xref: /openbmc/linux/arch/arm/mach-imx/avic.c (revision ee89bd6b)
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_MXC_IRQ_PRIOR
58 static int avic_irq_set_priority(unsigned char irq, unsigned char prio)
59 {
60 	struct irq_data *d = irq_get_irq_data(irq);
61 	unsigned int temp;
62 	unsigned int mask = 0x0F << irq % 8 * 4;
63 
64 	irq = d->hwirq;
65 
66 	if (irq >= AVIC_NUM_IRQS)
67 		return -EINVAL;
68 
69 	temp = __raw_readl(avic_base + AVIC_NIPRIORITY(irq / 8));
70 	temp &= ~mask;
71 	temp |= prio & mask;
72 
73 	__raw_writel(temp, avic_base + AVIC_NIPRIORITY(irq / 8));
74 
75 	return 0;
76 }
77 #endif
78 
79 #ifdef CONFIG_FIQ
80 static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
81 {
82 	struct irq_data *d = irq_get_irq_data(irq);
83 	unsigned int irqt;
84 
85 	irq = d->hwirq;
86 
87 	if (irq >= AVIC_NUM_IRQS)
88 		return -EINVAL;
89 
90 	if (irq < AVIC_NUM_IRQS / 2) {
91 		irqt = __raw_readl(avic_base + AVIC_INTTYPEL) & ~(1 << irq);
92 		__raw_writel(irqt | (!!type << irq), avic_base + AVIC_INTTYPEL);
93 	} else {
94 		irq -= AVIC_NUM_IRQS / 2;
95 		irqt = __raw_readl(avic_base + AVIC_INTTYPEH) & ~(1 << irq);
96 		__raw_writel(irqt | (!!type << irq), avic_base + AVIC_INTTYPEH);
97 	}
98 
99 	return 0;
100 }
101 #endif /* CONFIG_FIQ */
102 
103 
104 static struct mxc_extra_irq avic_extra_irq = {
105 #ifdef CONFIG_MXC_IRQ_PRIOR
106 	.set_priority = avic_irq_set_priority,
107 #endif
108 #ifdef CONFIG_FIQ
109 	.set_irq_fiq = avic_set_irq_fiq,
110 #endif
111 };
112 
113 #ifdef CONFIG_PM
114 static u32 avic_saved_mask_reg[2];
115 
116 static void avic_irq_suspend(struct irq_data *d)
117 {
118 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
119 	struct irq_chip_type *ct = gc->chip_types;
120 	int idx = d->hwirq >> 5;
121 
122 	avic_saved_mask_reg[idx] = __raw_readl(avic_base + ct->regs.mask);
123 	__raw_writel(gc->wake_active, avic_base + ct->regs.mask);
124 }
125 
126 static void avic_irq_resume(struct irq_data *d)
127 {
128 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
129 	struct irq_chip_type *ct = gc->chip_types;
130 	int idx = d->hwirq >> 5;
131 
132 	__raw_writel(avic_saved_mask_reg[idx], avic_base + ct->regs.mask);
133 }
134 
135 #else
136 #define avic_irq_suspend NULL
137 #define avic_irq_resume NULL
138 #endif
139 
140 static __init void avic_init_gc(int idx, unsigned int irq_start)
141 {
142 	struct irq_chip_generic *gc;
143 	struct irq_chip_type *ct;
144 
145 	gc = irq_alloc_generic_chip("mxc-avic", 1, irq_start, avic_base,
146 				    handle_level_irq);
147 	gc->private = &avic_extra_irq;
148 	gc->wake_enabled = IRQ_MSK(32);
149 
150 	ct = gc->chip_types;
151 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
152 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
153 	ct->chip.irq_ack = irq_gc_mask_clr_bit;
154 	ct->chip.irq_set_wake = irq_gc_set_wake;
155 	ct->chip.irq_suspend = avic_irq_suspend;
156 	ct->chip.irq_resume = avic_irq_resume;
157 	ct->regs.mask = !idx ? AVIC_INTENABLEL : AVIC_INTENABLEH;
158 	ct->regs.ack = ct->regs.mask;
159 
160 	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
161 }
162 
163 asmlinkage void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
164 {
165 	u32 nivector;
166 
167 	do {
168 		nivector = __raw_readl(avic_base + AVIC_NIVECSR) >> 16;
169 		if (nivector == 0xffff)
170 			break;
171 
172 		handle_IRQ(irq_find_mapping(domain, nivector), regs);
173 	} while (1);
174 }
175 
176 /*
177  * This function initializes the AVIC hardware and disables all the
178  * interrupts. It registers the interrupt enable and disable functions
179  * to the kernel for each interrupt source.
180  */
181 void __init mxc_init_irq(void __iomem *irqbase)
182 {
183 	struct device_node *np;
184 	int irq_base;
185 	int i;
186 
187 	avic_base = irqbase;
188 
189 	/* put the AVIC into the reset value with
190 	 * all interrupts disabled
191 	 */
192 	__raw_writel(0, avic_base + AVIC_INTCNTL);
193 	__raw_writel(0x1f, avic_base + AVIC_NIMASK);
194 
195 	/* disable all interrupts */
196 	__raw_writel(0, avic_base + AVIC_INTENABLEH);
197 	__raw_writel(0, avic_base + AVIC_INTENABLEL);
198 
199 	/* all IRQ no FIQ */
200 	__raw_writel(0, avic_base + AVIC_INTTYPEH);
201 	__raw_writel(0, avic_base + AVIC_INTTYPEL);
202 
203 	irq_base = irq_alloc_descs(-1, 0, AVIC_NUM_IRQS, numa_node_id());
204 	WARN_ON(irq_base < 0);
205 
206 	np = of_find_compatible_node(NULL, NULL, "fsl,avic");
207 	domain = irq_domain_add_legacy(np, AVIC_NUM_IRQS, irq_base, 0,
208 				       &irq_domain_simple_ops, NULL);
209 	WARN_ON(!domain);
210 
211 	for (i = 0; i < AVIC_NUM_IRQS / 32; i++, irq_base += 32)
212 		avic_init_gc(i, irq_base);
213 
214 	/* Set default priority value (0) for all IRQ's */
215 	for (i = 0; i < 8; i++)
216 		__raw_writel(0, avic_base + AVIC_NIPRIORITY(i));
217 
218 #ifdef CONFIG_FIQ
219 	/* Initialize FIQ */
220 	init_FIQ(FIQ_START);
221 #endif
222 
223 	printk(KERN_INFO "MXC IRQ initialized\n");
224 }
225