summaryrefslogtreecommitdiffstats
path: root/kernel/arch/powerpc/sysdev/uic.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/powerpc/sysdev/uic.c')
-rw-r--r--kernel/arch/powerpc/sysdev/uic.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/sysdev/uic.c b/kernel/arch/powerpc/sysdev/uic.c
new file mode 100644
index 000000000..7c37157d4
--- /dev/null
+++ b/kernel/arch/powerpc/sysdev/uic.c
@@ -0,0 +1,334 @@
+/*
+ * arch/powerpc/sysdev/uic.c
+ *
+ * IBM PowerPC 4xx Universal Interrupt Controller
+ *
+ * Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/dcr.h>
+
+#define NR_UIC_INTS 32
+
+#define UIC_SR 0x0
+#define UIC_ER 0x2
+#define UIC_CR 0x3
+#define UIC_PR 0x4
+#define UIC_TR 0x5
+#define UIC_MSR 0x6
+#define UIC_VR 0x7
+#define UIC_VCR 0x8
+
+struct uic *primary_uic;
+
+struct uic {
+ int index;
+ int dcrbase;
+
+ raw_spinlock_t lock;
+
+ /* The remapper for this UIC */
+ struct irq_domain *irqhost;
+};
+
+static void uic_unmask_irq(struct irq_data *d)
+{
+ struct uic *uic = irq_data_get_irq_chip_data(d);
+ unsigned int src = irqd_to_hwirq(d);
+ unsigned long flags;
+ u32 er, sr;
+
+ sr = 1 << (31-src);
+ raw_spin_lock_irqsave(&uic->lock, flags);
+ /* ack level-triggered interrupts here */
+ if (irqd_is_level_type(d))
+ mtdcr(uic->dcrbase + UIC_SR, sr);
+ er = mfdcr(uic->dcrbase + UIC_ER);
+ er |= sr;
+ mtdcr(uic->dcrbase + UIC_ER, er);
+ raw_spin_unlock_irqrestore(&uic->lock, flags);
+}
+
+static void uic_mask_irq(struct irq_data *d)
+{
+ struct uic *uic = irq_data_get_irq_chip_data(d);
+ unsigned int src = irqd_to_hwirq(d);
+ unsigned long flags;
+ u32 er;
+
+ raw_spin_lock_irqsave(&uic->lock, flags);
+ er = mfdcr(uic->dcrbase + UIC_ER);
+ er &= ~(1 << (31 - src));
+ mtdcr(uic->dcrbase + UIC_ER, er);
+ raw_spin_unlock_irqrestore(&uic->lock, flags);
+}
+
+static void uic_ack_irq(struct irq_data *d)
+{
+ struct uic *uic = irq_data_get_irq_chip_data(d);
+ unsigned int src = irqd_to_hwirq(d);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&uic->lock, flags);
+ mtdcr(uic->dcrbase + UIC_SR, 1 << (31-src));
+ raw_spin_unlock_irqrestore(&uic->lock, flags);
+}
+
+static void uic_mask_ack_irq(struct irq_data *d)
+{
+ struct uic *uic = irq_data_get_irq_chip_data(d);
+ unsigned int src = irqd_to_hwirq(d);
+ unsigned long flags;
+ u32 er, sr;
+
+ sr = 1 << (31-src);
+ raw_spin_lock_irqsave(&uic->lock, flags);
+ er = mfdcr(uic->dcrbase + UIC_ER);
+ er &= ~sr;
+ mtdcr(uic->dcrbase + UIC_ER, er);
+ /* On the UIC, acking (i.e. clearing the SR bit)
+ * a level irq will have no effect if the interrupt
+ * is still asserted by the device, even if
+ * the interrupt is already masked. Therefore
+ * we only ack the egde interrupts here, while
+ * level interrupts are ack'ed after the actual
+ * isr call in the uic_unmask_irq()
+ */
+ if (!irqd_is_level_type(d))
+ mtdcr(uic->dcrbase + UIC_SR, sr);
+ raw_spin_unlock_irqrestore(&uic->lock, flags);
+}
+
+static int uic_set_irq_type(struct irq_data *d, unsigned int flow_type)
+{
+ struct uic *uic = irq_data_get_irq_chip_data(d);
+ unsigned int src = irqd_to_hwirq(d);
+ unsigned long flags;
+ int trigger, polarity;
+ u32 tr, pr, mask;
+
+ switch (flow_type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_NONE:
+ uic_mask_irq(d);
+ return 0;
+
+ case IRQ_TYPE_EDGE_RISING:
+ trigger = 1; polarity = 1;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ trigger = 1; polarity = 0;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ trigger = 0; polarity = 1;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ trigger = 0; polarity = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mask = ~(1 << (31 - src));
+
+ raw_spin_lock_irqsave(&uic->lock, flags);
+ tr = mfdcr(uic->dcrbase + UIC_TR);
+ pr = mfdcr(uic->dcrbase + UIC_PR);
+ tr = (tr & mask) | (trigger << (31-src));
+ pr = (pr & mask) | (polarity << (31-src));
+
+ mtdcr(uic->dcrbase + UIC_PR, pr);
+ mtdcr(uic->dcrbase + UIC_TR, tr);
+
+ raw_spin_unlock_irqrestore(&uic->lock, flags);
+
+ return 0;
+}
+
+static struct irq_chip uic_irq_chip = {
+ .name = "UIC",
+ .irq_unmask = uic_unmask_irq,
+ .irq_mask = uic_mask_irq,
+ .irq_mask_ack = uic_mask_ack_irq,
+ .irq_ack = uic_ack_irq,
+ .irq_set_type = uic_set_irq_type,
+};
+
+static int uic_host_map(struct irq_domain *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct uic *uic = h->host_data;
+
+ irq_set_chip_data(virq, uic);
+ /* Despite the name, handle_level_irq() works for both level
+ * and edge irqs on UIC. FIXME: check this is correct */
+ irq_set_chip_and_handler(virq, &uic_irq_chip, handle_level_irq);
+
+ /* Set default irq type */
+ irq_set_irq_type(virq, IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+static struct irq_domain_ops uic_host_ops = {
+ .map = uic_host_map,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+void uic_irq_cascade(unsigned int virq, struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct irq_data *idata = irq_desc_get_irq_data(desc);
+ struct uic *uic = irq_get_handler_data(virq);
+ u32 msr;
+ int src;
+ int subvirq;
+
+ raw_spin_lock(&desc->lock);
+ if (irqd_is_level_type(idata))
+ chip->irq_mask(idata);
+ else
+ chip->irq_mask_ack(idata);
+ raw_spin_unlock(&desc->lock);
+
+ msr = mfdcr(uic->dcrbase + UIC_MSR);
+ if (!msr) /* spurious interrupt */
+ goto uic_irq_ret;
+
+ src = 32 - ffs(msr);
+
+ subvirq = irq_linear_revmap(uic->irqhost, src);
+ generic_handle_irq(subvirq);
+
+uic_irq_ret:
+ raw_spin_lock(&desc->lock);
+ if (irqd_is_level_type(idata))
+ chip->irq_ack(idata);
+ if (!irqd_irq_disabled(idata) && chip->irq_unmask)
+ chip->irq_unmask(idata);
+ raw_spin_unlock(&desc->lock);
+}
+
+static struct uic * __init uic_init_one(struct device_node *node)
+{
+ struct uic *uic;
+ const u32 *indexp, *dcrreg;
+ int len;
+
+ BUG_ON(! of_device_is_compatible(node, "ibm,uic"));
+
+ uic = kzalloc(sizeof(*uic), GFP_KERNEL);
+ if (! uic)
+ return NULL; /* FIXME: panic? */
+
+ raw_spin_lock_init(&uic->lock);
+ indexp = of_get_property(node, "cell-index", &len);
+ if (!indexp || (len != sizeof(u32))) {
+ printk(KERN_ERR "uic: Device node %s has missing or invalid "
+ "cell-index property\n", node->full_name);
+ return NULL;
+ }
+ uic->index = *indexp;
+
+ dcrreg = of_get_property(node, "dcr-reg", &len);
+ if (!dcrreg || (len != 2*sizeof(u32))) {
+ printk(KERN_ERR "uic: Device node %s has missing or invalid "
+ "dcr-reg property\n", node->full_name);
+ return NULL;
+ }
+ uic->dcrbase = *dcrreg;
+
+ uic->irqhost = irq_domain_add_linear(node, NR_UIC_INTS, &uic_host_ops,
+ uic);
+ if (! uic->irqhost)
+ return NULL; /* FIXME: panic? */
+
+ /* Start with all interrupts disabled, level and non-critical */
+ mtdcr(uic->dcrbase + UIC_ER, 0);
+ mtdcr(uic->dcrbase + UIC_CR, 0);
+ mtdcr(uic->dcrbase + UIC_TR, 0);
+ /* Clear any pending interrupts, in case the firmware left some */
+ mtdcr(uic->dcrbase + UIC_SR, 0xffffffff);
+
+ printk ("UIC%d (%d IRQ sources) at DCR 0x%x\n", uic->index,
+ NR_UIC_INTS, uic->dcrbase);
+
+ return uic;
+}
+
+void __init uic_init_tree(void)
+{
+ struct device_node *np;
+ struct uic *uic;
+ const u32 *interrupts;
+
+ /* First locate and initialize the top-level UIC */
+ for_each_compatible_node(np, NULL, "ibm,uic") {
+ interrupts = of_get_property(np, "interrupts", NULL);
+ if (!interrupts)
+ break;
+ }
+
+ BUG_ON(!np); /* uic_init_tree() assumes there's a UIC as the
+ * top-level interrupt controller */
+ primary_uic = uic_init_one(np);
+ if (!primary_uic)
+ panic("Unable to initialize primary UIC %s\n", np->full_name);
+
+ irq_set_default_host(primary_uic->irqhost);
+ of_node_put(np);
+
+ /* The scan again for cascaded UICs */
+ for_each_compatible_node(np, NULL, "ibm,uic") {
+ interrupts = of_get_property(np, "interrupts", NULL);
+ if (interrupts) {
+ /* Secondary UIC */
+ int cascade_virq;
+
+ uic = uic_init_one(np);
+ if (! uic)
+ panic("Unable to initialize a secondary UIC %s\n",
+ np->full_name);
+
+ cascade_virq = irq_of_parse_and_map(np, 0);
+
+ irq_set_handler_data(cascade_virq, uic);
+ irq_set_chained_handler(cascade_virq, uic_irq_cascade);
+
+ /* FIXME: setup critical cascade?? */
+ }
+ }
+}
+
+/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
+unsigned int uic_get_irq(void)
+{
+ u32 msr;
+ int src;
+
+ BUG_ON(! primary_uic);
+
+ msr = mfdcr(primary_uic->dcrbase + UIC_MSR);
+ src = 32 - ffs(msr);
+
+ return irq_linear_revmap(primary_uic->irqhost, src);
+}