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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/v850/kernel/gbus_int.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/v850/kernel/gbus_int.c')
-rw-r--r--arch/v850/kernel/gbus_int.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/arch/v850/kernel/gbus_int.c b/arch/v850/kernel/gbus_int.c
new file mode 100644
index 00000000000..92918b8d89e
--- /dev/null
+++ b/arch/v850/kernel/gbus_int.c
@@ -0,0 +1,271 @@
+/*
+ * arch/v850/kernel/gbus_int.c -- Midas labs GBUS interrupt support
+ *
+ * Copyright (C) 2001,02,03 NEC Electronics Corporation
+ * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
+ *
+ * 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.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/signal.h>
+
+#include <asm/machdep.h>
+
+
+/* The number of shared GINT interrupts. */
+#define NUM_GINTS 4
+
+/* For each GINT interrupt, how many GBUS interrupts are using it. */
+static unsigned gint_num_active_irqs[NUM_GINTS] = { 0 };
+
+/* A table of GINTn interrupts we actually use.
+ Note that we don't use GINT0 because all the boards we support treat it
+ specially. */
+struct used_gint {
+ unsigned gint;
+ unsigned priority;
+} used_gint[] = {
+ { 1, GBUS_INT_PRIORITY_HIGH },
+ { 3, GBUS_INT_PRIORITY_LOW }
+};
+#define NUM_USED_GINTS (sizeof used_gint / sizeof used_gint[0])
+
+/* A table of which GINT is used by each GBUS interrupts (they are
+ assigned based on priority). */
+static unsigned char gbus_int_gint[IRQ_GBUS_INT_NUM];
+
+
+/* Interrupt enabling/disabling. */
+
+/* Enable interrupt handling for interrupt IRQ. */
+void gbus_int_enable_irq (unsigned irq)
+{
+ unsigned gint = gbus_int_gint[irq - GBUS_INT_BASE_IRQ];
+ GBUS_INT_ENABLE (GBUS_INT_IRQ_WORD(irq), gint)
+ |= GBUS_INT_IRQ_MASK (irq);
+}
+
+/* Disable interrupt handling for interrupt IRQ. Note that any
+ interrupts received while disabled will be delivered once the
+ interrupt is enabled again, unless they are explicitly cleared using
+ `gbus_int_clear_pending_irq'. */
+void gbus_int_disable_irq (unsigned irq)
+{
+ unsigned gint = gbus_int_gint[irq - GBUS_INT_BASE_IRQ];
+ GBUS_INT_ENABLE (GBUS_INT_IRQ_WORD(irq), gint)
+ &= ~GBUS_INT_IRQ_MASK (irq);
+}
+
+/* Return true if interrupt handling for interrupt IRQ is enabled. */
+int gbus_int_irq_enabled (unsigned irq)
+{
+ unsigned gint = gbus_int_gint[irq - GBUS_INT_BASE_IRQ];
+ return (GBUS_INT_ENABLE (GBUS_INT_IRQ_WORD(irq), gint)
+ & GBUS_INT_IRQ_MASK(irq));
+}
+
+/* Disable all GBUS irqs. */
+void gbus_int_disable_irqs ()
+{
+ unsigned w, n;
+ for (w = 0; w < GBUS_INT_NUM_WORDS; w++)
+ for (n = 0; n < IRQ_GINT_NUM; n++)
+ GBUS_INT_ENABLE (w, n) = 0;
+}
+
+/* Clear any pending interrupts for IRQ. */
+void gbus_int_clear_pending_irq (unsigned irq)
+{
+ GBUS_INT_CLEAR (GBUS_INT_IRQ_WORD(irq)) = GBUS_INT_IRQ_MASK (irq);
+}
+
+/* Return true if interrupt IRQ is pending (but disabled). */
+int gbus_int_irq_pending (unsigned irq)
+{
+ return (GBUS_INT_STATUS (GBUS_INT_IRQ_WORD(irq))
+ & GBUS_INT_IRQ_MASK(irq));
+}
+
+
+/* Delegating interrupts. */
+
+/* Handle a shared GINT interrupt by passing to the appropriate GBUS
+ interrupt handler. */
+static irqreturn_t gbus_int_handle_irq (int irq, void *dev_id,
+ struct pt_regs *regs)
+{
+ unsigned w;
+ irqreturn_t rval = IRQ_NONE;
+ unsigned gint = irq - IRQ_GINT (0);
+
+ for (w = 0; w < GBUS_INT_NUM_WORDS; w++) {
+ unsigned status = GBUS_INT_STATUS (w);
+ unsigned enable = GBUS_INT_ENABLE (w, gint);
+
+ /* Only pay attention to enabled interrupts. */
+ status &= enable;
+ if (status) {
+ irq = IRQ_GBUS_INT (w * GBUS_INT_BITS_PER_WORD);
+ do {
+ /* There's an active interrupt in word
+ W, find out which one, and call its
+ handler. */
+
+ while (! (status & 0x1)) {
+ irq++;
+ status >>= 1;
+ }
+ status &= ~0x1;
+
+ /* Recursively call handle_irq to handle it. */
+ handle_irq (irq, regs);
+ rval = IRQ_HANDLED;
+ } while (status);
+ }
+ }
+
+ /* Toggle the `all enable' bit back and forth, which should cause
+ another edge transition if there are any other interrupts
+ still pending, and so result in another CPU interrupt. */
+ GBUS_INT_ENABLE (0, gint) &= ~0x1;
+ GBUS_INT_ENABLE (0, gint) |= 0x1;
+
+ return rval;
+}
+
+
+/* Initialize GBUS interrupt sources. */
+
+static void irq_nop (unsigned irq) { }
+
+static unsigned gbus_int_startup_irq (unsigned irq)
+{
+ unsigned gint = gbus_int_gint[irq - GBUS_INT_BASE_IRQ];
+
+ if (gint_num_active_irqs[gint] == 0) {
+ /* First enable the CPU interrupt. */
+ int rval =
+ request_irq (IRQ_GINT(gint), gbus_int_handle_irq,
+ SA_INTERRUPT,
+ "gbus_int_handler",
+ &gint_num_active_irqs[gint]);
+ if (rval != 0)
+ return rval;
+ }
+
+ gint_num_active_irqs[gint]++;
+
+ gbus_int_clear_pending_irq (irq);
+ gbus_int_enable_irq (irq);
+
+ return 0;
+}
+
+static void gbus_int_shutdown_irq (unsigned irq)
+{
+ unsigned gint = gbus_int_gint[irq - GBUS_INT_BASE_IRQ];
+
+ gbus_int_disable_irq (irq);
+
+ if (--gint_num_active_irqs[gint] == 0)
+ /* Disable the CPU interrupt. */
+ free_irq (IRQ_GINT(gint), &gint_num_active_irqs[gint]);
+}
+
+/* Initialize HW_IRQ_TYPES for INTC-controlled irqs described in array
+ INITS (which is terminated by an entry with the name field == 0). */
+void __init gbus_int_init_irq_types (struct gbus_int_irq_init *inits,
+ struct hw_interrupt_type *hw_irq_types)
+{
+ struct gbus_int_irq_init *init;
+ for (init = inits; init->name; init++) {
+ unsigned i;
+ struct hw_interrupt_type *hwit = hw_irq_types++;
+
+ hwit->typename = init->name;
+
+ hwit->startup = gbus_int_startup_irq;
+ hwit->shutdown = gbus_int_shutdown_irq;
+ hwit->enable = gbus_int_enable_irq;
+ hwit->disable = gbus_int_disable_irq;
+ hwit->ack = irq_nop;
+ hwit->end = irq_nop;
+
+ /* Initialize kernel IRQ infrastructure for this interrupt. */
+ init_irq_handlers(init->base, init->num, init->interval, hwit);
+
+ /* Set the interrupt priorities. */
+ for (i = 0; i < init->num; i++) {
+ unsigned j;
+ for (j = 0; j < NUM_USED_GINTS; j++)
+ if (used_gint[j].priority > init->priority)
+ break;
+ /* Wherever we stopped looking is one past the
+ GINT we want. */
+ gbus_int_gint[init->base + i * init->interval
+ - GBUS_INT_BASE_IRQ]
+ = used_gint[j > 0 ? j - 1 : 0].gint;
+ }
+ }
+}
+
+
+/* Initialize IRQS. */
+
+/* Chip interrupts (GINTn) shared among GBUS interrupts. */
+static struct hw_interrupt_type gint_hw_itypes[NUM_USED_GINTS];
+
+
+/* GBUS interrupts themselves. */
+
+struct gbus_int_irq_init gbus_irq_inits[] __initdata = {
+ /* First set defaults. */
+ { "GBUS_INT", IRQ_GBUS_INT(0), IRQ_GBUS_INT_NUM, 1, 6},
+ { 0 }
+};
+#define NUM_GBUS_IRQ_INITS \
+ ((sizeof gbus_irq_inits / sizeof gbus_irq_inits[0]) - 1)
+
+static struct hw_interrupt_type gbus_hw_itypes[NUM_GBUS_IRQ_INITS];
+
+
+/* Initialize GBUS interrupts. */
+void __init gbus_int_init_irqs (void)
+{
+ unsigned i;
+
+ /* First initialize the shared gint interrupts. */
+ for (i = 0; i < NUM_USED_GINTS; i++) {
+ unsigned gint = used_gint[i].gint;
+ struct v850e_intc_irq_init gint_irq_init[2];
+
+ /* We initialize one GINT interrupt at a time. */
+ gint_irq_init[0].name = "GINT";
+ gint_irq_init[0].base = IRQ_GINT (gint);
+ gint_irq_init[0].num = 1;
+ gint_irq_init[0].interval = 1;
+ gint_irq_init[0].priority = used_gint[i].priority;
+
+ gint_irq_init[1].name = 0; /* Terminate the vector. */
+
+ v850e_intc_init_irq_types (gint_irq_init, gint_hw_itypes);
+ }
+
+ /* Then the GBUS interrupts. */
+ gbus_int_disable_irqs ();
+ gbus_int_init_irq_types (gbus_irq_inits, gbus_hw_itypes);
+ /* Turn on the `all enable' bits, which are ANDed with
+ individual interrupt enable bits; we only want to bother with
+ the latter. They are the first bit in the first word of each
+ interrupt-enable area. */
+ for (i = 0; i < NUM_USED_GINTS; i++)
+ GBUS_INT_ENABLE (0, used_gint[i].gint) = 0x1;
+}