From b60e4ea4a400bde8a4811f94b84a9bb65f81b677 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Thu, 29 Sep 2016 16:39:41 +0300 Subject: ACPI / property: Allow holes in reference properties DT allows holes or empty phandles for references. This is used for example in SPI subsystem where some chip selects are native and others are regular GPIOs. In ACPI _DSD we currently do not support this but instead the preceding reference consumes all following integer arguments. For example we would like to support something like the below ASL fragment for SPI: Package () { "cs-gpios", Package () { ^GPIO, 19, 0, 0, // GPIO CS0 0, // Native CS ^GPIO, 20, 0, 0, // GPIO CS1 } } The zero in the middle means "no entry" or NULL reference. To support this we change acpi_data_get_property_reference() to take firmware node and num_args as argument and rename it to __acpi_node_get_property_reference(). The function returns -ENOENT if the given index resolves to "no entry" reference and -ENODATA when there are no more entries in the property. We then add static inline wrapper acpi_node_get_property_reference() that passes MAX_ACPI_REFERENCE_ARGS as num_args to support the existing behaviour which some drivers have been relying on. Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki --- include/linux/acpi.h | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 4d8452c2384b..632ec16a855e 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -927,9 +927,17 @@ struct acpi_reference_args { #ifdef CONFIG_ACPI int acpi_dev_get_property(struct acpi_device *adev, const char *name, acpi_object_type type, const union acpi_object **obj); -int acpi_node_get_property_reference(struct fwnode_handle *fwnode, - const char *name, size_t index, - struct acpi_reference_args *args); +int __acpi_node_get_property_reference(struct fwnode_handle *fwnode, + const char *name, size_t index, size_t num_args, + struct acpi_reference_args *args); + +static inline int acpi_node_get_property_reference(struct fwnode_handle *fwnode, + const char *name, size_t index, + struct acpi_reference_args *args) +{ + return __acpi_node_get_property_reference(fwnode, name, index, + MAX_ACPI_REFERENCE_ARGS, args); +} int acpi_node_prop_get(struct fwnode_handle *fwnode, const char *propname, void **valptr); @@ -1005,6 +1013,14 @@ static inline int acpi_dev_get_property(struct acpi_device *adev, return -ENXIO; } +static inline int +__acpi_node_get_property_reference(struct fwnode_handle *fwnode, + const char *name, size_t index, size_t num_args, + struct acpi_reference_args *args) +{ + return -ENXIO; +} + static inline int acpi_node_get_property_reference(struct fwnode_handle *fwnode, const char *name, size_t index, struct acpi_reference_args *args) -- cgit v1.2.3-70-g09d2