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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/alpha/kernel/irq_pyxis.c
Initial import
Diffstat (limited to 'arch/alpha/kernel/irq_pyxis.c')
-rw-r--r--arch/alpha/kernel/irq_pyxis.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/alpha/kernel/irq_pyxis.c b/arch/alpha/kernel/irq_pyxis.c
new file mode 100644
index 000000000..13c97a5b3
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+++ b/arch/alpha/kernel/irq_pyxis.c
@@ -0,0 +1,110 @@
+/*
+ * linux/arch/alpha/kernel/irq_pyxis.c
+ *
+ * Based on code written by David A Rusling (david.rusling@reo.mts.dec.com).
+ *
+ * IRQ Code common to all PYXIS core logic chips.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/irq.h>
+
+#include <asm/io.h>
+#include <asm/core_cia.h>
+
+#include "proto.h"
+#include "irq_impl.h"
+
+
+/* Note mask bit is true for ENABLED irqs. */
+static unsigned long cached_irq_mask;
+
+static inline void
+pyxis_update_irq_hw(unsigned long mask)
+{
+ *(vulp)PYXIS_INT_MASK = mask;
+ mb();
+ *(vulp)PYXIS_INT_MASK;
+}
+
+static inline void
+pyxis_enable_irq(struct irq_data *d)
+{
+ pyxis_update_irq_hw(cached_irq_mask |= 1UL << (d->irq - 16));
+}
+
+static void
+pyxis_disable_irq(struct irq_data *d)
+{
+ pyxis_update_irq_hw(cached_irq_mask &= ~(1UL << (d->irq - 16)));
+}
+
+static void
+pyxis_mask_and_ack_irq(struct irq_data *d)
+{
+ unsigned long bit = 1UL << (d->irq - 16);
+ unsigned long mask = cached_irq_mask &= ~bit;
+
+ /* Disable the interrupt. */
+ *(vulp)PYXIS_INT_MASK = mask;
+ wmb();
+ /* Ack PYXIS PCI interrupt. */
+ *(vulp)PYXIS_INT_REQ = bit;
+ mb();
+ /* Re-read to force both writes. */
+ *(vulp)PYXIS_INT_MASK;
+}
+
+static struct irq_chip pyxis_irq_type = {
+ .name = "PYXIS",
+ .irq_mask_ack = pyxis_mask_and_ack_irq,
+ .irq_mask = pyxis_disable_irq,
+ .irq_unmask = pyxis_enable_irq,
+};
+
+void
+pyxis_device_interrupt(unsigned long vector)
+{
+ unsigned long pld;
+ unsigned int i;
+
+ /* Read the interrupt summary register of PYXIS */
+ pld = *(vulp)PYXIS_INT_REQ;
+ pld &= cached_irq_mask;
+
+ /*
+ * Now for every possible bit set, work through them and call
+ * the appropriate interrupt handler.
+ */
+ while (pld) {
+ i = ffz(~pld);
+ pld &= pld - 1; /* clear least bit set */
+ if (i == 7)
+ isa_device_interrupt(vector);
+ else
+ handle_irq(16+i);
+ }
+}
+
+void __init
+init_pyxis_irqs(unsigned long ignore_mask)
+{
+ long i;
+
+ *(vulp)PYXIS_INT_MASK = 0; /* disable all */
+ *(vulp)PYXIS_INT_REQ = -1; /* flush all */
+ mb();
+
+ /* Send -INTA pulses to clear any pending interrupts ...*/
+ *(vuip) CIA_IACK_SC;
+
+ for (i = 16; i < 48; ++i) {
+ if ((ignore_mask >> i) & 1)
+ continue;
+ irq_set_chip_and_handler(i, &pyxis_irq_type, handle_level_irq);
+ irq_set_status_flags(i, IRQ_LEVEL);
+ }
+
+ setup_irq(16+7, &isa_cascade_irqaction);
+}