Subject: [PATCH 1/1] of: introduce helper to manage boolean

From: [email-masked] (Rob Herring)
Date: Tue, 07 Feb 2012 09:13:31 -0600

On 02/06/2012 10:13 PM, Jean-Christophe PLAGNIOL-VILLARD 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-masked]>
> Cc: devicetree-discuss at lists.ozlabs.org

Acked-by: Rob Herring <[email-masked]>

> ---
> Hi,
> 
> 	if this is ok I'll rebase my mtd and i2c patch to use it
> 

I'm assuming you'll want to merge this patch with your mtd and i2c
patches. If you want me to apply, let me know.

Rob

> 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, &reg);
> +
> +	switch (ret) {
> +	case -EINVAL:
> +		return false;
> +	case -ENODATA:
> +		return true;
> +	case 0:
> +		return reg == 1;
> +	default:
> +		return ret;
> +	}
> +}
> +EXPORT_SYMBOL_GPL(of_property_read_bool);
> +
> +/**
>   * of_property_read_string - Find and read a string from a property
>   * @np:		device node from which the property value is to be read.
>   * @propname:	name of the property to be searched.
> diff --git a/include/linux/of.h b/include/linux/of.h
> index a75a831..2e5f77b 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -210,6 +210,8 @@ extern int of_property_read_u32_array(const struct device_node *np,
>  				      size_t sz);
>  extern int of_property_read_u64(const struct device_node *np,
>  				const char *propname, u64 *out_value);
> +extern int of_property_read_bool(const struct device_node *np,
> +				const char *propname);
>  
>  extern int of_property_read_string(struct device_node *np,
>  				   const char *propname,
> @@ -288,6 +290,12 @@ static inline int of_property_read_u32_array(const struct device_node *np,
>  	return -ENOSYS;
>  }
>  
> +static inline int of_property_read_bool(const struct device_node *np,
> +				const char *propname)
> +{
> +	return -ENOSYS;
> +}
> +
>  static inline int of_property_read_string(struct device_node *np,
>  					  const char *propname,
>  					  const char **out_string)