Re: [PATCH 4/10] Add arch/powerpc driver for UIC, PPC4xx interrupt controller

On Thu, 2007-03-22 at 20:22 +1100, David Gibson wrote:

Index: working-2.6/arch/powerpc/sysdev/uic.c
===================================================================

 <snip>

+static struct uic * __init uic_init_one(struct device_node *node)
+{
+	struct uic *uic;
+	const u32 *indexp, *dcrreg;
+	int len;
+
+	BUG_ON(! device_is_compatible(node, "ibm,uic"));
+
+	uic = alloc_bootmem(sizeof(*uic));
+	if (! uic)
+		return NULL; /* FIXME: panic? */
+
+	memset(uic, 0, sizeof(*uic));
+	uic->of_node = of_node_get(node);
+	indexp = 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 = 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_alloc_host(IRQ_HOST_MAP_LINEAR, NR_UIC_INTS,
+				      &uic_host_ops, -1);
+	if (! uic->irqhost) {
+		of_node_put(node);
+		return NULL; /* FIXME: panic? */
+	}
+
+	uic->irqhost->host_data = uic;
+
+	/* Start with all interrupts disable and non-critical */
+	mtdcr(uic->dcrbase + UIC_ER, 0);
+	mtdcr(uic->dcrbase + UIC_CR, 0);

I think at this point we should also clear the interrupts in the SR
register as well.  When playing with the Bamboo port, I found that the
firmware leaves pending interrupts, which can lead to some not nice
results when the cascade bits are enabled.

josh