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Message-ID: <515B6CCD.9060703@gmail.com>
Date: Tue, 02 Apr 2013 18:42:05 -0500
From: Rob Herring <robherring2@...il.com>
To: Tony Prisk <linux@...sktech.co.nz>
CC: linus.walleij@...aro.org,
vt8500-wm8505-linux-kernel@...glegroups.com,
linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
swarren@...dotorg.org
Subject: Re: [PATCHv4 1/6] of: Add support for reading a u32 from a multi-value
property.
On 04/01/2013 11:40 PM, Tony Prisk wrote:
> This patch adds an of_property_read_u32_index() function to allow
> reading a single indexed u32 value from a property containing multiple
> u32 values.
>
> Signed-off-by: Tony Prisk <linux@...sktech.co.nz>
> Reviewed-by: Stephen Warren <swarren@...dia.com>
> ---
> drivers/of/base.c | 33 +++++++++++++++++++++++++++++++++
> include/linux/of.h | 9 +++++++++
> 2 files changed, 42 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 321d3ef..f6c89ed 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -746,6 +746,39 @@ struct device_node *of_find_node_by_phandle(phandle handle)
> EXPORT_SYMBOL(of_find_node_by_phandle);
>
> /**
> + * of_property_read_u32_index - Find and read a u32 from a multi-value property.
> + *
> + * @np: device node from which the property value is to be read.
> + * @propname: name of the property to be searched.
> + * @index: index of the u32 in the list of values
> + * @out_value: pointer to return value, modified only if no error.
> + *
> + * Search for a property in a device node and read nth 32-bit value 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.
> + *
> + * The out_value is modified only if a valid u32 value can be decoded.
> + */
> +int of_property_read_u32_index(const struct device_node *np,
> + const char *propname,
> + u32 index, u32 *out_value)
> +{
> + struct property *prop = of_find_property(np, propname, NULL);
> +
> + if (!prop)
> + return -EINVAL;
> + if (!prop->value)
> + return -ENODATA;
> + if (((index + 1) * sizeof(*out_value)) > prop->length)
> + return -EOVERFLOW;
Yet another copy of almost the same code...
Can you re-factor things to do something like this:
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 321d3ef..482d29c 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -745,6 +745,21 @@ struct device_node *of_find_node_by_phandle(phandle handle)
}
EXPORT_SYMBOL(of_find_node_by_phandle);
+static void *of_find_property_value_of_size(const struct device_node *np,
+ const char *propname, u32 len)
+{
+ struct property *prop = of_find_property(np, propname, NULL);
+
+ if (!prop)
+ return -EINVAL;
+ if (!prop->value)
+ return -ENODATA;
+ if (len > prop->length)
+ return -EOVERFLOW;
+
+ return prop->value;
+}
+
/**
* of_property_read_u8_array - Find and read an array of u8 from a property.
*
@@ -766,17 +781,11 @@ EXPORT_SYMBOL(of_find_node_by_phandle);
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;
+ const u8 *val = of_find_property_value_of_size(np, propname, sz * sizeof(*out_values));
- if (!prop)
- return -EINVAL;
- if (!prop->value)
- return -ENODATA;
- if ((sz * sizeof(*out_values)) > prop->length)
- return -EOVERFLOW;
+ if (IS_ERR(val))
+ return PTR_ERR(val);
- val = prop->value;
while (sz--)
*out_values++ = *val++;
return 0;
> + *out_value = be32_to_cpup(((__be32 *)prop->value) + index);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_property_read_u32_index);
> +
> +/**
> * 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.
> diff --git a/include/linux/of.h b/include/linux/of.h
> index a0f1292..c0747a4 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -235,6 +235,9 @@ 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_u32_index(const struct device_node *np,
> + const char *propname,
> + u32 index, u32 *out_value);
> 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,
> @@ -394,6 +397,12 @@ static inline struct device_node *of_find_compatible_node(
> return NULL;
> }
>
> +static inline int of_property_read_u32_index(const struct device_node *np,
> + const char *propname, u32 index, u32 *out_value)
> +{
> + return -ENOSYS;
> +}
> +
> static inline int of_property_read_u8_array(const struct device_node *np,
> const char *propname, u8 *out_values, size_t sz)
> {
>
--
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