diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /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.c | 271 |
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; +} |