Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Tony Lindgren | 7c38cf0 | 2005-09-08 23:07:38 +0100 | [diff] [blame] | 2 | * linux/arch/arm/mach-omap1/fpga.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Interrupt handler for OMAP-1510 Innovator FPGA |
| 5 | * |
| 6 | * Copyright (C) 2001 RidgeRun, Inc. |
| 7 | * Author: Greg Lonnon <glonnon@ridgerun.com> |
| 8 | * |
| 9 | * Copyright (C) 2002 MontaVista Software, Inc. |
| 10 | * |
| 11 | * Separated FPGA interrupts from innovator1510.c and cleaned up for 2.6 |
| 12 | * Copyright (C) 2004 Nokia Corporation by Tony Lindrgen <tony@atomide.com> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License version 2 as |
| 16 | * published by the Free Software Foundation. |
| 17 | */ |
| 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/types.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/device.h> |
| 23 | #include <linux/errno.h> |
Russell King | fced80c | 2008-09-06 12:10:45 +0100 | [diff] [blame] | 24 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 26 | #include <mach/hardware.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <asm/irq.h> |
| 28 | #include <asm/mach/irq.h> |
| 29 | |
Tony Lindgren | ce491cf | 2009-10-20 09:40:47 -0700 | [diff] [blame] | 30 | #include <plat/fpga.h> |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 31 | #include <mach/gpio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
| 33 | static void fpga_mask_irq(unsigned int irq) |
| 34 | { |
Tony Lindgren | 44f78f4 | 2008-07-03 12:24:41 +0300 | [diff] [blame] | 35 | irq -= OMAP_FPGA_IRQ_BASE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
| 37 | if (irq < 8) |
| 38 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) |
| 39 | & ~(1 << irq)), OMAP1510_FPGA_IMR_LO); |
| 40 | else if (irq < 16) |
| 41 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) |
| 42 | & ~(1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); |
| 43 | else |
| 44 | __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) |
| 45 | & ~(1 << (irq - 16))), INNOVATOR_FPGA_IMR2); |
| 46 | } |
| 47 | |
| 48 | |
| 49 | static inline u32 get_fpga_unmasked_irqs(void) |
| 50 | { |
| 51 | return |
| 52 | ((__raw_readb(OMAP1510_FPGA_ISR_LO) & |
| 53 | __raw_readb(OMAP1510_FPGA_IMR_LO))) | |
| 54 | ((__raw_readb(OMAP1510_FPGA_ISR_HI) & |
| 55 | __raw_readb(OMAP1510_FPGA_IMR_HI)) << 8) | |
| 56 | ((__raw_readb(INNOVATOR_FPGA_ISR2) & |
| 57 | __raw_readb(INNOVATOR_FPGA_IMR2)) << 16); |
| 58 | } |
| 59 | |
| 60 | |
| 61 | static void fpga_ack_irq(unsigned int irq) |
| 62 | { |
| 63 | /* Don't need to explicitly ACK FPGA interrupts */ |
| 64 | } |
| 65 | |
| 66 | static void fpga_unmask_irq(unsigned int irq) |
| 67 | { |
Tony Lindgren | 44f78f4 | 2008-07-03 12:24:41 +0300 | [diff] [blame] | 68 | irq -= OMAP_FPGA_IRQ_BASE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | |
| 70 | if (irq < 8) |
| 71 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | (1 << irq)), |
| 72 | OMAP1510_FPGA_IMR_LO); |
| 73 | else if (irq < 16) |
| 74 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) |
| 75 | | (1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); |
| 76 | else |
| 77 | __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) |
| 78 | | (1 << (irq - 16))), INNOVATOR_FPGA_IMR2); |
| 79 | } |
| 80 | |
| 81 | static void fpga_mask_ack_irq(unsigned int irq) |
| 82 | { |
| 83 | fpga_mask_irq(irq); |
| 84 | fpga_ack_irq(irq); |
| 85 | } |
| 86 | |
Russell King | 10dd5ce | 2006-11-23 11:41:32 +0000 | [diff] [blame] | 87 | void innovator_fpga_IRQ_demux(unsigned int irq, struct irq_desc *desc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | u32 stat; |
| 90 | int fpga_irq; |
| 91 | |
| 92 | stat = get_fpga_unmasked_irqs(); |
| 93 | |
| 94 | if (!stat) |
| 95 | return; |
| 96 | |
Tony Lindgren | 44f78f4 | 2008-07-03 12:24:41 +0300 | [diff] [blame] | 97 | for (fpga_irq = OMAP_FPGA_IRQ_BASE; |
| 98 | (fpga_irq < OMAP_FPGA_IRQ_END) && stat; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | fpga_irq++, stat >>= 1) { |
| 100 | if (stat & 1) { |
Dmitry Baryshkov | d8aa025 | 2008-10-09 13:36:24 +0100 | [diff] [blame] | 101 | generic_handle_irq(fpga_irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
David Brownell | 38c677c | 2006-08-01 22:26:25 +0100 | [diff] [blame] | 106 | static struct irq_chip omap_fpga_irq_ack = { |
| 107 | .name = "FPGA-ack", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | .ack = fpga_mask_ack_irq, |
| 109 | .mask = fpga_mask_irq, |
| 110 | .unmask = fpga_unmask_irq, |
| 111 | }; |
| 112 | |
| 113 | |
David Brownell | 38c677c | 2006-08-01 22:26:25 +0100 | [diff] [blame] | 114 | static struct irq_chip omap_fpga_irq = { |
| 115 | .name = "FPGA", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | .ack = fpga_ack_irq, |
| 117 | .mask = fpga_mask_irq, |
| 118 | .unmask = fpga_unmask_irq, |
| 119 | }; |
| 120 | |
| 121 | /* |
| 122 | * All of the FPGA interrupt request inputs except for the touchscreen are |
| 123 | * edge-sensitive; the touchscreen is level-sensitive. The edge-sensitive |
| 124 | * interrupts are acknowledged as a side-effect of reading the interrupt |
| 125 | * status register from the FPGA. The edge-sensitive interrupt inputs |
| 126 | * cause a problem with level interrupt requests, such as Ethernet. The |
| 127 | * problem occurs when a level interrupt request is asserted while its |
| 128 | * interrupt input is masked in the FPGA, which results in a missed |
| 129 | * interrupt. |
| 130 | * |
| 131 | * In an attempt to workaround the problem with missed interrupts, the |
| 132 | * mask_ack routine for all of the FPGA interrupts has been changed from |
| 133 | * fpga_mask_ack_irq() to fpga_ack_irq() so that the specific FPGA interrupt |
| 134 | * being serviced is left unmasked. We can do this because the FPGA cascade |
Thomas Gleixner | 52e405e | 2006-07-03 02:20:05 +0200 | [diff] [blame] | 135 | * interrupt is installed with the IRQF_DISABLED flag, which leaves all |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | * interrupts masked at the CPU while an FPGA interrupt handler executes. |
| 137 | * |
| 138 | * Limited testing indicates that this workaround appears to be effective |
| 139 | * for the smc9194 Ethernet driver used on the Innovator. It should work |
| 140 | * on other FPGA interrupts as well, but any drivers that explicitly mask |
| 141 | * interrupts at the interrupt controller via disable_irq/enable_irq |
| 142 | * could pose a problem. |
| 143 | */ |
| 144 | void omap1510_fpga_init_irq(void) |
| 145 | { |
| 146 | int i; |
| 147 | |
| 148 | __raw_writeb(0, OMAP1510_FPGA_IMR_LO); |
| 149 | __raw_writeb(0, OMAP1510_FPGA_IMR_HI); |
| 150 | __raw_writeb(0, INNOVATOR_FPGA_IMR2); |
| 151 | |
Tony Lindgren | 44f78f4 | 2008-07-03 12:24:41 +0300 | [diff] [blame] | 152 | for (i = OMAP_FPGA_IRQ_BASE; i < OMAP_FPGA_IRQ_END; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
| 154 | if (i == OMAP1510_INT_FPGA_TS) { |
| 155 | /* |
| 156 | * The touchscreen interrupt is level-sensitive, so |
| 157 | * we'll use the regular mask_ack routine for it. |
| 158 | */ |
| 159 | set_irq_chip(i, &omap_fpga_irq_ack); |
| 160 | } |
| 161 | else { |
| 162 | /* |
| 163 | * All FPGA interrupts except the touchscreen are |
| 164 | * edge-sensitive, so we won't mask them. |
| 165 | */ |
| 166 | set_irq_chip(i, &omap_fpga_irq); |
| 167 | } |
| 168 | |
Russell King | 10dd5ce | 2006-11-23 11:41:32 +0000 | [diff] [blame] | 169 | set_irq_handler(i, handle_edge_irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | set_irq_flags(i, IRQF_VALID); |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * The FPGA interrupt line is connected to GPIO13. Claim this pin for |
| 175 | * the ARM. |
| 176 | * |
| 177 | * NOTE: For general GPIO/MPUIO access and interrupts, please see |
| 178 | * gpio.[ch] |
| 179 | */ |
Jarkko Nikula | f2d18fe | 2008-12-10 17:35:30 -0800 | [diff] [blame] | 180 | gpio_request(13, "FPGA irq"); |
David Brownell | 40e3925 | 2008-12-10 17:35:26 -0800 | [diff] [blame] | 181 | gpio_direction_input(13); |
David Brownell | 15f74b0 | 2008-12-10 17:35:26 -0800 | [diff] [blame] | 182 | set_irq_type(gpio_to_irq(13), IRQ_TYPE_EDGE_RISING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | set_irq_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux); |
| 184 | } |
| 185 | |
| 186 | EXPORT_SYMBOL(omap1510_fpga_init_irq); |