From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kefeng Wang Subject: [RFC PATCH 1/4] acpi: property: Introduce helper acpi_dev_get_reference_device() Date: Wed, 2 Dec 2015 17:09:25 +0800 Message-ID: <1449047368-5768-2-git-send-email-wangkefeng.wang@huawei.com> References: <1449047368-5768-1-git-send-email-wangkefeng.wang@huawei.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from szxga01-in.huawei.com ([58.251.152.64]:12367 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756878AbbLBJM3 (ORCPT ); Wed, 2 Dec 2015 04:12:29 -0500 In-Reply-To: <1449047368-5768-1-git-send-email-wangkefeng.wang@huawei.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" , Arnd Bergmann Cc: Hanjun Guo , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Kefeng Wang Like of_parse_phandle() helper function to read and parse a phandle property and return a pointer to the resulting device_node, introduce helper function acpi_dev_get_reference_device() to read and parse a device properties(used in _DSD method) and return a pointer to the resulting acpi_device. Signed-off-by: Kefeng Wang --- drivers/acpi/property.c | 23 +++++++++++++++++++++++ include/linux/acpi.h | 7 +++++++ 2 files changed, 30 insertions(+) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 88f4306..e2e7754 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -398,6 +398,29 @@ int acpi_dev_get_property(struct acpi_device *adev, const char *name, } EXPORT_SYMBOL_GPL(acpi_dev_get_property); +/** + * acpi_dev_get_reference_device - return the acpi_device referenced + * @adev: ACPI device to get the property from. + * @name: Name of the property. + * @index: Index of the reference to return + * + * Returns referenced ACPI device pointer, or NULL if not found + */ +struct acpi_device *acpi_dev_get_reference_device(struct acpi_device *adev, + const char *name, size_t index) +{ + struct acpi_reference_args args; + int ret; + + ret = acpi_node_get_property_reference(acpi_fwnode_handle(adev), name, index, &args); + + if (ret) + return NULL; + + return args.adev; +} +EXPORT_SYMBOL(acpi_dev_get_reference_device); + static struct acpi_device_data *acpi_device_data_of_node(struct fwnode_handle *fwnode) { if (fwnode->type == FWNODE_ACPI) { diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 93811dc..d76a688 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -793,6 +793,8 @@ struct acpi_reference_args { #ifdef CONFIG_ACPI int acpi_dev_get_property(struct acpi_device *adev, const char *name, acpi_object_type type, const union acpi_object **obj); +struct acpi_device *acpi_dev_get_reference_device(struct acpi_device *adev, + const char *name, size_t index); int acpi_node_get_property_reference(struct fwnode_handle *fwnode, const char *name, size_t index, struct acpi_reference_args *args); @@ -870,6 +872,11 @@ static inline int acpi_dev_get_property(struct acpi_device *adev, { return -ENXIO; } +static inline struct acpi_device *acpi_dev_get_reference_device(struct acpi_device *adev, + const char *name, size_t index) +{ + return NULL; +} static inline int acpi_node_get_property_reference(struct fwnode_handle *fwnode, const char *name, const char *cells_name, -- 1.7.12.4