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-rw-r--r--arch/arm/mach-omap1/fpga.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/fpga.c b/arch/arm/mach-omap1/fpga.c
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index 00000000000..7c08f6c2e1d
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+++ b/arch/arm/mach-omap1/fpga.c
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+/*
+ * linux/arch/arm/mach-omap/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/config.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+
+#include <asm/arch/fpga.h>
+#include <asm/arch/gpio.h>
+
+static void fpga_mask_irq(unsigned int irq)
+{
+ irq -= OMAP1510_IH_FPGA_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 -= OMAP1510_IH_FPGA_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 irqdesc *desc,
+ struct pt_regs *regs)
+{
+ struct irqdesc *d;
+ u32 stat;
+ int fpga_irq;
+
+ stat = get_fpga_unmasked_irqs();
+
+ if (!stat)
+ return;
+
+ for (fpga_irq = OMAP1510_IH_FPGA_BASE;
+ (fpga_irq < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS)) && stat;
+ fpga_irq++, stat >>= 1) {
+ if (stat & 1) {
+ d = irq_desc + fpga_irq;
+ d->handle(fpga_irq, d, regs);
+ }
+ }
+}
+
+static struct irqchip omap_fpga_irq_ack = {
+ .ack = fpga_mask_ack_irq,
+ .mask = fpga_mask_irq,
+ .unmask = fpga_unmask_irq,
+};
+
+
+static struct irqchip omap_fpga_irq = {
+ .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 SA_INTERRUPT 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 = OMAP1510_IH_FPGA_BASE; i < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS); 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, do_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]
+ */
+ omap_request_gpio(13);
+ omap_set_gpio_direction(13, 1);
+ omap_set_gpio_edge_ctrl(13, OMAP_GPIO_RISING_EDGE);
+ set_irq_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux);
+}
+
+EXPORT_SYMBOL(omap1510_fpga_init_irq);