xref: /openbmc/linux/arch/hexagon/kernel/irq_cpu.c (revision 615c36f5)
1 /*
2  * First-level interrupt controller model for Hexagon.
3  *
4  * Copyright (c) 2010-2011 Code Aurora Forum. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 and
8  * only version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA.
19  */
20 
21 #include <linux/interrupt.h>
22 #include <asm/irq.h>
23 #include <asm/hexagon_vm.h>
24 
25 static void mask_irq(struct irq_data *data)
26 {
27 	__vmintop_locdis((long) data->irq);
28 }
29 
30 static void mask_irq_num(unsigned int irq)
31 {
32 	__vmintop_locdis((long) irq);
33 }
34 
35 static void unmask_irq(struct irq_data *data)
36 {
37 	__vmintop_locen((long) data->irq);
38 }
39 
40 /*  This is actually all we need for handle_fasteoi_irq  */
41 static void eoi_irq(struct irq_data *data)
42 {
43 	__vmintop_globen((long) data->irq);
44 }
45 
46 /* Power mamangement wake call. We don't need this, however,
47  * if this is absent, then an -ENXIO error is returned to the
48  * msm_serial driver, and it fails to correctly initialize.
49  * This is a bug in the msm_serial driver, but, for now, we
50  * work around it here, by providing this bogus handler.
51  * XXX FIXME!!! remove this when msm_serial is fixed.
52  */
53 static int set_wake(struct irq_data *data, unsigned int on)
54 {
55 	return 0;
56 }
57 
58 static struct irq_chip hexagon_irq_chip = {
59 	.name		= "HEXAGON",
60 	.irq_mask	= mask_irq,
61 	.irq_unmask	= unmask_irq,
62 	.irq_set_wake	= set_wake,
63 	.irq_eoi	= eoi_irq
64 };
65 
66 /**
67  * The hexagon core comes with a first-level interrupt controller
68  * with 32 total possible interrupts.  When the core is embedded
69  * into different systems/platforms, it is typically wrapped by
70  * macro cells that provide one or more second-level interrupt
71  * controllers that are cascaded into one or more of the first-level
72  * interrupts handled here. The precise wiring of these other
73  * irqs varies from platform to platform, and are set up & configured
74  * in the platform-specific files.
75  *
76  * The first-level interrupt controller is wrapped by the VM, which
77  * virtualizes the interrupt controller for us.  It provides a very
78  * simple, fast & efficient API, and so the fasteoi handler is
79  * appropriate for this case.
80  */
81 void __init init_IRQ(void)
82 {
83 	int irq;
84 
85 	for (irq = 0; irq < HEXAGON_CPUINTS; irq++) {
86 		mask_irq_num(irq);
87 		irq_set_chip_and_handler(irq, &hexagon_irq_chip,
88 						 handle_fasteoi_irq);
89 	}
90 }
91