1 files changed, 188 insertions, 0 deletions

diff --git a/arch/arm/mach-omap/fpga.c b/arch/arm/mach-omap/fpga.c
new file mode 100644
index 000000000000..7c08f6c2e1d0
--- /dev/null
+++ b/arch/arm/mach-omap/fpga.c
@@ -0,0 +1,188 @@
+/*
+ * 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);