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-rw-r--r--arch/mips/sni/irq.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/mips/sni/irq.c b/arch/mips/sni/irq.c
new file mode 100644
index 000000000000..62c760f14674
--- /dev/null
+++ b/arch/mips/sni/irq.c
@@ -0,0 +1,194 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Copyright (C) 1994 - 2000 Ralf Baechle
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+
+#include <asm/i8259.h>
+#include <asm/io.h>
+#include <asm/sni.h>
+
+DEFINE_SPINLOCK(pciasic_lock);
+
+extern asmlinkage void sni_rm200_pci_handle_int(void);
+
+static void enable_pciasic_irq(unsigned int irq)
+{
+ unsigned int mask = 1 << (irq - PCIMT_IRQ_INT2);
+ unsigned long flags;
+
+ spin_lock_irqsave(&pciasic_lock, flags);
+ *(volatile u8 *) PCIMT_IRQSEL |= mask;
+ spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+static unsigned int startup_pciasic_irq(unsigned int irq)
+{
+ enable_pciasic_irq(irq);
+ return 0; /* never anything pending */
+}
+
+#define shutdown_pciasic_irq disable_pciasic_irq
+
+void disable_pciasic_irq(unsigned int irq)
+{
+ unsigned int mask = ~(1 << (irq - PCIMT_IRQ_INT2));
+ unsigned long flags;
+
+ spin_lock_irqsave(&pciasic_lock, flags);
+ *(volatile u8 *) PCIMT_IRQSEL &= mask;
+ spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+#define mask_and_ack_pciasic_irq disable_pciasic_irq
+
+static void end_pciasic_irq(unsigned int irq)
+{
+ if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+ enable_pciasic_irq(irq);
+}
+
+static struct hw_interrupt_type pciasic_irq_type = {
+ "ASIC-PCI",
+ startup_pciasic_irq,
+ shutdown_pciasic_irq,
+ enable_pciasic_irq,
+ disable_pciasic_irq,
+ mask_and_ack_pciasic_irq,
+ end_pciasic_irq,
+ NULL
+};
+
+/*
+ * hwint0 should deal with MP agent, ASIC PCI, EISA NMI and debug
+ * button interrupts. Later ...
+ */
+void pciasic_hwint0(struct pt_regs *regs)
+{
+ panic("Received int0 but no handler yet ...");
+}
+
+/* This interrupt was used for the com1 console on the first prototypes. */
+void pciasic_hwint2(struct pt_regs *regs)
+{
+ /* I think this shouldn't happen on production machines. */
+ panic("hwint2 and no handler yet");
+}
+
+/* hwint5 is the r4k count / compare interrupt */
+void pciasic_hwint5(struct pt_regs *regs)
+{
+ panic("hwint5 and no handler yet");
+}
+
+static unsigned int ls1bit8(unsigned int x)
+{
+ int b = 7, s;
+
+ s = 4; if ((x & 0x0f) == 0) s = 0; b -= s; x <<= s;
+ s = 2; if ((x & 0x30) == 0) s = 0; b -= s; x <<= s;
+ s = 1; if ((x & 0x40) == 0) s = 0; b -= s;
+
+ return b;
+}
+
+/*
+ * hwint 1 deals with EISA and SCSI interrupts,
+ *
+ * The EISA_INT bit in CSITPEND is high active, all others are low active.
+ */
+void pciasic_hwint1(struct pt_regs *regs)
+{
+ u8 pend = *(volatile char *)PCIMT_CSITPEND;
+ unsigned long flags;
+
+ if (pend & IT_EISA) {
+ int irq;
+ /*
+ * Note: ASIC PCI's builtin interrupt achknowledge feature is
+ * broken. Using it may result in loss of some or all i8259
+ * interupts, so don't use PCIMT_INT_ACKNOWLEDGE ...
+ */
+ irq = i8259_irq();
+ if (unlikely(irq < 0))
+ return;
+
+ do_IRQ(irq, regs);
+ }
+
+ if (!(pend & IT_SCSI)) {
+ flags = read_c0_status();
+ clear_c0_status(ST0_IM);
+ do_IRQ(PCIMT_IRQ_SCSI, regs);
+ write_c0_status(flags);
+ }
+}
+
+/*
+ * hwint 3 should deal with the PCI A - D interrupts,
+ */
+void pciasic_hwint3(struct pt_regs *regs)
+{
+ u8 pend = *(volatile char *)PCIMT_CSITPEND;
+ int irq;
+
+ pend &= (IT_INTA | IT_INTB | IT_INTC | IT_INTD);
+ clear_c0_status(IE_IRQ3);
+ irq = PCIMT_IRQ_INT2 + ls1bit8(pend);
+ do_IRQ(irq, regs);
+ set_c0_status(IE_IRQ3);
+}
+
+/*
+ * hwint 4 is used for only the onboard PCnet 32.
+ */
+void pciasic_hwint4(struct pt_regs *regs)
+{
+ clear_c0_status(IE_IRQ4);
+ do_IRQ(PCIMT_IRQ_ETHERNET, regs);
+ set_c0_status(IE_IRQ4);
+}
+
+void __init init_pciasic(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pciasic_lock, flags);
+ * (volatile u8 *) PCIMT_IRQSEL =
+ IT_EISA | IT_INTA | IT_INTB | IT_INTC | IT_INTD;
+ spin_unlock_irqrestore(&pciasic_lock, flags);
+}
+
+/*
+ * On systems with i8259-style interrupt controllers we assume for
+ * driver compatibility reasons interrupts 0 - 15 to be the i8295
+ * interrupts even if the hardware uses a different interrupt numbering.
+ */
+void __init arch_init_irq(void)
+{
+ int i;
+
+ set_except_vector(0, sni_rm200_pci_handle_int);
+
+ init_i8259_irqs(); /* Integrated i8259 */
+ init_pciasic();
+
+ /* Actually we've got more interrupts to handle ... */
+ for (i = PCIMT_IRQ_INT2; i <= PCIMT_IRQ_ETHERNET; i++) {
+ irq_desc[i].status = IRQ_DISABLED;
+ irq_desc[i].action = 0;
+ irq_desc[i].depth = 1;
+ irq_desc[i].handler = &pciasic_irq_type;
+ }
+
+ change_c0_status(ST0_IM, IE_IRQ1|IE_IRQ2|IE_IRQ3|IE_IRQ4);
+}