Re: [net-next: PATCH v4 3/7] device property: Introduce fwnode_irq_get()

[Rafael J. Wysocki]

On Thu, Jan 18, 2018 at 1:31 PM, Marcin Wojtas <mw@xxxxxxxxxxxx> wrote:
> Until now there were two very similar functions allowing
> to get Linux IRQ number from ACPI handle (acpi_irq_get())
> and OF node (of_irq_get()). The first one appeared to be used
> only as a subroutine of platform_irq_get(), which (in the generic
> code) limited IRQ obtaining from _CRS method only to nodes
> associated to kernel's struct platform_device.
>
> This patch introduces a new helper routine - fwnode_irq_get(),
> which allows to get the IRQ number directly from the fwnode
> to be used as common for OF/ACPI worlds. It is usable not
> only for the parents fwnodes, but also for the child nodes
> comprising their own _CRS methods with interrupts description.
>
> In order to be able o satisfy compilation with !CONFIG_ACPI
> and also simplify the new code, introduce a helper macro
> (ACPI_HANDLE_FWNODE), with which it is possible to reach
> an ACPI handle directly from its fwnode.
>
> Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
> ---
>  drivers/base/property.c  | 26 ++++++++++++++++++++
>  include/linux/acpi.h     |  3 +++
>  include/linux/property.h |  2 ++
>  3 files changed, 31 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 7c4a53d..1d6c9d9 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -16,6 +16,7 @@
>  #include <linux/of.h>
>  #include <linux/of_address.h>
>  #include <linux/of_graph.h>
> +#include <linux/of_irq.h>
>  #include <linux/property.h>
>  #include <linux/etherdevice.h>
>  #include <linux/phy.h>
> @@ -1230,6 +1231,31 @@ void *device_get_mac_address(struct device *dev, char *addr, int alen)
>  EXPORT_SYMBOL(device_get_mac_address);
>
>  /**
> + * fwnode_irq_get - Get IRQ directly from a fwnode
> + * @fwnode:    Pointer to the firmware node
> + * @index:     Zero-based index of the IRQ
> + *
> + * Returns Linux IRQ number on success. Other values are determined
> + * accordingly to acpi_/of_ irq_get() operation.
> + */
> +int fwnode_irq_get(struct fwnode_handle *fwnode, unsigned int index)
> +{
> +       struct device_node *of_node = to_of_node(fwnode);
> +       struct resource res;
> +       int ret;
> +
> +       if (IS_ENABLED(CONFIG_OF) && of_node)
> +               return of_irq_get(of_node, index);
> +
> +       ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), index, &res);
> +       if (ret)
> +               return ret;
> +
> +       return res.start;
> +}
> +EXPORT_SYMBOL(fwnode_irq_get);

EXPORT_SYMBOL_GPL(), please.

> +
> +/**
>   * device_graph_get_next_endpoint - Get next endpoint firmware node
>   * @fwnode: Pointer to the parent firmware node
>   * @prev: Previous endpoint node or %NULL to get the first
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index dc1ebfe..f05b9b6 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -56,6 +56,8 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev)
>  #define ACPI_COMPANION_SET(dev, adev)  set_primary_fwnode(dev, (adev) ? \
>         acpi_fwnode_handle(adev) : NULL)
>  #define ACPI_HANDLE(dev)               acpi_device_handle(ACPI_COMPANION(dev))
> +#define ACPI_HANDLE_FWNODE(fwnode)     \
> +                               acpi_device_handle(to_acpi_device_node(fwnode))
>

This change should go as a separate patch with a clear explanation why
it is needed in the changelog.

>  static inline struct fwnode_handle *acpi_alloc_fwnode_static(void)
>  {
> @@ -626,6 +628,7 @@ int acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem, int *timer_count)
>  #define ACPI_COMPANION(dev)            (NULL)
>  #define ACPI_COMPANION_SET(dev, adev)  do { } while (0)
>  #define ACPI_HANDLE(dev)               (NULL)
> +#define ACPI_HANDLE_FWNODE(fwnode)     (NULL)
>  #define ACPI_DEVICE_CLASS(_cls, _msk)  .cls = (0), .cls_msk = (0),
>
>  struct fwnode_handle;
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 9b13332..e05889f 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -103,6 +103,8 @@ struct fwnode_handle *device_get_named_child_node(struct device *dev,
>  struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode);
>  void fwnode_handle_put(struct fwnode_handle *fwnode);
>
> +int fwnode_irq_get(struct fwnode_handle *fwnode, unsigned int index);
> +
>  unsigned int device_get_child_node_count(struct device *dev);
>
>  static inline bool device_property_read_bool(struct device *dev,
> --