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Message-ID: <50AC5764.7030401@gmail.com>
Date: Tue, 20 Nov 2012 22:24:04 -0600
From: Rob Herring <robherring2@...il.com>
To: Viresh Kumar <viresh.kumar@...aro.org>
CC: rob.herring@...xeda.com, grant.likely@...retlab.ca,
linaro-dev@...ts.linaro.org, andriy.shevchenko@...el.com,
swarren@...dotorg.org, patches@...aro.org,
devicetree-discuss@...ts.ozlabs.org, spear-devel@...t.st.com,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] dt: add helper function to read u8 & u16 variables &
arrays
On 11/19/2012 10:45 PM, Viresh Kumar wrote:
> This adds following helper routines:
> - of_property_read_u8_array()
> - of_property_read_u16_array()
> - of_property_read_u8()
> - of_property_read_u16()
>
> This expects arrays from DT to be passed as:
> - u8 array:
> property = /bits/ 8 <0x50 0x60 0x70>;
> - u16 array:
> property = /bits/ 16 <0x5000 0x6000 0x7000>;
>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Applied.
Rob
> ---
> V2->V3:
> - Expect u8 & u16 arrays to be passed using: /bits/ 8 or 16
> - remove common macro, as not much common now :(
> - Tested on ARM platform.
>
> drivers/of/base.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/of.h | 30 +++++++++++++++++++++
> 2 files changed, 107 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index af3b22a..f564e31 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -671,12 +671,89 @@ struct device_node *of_find_node_by_phandle(phandle handle)
> EXPORT_SYMBOL(of_find_node_by_phandle);
>
> /**
> + * of_property_read_u8_array - Find and read an array of u8 from a property.
> + *
> + * @np: device node from which the property value is to be read.
> + * @propname: name of the property to be searched.
> + * @out_value: pointer to return value, modified only if return value is 0.
> + * @sz: number of array elements to read
> + *
> + * Search for a property in a device node and read 8-bit value(s) from
> + * it. Returns 0 on success, -EINVAL if the property does not exist,
> + * -ENODATA if property does not have a value, and -EOVERFLOW if the
> + * property data isn't large enough.
> + *
> + * dts entry of array should be like:
> + * property = /bits/ 8 <0x50 0x60 0x70>;
> + *
> + * The out_value is modified only if a valid u8 value can be decoded.
> + */
> +int of_property_read_u8_array(const struct device_node *np,
> + const char *propname, u8 *out_values, size_t sz)
> +{
> + struct property *prop = of_find_property(np, propname, NULL);
> + const u8 *val;
> +
> + if (!prop)
> + return -EINVAL;
> + if (!prop->value)
> + return -ENODATA;
> + if ((sz * sizeof(*out_values)) > prop->length)
> + return -EOVERFLOW;
> +
> + val = prop->value;
> + while (sz--)
> + *out_values++ = *val++;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_property_read_u8_array);
> +
> +/**
> + * of_property_read_u16_array - Find and read an array of u16 from a property.
> + *
> + * @np: device node from which the property value is to be read.
> + * @propname: name of the property to be searched.
> + * @out_value: pointer to return value, modified only if return value is 0.
> + * @sz: number of array elements to read
> + *
> + * Search for a property in a device node and read 16-bit value(s) from
> + * it. Returns 0 on success, -EINVAL if the property does not exist,
> + * -ENODATA if property does not have a value, and -EOVERFLOW if the
> + * property data isn't large enough.
> + *
> + * dts entry of array should be like:
> + * property = /bits/ 16 <0x5000 0x6000 0x7000>;
> + *
> + * The out_value is modified only if a valid u16 value can be decoded.
> + */
> +int of_property_read_u16_array(const struct device_node *np,
> + const char *propname, u16 *out_values, size_t sz)
> +{
> + struct property *prop = of_find_property(np, propname, NULL);
> + const __be16 *val;
> +
> + if (!prop)
> + return -EINVAL;
> + if (!prop->value)
> + return -ENODATA;
> + if ((sz * sizeof(*out_values)) > prop->length)
> + return -EOVERFLOW;
> +
> + val = prop->value;
> + while (sz--)
> + *out_values++ = be16_to_cpup(val++);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_property_read_u16_array);
> +
> +/**
> * of_property_read_u32_array - Find and read an array of 32 bit integers
> * from a property.
> *
> * @np: device node from which the property value is to be read.
> * @propname: name of the property to be searched.
> * @out_value: pointer to return value, modified only if return value is 0.
> + * @sz: number of array elements to read
> *
> * Search for a property in a device node and read 32-bit value(s) from
> * it. Returns 0 on success, -EINVAL if the property does not exist,
> diff --git a/include/linux/of.h b/include/linux/of.h
> index b4e50d5..bfdc130 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -223,6 +223,10 @@ extern struct device_node *of_find_node_with_property(
> extern struct property *of_find_property(const struct device_node *np,
> const char *name,
> int *lenp);
> +extern int of_property_read_u8_array(const struct device_node *np,
> + const char *propname, u8 *out_values, size_t sz);
> +extern int of_property_read_u16_array(const struct device_node *np,
> + const char *propname, u16 *out_values, size_t sz);
> extern int of_property_read_u32_array(const struct device_node *np,
> const char *propname,
> u32 *out_values,
> @@ -364,6 +368,18 @@ static inline struct device_node *of_find_compatible_node(
> return NULL;
> }
>
> +static inline int of_property_read_u8_array(const struct device_node *np,
> + const char *propname, u8 *out_values, size_t sz)
> +{
> + return -ENOSYS;
> +}
> +
> +static inline int of_property_read_u16_array(const struct device_node *np,
> + const char *propname, u16 *out_values, size_t sz)
> +{
> + return -ENOSYS;
> +}
> +
> static inline int of_property_read_u32_array(const struct device_node *np,
> const char *propname,
> u32 *out_values, size_t sz)
> @@ -470,6 +486,20 @@ static inline bool of_property_read_bool(const struct device_node *np,
> return prop ? true : false;
> }
>
> +static inline int of_property_read_u8(const struct device_node *np,
> + const char *propname,
> + u8 *out_value)
> +{
> + return of_property_read_u8_array(np, propname, out_value, 1);
> +}
> +
> +static inline int of_property_read_u16(const struct device_node *np,
> + const char *propname,
> + u16 *out_value)
> +{
> + return of_property_read_u16_array(np, propname, out_value, 1);
> +}
> +
> static inline int of_property_read_u32(const struct device_node *np,
> const char *propname,
> u32 *out_value)
>
--
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