1 // SPDX-License-Identifier: GPL-2.0
3 * System Control and Management Interface (SCMI) Message Protocol bus layer
5 * Copyright (C) 2018 ARM Ltd.
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/types.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/device.h>
18 static DEFINE_IDA(scmi_bus_id);
19 static DEFINE_IDR(scmi_protocols);
20 static DEFINE_SPINLOCK(protocol_lock);
22 static const struct scmi_device_id *
23 scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
25 const struct scmi_device_id *id = scmi_drv->id_table;
30 for (; id->protocol_id; id++)
31 if (id->protocol_id == scmi_dev->protocol_id)
37 static int scmi_dev_match(struct device *dev, struct device_driver *drv)
39 struct scmi_driver *scmi_drv = to_scmi_driver(drv);
40 struct scmi_device *scmi_dev = to_scmi_dev(dev);
41 const struct scmi_device_id *id;
43 id = scmi_dev_match_id(scmi_dev, scmi_drv);
50 static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle)
52 scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id);
59 static int scmi_dev_probe(struct device *dev)
61 struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
62 struct scmi_device *scmi_dev = to_scmi_dev(dev);
63 const struct scmi_device_id *id;
66 id = scmi_dev_match_id(scmi_dev, scmi_drv);
70 if (!scmi_dev->handle)
73 ret = scmi_protocol_init(scmi_dev->protocol_id, scmi_dev->handle);
77 return scmi_drv->probe(scmi_dev);
80 static int scmi_dev_remove(struct device *dev)
82 struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
83 struct scmi_device *scmi_dev = to_scmi_dev(dev);
86 scmi_drv->remove(scmi_dev);
91 static struct bus_type scmi_bus_type = {
92 .name = "scmi_protocol",
93 .match = scmi_dev_match,
94 .probe = scmi_dev_probe,
95 .remove = scmi_dev_remove,
98 int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
106 driver->driver.bus = &scmi_bus_type;
107 driver->driver.name = driver->name;
108 driver->driver.owner = owner;
109 driver->driver.mod_name = mod_name;
111 retval = driver_register(&driver->driver);
113 pr_debug("registered new scmi driver %s\n", driver->name);
117 EXPORT_SYMBOL_GPL(scmi_driver_register);
119 void scmi_driver_unregister(struct scmi_driver *driver)
121 driver_unregister(&driver->driver);
123 EXPORT_SYMBOL_GPL(scmi_driver_unregister);
125 static void scmi_device_release(struct device *dev)
127 kfree(to_scmi_dev(dev));
131 scmi_device_create(struct device_node *np, struct device *parent, int protocol)
134 struct scmi_device *scmi_dev;
136 scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
140 id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
147 scmi_dev->protocol_id = protocol;
148 scmi_dev->dev.parent = parent;
149 scmi_dev->dev.of_node = np;
150 scmi_dev->dev.bus = &scmi_bus_type;
151 scmi_dev->dev.release = scmi_device_release;
152 dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);
154 retval = device_register(&scmi_dev->dev);
160 put_device(&scmi_dev->dev);
161 ida_simple_remove(&scmi_bus_id, id);
165 void scmi_device_destroy(struct scmi_device *scmi_dev)
167 scmi_handle_put(scmi_dev->handle);
168 ida_simple_remove(&scmi_bus_id, scmi_dev->id);
169 device_unregister(&scmi_dev->dev);
172 void scmi_set_handle(struct scmi_device *scmi_dev)
174 scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
177 int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
181 spin_lock(&protocol_lock);
182 ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1,
184 spin_unlock(&protocol_lock);
185 if (ret != protocol_id)
186 pr_err("unable to allocate SCMI idr slot, err %d\n", ret);
190 EXPORT_SYMBOL_GPL(scmi_protocol_register);
192 void scmi_protocol_unregister(int protocol_id)
194 spin_lock(&protocol_lock);
195 idr_remove(&scmi_protocols, protocol_id);
196 spin_unlock(&protocol_lock);
198 EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
200 static int __scmi_devices_unregister(struct device *dev, void *data)
202 struct scmi_device *scmi_dev = to_scmi_dev(dev);
204 scmi_device_destroy(scmi_dev);
208 static void scmi_devices_unregister(void)
210 bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister);
213 static int __init scmi_bus_init(void)
217 retval = bus_register(&scmi_bus_type);
219 pr_err("scmi protocol bus register failed (%d)\n", retval);
223 subsys_initcall(scmi_bus_init);
225 static void __exit scmi_bus_exit(void)
227 scmi_devices_unregister();
228 bus_unregister(&scmi_bus_type);
229 ida_destroy(&scmi_bus_id);
231 module_exit(scmi_bus_exit);