1/* ASB2364 FPGA interrupt multiplexing 2 * 3 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 12#include <linux/interrupt.h> 13#include <linux/init.h> 14#include <linux/irq.h> 15#include <unit/fpga-regs.h> 16 17/* 18 * FPGA PIC operations 19 */ 20static void asb2364_fpga_mask(struct irq_data *d) 21{ 22 ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0001; 23 SyncExBus(); 24} 25 26static void asb2364_fpga_ack(struct irq_data *d) 27{ 28 ASB2364_FPGA_REG_IRQ(d->irq - NR_CPU_IRQS) = 0x0001; 29 SyncExBus(); 30} 31 32static void asb2364_fpga_mask_ack(struct irq_data *d) 33{ 34 ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0001; 35 SyncExBus(); 36 ASB2364_FPGA_REG_IRQ(d->irq - NR_CPU_IRQS) = 0x0001; 37 SyncExBus(); 38} 39 40static void asb2364_fpga_unmask(struct irq_data *d) 41{ 42 ASB2364_FPGA_REG_MASK(d->irq - NR_CPU_IRQS) = 0x0000; 43 SyncExBus(); 44} 45 46static struct irq_chip asb2364_fpga_pic = { 47 .name = "fpga", 48 .irq_ack = asb2364_fpga_ack, 49 .irq_mask = asb2364_fpga_mask, 50 .irq_mask_ack = asb2364_fpga_mask_ack, 51 .irq_unmask = asb2364_fpga_unmask, 52}; 53 54/* 55 * FPGA PIC interrupt handler 56 */ 57static irqreturn_t fpga_interrupt(int irq, void *_mask) 58{ 59 if ((ASB2364_FPGA_REG_IRQ_LAN & 0x0001) != 0x0001) 60 generic_handle_irq(FPGA_LAN_IRQ); 61 if ((ASB2364_FPGA_REG_IRQ_UART & 0x0001) != 0x0001) 62 generic_handle_irq(FPGA_UART_IRQ); 63 if ((ASB2364_FPGA_REG_IRQ_I2C & 0x0001) != 0x0001) 64 generic_handle_irq(FPGA_I2C_IRQ); 65 if ((ASB2364_FPGA_REG_IRQ_USB & 0x0001) != 0x0001) 66 generic_handle_irq(FPGA_USB_IRQ); 67 if ((ASB2364_FPGA_REG_IRQ_FPGA & 0x0001) != 0x0001) 68 generic_handle_irq(FPGA_FPGA_IRQ); 69 70 return IRQ_HANDLED; 71} 72 73/* 74 * Define an interrupt action for each FPGA PIC output 75 */ 76static struct irqaction fpga_irq[] = { 77 [0] = { 78 .handler = fpga_interrupt, 79 .flags = IRQF_SHARED, 80 .name = "fpga", 81 }, 82}; 83 84/* 85 * Initialise the FPGA's PIC 86 */ 87void __init irq_fpga_init(void) 88{ 89 int irq; 90 91 ASB2364_FPGA_REG_MASK_LAN = 0x0001; 92 SyncExBus(); 93 ASB2364_FPGA_REG_MASK_UART = 0x0001; 94 SyncExBus(); 95 ASB2364_FPGA_REG_MASK_I2C = 0x0001; 96 SyncExBus(); 97 ASB2364_FPGA_REG_MASK_USB = 0x0001; 98 SyncExBus(); 99 ASB2364_FPGA_REG_MASK_FPGA = 0x0001; 100 SyncExBus(); 101 102 for (irq = NR_CPU_IRQS; irq < NR_IRQS; irq++) 103 irq_set_chip_and_handler(irq, &asb2364_fpga_pic, 104 handle_level_irq); 105 106 /* the FPGA drives the XIRQ1 input on the CPU PIC */ 107 setup_irq(XIRQ1, &fpga_irq[0]); 108} 109