/* * linux/arch/arm/mach-omap1/fpga.c * * Interrupt handler for OMAP-1510 Innovator FPGA * * Copyright (C) 2001 RidgeRun, Inc. * Author: Greg Lonnon <glonnon@ridgerun.com> * * Copyright (C) 2002 MontaVista Software, Inc. * * Separated FPGA interrupts from innovator1510.c and cleaned up for 2.6 * Copyright (C) 2004 Nokia Corporation by Tony Lindrgen <tony@atomide.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/types.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/io.h> #include <mach/hardware.h> #include <asm/irq.h> #include <asm/mach/irq.h> #include <mach/fpga.h> #include <mach/gpio.h> static void fpga_mask_irq(unsigned int irq) { irq -= OMAP_FPGA_IRQ_BASE; if (irq < 8) __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) & ~(1 << irq)), OMAP1510_FPGA_IMR_LO); else if (irq < 16) __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) & ~(1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); else __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) & ~(1 << (irq - 16))), INNOVATOR_FPGA_IMR2); } static inline u32 get_fpga_unmasked_irqs(void) { return ((__raw_readb(OMAP1510_FPGA_ISR_LO) & __raw_readb(OMAP1510_FPGA_IMR_LO))) | ((__raw_readb(OMAP1510_FPGA_ISR_HI) & __raw_readb(OMAP1510_FPGA_IMR_HI)) << 8) | ((__raw_readb(INNOVATOR_FPGA_ISR2) & __raw_readb(INNOVATOR_FPGA_IMR2)) << 16); } static void fpga_ack_irq(unsigned int irq) { /* Don't need to explicitly ACK FPGA interrupts */ } static void fpga_unmask_irq(unsigned int irq) { irq -= OMAP_FPGA_IRQ_BASE; if (irq < 8) __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | (1 << irq)), OMAP1510_FPGA_IMR_LO); else if (irq < 16) __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) | (1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); else __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) | (1 << (irq - 16))), INNOVATOR_FPGA_IMR2); } static void fpga_mask_ack_irq(unsigned int irq) { fpga_mask_irq(irq); fpga_ack_irq(irq); } void innovator_fpga_IRQ_demux(unsigned int irq, struct irq_desc *desc) { u32 stat; int fpga_irq; stat = get_fpga_unmasked_irqs(); if (!stat) return; for (fpga_irq = OMAP_FPGA_IRQ_BASE; (fpga_irq < OMAP_FPGA_IRQ_END) && stat; fpga_irq++, stat >>= 1) { if (stat & 1) { generic_handle_irq(fpga_irq); } } } static struct irq_chip omap_fpga_irq_ack = { .name = "FPGA-ack", .ack = fpga_mask_ack_irq, .mask = fpga_mask_irq, .unmask = fpga_unmask_irq, }; static struct irq_chip omap_fpga_irq = { .name = "FPGA", .ack = fpga_ack_irq, .mask = fpga_mask_irq, .unmask = fpga_unmask_irq, }; /* * All of the FPGA interrupt request inputs except for the touchscreen are * edge-sensitive; the touchscreen is level-sensitive. The edge-sensitive * interrupts are acknowledged as a side-effect of reading the interrupt * status register from the FPGA. The edge-sensitive interrupt inputs * cause a problem with level interrupt requests, such as Ethernet. The * problem occurs when a level interrupt request is asserted while its * interrupt input is masked in the FPGA, which results in a missed * interrupt. * * In an attempt to workaround the problem with missed interrupts, the * mask_ack routine for all of the FPGA interrupts has been changed from * fpga_mask_ack_irq() to fpga_ack_irq() so that the specific FPGA interrupt * being serviced is left unmasked. We can do this because the FPGA cascade * interrupt is installed with the IRQF_DISABLED flag, which leaves all * interrupts masked at the CPU while an FPGA interrupt handler executes. * * Limited testing indicates that this workaround appears to be effective * for the smc9194 Ethernet driver used on the Innovator. It should work * on other FPGA interrupts as well, but any drivers that explicitly mask * interrupts at the interrupt controller via disable_irq/enable_irq * could pose a problem. */ void omap1510_fpga_init_irq(void) { int i; __raw_writeb(0, OMAP1510_FPGA_IMR_LO); __raw_writeb(0, OMAP1510_FPGA_IMR_HI); __raw_writeb(0, INNOVATOR_FPGA_IMR2); for (i = OMAP_FPGA_IRQ_BASE; i < OMAP_FPGA_IRQ_END; i++) { if (i == OMAP1510_INT_FPGA_TS) { /* * The touchscreen interrupt is level-sensitive, so * we'll use the regular mask_ack routine for it. */ set_irq_chip(i, &omap_fpga_irq_ack); } else { /* * All FPGA interrupts except the touchscreen are * edge-sensitive, so we won't mask them. */ set_irq_chip(i, &omap_fpga_irq); } set_irq_handler(i, handle_edge_irq); set_irq_flags(i, IRQF_VALID); } /* * The FPGA interrupt line is connected to GPIO13. Claim this pin for * the ARM. * * NOTE: For general GPIO/MPUIO access and interrupts, please see * gpio.[ch] */ gpio_request(13, "FPGA irq"); gpio_direction_input(13); set_irq_type(gpio_to_irq(13), IRQ_TYPE_EDGE_RISING); set_irq_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux); } EXPORT_SYMBOL(omap1510_fpga_init_irq);