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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2021-03-09 12:37:31 +0300
committerBartosz Golaszewski <bgolaszewski@baylibre.com>2021-03-26 16:56:18 +0300
commit67196fea0fcef92b25608882f62f3985bc59f1fe (patch)
tree7acb2e02828218ff5123cd3cbd3a81656f27f528 /Documentation/core-api/irq
parent3fd19d4b565dafd690a262fa95d25927bc797e42 (diff)
downloadlinux-67196fea0fcef92b25608882f62f3985bc59f1fe.tar.xz
irqdomain: Introduce irq_domain_create_simple() API
Linus Walleij pointed out that ird_domain_add_simple() gained additional functionality and can't be anymore replaced with a simple conditional. In preparation to upgrade GPIO library to use fwnode, introduce irq_domain_create_simple() API which is functional equivalent to the existing irq_domain_add_simple(), but takes a pointer to the struct fwnode_handle as a parameter. While at it, amend documentation to mention irq_domain_create_*() functions where it makes sense. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'Documentation/core-api/irq')
-rw-r--r--Documentation/core-api/irq/irq-domain.rst22
1 files changed, 12 insertions, 10 deletions
diff --git a/Documentation/core-api/irq/irq-domain.rst b/Documentation/core-api/irq/irq-domain.rst
index a77c24c27f7b..8214e215a8bf 100644
--- a/Documentation/core-api/irq/irq-domain.rst
+++ b/Documentation/core-api/irq/irq-domain.rst
@@ -42,10 +42,10 @@ irq_domain usage
================
An interrupt controller driver creates and registers an irq_domain by
-calling one of the irq_domain_add_*() functions (each mapping method
-has a different allocator function, more on that later). The function
-will return a pointer to the irq_domain on success. The caller must
-provide the allocator function with an irq_domain_ops structure.
+calling one of the irq_domain_add_*() or irq_domain_create_*() functions
+(each mapping method has a different allocator function, more on that later).
+The function will return a pointer to the irq_domain on success. The caller
+must provide the allocator function with an irq_domain_ops structure.
In most cases, the irq_domain will begin empty without any mappings
between hwirq and IRQ numbers. Mappings are added to the irq_domain
@@ -147,6 +147,7 @@ Legacy
irq_domain_add_simple()
irq_domain_add_legacy()
irq_domain_add_legacy_isa()
+ irq_domain_create_simple()
irq_domain_create_legacy()
The Legacy mapping is a special case for drivers that already have a
@@ -169,13 +170,13 @@ supported. For example, ISA controllers would use the legacy map for
mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ
numbers.
-Most users of legacy mappings should use irq_domain_add_simple() which
-will use a legacy domain only if an IRQ range is supplied by the
-system and will otherwise use a linear domain mapping. The semantics
-of this call are such that if an IRQ range is specified then
+Most users of legacy mappings should use irq_domain_add_simple() or
+irq_domain_create_simple() which will use a legacy domain only if an IRQ range
+is supplied by the system and will otherwise use a linear domain mapping.
+The semantics of this call are such that if an IRQ range is specified then
descriptors will be allocated on-the-fly for it, and if no range is
-specified it will fall through to irq_domain_add_linear() which means
-*no* irq descriptors will be allocated.
+specified it will fall through to irq_domain_add_linear() or
+irq_domain_create_linear() which means *no* irq descriptors will be allocated.
A typical use case for simple domains is where an irqchip provider
is supporting both dynamic and static IRQ assignments.
@@ -186,6 +187,7 @@ that the driver using the simple domain call irq_create_mapping()
before any irq_find_mapping() since the latter will actually work
for the static IRQ assignment case.
+irq_domain_add_simple() and irq_domain_create_simple() as well as
irq_domain_add_legacy() and irq_domain_create_legacy() are functionally
equivalent, except for the first argument is different - the former
accepts an Open Firmware specific 'struct device_node', while the latter