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Diffstat (limited to 'arch/powerpc/platforms/wsp/opb_pic.c')
-rw-r--r--arch/powerpc/platforms/wsp/opb_pic.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/wsp/opb_pic.c b/arch/powerpc/platforms/wsp/opb_pic.c
new file mode 100644
index 000000000000..be05631a3c1c
--- /dev/null
+++ b/arch/powerpc/platforms/wsp/opb_pic.c
@@ -0,0 +1,332 @@
+/*
+ * IBM Onboard Peripheral Bus Interrupt Controller
+ *
+ * Copyright 2010 Jack Miller, 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+
+#include <asm/reg_a2.h>
+#include <asm/irq.h>
+
+#define OPB_NR_IRQS 32
+
+#define OPB_MLSASIER 0x04 /* MLS Accumulated Status IER */
+#define OPB_MLSIR 0x50 /* MLS Interrupt Register */
+#define OPB_MLSIER 0x54 /* MLS Interrupt Enable Register */
+#define OPB_MLSIPR 0x58 /* MLS Interrupt Polarity Register */
+#define OPB_MLSIIR 0x5c /* MLS Interrupt Inputs Register */
+
+static int opb_index = 0;
+
+struct opb_pic {
+ struct irq_host *host;
+ void *regs;
+ int index;
+ spinlock_t lock;
+};
+
+static u32 opb_in(struct opb_pic *opb, int offset)
+{
+ return in_be32(opb->regs + offset);
+}
+
+static void opb_out(struct opb_pic *opb, int offset, u32 val)
+{
+ out_be32(opb->regs + offset, val);
+}
+
+static void opb_unmask_irq(struct irq_data *d)
+{
+ struct opb_pic *opb;
+ unsigned long flags;
+ u32 ier, bitset;
+
+ opb = d->chip_data;
+ bitset = (1 << (31 - irqd_to_hwirq(d)));
+
+ spin_lock_irqsave(&opb->lock, flags);
+
+ ier = opb_in(opb, OPB_MLSIER);
+ opb_out(opb, OPB_MLSIER, ier | bitset);
+ ier = opb_in(opb, OPB_MLSIER);
+
+ spin_unlock_irqrestore(&opb->lock, flags);
+}
+
+static void opb_mask_irq(struct irq_data *d)
+{
+ struct opb_pic *opb;
+ unsigned long flags;
+ u32 ier, mask;
+
+ opb = d->chip_data;
+ mask = ~(1 << (31 - irqd_to_hwirq(d)));
+
+ spin_lock_irqsave(&opb->lock, flags);
+
+ ier = opb_in(opb, OPB_MLSIER);
+ opb_out(opb, OPB_MLSIER, ier & mask);
+ ier = opb_in(opb, OPB_MLSIER); // Flush posted writes
+
+ spin_unlock_irqrestore(&opb->lock, flags);
+}
+
+static void opb_ack_irq(struct irq_data *d)
+{
+ struct opb_pic *opb;
+ unsigned long flags;
+ u32 bitset;
+
+ opb = d->chip_data;
+ bitset = (1 << (31 - irqd_to_hwirq(d)));
+
+ spin_lock_irqsave(&opb->lock, flags);
+
+ opb_out(opb, OPB_MLSIR, bitset);
+ opb_in(opb, OPB_MLSIR); // Flush posted writes
+
+ spin_unlock_irqrestore(&opb->lock, flags);
+}
+
+static void opb_mask_ack_irq(struct irq_data *d)
+{
+ struct opb_pic *opb;
+ unsigned long flags;
+ u32 bitset;
+ u32 ier, ir;
+
+ opb = d->chip_data;
+ bitset = (1 << (31 - irqd_to_hwirq(d)));
+
+ spin_lock_irqsave(&opb->lock, flags);
+
+ ier = opb_in(opb, OPB_MLSIER);
+ opb_out(opb, OPB_MLSIER, ier & ~bitset);
+ ier = opb_in(opb, OPB_MLSIER); // Flush posted writes
+
+ opb_out(opb, OPB_MLSIR, bitset);
+ ir = opb_in(opb, OPB_MLSIR); // Flush posted writes
+
+ spin_unlock_irqrestore(&opb->lock, flags);
+}
+
+static int opb_set_irq_type(struct irq_data *d, unsigned int flow)
+{
+ struct opb_pic *opb;
+ unsigned long flags;
+ int invert, ipr, mask, bit;
+
+ opb = d->chip_data;
+
+ /* The only information we're interested in in the type is whether it's
+ * a high or low trigger. For high triggered interrupts, the polarity
+ * set for it in the MLS Interrupt Polarity Register is 0, for low
+ * interrupts it's 1 so that the proper input in the MLS Interrupt Input
+ * Register is interrupted as asserting the interrupt. */
+
+ switch (flow) {
+ case IRQ_TYPE_NONE:
+ opb_mask_irq(d);
+ return 0;
+
+ case IRQ_TYPE_LEVEL_HIGH:
+ invert = 0;
+ break;
+
+ case IRQ_TYPE_LEVEL_LOW:
+ invert = 1;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ bit = (1 << (31 - irqd_to_hwirq(d)));
+ mask = ~bit;
+
+ spin_lock_irqsave(&opb->lock, flags);
+
+ ipr = opb_in(opb, OPB_MLSIPR);
+ ipr = (ipr & mask) | (invert ? bit : 0);
+ opb_out(opb, OPB_MLSIPR, ipr);
+ ipr = opb_in(opb, OPB_MLSIPR); // Flush posted writes
+
+ spin_unlock_irqrestore(&opb->lock, flags);
+
+ /* Record the type in the interrupt descriptor */
+ irqd_set_trigger_type(d, flow);
+
+ return 0;
+}
+
+static struct irq_chip opb_irq_chip = {
+ .name = "OPB",
+ .irq_mask = opb_mask_irq,
+ .irq_unmask = opb_unmask_irq,
+ .irq_mask_ack = opb_mask_ack_irq,
+ .irq_ack = opb_ack_irq,
+ .irq_set_type = opb_set_irq_type
+};
+
+static int opb_host_map(struct irq_host *host, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ struct opb_pic *opb;
+
+ opb = host->host_data;
+
+ /* Most of the important stuff is handled by the generic host code, like
+ * the lookup, so just attach some info to the virtual irq */
+
+ irq_set_chip_data(virq, opb);
+ irq_set_chip_and_handler(virq, &opb_irq_chip, handle_level_irq);
+ irq_set_irq_type(virq, IRQ_TYPE_NONE);
+
+ return 0;
+}
+
+static int opb_host_xlate(struct irq_host *host, struct device_node *dn,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq, unsigned int *out_type)
+{
+ /* Interrupt size must == 2 */
+ BUG_ON(intsize != 2);
+ *out_hwirq = intspec[0];
+ *out_type = intspec[1];
+ return 0;
+}
+
+static struct irq_host_ops opb_host_ops = {
+ .map = opb_host_map,
+ .xlate = opb_host_xlate,
+};
+
+irqreturn_t opb_irq_handler(int irq, void *private)
+{
+ struct opb_pic *opb;
+ u32 ir, src, subvirq;
+
+ opb = (struct opb_pic *) private;
+
+ /* Read the OPB MLS Interrupt Register for
+ * asserted interrupts */
+ ir = opb_in(opb, OPB_MLSIR);
+ if (!ir)
+ return IRQ_NONE;
+
+ do {
+ /* Get 1 - 32 source, *NOT* bit */
+ src = 32 - ffs(ir);
+
+ /* Translate from the OPB's conception of interrupt number to
+ * Linux's virtual IRQ */
+
+ subvirq = irq_linear_revmap(opb->host, src);
+
+ generic_handle_irq(subvirq);
+ } while ((ir = opb_in(opb, OPB_MLSIR)));
+
+ return IRQ_HANDLED;
+}
+
+struct opb_pic *opb_pic_init_one(struct device_node *dn)
+{
+ struct opb_pic *opb;
+ struct resource res;
+
+ if (of_address_to_resource(dn, 0, &res)) {
+ printk(KERN_ERR "opb: Couldn't translate resource\n");
+ return NULL;
+ }
+
+ opb = kzalloc(sizeof(struct opb_pic), GFP_KERNEL);
+ if (!opb) {
+ printk(KERN_ERR "opb: Failed to allocate opb struct!\n");
+ return NULL;
+ }
+
+ /* Get access to the OPB MMIO registers */
+ opb->regs = ioremap(res.start + 0x10000, 0x1000);
+ if (!opb->regs) {
+ printk(KERN_ERR "opb: Failed to allocate register space!\n");
+ goto free_opb;
+ }
+
+ /* Allocate an irq host so that Linux knows that despite only
+ * having one interrupt to issue, we're the controller for multiple
+ * hardware IRQs, so later we can lookup their virtual IRQs. */
+
+ opb->host = irq_alloc_host(dn, IRQ_HOST_MAP_LINEAR,
+ OPB_NR_IRQS, &opb_host_ops, -1);
+
+ if (!opb->host) {
+ printk(KERN_ERR "opb: Failed to allocate IRQ host!\n");
+ goto free_regs;
+ }
+
+ opb->index = opb_index++;
+ spin_lock_init(&opb->lock);
+ opb->host->host_data = opb;
+
+ /* Disable all interrupts by default */
+ opb_out(opb, OPB_MLSASIER, 0);
+ opb_out(opb, OPB_MLSIER, 0);
+
+ /* ACK any interrupts left by FW */
+ opb_out(opb, OPB_MLSIR, 0xFFFFFFFF);
+
+ return opb;
+
+free_regs:
+ iounmap(opb->regs);
+free_opb:
+ kfree(opb);
+ return NULL;
+}
+
+void __init opb_pic_init(void)
+{
+ struct device_node *dn;
+ struct opb_pic *opb;
+ int virq;
+ int rc;
+
+ /* Call init_one for each OPB device */
+ for_each_compatible_node(dn, NULL, "ibm,opb") {
+
+ /* Fill in an OPB struct */
+ opb = opb_pic_init_one(dn);
+ if (!opb) {
+ printk(KERN_WARNING "opb: Failed to init node, skipped!\n");
+ continue;
+ }
+
+ /* Map / get opb's hardware virtual irq */
+ virq = irq_of_parse_and_map(dn, 0);
+ if (virq <= 0) {
+ printk("opb: irq_op_parse_and_map failed!\n");
+ continue;
+ }
+
+ /* Attach opb interrupt handler to new virtual IRQ */
+ rc = request_irq(virq, opb_irq_handler, 0, "OPB LS Cascade", opb);
+ if (rc) {
+ printk("opb: request_irq failed: %d\n", rc);
+ continue;
+ }
+
+ printk("OPB%d init with %d IRQs at %p\n", opb->index,
+ OPB_NR_IRQS, opb->regs);
+ }
+}