| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (c) 2019-2020 Intel Corporation |
| * |
| * Please see Documentation/driver-api/auxiliary_bus.rst for more information. |
| */ |
| |
| #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__ |
| |
| #include <linux/device.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/pm_domain.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/string.h> |
| #include <linux/auxiliary_bus.h> |
| #include "base.h" |
| |
| static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id, |
| const struct auxiliary_device *auxdev) |
| { |
| for (; id->name[0]; id++) { |
| const char *p = strrchr(dev_name(&auxdev->dev), '.'); |
| int match_size; |
| |
| if (!p) |
| continue; |
| match_size = p - dev_name(&auxdev->dev); |
| |
| /* use dev_name(&auxdev->dev) prefix before last '.' char to match to */ |
| if (strlen(id->name) == match_size && |
| !strncmp(dev_name(&auxdev->dev), id->name, match_size)) |
| return id; |
| } |
| return NULL; |
| } |
| |
| static int auxiliary_match(struct device *dev, struct device_driver *drv) |
| { |
| struct auxiliary_device *auxdev = to_auxiliary_dev(dev); |
| struct auxiliary_driver *auxdrv = to_auxiliary_drv(drv); |
| |
| return !!auxiliary_match_id(auxdrv->id_table, auxdev); |
| } |
| |
| static int auxiliary_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| const char *name, *p; |
| |
| name = dev_name(dev); |
| p = strrchr(name, '.'); |
| |
| return add_uevent_var(env, "MODALIAS=%s%.*s", AUXILIARY_MODULE_PREFIX, |
| (int)(p - name), name); |
| } |
| |
| static const struct dev_pm_ops auxiliary_dev_pm_ops = { |
| SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL) |
| SET_SYSTEM_SLEEP_PM_OPS(pm_generic_suspend, pm_generic_resume) |
| }; |
| |
| static int auxiliary_bus_probe(struct device *dev) |
| { |
| struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver); |
| struct auxiliary_device *auxdev = to_auxiliary_dev(dev); |
| int ret; |
| |
| ret = dev_pm_domain_attach(dev, true); |
| if (ret) { |
| dev_warn(dev, "Failed to attach to PM Domain : %d\n", ret); |
| return ret; |
| } |
| |
| ret = auxdrv->probe(auxdev, auxiliary_match_id(auxdrv->id_table, auxdev)); |
| if (ret) |
| dev_pm_domain_detach(dev, true); |
| |
| return ret; |
| } |
| |
| static int auxiliary_bus_remove(struct device *dev) |
| { |
| struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver); |
| struct auxiliary_device *auxdev = to_auxiliary_dev(dev); |
| |
| if (auxdrv->remove) |
| auxdrv->remove(auxdev); |
| dev_pm_domain_detach(dev, true); |
| |
| return 0; |
| } |
| |
| static void auxiliary_bus_shutdown(struct device *dev) |
| { |
| struct auxiliary_driver *auxdrv = NULL; |
| struct auxiliary_device *auxdev; |
| |
| if (dev->driver) { |
| auxdrv = to_auxiliary_drv(dev->driver); |
| auxdev = to_auxiliary_dev(dev); |
| } |
| |
| if (auxdrv && auxdrv->shutdown) |
| auxdrv->shutdown(auxdev); |
| } |
| |
| static struct bus_type auxiliary_bus_type = { |
| .name = "auxiliary", |
| .probe = auxiliary_bus_probe, |
| .remove = auxiliary_bus_remove, |
| .shutdown = auxiliary_bus_shutdown, |
| .match = auxiliary_match, |
| .uevent = auxiliary_uevent, |
| .pm = &auxiliary_dev_pm_ops, |
| }; |
| |
| /** |
| * auxiliary_device_init - check auxiliary_device and initialize |
| * @auxdev: auxiliary device struct |
| * |
| * This is the first step in the two-step process to register an |
| * auxiliary_device. |
| * |
| * When this function returns an error code, then the device_initialize will |
| * *not* have been performed, and the caller will be responsible to free any |
| * memory allocated for the auxiliary_device in the error path directly. |
| * |
| * It returns 0 on success. On success, the device_initialize has been |
| * performed. After this point any error unwinding will need to include a call |
| * to auxiliary_device_uninit(). In this post-initialize error scenario, a call |
| * to the device's .release callback will be triggered, and all memory clean-up |
| * is expected to be handled there. |
| */ |
| int auxiliary_device_init(struct auxiliary_device *auxdev) |
| { |
| struct device *dev = &auxdev->dev; |
| |
| if (!dev->parent) { |
| pr_err("auxiliary_device has a NULL dev->parent\n"); |
| return -EINVAL; |
| } |
| |
| if (!auxdev->name) { |
| pr_err("auxiliary_device has a NULL name\n"); |
| return -EINVAL; |
| } |
| |
| dev->bus = &auxiliary_bus_type; |
| device_initialize(&auxdev->dev); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(auxiliary_device_init); |
| |
| /** |
| * __auxiliary_device_add - add an auxiliary bus device |
| * @auxdev: auxiliary bus device to add to the bus |
| * @modname: name of the parent device's driver module |
| * |
| * This is the second step in the two-step process to register an |
| * auxiliary_device. |
| * |
| * This function must be called after a successful call to |
| * auxiliary_device_init(), which will perform the device_initialize. This |
| * means that if this returns an error code, then a call to |
| * auxiliary_device_uninit() must be performed so that the .release callback |
| * will be triggered to free the memory associated with the auxiliary_device. |
| * |
| * The expectation is that users will call the "auxiliary_device_add" macro so |
| * that the caller's KBUILD_MODNAME is automatically inserted for the modname |
| * parameter. Only if a user requires a custom name would this version be |
| * called directly. |
| */ |
| int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) |
| { |
| struct device *dev = &auxdev->dev; |
| int ret; |
| |
| if (!modname) { |
| dev_err(dev, "auxiliary device modname is NULL\n"); |
| return -EINVAL; |
| } |
| |
| ret = dev_set_name(dev, "%s.%s.%d", modname, auxdev->name, auxdev->id); |
| if (ret) { |
| dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret); |
| return ret; |
| } |
| |
| ret = device_add(dev); |
| if (ret) |
| dev_err(dev, "adding auxiliary device failed!: %d\n", ret); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__auxiliary_device_add); |
| |
| /** |
| * auxiliary_find_device - auxiliary device iterator for locating a particular device. |
| * @start: Device to begin with |
| * @data: Data to pass to match function |
| * @match: Callback function to check device |
| * |
| * This function returns a reference to a device that is 'found' |
| * for later use, as determined by the @match callback. |
| * |
| * The callback should return 0 if the device doesn't match and non-zero |
| * if it does. If the callback returns non-zero, this function will |
| * return to the caller and not iterate over any more devices. |
| */ |
| struct auxiliary_device *auxiliary_find_device(struct device *start, |
| const void *data, |
| int (*match)(struct device *dev, const void *data)) |
| { |
| struct device *dev; |
| |
| dev = bus_find_device(&auxiliary_bus_type, start, data, match); |
| if (!dev) |
| return NULL; |
| |
| return to_auxiliary_dev(dev); |
| } |
| EXPORT_SYMBOL_GPL(auxiliary_find_device); |
| |
| /** |
| * __auxiliary_driver_register - register a driver for auxiliary bus devices |
| * @auxdrv: auxiliary_driver structure |
| * @owner: owning module/driver |
| * @modname: KBUILD_MODNAME for parent driver |
| */ |
| int __auxiliary_driver_register(struct auxiliary_driver *auxdrv, |
| struct module *owner, const char *modname) |
| { |
| int ret; |
| |
| if (WARN_ON(!auxdrv->probe) || WARN_ON(!auxdrv->id_table)) |
| return -EINVAL; |
| |
| if (auxdrv->name) |
| auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s.%s", modname, |
| auxdrv->name); |
| else |
| auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s", modname); |
| if (!auxdrv->driver.name) |
| return -ENOMEM; |
| |
| auxdrv->driver.owner = owner; |
| auxdrv->driver.bus = &auxiliary_bus_type; |
| auxdrv->driver.mod_name = modname; |
| |
| ret = driver_register(&auxdrv->driver); |
| if (ret) |
| kfree(auxdrv->driver.name); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__auxiliary_driver_register); |
| |
| /** |
| * auxiliary_driver_unregister - unregister a driver |
| * @auxdrv: auxiliary_driver structure |
| */ |
| void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv) |
| { |
| driver_unregister(&auxdrv->driver); |
| kfree(auxdrv->driver.name); |
| } |
| EXPORT_SYMBOL_GPL(auxiliary_driver_unregister); |
| |
| void __init auxiliary_bus_init(void) |
| { |
| WARN_ON(bus_register(&auxiliary_bus_type)); |
| } |
| |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("Auxiliary Bus"); |
| MODULE_AUTHOR("David Ertman <david.m.ertman@intel.com>"); |
| MODULE_AUTHOR("Kiran Patil <kiran.patil@intel.com>"); |