */
175 	__raw_writel(0, avic_base + AVIC_INTTYPEH);
176 	__raw_writel(0, avic_base + AVIC_INTTYPEL);
177 
178 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
179 	WARN_ON(irq_base < 0);
180 
181 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
182 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
183 				       &irq_domain_simple_ops, NULL);
184 	WARN_ON(!domain);
185 
186 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
187 		avic_init_gc(i, irq_base);
188 
189 	/* Set default priority value (0) for all IRQ's */
190 	for (i = 0; i < 8; i++)
191 		__raw_writel(0, avic_base + AVIC_NIPRIORITY(i));
192 
193 	set_handle_irq(avic_handle_irq);
194 
195 #ifdef CONFIG_FIQ
196 	/* Initialize FIQ */
197 	init_FIQ(FIQ_START);
198 #endif
199 
200 	printk(KERN_INFO "MXC IRQ initialized\n");
201 }
202