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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2006-07-04 07:31:37 +1000
committerPaul Mackerras <paulus@samba.org>2006-07-04 07:31:37 +1000
commit0fbfb036adee72cbfff170075e84ffd9e54f1938 (patch)
treeb6c8173e73eac17fc9ea5133b6af78c5a1cdc3e7 /arch/ppc/syslib
parent0ebfff1491ef85d41ddf9c633834838be144f69f (diff)
downloadlinux-linaro-stable-0fbfb036adee72cbfff170075e84ffd9e54f1938.tar.gz
[POWERPC] Actually copy over i8259.c to arch/ppc/syslib this time
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc/syslib')
-rw-r--r--arch/ppc/syslib/i8259.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/arch/ppc/syslib/i8259.c b/arch/ppc/syslib/i8259.c
new file mode 100644
index 000000000000..eb35353af837
--- /dev/null
+++ b/arch/ppc/syslib/i8259.c
@@ -0,0 +1,212 @@
+/*
+ * i8259 interrupt controller driver.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <asm/io.h>
+#include <asm/i8259.h>
+
+static volatile void __iomem *pci_intack; /* RO, gives us the irq vector */
+
+static unsigned char cached_8259[2] = { 0xff, 0xff };
+#define cached_A1 (cached_8259[0])
+#define cached_21 (cached_8259[1])
+
+static DEFINE_SPINLOCK(i8259_lock);
+
+static int i8259_pic_irq_offset;
+
+/*
+ * Acknowledge the IRQ using either the PCI host bridge's interrupt
+ * acknowledge feature or poll. How i8259_init() is called determines
+ * which is called. It should be noted that polling is broken on some
+ * IBM and Motorola PReP boxes so we must use the int-ack feature on them.
+ */
+int i8259_irq(struct pt_regs *regs)
+{
+ int irq;
+
+ spin_lock(&i8259_lock);
+
+ /* Either int-ack or poll for the IRQ */
+ if (pci_intack)
+ irq = readb(pci_intack);
+ else {
+ /* Perform an interrupt acknowledge cycle on controller 1. */
+ outb(0x0C, 0x20); /* prepare for poll */
+ irq = inb(0x20) & 7;
+ if (irq == 2 ) {
+ /*
+ * Interrupt is cascaded so perform interrupt
+ * acknowledge on controller 2.
+ */
+ outb(0x0C, 0xA0); /* prepare for poll */
+ irq = (inb(0xA0) & 7) + 8;
+ }
+ }
+
+ if (irq == 7) {
+ /*
+ * This may be a spurious interrupt.
+ *
+ * Read the interrupt status register (ISR). If the most
+ * significant bit is not set then there is no valid
+ * interrupt.
+ */
+ if (!pci_intack)
+ outb(0x0B, 0x20); /* ISR register */
+ if(~inb(0x20) & 0x80)
+ irq = -1;
+ }
+
+ spin_unlock(&i8259_lock);
+ return irq + i8259_pic_irq_offset;
+}
+
+static void i8259_mask_and_ack_irq(unsigned int irq_nr)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&i8259_lock, flags);
+ irq_nr -= i8259_pic_irq_offset;
+ if (irq_nr > 7) {
+ cached_A1 |= 1 << (irq_nr-8);
+ inb(0xA1); /* DUMMY */
+ outb(cached_A1, 0xA1);
+ outb(0x20, 0xA0); /* Non-specific EOI */
+ outb(0x20, 0x20); /* Non-specific EOI to cascade */
+ } else {
+ cached_21 |= 1 << irq_nr;
+ inb(0x21); /* DUMMY */
+ outb(cached_21, 0x21);
+ outb(0x20, 0x20); /* Non-specific EOI */
+ }
+ spin_unlock_irqrestore(&i8259_lock, flags);
+}
+
+static void i8259_set_irq_mask(int irq_nr)
+{
+ outb(cached_A1,0xA1);
+ outb(cached_21,0x21);
+}
+
+static void i8259_mask_irq(unsigned int irq_nr)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&i8259_lock, flags);
+ irq_nr -= i8259_pic_irq_offset;
+ if (irq_nr < 8)
+ cached_21 |= 1 << irq_nr;
+ else
+ cached_A1 |= 1 << (irq_nr-8);
+ i8259_set_irq_mask(irq_nr);
+ spin_unlock_irqrestore(&i8259_lock, flags);
+}
+
+static void i8259_unmask_irq(unsigned int irq_nr)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&i8259_lock, flags);
+ irq_nr -= i8259_pic_irq_offset;
+ if (irq_nr < 8)
+ cached_21 &= ~(1 << irq_nr);
+ else
+ cached_A1 &= ~(1 << (irq_nr-8));
+ i8259_set_irq_mask(irq_nr);
+ spin_unlock_irqrestore(&i8259_lock, flags);
+}
+
+static struct irq_chip i8259_pic = {
+ .typename = " i8259 ",
+ .mask = i8259_mask_irq,
+ .unmask = i8259_unmask_irq,
+ .mask_ack = i8259_mask_and_ack_irq,
+};
+
+static struct resource pic1_iores = {
+ .name = "8259 (master)",
+ .start = 0x20,
+ .end = 0x21,
+ .flags = IORESOURCE_BUSY,
+};
+
+static struct resource pic2_iores = {
+ .name = "8259 (slave)",
+ .start = 0xa0,
+ .end = 0xa1,
+ .flags = IORESOURCE_BUSY,
+};
+
+static struct resource pic_edgectrl_iores = {
+ .name = "8259 edge control",
+ .start = 0x4d0,
+ .end = 0x4d1,
+ .flags = IORESOURCE_BUSY,
+};
+
+static struct irqaction i8259_irqaction = {
+ .handler = no_action,
+ .flags = SA_INTERRUPT,
+ .mask = CPU_MASK_NONE,
+ .name = "82c59 secondary cascade",
+};
+
+/*
+ * i8259_init()
+ * intack_addr - PCI interrupt acknowledge (real) address which will return
+ * the active irq from the 8259
+ */
+void __init i8259_init(unsigned long intack_addr, int offset)
+{
+ unsigned long flags;
+ int i;
+
+ spin_lock_irqsave(&i8259_lock, flags);
+ i8259_pic_irq_offset = offset;
+
+ /* init master interrupt controller */
+ outb(0x11, 0x20); /* Start init sequence */
+ outb(0x00, 0x21); /* Vector base */
+ outb(0x04, 0x21); /* edge tiggered, Cascade (slave) on IRQ2 */
+ outb(0x01, 0x21); /* Select 8086 mode */
+
+ /* init slave interrupt controller */
+ outb(0x11, 0xA0); /* Start init sequence */
+ outb(0x08, 0xA1); /* Vector base */
+ outb(0x02, 0xA1); /* edge triggered, Cascade (slave) on IRQ2 */
+ outb(0x01, 0xA1); /* Select 8086 mode */
+
+ /* always read ISR */
+ outb(0x0B, 0x20);
+ outb(0x0B, 0xA0);
+
+ /* Mask all interrupts */
+ outb(cached_A1, 0xA1);
+ outb(cached_21, 0x21);
+
+ spin_unlock_irqrestore(&i8259_lock, flags);
+
+ for (i = 0; i < NUM_ISA_INTERRUPTS; ++i) {
+ set_irq_chip_and_handler(offset + i, &i8259_pic,
+ handle_level_irq);
+ irq_desc[offset + i].status |= IRQ_LEVEL;
+ }
+
+ /* reserve our resources */
+ setup_irq(offset + 2, &i8259_irqaction);
+ request_resource(&ioport_resource, &pic1_iores);
+ request_resource(&ioport_resource, &pic2_iores);
+ request_resource(&ioport_resource, &pic_edgectrl_iores);
+
+ if (intack_addr != 0)
+ pci_intack = ioremap(intack_addr, 1);
+
+}