From: Grant Likely <grant.lik...@secretlab.ca>
prototype implementation. This probably doesn't work at all right now.
Ben, I'm posting this now to get your thoughts before I go too far down
this path.
Cheers,
g.
---
arch/powerpc/include/asm/irq.h | 3 ++
arch/powerpc/kernel/irq.c | 20 +++++++++++++++
arch/powerpc/platforms/52xx/mpc52xx_pic.c | 39 +++++++++++++++++++++++++++++
3 files changed, 62 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 0a51376..014e1e8 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -90,6 +90,9 @@ struct irq_host_ops {
/* Update of such a mapping */
void (*remap)(struct irq_host *h, unsigned int virq, irq_hw_number_t
hw);
+ /* Setup hook for cascade irqs */
+ int (*cascade_setup)(int virq, int (*get_irq)(void *data), void *data);
+
/* Translate device-tree interrupt specifier from raw format coming
* from the firmware to a irq_hw_number_t (interrupt line number) and
* type (sense) that can be passed to set_irq_type(). In the absence
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index f7f376e..5a9cb46 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -750,6 +750,26 @@ unsigned int irq_of_parse_and_map(struct device_node *dev,
int index)
}
EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
+unsigned int irq_of_cascade_setup(int virq, int (*get_irq)(void *data),
+ void *data)
+{
+ struct irq_host *host = irq_map[virq].host;
+
+ if (!host) {
+ pr_err("error: no irq host found virq %i !\n", virq);
+ return -ENODEV;
+ }
+
+ /* If host has no cascade setup function, then this method for
+ * setting up a cascade is not available */
+ if (!host->ops->cascade_setup) {
+ pr_err("error: no cascade_setup support on virq %i\n", virq);
+ return -EINVAL;
+ }
+
+ return host->ops->cascade_setup(virq, get_irq, data);
+}
+
void irq_dispose_mapping(unsigned int virq)
{
struct irq_host *host;
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index 480f806..a91c69b 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -437,9 +437,48 @@ static int mpc52xx_irqhost_map(struct irq_host *h,
unsigned int virq,
return 0;
}
+struct mpc52xx_cascade_data {
+ int (*get_irq)(void *data);
+ void *data;
+};
+
+void mpc52xx_handle_level_cascade(unsigned int irq, struct irq_desc *desc)
+{
+ struct mpc52xx_cascade_data *cascade_data = get_irq_desc_data(desc);
+ int cascade_virq;
+
+ cascade_virq = cascade_data->get_irq(cascade_data->data);
+ if (cascade_virq)
+ generic_handle_irq(cascade_virq);
+}
+
+void mpc52xx_handle_edge_cascade(unsigned int virq, struct irq_desc *desc)
+{
+ mpc52xx_handle_level_cascade(virq, desc);
+ /** TODO: clear edge IRQ here **/
+}
+
+int mpc52xx_cascade_setup(int virq, int (*get_irq)(void *data), void *data)
+{
+ struct mpc52xx_cascade_data *cascade_data;
+
+ cascade_data = kzalloc(sizeof(struct mpc52xx_cascade_data), GFP_KERNEL);
+ if (!cascade_data)
+ return -ENOMEM;
+
+ /* TODO: make this handle edge cascades too */
+ cascade_data->get_irq = get_irq;
+ cascade_data->data = data;
+ set_irq_data(virq, cascade_data);
+ set_irq_chained_handler(virq, mpc52xx_handle_level_cascade);
+
+ return 0;
+}
+
static struct irq_host_ops mpc52xx_irqhost_ops = {
.xlate = mpc52xx_irqhost_xlate,
.map = mpc52xx_irqhost_map,
+ .cascade_setup = mpc52xx_cascade_setup,
};
/**
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