Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762473Ab3DCGYx (ORCPT ); Wed, 3 Apr 2013 02:24:53 -0400 Received: from server.prisktech.co.nz ([115.188.14.127]:54093 "EHLO server.prisktech.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762335Ab3DCGYw (ORCPT ); Wed, 3 Apr 2013 02:24:52 -0400 From: Tony Prisk To: linus.walleij@linaro.org Cc: robherring2@gmail.com, swarren@wwwdotorg.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, vt8500-wm8505-linux-kernel@googlegroups.com, Tony Prisk Subject: [PATCHv5 1/7] of: Add support for reading a u32 from a multi-value property. Date: Wed, 3 Apr 2013 19:24:45 +1300 Message-Id: <1364970291-17721-2-git-send-email-linux@prisktech.co.nz> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1364970291-17721-1-git-send-email-linux@prisktech.co.nz> References: <1364970291-17721-1-git-send-email-linux@prisktech.co.nz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3246 Lines: 90 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 Reviewed-by: Stephen Warren --- 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; + + *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) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/