On 18:44 Thu 08 Mar , Grant Likely wrote: > On Tue, 7 Feb 2012 05:13:48 +0100, Jean-Christophe PLAGNIOL-VILLARD > <[email protected]> wrote: > > of_property_read_bool > > > > Search for a property in a device node and read a 32-bit value from > > it. Returns 0 if <0> or if the property does not exist, 1 if <1> or none. > > > > this will allow to disable a boolean > > > > is-ok; => true > > is-ok = <1>; => true > > is-ok = <0>; => false > > > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]> > > Cc: [email protected] > > --- > > Hi, > > > > if this is ok I'll rebase my mtd and i2c patch to use it > > > > Best Regards, > > J. > > drivers/of/base.c | 30 ++++++++++++++++++++++++++++++ > > include/linux/of.h | 8 ++++++++ > > 2 files changed, 38 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index 133908a..a0eaf08 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -686,6 +686,36 @@ int of_property_read_u64(const struct device_node *np, > > const char *propname, > > EXPORT_SYMBOL_GPL(of_property_read_u64); > > > > /** > > + * of_property_read_bool - Find and read a boolean from a property > > + * @np: device node from which the property value is to be read. > > + * @propname: name of the property to be searched. > > + * > > + * Search for a property in a device node and read a 32-bit value from > > + * it. Returns 0 if <0> or if the property does not exist, 1 if <1> or > > none. > > + * > > + * is-ok; => true > > + * is-ok = <1>; => true > > + * is-ok = <0>; => false > > + */ > > +int of_property_read_bool(const struct device_node *np, const char > > *propname) > > +{ > > + u32 reg; > > + int ret = of_property_read_u32(np, propname, ®); > > + > > + switch (ret) { > > + case -EINVAL: > > + return false; > > + case -ENODATA: > > + return true; > > + case 0: > > + return reg == 1; > > Ugh. so any value other than 1 returns false? I think that will surprise > most people. > > I don't like this api or binding. If it is a bool property, then why isn't > simply testing for the property existance sufficient? no if you want to disable it
if a bool is define in the dtsi and want to disable it int the dts if you we can do the the invert if !0 => true is-ok; => true is-ok = <val != 0>; => true is-ok = <0>; => false Best Regards, J. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
