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| -rw-r--r-- | Documentation/IRQ-domain.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt index 8d990bde8693..82001a25a14b 100644 --- a/Documentation/IRQ-domain.txt +++ b/Documentation/IRQ-domain.txt @@ -70,6 +70,7 @@ of the reverse map types are described below: ==== Linear ==== irq_domain_add_linear() +irq_domain_create_linear() The linear reverse map maintains a fixed size table indexed by the hwirq number. When a hwirq is mapped, an irq_desc is allocated for @@ -81,10 +82,16 @@ map are fixed time lookup for IRQ numbers, and irq_descs are only allocated for in-use IRQs. The disadvantage is that the table must be as large as the largest possible hwirq number. +irq_domain_add_linear() and irq_domain_create_linear() are functionally +equivalent, except for the first argument is different - the former +accepts an Open Firmware specific 'struct device_node', while the latter +accepts a more general abstraction 'struct fwnode_handle'. + The majority of drivers should use the linear map. ==== Tree ==== irq_domain_add_tree() +irq_domain_create_tree() The irq_domain maintains a radix tree map from hwirq numbers to Linux IRQs. When an hwirq is mapped, an irq_desc is allocated and the @@ -95,6 +102,11 @@ since it doesn't need to allocate a table as large as the largest hwirq number. The disadvantage is that hwirq to IRQ number lookup is dependent on how many entries are in the table. +irq_domain_add_tree() and irq_domain_create_tree() are functionally +equivalent, except for the first argument is different - the former +accepts an Open Firmware specific 'struct device_node', while the latter +accepts a more general abstraction 'struct fwnode_handle'. + Very few drivers should need this mapping. ==== No Map ===- |