Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2002 Momentum Computer |
| 3 | * Author: mdharm@momenco.com |
| 4 | * |
| 5 | * arch/mips/momentum/ocelot_c/cpci-irq.c |
| 6 | * Interrupt routines for cpci. Interrupt numbers are assigned from |
| 7 | * CPCI_IRQ_BASE to CPCI_IRQ_BASE+8 (8 interrupt sources). |
| 8 | * |
| 9 | * Note that the high-level software will need to be careful about using |
| 10 | * these interrupts. If this board is asserting a cPCI interrupt, it will |
| 11 | * also see the asserted interrupt. Care must be taken to avoid an |
| 12 | * interrupt flood. |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify it |
| 15 | * under the terms of the GNU General Public License as published by the |
| 16 | * Free Software Foundation; either version 2 of the License, or (at your |
| 17 | * option) any later version. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/irq.h> |
| 23 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/sched.h> |
| 25 | #include <linux/kernel_stat.h> |
| 26 | #include <asm/io.h> |
| 27 | #include "ocelot_c_fpga.h" |
| 28 | |
| 29 | #define CPCI_IRQ_BASE 8 |
| 30 | |
| 31 | static inline int ls1bit8(unsigned int x) |
| 32 | { |
| 33 | int b = 7, s; |
| 34 | |
| 35 | s = 4; if (((unsigned char)(x << 4)) == 0) s = 0; b -= s; x <<= s; |
| 36 | s = 2; if (((unsigned char)(x << 2)) == 0) s = 0; b -= s; x <<= s; |
| 37 | s = 1; if (((unsigned char)(x << 1)) == 0) s = 0; b -= s; |
| 38 | |
| 39 | return b; |
| 40 | } |
| 41 | |
| 42 | /* mask off an interrupt -- 0 is enable, 1 is disable */ |
| 43 | static inline void mask_cpci_irq(unsigned int irq) |
| 44 | { |
| 45 | uint32_t value; |
| 46 | |
| 47 | value = OCELOT_FPGA_READ(INTMASK); |
| 48 | value |= 1 << (irq - CPCI_IRQ_BASE); |
| 49 | OCELOT_FPGA_WRITE(value, INTMASK); |
| 50 | |
| 51 | /* read the value back to assure that it's really been written */ |
| 52 | value = OCELOT_FPGA_READ(INTMASK); |
| 53 | } |
| 54 | |
| 55 | /* unmask an interrupt -- 0 is enable, 1 is disable */ |
| 56 | static inline void unmask_cpci_irq(unsigned int irq) |
| 57 | { |
| 58 | uint32_t value; |
| 59 | |
| 60 | value = OCELOT_FPGA_READ(INTMASK); |
| 61 | value &= ~(1 << (irq - CPCI_IRQ_BASE)); |
| 62 | OCELOT_FPGA_WRITE(value, INTMASK); |
| 63 | |
| 64 | /* read the value back to assure that it's really been written */ |
| 65 | value = OCELOT_FPGA_READ(INTMASK); |
| 66 | } |
| 67 | |
| 68 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | * Interrupt handler for interrupts coming from the FPGA chip. |
| 70 | * It could be built in ethernet ports etc... |
| 71 | */ |
Ralf Baechle | 937a801 | 2006-10-07 19:44:33 +0100 | [diff] [blame] | 72 | void ll_cpci_irq(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | { |
| 74 | unsigned int irq_src, irq_mask; |
| 75 | |
| 76 | /* read the interrupt status registers */ |
| 77 | irq_src = OCELOT_FPGA_READ(INTSTAT); |
| 78 | irq_mask = OCELOT_FPGA_READ(INTMASK); |
| 79 | |
| 80 | /* mask for just the interrupts we want */ |
| 81 | irq_src &= ~irq_mask; |
| 82 | |
Ralf Baechle | 937a801 | 2006-10-07 19:44:33 +0100 | [diff] [blame] | 83 | do_IRQ(ls1bit8(irq_src) + CPCI_IRQ_BASE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | } |
| 85 | |
Ralf Baechle | 94dee17 | 2006-07-02 14:41:42 +0100 | [diff] [blame] | 86 | struct irq_chip cpci_irq_type = { |
Atsushi Nemoto | 70d21cd | 2007-01-15 00:07:25 +0900 | [diff] [blame^] | 87 | .name = "CPCI/FPGA", |
Atsushi Nemoto | 1603b5a | 2006-11-02 02:08:36 +0900 | [diff] [blame] | 88 | .ack = mask_cpci_irq, |
| 89 | .mask = mask_cpci_irq, |
| 90 | .mask_ack = mask_cpci_irq, |
| 91 | .unmask = unmask_cpci_irq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | }; |
| 93 | |
| 94 | void cpci_irq_init(void) |
| 95 | { |
| 96 | int i; |
| 97 | |
Atsushi Nemoto | 1603b5a | 2006-11-02 02:08:36 +0900 | [diff] [blame] | 98 | for (i = CPCI_IRQ_BASE; i < (CPCI_IRQ_BASE + 8); i++) |
Atsushi Nemoto | 1417836 | 2006-11-14 01:13:18 +0900 | [diff] [blame] | 99 | set_irq_chip_and_handler(i, &cpci_irq_type, handle_level_irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | } |