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