#undef IRQ
#undef IRQLIST_16
-/*
- * This is the 'legacy' 8259A Programmable Interrupt Controller,
- * present in the majority of PC/AT boxes.
- * plus some generic x86 specific things if generic specifics makes
- * any sense at all.
- * this file should become arch/i386/kernel/irq.c when the old irq.c
- * moves to arch independent land
- */
-
-static int i8259A_auto_eoi;
-DEFINE_SPINLOCK(i8259A_lock);
-static void mask_and_ack_8259A(unsigned int);
-
-static struct irq_chip i8259A_chip = {
- .name = "XT-PIC",
- .mask = disable_8259A_irq,
- .disable = disable_8259A_irq,
- .unmask = enable_8259A_irq,
- .mask_ack = mask_and_ack_8259A,
-};
-
-/*
- * 8259A PIC functions to handle ISA devices:
- */
-
-/*
- * This contains the irq mask for both 8259A irq controllers,
- */
-unsigned int cached_irq_mask = 0xffff;
-
-/*
- * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
- * boards the timer interrupt is not really connected to any IO-APIC pin,
- * it's fed to the master 8259A's IR0 line only.
- *
- * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
- * this 'mixed mode' IRQ handling costs nothing because it's only used
- * at IRQ setup time.
- */
-unsigned long io_apic_irqs;
-
-void disable_8259A_irq(unsigned int irq)
-{
- unsigned int mask = 1 << irq;
- unsigned long flags;
-
- spin_lock_irqsave(&i8259A_lock, flags);
- cached_irq_mask |= mask;
- if (irq & 8)
- outb(cached_slave_mask, PIC_SLAVE_IMR);
- else
- outb(cached_master_mask, PIC_MASTER_IMR);
- spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
-void enable_8259A_irq(unsigned int irq)
-{
- unsigned int mask = ~(1 << irq);
- unsigned long flags;
-
- spin_lock_irqsave(&i8259A_lock, flags);
- cached_irq_mask &= mask;
- if (irq & 8)
- outb(cached_slave_mask, PIC_SLAVE_IMR);
- else
- outb(cached_master_mask, PIC_MASTER_IMR);
- spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
-int i8259A_irq_pending(unsigned int irq)
-{
- unsigned int mask = 1<<irq;
- unsigned long flags;
- int ret;
-
- spin_lock_irqsave(&i8259A_lock, flags);
- if (irq < 8)
- ret = inb(PIC_MASTER_CMD) & mask;
- else
- ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
- spin_unlock_irqrestore(&i8259A_lock, flags);
-
- return ret;
-}
-
-void make_8259A_irq(unsigned int irq)
-{
- disable_irq_nosync(irq);
- io_apic_irqs &= ~(1<<irq);
- set_irq_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq,
- "XT");
- enable_irq(irq);
-}
-
-/*
- * This function assumes to be called rarely. Switching between
- * 8259A registers is slow.
- * This has to be protected by the irq controller spinlock
- * before being called.
- */
-static inline int i8259A_irq_real(unsigned int irq)
-{
- int value;
- int irqmask = 1<<irq;
-
- if (irq < 8) {
- outb(0x0B,PIC_MASTER_CMD); /* ISR register */
- value = inb(PIC_MASTER_CMD) & irqmask;
- outb(0x0A,PIC_MASTER_CMD); /* back to the IRR register */
- return value;
- }
- outb(0x0B,PIC_SLAVE_CMD); /* ISR register */
- value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
- outb(0x0A,PIC_SLAVE_CMD); /* back to the IRR register */
- return value;
-}
-
-/*
- * Careful! The 8259A is a fragile beast, it pretty
- * much _has_ to be done exactly like this (mask it
- * first, _then_ send the EOI, and the order of EOI
- * to the two 8259s is important!
- */
-static void mask_and_ack_8259A(unsigned int irq)
-{
- unsigned int irqmask = 1 << irq;
- unsigned long flags;
-
- spin_lock_irqsave(&i8259A_lock, flags);
- /*
- * Lightweight spurious IRQ detection. We do not want
- * to overdo spurious IRQ handling - it's usually a sign
- * of hardware problems, so we only do the checks we can
- * do without slowing down good hardware unnecessarily.
- *
- * Note that IRQ7 and IRQ15 (the two spurious IRQs
- * usually resulting from the 8259A-1|2 PICs) occur
- * even if the IRQ is masked in the 8259A. Thus we
- * can check spurious 8259A IRQs without doing the
- * quite slow i8259A_irq_real() call for every IRQ.
- * This does not cover 100% of spurious interrupts,
- * but should be enough to warn the user that there
- * is something bad going on ...
- */
- if (cached_irq_mask & irqmask)
- goto spurious_8259A_irq;
- cached_irq_mask |= irqmask;
-
-handle_real_irq:
- if (irq & 8) {
- inb(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */
- outb(cached_slave_mask, PIC_SLAVE_IMR);
- /* 'Specific EOI' to slave */
- outb(0x60+(irq&7),PIC_SLAVE_CMD);
- /* 'Specific EOI' to master-IRQ2 */
- outb(0x60+PIC_CASCADE_IR,PIC_MASTER_CMD);
- } else {
- inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */
- outb(cached_master_mask, PIC_MASTER_IMR);
- /* 'Specific EOI' to master */
- outb(0x60+irq,PIC_MASTER_CMD);
- }
- spin_unlock_irqrestore(&i8259A_lock, flags);
- return;
-
-spurious_8259A_irq:
- /*
- * this is the slow path - should happen rarely.
- */
- if (i8259A_irq_real(irq))
- /*
- * oops, the IRQ _is_ in service according to the
- * 8259A - not spurious, go handle it.
- */
- goto handle_real_irq;
-
- {
- static int spurious_irq_mask;
- /*
- * At this point we can be sure the IRQ is spurious,
- * lets ACK and report it. [once per IRQ]
- */
- if (!(spurious_irq_mask & irqmask)) {
- printk(KERN_DEBUG
- "spurious 8259A interrupt: IRQ%d.\n", irq);
- spurious_irq_mask |= irqmask;
- }
- atomic_inc(&irq_err_count);
- /*
- * Theoretically we do not have to handle this IRQ,
- * but in Linux this does not cause problems and is
- * simpler for us.
- */
- goto handle_real_irq;
- }
-}
-
-static char irq_trigger[2];
-/**
- * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
- */
-static void restore_ELCR(char *trigger)
-{
- outb(trigger[0], 0x4d0);
- outb(trigger[1], 0x4d1);
-}
-
-static void save_ELCR(char *trigger)
-{
- /* IRQ 0,1,2,8,13 are marked as reserved */
- trigger[0] = inb(0x4d0) & 0xF8;
- trigger[1] = inb(0x4d1) & 0xDE;
-}
-
-static int i8259A_resume(struct sys_device *dev)
-{
- init_8259A(i8259A_auto_eoi);
- restore_ELCR(irq_trigger);
- return 0;
-}
-
-static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
-{
- save_ELCR(irq_trigger);
- return 0;
-}
-
-static int i8259A_shutdown(struct sys_device *dev)
-{
- /* Put the i8259A into a quiescent state that
- * the kernel initialization code can get it
- * out of.
- */
- outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
- outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */
- return 0;
-}
-
-static struct sysdev_class i8259_sysdev_class = {
- .name = "i8259",
- .suspend = i8259A_suspend,
- .resume = i8259A_resume,
- .shutdown = i8259A_shutdown,
-};
-
-static struct sys_device device_i8259A = {
- .id = 0,
- .cls = &i8259_sysdev_class,
-};
-
-static int __init i8259A_init_sysfs(void)
-{
- int error = sysdev_class_register(&i8259_sysdev_class);
- if (!error)
- error = sysdev_register(&device_i8259A);
- return error;
-}
-
-device_initcall(i8259A_init_sysfs);
-
-void init_8259A(int auto_eoi)
-{
- unsigned long flags;
-
- i8259A_auto_eoi = auto_eoi;
-
- spin_lock_irqsave(&i8259A_lock, flags);
-
- outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
- outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
-
- /*
- * outb_pic - this has to work on a wide range of PC hardware.
- */
- outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
- /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
- outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
- /* 8259A-1 (the master) has a slave on IR2 */
- outb_pic(0x04, PIC_MASTER_IMR);
- if (auto_eoi) /* master does Auto EOI */
- outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
- else /* master expects normal EOI */
- outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
-
- outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */
- /* ICW2: 8259A-2 IR0-7 mapped to 0x38-0x3f */
- outb_pic(IRQ8_VECTOR, PIC_SLAVE_IMR);
- /* 8259A-2 is a slave on master's IR2 */
- outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR);
- /* (slave's support for AEOI in flat mode is to be investigated) */
- outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR);
-
- if (auto_eoi)
- /*
- * In AEOI mode we just have to mask the interrupt
- * when acking.
- */
- i8259A_chip.mask_ack = disable_8259A_irq;
- else
- i8259A_chip.mask_ack = mask_and_ack_8259A;
-
- udelay(100); /* wait for 8259A to initialize */
-
- outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
- outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
-
- spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
projects / linux-2.6-omap-h63xx.git / blobdiff