On Tue, 7 Feb 2012 05:13:48 +0100, Jean-Christophe PLAGNIOL-VILLARD
<plagn...@jcrosoft.com> 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 <plagn...@jcrosoft.com>
> Cc: devicetree-discuss@lists.ozlabs.org
> ---
> 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?
g.
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