lkml.org 
[lkml]   [2014]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH v5 09/12] Driver core: Unified interface for firmware node properties
    Date
    On Monday 20 October 2014 01:46:00 Rafael J. Wysocki wrote:
    >
    > > Something like:
    > >
    > > #define define_fwnode_accessors(__type, __devprop_type) \
    > > int device_property_read_##__type(struct device *dev, \
    > > const char *propname, __type *val) \
    > > { \
    > > if (IS_ENABLED(CONFIG_OF) && dev->of_node) \
    > > return of_property_read_##__type(dev->of_node, propname, val); \
    > > return acpi_dev_prop_read(ACPI_COMPANION(dev), propname, \
    > > __devprop_type, val); \
    > > } \
    > > int fwnode_property_read_##__type(struct fwnode_handle *fwnode, \
    > > const char *propname, __type *val) \
    > > { \
    > > if (IS_ENABLED(CONFIG_OF) && is_of_node(fwnode)) \
    > > return of_property_read_##__type(of_node(fwnode), propname, val); \
    > > else if (IS_ENABLED(CONFIG_ACPI) && is_acpi_node(fwnode)) \
    > > return acpi_dev_prop_read(acpi_node(fwnode), propname, \
    > > __devprop_type, val); \
    > > return -ENXIO; \
    > > }
    > >
    > > define_fwnode_accessors(u8, DEV_PROP_U8);
    > > define_fwnode_accessors(u16, DEV_PROP_U16);
    > > define_fwnode_accessors(u32, DEV_PROP_U32);
    > > define_fwnode_accessors(u64, DEV_PROP_U64);
    > >
    > > That significantly reduces the code size for these things.
    >
    > So I was considering to do that, but eventually decided not to, because (1)
    > adding kerneldoc comments to such things looks odd and (2) (which IMO is
    > more important) this breaks LXR (for example, the thing at lxr.free-electrons.com
    > that some people, including me in particular, occasionally use to check how things
    > are defined). And even if you used the old good grep to look for a definition of
    > fwnode_property_read_u8, say, this wouldn't work exactly as expected I'm afraid.

    Agreed, I'd also prefer your proposed code over Grant's macros.

    > I would very much like to retain the headers at least for this reason, if that's
    > not a big deal.
    >
    > What I can do, however, is to use macros for generating the bodies of those
    > functions.

    Yes, just don't do any concatenation to generate the names of the called
    functions, i.e.

    return fwnode_call(of_property_read_u32, acpi_dev_prop_read, DEV_PROP_U32, node, propname, val);

    is better than

    return fwnode_call(u32, DEV_PROP_U32, node, propname, val);

    because it's easier to understand the call chain.

    Arnd


    \
     
     \ /
      Last update: 2014-10-20 16:41    [W:6.742 / U:0.088 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site