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-rw-r--r--arch/arm/mach-footbridge/isa-irq.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/arm/mach-footbridge/isa-irq.c b/arch/arm/mach-footbridge/isa-irq.c
new file mode 100644
index 000000000..842ddb412
--- /dev/null
+++ b/arch/arm/mach-footbridge/isa-irq.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/mach-footbridge/irq.c
+ *
+ * Copyright (C) 1996-2000 Russell King
+ *
+ * Changelog:
+ * 22-Aug-1998 RMK Restructured IRQ routines
+ * 03-Sep-1998 PJB Merged CATS support
+ * 20-Jan-1998 RMK Started merge of EBSA286, CATS and NetWinder
+ * 26-Jan-1999 PJB Don't use IACK on CATS
+ * 16-Mar-1999 RMK Added autodetect of ISA PICs
+ */
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+#include <asm/mach/irq.h>
+
+#include <mach/hardware.h>
+#include <asm/hardware/dec21285.h>
+#include <asm/irq.h>
+#include <asm/mach-types.h>
+
+#include "common.h"
+
+static void isa_mask_pic_lo_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
+}
+
+static void isa_ack_pic_lo_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
+ outb(0x20, PIC_LO);
+}
+
+static void isa_unmask_pic_lo_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
+}
+
+static struct irq_chip isa_lo_chip = {
+ .irq_ack = isa_ack_pic_lo_irq,
+ .irq_mask = isa_mask_pic_lo_irq,
+ .irq_unmask = isa_unmask_pic_lo_irq,
+};
+
+static void isa_mask_pic_hi_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
+}
+
+static void isa_ack_pic_hi_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
+ outb(0x62, PIC_LO);
+ outb(0x20, PIC_HI);
+}
+
+static void isa_unmask_pic_hi_irq(struct irq_data *d)
+{
+ unsigned int mask = 1 << (d->irq & 7);
+
+ outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
+}
+
+static struct irq_chip isa_hi_chip = {
+ .irq_ack = isa_ack_pic_hi_irq,
+ .irq_mask = isa_mask_pic_hi_irq,
+ .irq_unmask = isa_unmask_pic_hi_irq,
+};
+
+static void isa_irq_handler(struct irq_desc *desc)
+{
+ unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;
+
+ if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
+ do_bad_IRQ(desc);
+ return;
+ }
+
+ generic_handle_irq(isa_irq);
+}
+
+static struct resource pic1_resource = {
+ .name = "pic1",
+ .start = 0x20,
+ .end = 0x3f,
+};
+
+static struct resource pic2_resource = {
+ .name = "pic2",
+ .start = 0xa0,
+ .end = 0xbf,
+};
+
+void __init isa_init_irq(unsigned int host_irq)
+{
+ unsigned int irq;
+
+ /*
+ * Setup, and then probe for an ISA PIC
+ * If the PIC is not there, then we
+ * ignore the PIC.
+ */
+ outb(0x11, PIC_LO);
+ outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number */
+ outb(0x04, PIC_MASK_LO); /* Slave on Ch2 */
+ outb(0x01, PIC_MASK_LO); /* x86 */
+ outb(0xf5, PIC_MASK_LO); /* pattern: 11110101 */
+
+ outb(0x11, PIC_HI);
+ outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number */
+ outb(0x02, PIC_MASK_HI); /* Slave on Ch1 */
+ outb(0x01, PIC_MASK_HI); /* x86 */
+ outb(0xfa, PIC_MASK_HI); /* pattern: 11111010 */
+
+ outb(0x0b, PIC_LO);
+ outb(0x0b, PIC_HI);
+
+ if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
+ outb(0xff, PIC_MASK_LO);/* mask all IRQs */
+ outb(0xff, PIC_MASK_HI);/* mask all IRQs */
+ } else {
+ printk(KERN_INFO "IRQ: ISA PIC not found\n");
+ host_irq = (unsigned int)-1;
+ }
+
+ if (host_irq != (unsigned int)-1) {
+ for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
+ irq_set_chip_and_handler(irq, &isa_lo_chip,
+ handle_level_irq);
+ irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
+ }
+
+ for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
+ irq_set_chip_and_handler(irq, &isa_hi_chip,
+ handle_level_irq);
+ irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
+ }
+
+ request_resource(&ioport_resource, &pic1_resource);
+ request_resource(&ioport_resource, &pic2_resource);
+
+ irq = IRQ_ISA_CASCADE;
+ if (request_irq(irq, no_action, 0, "cascade", NULL))
+ pr_err("Failed to request irq %u (cascade)\n", irq);
+
+ irq_set_chained_handler(host_irq, isa_irq_handler);
+
+ /*
+ * On the NetWinder, don't automatically
+ * enable ISA IRQ11 when it is requested.
+ * There appears to be a missing pull-up
+ * resistor on this line.
+ */
+ if (machine_is_netwinder())
+ irq_modify_status(_ISA_IRQ(11),
+ IRQ_NOREQUEST | IRQ_NOPROBE, IRQ_NOAUTOEN);
+ }
+}
+
+