irqchip: crossbar: Allow for quirky hardware with direct hardwiring of GIC

On certain platforms such as DRA7, SPIs 0, 1, 2, 3, 5, 6, 10, 131,
132, 133 are direct wired to hardware blocks bypassing crossbar.
This quirky implementation is *NOT* supposed to be the expectation
of crossbar hardware usage. However, these are already marked in our
description of the hardware with SKIP and RESERVED where appropriate.

Unfortunately, we need to be able to refer to these hardwired IRQs.
So, to request these, crossbar driver can use the existing information
from it's table that these SKIP/RESERVED maps are direct wired sources
and generic allocation/programming of crossbar should be avoided.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-17-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 18 insertions, 2 deletions

diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index 83f803bfab76..85c2985d8bcb 100644
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -86,8 +86,13 @@ static inline int allocate_free_irq(int cb_no)
 
 static inline bool needs_crossbar_write(irq_hw_number_t hw)
 {
-        if (hw > GIC_IRQ_START)
-                return true;
+        int cb_no;
+
+        if (hw > GIC_IRQ_START) {
+                cb_no = cb->irq_map[hw - GIC_IRQ_START];
+                if (cb_no != IRQ_RESERVED && cb_no != IRQ_SKIP)
+                        return true;
+        }
 
         return false;
 }
@@ -130,8 +135,19 @@ static int crossbar_domain_xlate(struct irq_domain *d,
 {
         int ret;
         int req_num = intspec[1];
+        int direct_map_num;
 
         if (req_num >= cb->max_crossbar_sources) {
+                direct_map_num = req_num - cb->max_crossbar_sources;
+                if (direct_map_num < cb->int_max) {
+                        ret = cb->irq_map[direct_map_num];
+                        if (ret == IRQ_RESERVED || ret == IRQ_SKIP) {
+                                /* We use the interrupt num as h/w irq num */
+                                ret = direct_map_num;
+                                goto found;
+                        }
+                }
+
                 pr_err("%s: requested crossbar number %d > max %d\n",
                        __func__, req_num, cb->max_crossbar_sources);
                 return -EINVAL;