From 4a4ab610b8ae912c28a4fd28442ef24ed7a1a5bd Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Fri, 24 Jun 2022 22:57:58 +0200 Subject: [PATCH] platform/surface: aggregator: Move device registry helper functions to core module Move helper functions for client device registration to the core module. This simplifies addition of future DT/OF support and also allows us to split out the device hub drivers into their own module. At the same time, also improve device node validation a bit by not silently skipping devices with invalid device UID specifiers. Further, ensure proper lifetime management for the firmware/software nodes associated with the added devices. Signed-off-by: Maximilian Luz Link: https://lore.kernel.org/r/20220624205800.1355621-2-luzmaximilian@gmail.com Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/platform/surface/aggregator/bus.c | 149 ++++++++++++++++++--- .../platform/surface/surface_aggregator_registry.c | 75 +---------- include/linux/surface_aggregator/device.h | 52 +++++++ 3 files changed, 187 insertions(+), 89 deletions(-) diff --git a/drivers/platform/surface/aggregator/bus.c b/drivers/platform/surface/aggregator/bus.c index abbbb5b..e0b0381 100644 --- a/drivers/platform/surface/aggregator/bus.c +++ b/drivers/platform/surface/aggregator/bus.c @@ -6,6 +6,7 @@ */ #include +#include #include #include @@ -14,6 +15,9 @@ #include "bus.h" #include "controller.h" + +/* -- Device and bus functions. --------------------------------------------- */ + static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -46,6 +50,7 @@ static void ssam_device_release(struct device *dev) struct ssam_device *sdev = to_ssam_device(dev); ssam_controller_put(sdev->ctrl); + fwnode_handle_put(sdev->dev.fwnode); kfree(sdev); } @@ -363,6 +368,134 @@ void ssam_device_driver_unregister(struct ssam_device_driver *sdrv) } EXPORT_SYMBOL_GPL(ssam_device_driver_unregister); + +/* -- Bus registration. ----------------------------------------------------- */ + +/** + * ssam_bus_register() - Register and set-up the SSAM client device bus. + */ +int ssam_bus_register(void) +{ + return bus_register(&ssam_bus_type); +} + +/** + * ssam_bus_unregister() - Unregister the SSAM client device bus. + */ +void ssam_bus_unregister(void) +{ + return bus_unregister(&ssam_bus_type); +} + + +/* -- Helpers for controller and hub devices. ------------------------------- */ + +static int ssam_device_uid_from_string(const char *str, struct ssam_device_uid *uid) +{ + u8 d, tc, tid, iid, fn; + int n; + + n = sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx", &d, &tc, &tid, &iid, &fn); + if (n != 5) + return -EINVAL; + + uid->domain = d; + uid->category = tc; + uid->target = tid; + uid->instance = iid; + uid->function = fn; + + return 0; +} + +static int ssam_get_uid_for_node(struct fwnode_handle *node, struct ssam_device_uid *uid) +{ + const char *str = fwnode_get_name(node); + + /* + * To simplify definitions of firmware nodes, we set the device name + * based on the UID of the device, prefixed with "ssam:". + */ + if (strncmp(str, "ssam:", strlen("ssam:")) != 0) + return -ENODEV; + + str += strlen("ssam:"); + return ssam_device_uid_from_string(str, uid); +} + +static int ssam_add_client_device(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + struct ssam_device_uid uid; + struct ssam_device *sdev; + int status; + + status = ssam_get_uid_for_node(node, &uid); + if (status) + return status; + + sdev = ssam_device_alloc(ctrl, uid); + if (!sdev) + return -ENOMEM; + + sdev->dev.parent = parent; + sdev->dev.fwnode = fwnode_handle_get(node); + + status = ssam_device_add(sdev); + if (status) + ssam_device_put(sdev); + + return status; +} + +/** + * __ssam_register_clients() - Register client devices defined under the + * given firmware node as children of the given device. + * @parent: The parent device under which clients should be registered. + * @ctrl: The controller with which client should be registered. + * @node: The firmware node holding definitions of the devices to be added. + * + * Register all clients that have been defined as children of the given root + * firmware node as children of the given parent device. The respective child + * firmware nodes will be associated with the correspondingly created child + * devices. + * + * The given controller will be used to instantiate the new devices. See + * ssam_device_add() for details. + * + * Note that, generally, the use of either ssam_device_register_clients() or + * ssam_register_clients() should be preferred as they directly use the + * firmware node and/or controller associated with the given device. This + * function is only intended for use when different device specifications (e.g. + * ACPI and firmware nodes) need to be combined (as is done in the platform hub + * of the device registry). + * + * Return: Returns zero on success, nonzero on failure. + */ +int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + struct fwnode_handle *child; + int status; + + fwnode_for_each_child_node(node, child) { + /* + * Try to add the device specified in the firmware node. If + * this fails with -ENODEV, the node does not specify any SSAM + * device, so ignore it and continue with the next one. + */ + status = ssam_add_client_device(parent, ctrl, child); + if (status && status != -ENODEV) + goto err; + } + + return 0; +err: + ssam_remove_clients(parent); + return status; +} +EXPORT_SYMBOL_GPL(__ssam_register_clients); + static int ssam_remove_device(struct device *dev, void *_data) { struct ssam_device *sdev = to_ssam_device(dev); @@ -387,19 +520,3 @@ void ssam_remove_clients(struct device *dev) device_for_each_child_reverse(dev, NULL, ssam_remove_device); } EXPORT_SYMBOL_GPL(ssam_remove_clients); - -/** - * ssam_bus_register() - Register and set-up the SSAM client device bus. - */ -int ssam_bus_register(void) -{ - return bus_register(&ssam_bus_type); -} - -/** - * ssam_bus_unregister() - Unregister the SSAM client device bus. - */ -void ssam_bus_unregister(void) -{ - return bus_unregister(&ssam_bus_type); -} diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c index f1c5905..c680792 100644 --- a/drivers/platform/surface/surface_aggregator_registry.c +++ b/drivers/platform/surface/surface_aggregator_registry.c @@ -286,76 +286,6 @@ static const struct software_node *ssam_node_group_sp8[] = { }; -/* -- Device registry helper functions. ------------------------------------- */ - -static int ssam_uid_from_string(const char *str, struct ssam_device_uid *uid) -{ - u8 d, tc, tid, iid, fn; - int n; - - n = sscanf(str, "ssam:%hhx:%hhx:%hhx:%hhx:%hhx", &d, &tc, &tid, &iid, &fn); - if (n != 5) - return -EINVAL; - - uid->domain = d; - uid->category = tc; - uid->target = tid; - uid->instance = iid; - uid->function = fn; - - return 0; -} - -static int ssam_hub_add_device(struct device *parent, struct ssam_controller *ctrl, - struct fwnode_handle *node) -{ - struct ssam_device_uid uid; - struct ssam_device *sdev; - int status; - - status = ssam_uid_from_string(fwnode_get_name(node), &uid); - if (status) - return status; - - sdev = ssam_device_alloc(ctrl, uid); - if (!sdev) - return -ENOMEM; - - sdev->dev.parent = parent; - sdev->dev.fwnode = node; - - status = ssam_device_add(sdev); - if (status) - ssam_device_put(sdev); - - return status; -} - -static int ssam_hub_register_clients(struct device *parent, struct ssam_controller *ctrl, - struct fwnode_handle *node) -{ - struct fwnode_handle *child; - int status; - - fwnode_for_each_child_node(node, child) { - /* - * Try to add the device specified in the firmware node. If - * this fails with -EINVAL, the node does not specify any SSAM - * device, so ignore it and continue with the next one. - */ - - status = ssam_hub_add_device(parent, ctrl, child); - if (status && status != -EINVAL) - goto err; - } - - return 0; -err: - ssam_remove_clients(parent); - return status; -} - - /* -- SSAM generic subsystem hub driver framework. -------------------------- */ enum ssam_hub_state { @@ -385,7 +315,6 @@ struct ssam_hub { static void ssam_hub_update_workfn(struct work_struct *work) { struct ssam_hub *hub = container_of(work, struct ssam_hub, update_work.work); - struct fwnode_handle *node = dev_fwnode(&hub->sdev->dev); enum ssam_hub_state state; int status = 0; @@ -425,7 +354,7 @@ static void ssam_hub_update_workfn(struct work_struct *work) hub->state = state; if (hub->state == SSAM_HUB_CONNECTED) - status = ssam_hub_register_clients(&hub->sdev->dev, hub->sdev->ctrl, node); + status = ssam_device_register_clients(hub->sdev); else ssam_remove_clients(&hub->sdev->dev); @@ -769,7 +698,7 @@ static int ssam_platform_hub_probe(struct platform_device *pdev) set_secondary_fwnode(&pdev->dev, root); - status = ssam_hub_register_clients(&pdev->dev, ctrl, root); + status = __ssam_register_clients(&pdev->dev, ctrl, root); if (status) { set_secondary_fwnode(&pdev->dev, NULL); software_node_unregister_node_group(nodes); diff --git a/include/linux/surface_aggregator/device.h b/include/linux/surface_aggregator/device.h index 6cf7e80..46c45d1 100644 --- a/include/linux/surface_aggregator/device.h +++ b/include/linux/surface_aggregator/device.h @@ -15,6 +15,7 @@ #include #include +#include #include #include @@ -375,11 +376,62 @@ void ssam_device_driver_unregister(struct ssam_device_driver *d); /* -- Helpers for controller and hub devices. ------------------------------- */ #ifdef CONFIG_SURFACE_AGGREGATOR_BUS + +int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node); void ssam_remove_clients(struct device *dev); + #else /* CONFIG_SURFACE_AGGREGATOR_BUS */ + +static inline int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + return 0; +} + static inline void ssam_remove_clients(struct device *dev) {} + #endif /* CONFIG_SURFACE_AGGREGATOR_BUS */ +/** + * ssam_register_clients() - Register all client devices defined under the + * given parent device. + * @dev: The parent device under which clients should be registered. + * @ctrl: The controller with which client should be registered. + * + * Register all clients that have via firmware nodes been defined as children + * of the given (parent) device. The respective child firmware nodes will be + * associated with the correspondingly created child devices. + * + * The given controller will be used to instantiate the new devices. See + * ssam_device_add() for details. + * + * Return: Returns zero on success, nonzero on failure. + */ +static inline int ssam_register_clients(struct device *dev, struct ssam_controller *ctrl) +{ + return __ssam_register_clients(dev, ctrl, dev_fwnode(dev)); +} + +/** + * ssam_device_register_clients() - Register all client devices defined under + * the given SSAM parent device. + * @sdev: The parent device under which clients should be registered. + * + * Register all clients that have via firmware nodes been defined as children + * of the given (parent) device. The respective child firmware nodes will be + * associated with the correspondingly created child devices. + * + * The controller used by the parent device will be used to instantiate the new + * devices. See ssam_device_add() for details. + * + * Return: Returns zero on success, nonzero on failure. + */ +static inline int ssam_device_register_clients(struct ssam_device *sdev) +{ + return ssam_register_clients(&sdev->dev, sdev->ctrl); +} + /* -- Helpers for client-device requests. ----------------------------------- */ -- 2.7.4