Use 'suspend-dependencies' property from device node to ensure that the listed devices will suspended after it and resumed before it.
Signed-off-by: Benjamin Gaignard <[email protected]> --- CC: Rafael J. Wysocki <[email protected]> version 2: - only keep of_device_links_add() and use DL_FLAG_PM_RUNTIME and DL_FLAG_AUTOREMOVE_CONSUMER flags to follow Rafael advices - reword function description - try to use a more explicit property name drivers/of/device.c | 37 +++++++++++++++++++++++++++++++++++++ include/linux/of_device.h | 7 +++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/of/device.c b/drivers/of/device.c index 3717f2a20d0d..44ec84eee310 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -336,3 +336,40 @@ int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) return 0; } EXPORT_SYMBOL_GPL(of_device_uevent_modalias); + +/** + * of_device_links_add - Create links between a consumer device + * and it listed dependencies from device tree data + * + * @consumer: consumer device + * + * Ensure that consumer's dependencies will be suspended after it + * and resumed before it. + * + * Returns 0 on success, < 0 on failure. + */ +int of_device_links_add(struct device *consumer) +{ + struct device_node *np; + struct platform_device *pdev; + int i = 0; + + np = of_parse_phandle(consumer->of_node, "suspend-dependencies", i++); + while (np) { + pdev = of_find_device_by_node(np); + of_node_put(np); + if (!pdev) + return -EINVAL; + + device_link_add(consumer, &pdev->dev, + DL_FLAG_PM_RUNTIME | + DL_FLAG_AUTOREMOVE_CONSUMER); + platform_device_put(pdev); + + np = of_parse_phandle(consumer->of_node, "suspend-dependencies", + i++); + } + + return 0; +} +EXPORT_SYMBOL_GPL(of_device_links_add); diff --git a/include/linux/of_device.h b/include/linux/of_device.h index 8d31e39dd564..83f24c386d51 100644 --- a/include/linux/of_device.h +++ b/include/linux/of_device.h @@ -41,6 +41,8 @@ extern int of_device_request_module(struct device *dev); extern void of_device_uevent(struct device *dev, struct kobj_uevent_env *env); extern int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env); +extern int of_device_links_add(struct device *consumer); + static inline void of_device_node_put(struct device *dev) { of_node_put(dev->of_node); @@ -91,6 +93,11 @@ static inline int of_device_uevent_modalias(struct device *dev, return -ENODEV; } +static int of_device_links_add(struct device *consumer) +{ + return 0; +} + static inline void of_device_node_put(struct device *dev) { } static inline const struct of_device_id *__of_match_device( -- 2.15.0
