xref: /openbmc/linux/arch/arm/mach-imx/avic.c (revision bbecb07f)
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 hwirq, unsigned int type)
59 {
60 	unsigned int irqt;
61 
62 	if (hwirq >= AVIC_NUM_IRQS)
63 		return -EINVAL;
64 
65 	if (hwirq < AVIC_NUM_IRQS / 2) {
66 		irqt = imx_readl(avic_base + AVIC_INTTYPEL) & ~(1 << hwirq);
67 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEL);
68 	} else {
69 		hwirq -= AVIC_NUM_IRQS / 2;
70 		irqt = imx_readl(avic_base + AVIC_INTTYPEH) & ~(1 << hwirq);
71 		imx_writel(irqt | (!!type << hwirq), avic_base + AVIC_INTTYPEH);
72 	}
73 
74 	return 0;
75 }
76 #endif /* CONFIG_FIQ */
77 
78 
79 static struct mxc_extra_irq avic_extra_irq = {
80 #ifdef CONFIG_FIQ
81 	.set_irq_fiq = avic_set_irq_fiq,
82 #endif
83 };
84 
85 #ifdef CONFIG_PM
86 static u32 avic_saved_mask_reg[2];
87 
88 static void avic_irq_suspend(struct irq_data *d)
89 {
90 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
91 	struct irq_chip_type *ct = gc->chip_types;
92 	int idx = d->hwirq >> 5;
93 
94 	avic_saved_mask_reg[idx] = imx_readl(avic_base + ct->regs.mask);
95 	imx_writel(gc->wake_active, avic_base + ct->regs.mask);
96 }
97 
98 static void avic_irq_resume(struct irq_data *d)
99 {
100 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
101 	struct irq_chip_type *ct = gc->chip_types;
102 	int idx = d->hwirq >> 5;
103 
104 	imx_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
105 }
106 
107 #else
108 #define avic_irq_suspend NULL
109 #define avic_irq_resume NULL
110 #endif
111 
112 static __init void avic_init_gc(int idx, unsigned int irq_start)
113 {
114 	struct irq_chip_generic *gc;
115 	struct irq_chip_type *ct;
116 
117 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
118 				    handle_level_irq);
119 	gc->private = &avic_extra_irq;
120 	gc->wake_enabled = IRQ_MSK(32);
121 
122 	ct = gc->chip_types;
123 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
124 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
125 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
126 	ct->chip.irq_set_wake = irq_gc_set_wake;
127 	ct->chip.irq_suspend = avic_irq_suspend;
128 	ct->chip.irq_resume = avic_irq_resume;
129 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
130 	ct->regs.ack = ct->regs.mask;
131 
132 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
133 }
134 
135 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
136 {
137 	u32 nivector;
138 
139 	do {
140 		nivector = imx_readl(avic_base + AVIC_NIVECSR) >> 16;
141 		if (nivector == 0xffff)
142 			break;
143 
144 		handle_domain_irq(domain, nivector, regs);
145 	} while (1);
146 }
147 
148 /*
149  * This function initializes the AVIC hardware and disables all the
150  * interrupts. It registers the interrupt enable and disable functions
151  * to the kernel for each interrupt source.
152  */
153 void __init mxc_init_irq(void __iomem *irqbase)
154 {
155 	struct device_node *np;
156 	int irq_base;
157 	int i;
158 
159 	avic_base = irqbase;
160 
161 	/* put the AVIC into the reset value with
162 	 * all interrupts disabled
163 	 */
164 	imx_writel(0, avic_base + AVIC_INTCNTL);
165 	imx_writel(0x1f, avic_base + AVIC_NIMASK);
166 
167 	/* disable all interrupts */
168 	imx_writel(0, avic_base + AVIC_INTENABLEH);
169 	imx_writel(0, avic_base + AVIC_INTENABLEL);
170 
171 	/* all IRQ no FIQ */
172 	imx_writel(0, avic_base + AVIC_INTTYPEH);
173 	imx_writel(0, avic_base + AVIC_INTTYPEL);
174 
175 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
176 	WARN_ON(irq_base < 0);
177 
178 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
179 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
180 				       &irq_domain_simple_ops, NULL);
181 	WARN_ON(!domain);
182 
183 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
184 		avic_init_gc(i, irq_base);
185 
186 	/* Set default priority value (0) for all IRQ's */
187 	for (i = 0; i < 8; i++)
188 		imx_writel(0, avic_base + AVIC_NIPRIORITY(i));
189 
190 	set_handle_irq(avic_handle_irq);
191 
192 #ifdef CONFIG_FIQ
193 	/* Initialize FIQ */
194 	init_FIQ(FIQ_START);
195 #endif
196 
197 	printk(KERN_INFO "MXC IRQ initialized\n");
198 }
199