1 /*
2  * BRIEF MODULE DESCRIPTION
3  * Code to handle irqs on GT64120A boards
4  *  Derived from mips/orion and Cort <cort@fsmlabs.com>
5  *
6  * Copyright (C) 2000 RidgeRun, Inc.
7  * Author: RidgeRun, Inc.
8  *   glonnon@ridgerun.com, skranz@ridgerun.com, stevej@ridgerun.com
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  *
15  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
16  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
17  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
18  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
19  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
21  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
22  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
23  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  *  You should have received a copy of the  GNU General Public License along
27  *  with this program; if not, write  to the Free Software Foundation, Inc.,
28  *  675 Mass Ave, Cambridge, MA 02139, USA.
29  */
30 #include <linux/errno.h>
31 #include <linux/init.h>
32 #include <linux/kernel_stat.h>
33 #include <linux/module.h>
34 #include <linux/signal.h>
35 #include <linux/sched.h>
36 #include <linux/types.h>
37 #include <linux/interrupt.h>
38 #include <linux/ioport.h>
39 #include <linux/timex.h>
40 #include <linux/slab.h>
41 #include <linux/random.h>
42 #include <asm/bitops.h>
43 #include <asm/bootinfo.h>
44 #include <asm/io.h>
45 #include <asm/mipsregs.h>
46 #include <asm/system.h>
47 #include <asm/gt64120/gt64120.h>
48 
pci_intA(struct pt_regs * regs)49 asmlinkage inline void pci_intA(struct pt_regs *regs)
50 {
51 	do_IRQ(GT_INTA, regs);
52 }
53 
pci_intD(struct pt_regs * regs)54 asmlinkage inline void pci_intD(struct pt_regs *regs)
55 {
56 	do_IRQ(GT_INTD, regs);
57 }
58 
disable_ev64120_irq(unsigned int irq_nr)59 static void disable_ev64120_irq(unsigned int irq_nr)
60 {
61 	unsigned long flags;
62 
63 	local_irq_save(flags);
64 	if (irq_nr >= 8) {	// All PCI interrupts are on line 5 or 2
65 		clear_c0_status(9 << 10);
66 	} else {
67 		clear_c0_status(1 << (irq_nr + 8));
68 	}
69 	local_irq_restore(flags);
70 }
71 
enable_ev64120_irq(unsigned int irq_nr)72 static void enable_ev64120_irq(unsigned int irq_nr)
73 {
74 	unsigned long flags;
75 
76 	local_irq_save(flags);
77 	if (irq_nr >= 8)	// All PCI interrupts are on line 5 or 2
78 		set_c0_status(9 << 10);
79 	else
80 		set_c0_status(1 << (irq_nr + 8));
81 	local_irq_restore(flags);
82 }
83 
startup_ev64120_irq(unsigned int irq)84 static unsigned int startup_ev64120_irq(unsigned int irq)
85 {
86 	enable_ev64120_irq(irq);
87 	return 0;		/* Never anything pending  */
88 }
89 
90 #define shutdown_ev64120_irq     disable_ev64120_irq
91 #define mask_and_ack_ev64120_irq disable_ev64120_irq
92 
end_ev64120_irq(unsigned int irq)93 static void end_ev64120_irq(unsigned int irq)
94 {
95 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
96 		enable_ev64120_irq(irq);
97 }
98 
99 static struct hw_interrupt_type ev64120_irq_type = {
100 	.typename	= "EV64120",
101 	.startup	= startup_ev64120_irq,
102 	.shutdown	= shutdown_ev64120_irq,
103 	.enable		= enable_ev64120_irq,
104 	.disable	= disable_ev64120_irq,
105 	.ack		= mask_and_ack_ev64120_irq,
106 	.end		= end_ev64120_irq,
107 	.set_affinity	= NULL
108 };
109 
gt64120_irq_setup(void)110 void gt64120_irq_setup(void)
111 {
112 	extern asmlinkage void galileo_handle_int(void);
113 
114 	/*
115 	 * Clear all of the interrupts while we change the able around a bit.
116 	 */
117 	clear_c0_status(ST0_IM);
118 
119 	/* Sets the exception_handler array. */
120 	set_except_vector(0, galileo_handle_int);
121 
122 	cli();
123 
124 	/*
125 	 * Enable timer.  Other interrupts will be enabled as they are
126 	 * registered.
127 	 */
128 	set_c0_status(IE_IRQ2);
129 }
130 
init_IRQ(void)131 void __init init_IRQ(void)
132 {
133 	int i;
134 
135 	/*  Let's initialize our IRQ descriptors  */
136 	for (i = 0; i < NR_IRQS; i++) {
137 		irq_desc[i].status = 0;
138 		irq_desc[i].handler = &no_irq_type;
139 		irq_desc[i].action = NULL;
140 		irq_desc[i].depth = 0;
141 		irq_desc[i].lock = SPIN_LOCK_UNLOCKED;
142 	}
143 
144 	gt64120_irq_setup();
145 }
146