1 /* irq-mb93093.c: MB93093 FPGA interrupt handling
3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/ptrace.h>
13 #include <linux/errno.h>
14 #include <linux/signal.h>
15 #include <linux/sched.h>
16 #include <linux/ioport.h>
17 #include <linux/interrupt.h>
18 #include <linux/init.h>
19 #include <linux/irq.h>
22 #include <asm/system.h>
23 #include <asm/bitops.h>
24 #include <asm/delay.h>
26 #include <asm/irc-regs.h>
28 #define __reg16(ADDR) (*(volatile unsigned short *)(__region_CS2 + (ADDR)))
30 #define __get_IMR() ({ __reg16(0x0a); })
31 #define __set_IMR(M) do { __reg16(0x0a) = (M); wmb(); } while(0)
32 #define __get_IFR() ({ __reg16(0x02); })
33 #define __clr_IFR(M) do { __reg16(0x02) = ~(M); wmb(); } while(0)
36 * off-CPU FPGA PIC operations
38 static void frv_fpga_enable(unsigned int irq)
40 uint16_t imr = __get_IMR();
42 imr &= ~(1 << (irq - IRQ_BASE_FPGA));
47 static void frv_fpga_disable(unsigned int irq)
49 uint16_t imr = __get_IMR();
51 imr |= 1 << (irq - IRQ_BASE_FPGA);
56 static void frv_fpga_ack(unsigned int irq)
58 __clr_IFR(1 << (irq - IRQ_BASE_FPGA));
61 static void frv_fpga_end(unsigned int irq)
65 static struct irq_chip frv_fpga_pic = {
67 .enable = frv_fpga_enable,
68 .disable = frv_fpga_disable,
70 .mask = frv_fpga_disable,
71 .unmask = frv_fpga_enable,
76 * FPGA PIC interrupt handler
78 static irqreturn_t fpga_interrupt(int irq, void *_mask, struct pt_regs *regs)
80 uint16_t imr, mask = (unsigned long) _mask;
84 mask = mask & ~imr & __get_IFR();
86 /* poll all the triggered IRQs */
90 asm("scan %1,gr0,%0" : "=r"(irq) : "r"(mask));
94 if (__do_IRQ(IRQ_BASE_FPGA + irq, regs))
102 * define an interrupt action for each FPGA PIC output
103 * - use dev_id to indicate the FPGA PIC input to output mappings
105 static struct irqaction fpga_irq[1] = {
107 .handler = fpga_interrupt,
108 .flags = IRQF_DISABLED,
109 .mask = CPU_MASK_NONE,
111 .dev_id = (void *) 0x0700UL,
116 * initialise the motherboard FPGA's PIC
118 void __init fpga_init(void)
122 /* all PIC inputs are all set to be edge triggered */
126 for (irq = IRQ_BASE_FPGA + 8; irq <= IRQ_BASE_FPGA + 10; irq++)
127 set_irq_chip_and_handler(irq, &frv_fpga_pic, handle_edge_irq);
129 /* the FPGA drives external IRQ input #2 on the CPU PIC */
130 setup_irq(IRQ_CPU_EXTERNAL2, &fpga_irq[0]);