Merge tag 'dt-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

[karo-tx-linux.git] / drivers / irqchip / irq-crossbar.c

diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index a8c615692803b67da47f2f8c88ad12d58aa4ad50..85c2985d8bcb5040aeae9c343cacc1352fafe125 100644 (file)
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -26,6 +26,7 @@
  * struct crossbar_device - crossbar device description
  * @int_max: maximum number of supported interrupts
  * @safe_map: safe default value to initialize the crossbar
+ * @max_crossbar_sources: Maximum number of crossbar sources
  * @irq_map: array of interrupts to crossbar number mapping
  * @crossbar_base: crossbar base address
  * @register_offsets: offsets for each irq number
@@ -34,6 +35,7 @@
 struct crossbar_device {
        uint int_max;
        uint safe_map;
+       uint max_crossbar_sources;
        uint *irq_map;
        void __iomem *crossbar_base;
        int *register_offsets;
@@ -82,18 +84,44 @@ static inline int allocate_free_irq(int cb_no)
        return -ENODEV;
 }
 
+static inline bool needs_crossbar_write(irq_hw_number_t hw)
+{
+       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;
+}
+
 static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
                               irq_hw_number_t hw)
 {
-       cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
+       if (needs_crossbar_write(hw))
+               cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
+
        return 0;
 }
 
+/**
+ * crossbar_domain_unmap - unmap a crossbar<->irq connection
+ * @d: domain of irq to unmap
+ * @irq: virq number
+ *
+ * We do not maintain a use count of total number of map/unmap
+ * calls for a particular irq to find out if a irq can be really
+ * unmapped. This is because unmap is called during irq_dispose_mapping(irq),
+ * after which irq is anyways unusable. So an explicit map has to be called
+ * after that.
+ */
 static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
 {
        irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
 
-       if (hw > GIC_IRQ_START) {
+       if (needs_crossbar_write(hw)) {
                cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
                cb->write(hw - GIC_IRQ_START, cb->safe_map);
        }
@@ -106,12 +134,30 @@ static int crossbar_domain_xlate(struct irq_domain *d,
                                 unsigned int *out_type)
 {
        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;
+       }
 
-       ret = get_prev_map_irq(intspec[1]);
+       ret = get_prev_map_irq(req_num);
        if (ret >= 0)
                goto found;
 
-       ret = allocate_free_irq(intspec[1]);
+       ret = allocate_free_irq(req_num);
 
        if (ret < 0)
                return ret;
@@ -142,6 +188,14 @@ static int __init crossbar_of_init(struct device_node *node)
        if (!cb->crossbar_base)
                goto err_cb;
 
+       of_property_read_u32(node, "ti,max-crossbar-sources",
+                            &cb->max_crossbar_sources);
+       if (!cb->max_crossbar_sources) {
+               pr_err("missing 'ti,max-crossbar-sources' property\n");
+               ret = -EINVAL;
+               goto err_base;
+       }
+
        of_property_read_u32(node, "ti,max-irqs", &max);
        if (!max) {
                pr_err("missing 'ti,max-irqs' property\n");