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7de3697e DE |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Copyright (c) 2019-2020 Intel Corporation | |
4 | * | |
5 | * Please see Documentation/driver-api/auxiliary_bus.rst for more information. | |
6 | */ | |
7 | ||
8 | #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__ | |
9 | ||
10 | #include <linux/device.h> | |
11 | #include <linux/init.h> | |
7bbb79ff | 12 | #include <linux/slab.h> |
7de3697e DE |
13 | #include <linux/module.h> |
14 | #include <linux/pm_domain.h> | |
15 | #include <linux/pm_runtime.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/auxiliary_bus.h> | |
471b12c4 | 18 | #include "base.h" |
7de3697e DE |
19 | |
20 | static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id, | |
21 | const struct auxiliary_device *auxdev) | |
22 | { | |
23 | for (; id->name[0]; id++) { | |
24 | const char *p = strrchr(dev_name(&auxdev->dev), '.'); | |
25 | int match_size; | |
26 | ||
27 | if (!p) | |
28 | continue; | |
29 | match_size = p - dev_name(&auxdev->dev); | |
30 | ||
31 | /* use dev_name(&auxdev->dev) prefix before last '.' char to match to */ | |
32 | if (strlen(id->name) == match_size && | |
33 | !strncmp(dev_name(&auxdev->dev), id->name, match_size)) | |
34 | return id; | |
35 | } | |
36 | return NULL; | |
37 | } | |
38 | ||
39 | static int auxiliary_match(struct device *dev, struct device_driver *drv) | |
40 | { | |
41 | struct auxiliary_device *auxdev = to_auxiliary_dev(dev); | |
42 | struct auxiliary_driver *auxdrv = to_auxiliary_drv(drv); | |
43 | ||
44 | return !!auxiliary_match_id(auxdrv->id_table, auxdev); | |
45 | } | |
46 | ||
47 | static int auxiliary_uevent(struct device *dev, struct kobj_uevent_env *env) | |
48 | { | |
49 | const char *name, *p; | |
50 | ||
51 | name = dev_name(dev); | |
52 | p = strrchr(name, '.'); | |
53 | ||
0d2bf11a GKH |
54 | return add_uevent_var(env, "MODALIAS=%s%.*s", AUXILIARY_MODULE_PREFIX, |
55 | (int)(p - name), name); | |
7de3697e DE |
56 | } |
57 | ||
58 | static const struct dev_pm_ops auxiliary_dev_pm_ops = { | |
59 | SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL) | |
60 | SET_SYSTEM_SLEEP_PM_OPS(pm_generic_suspend, pm_generic_resume) | |
61 | }; | |
62 | ||
63 | static int auxiliary_bus_probe(struct device *dev) | |
64 | { | |
65 | struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver); | |
66 | struct auxiliary_device *auxdev = to_auxiliary_dev(dev); | |
67 | int ret; | |
68 | ||
69 | ret = dev_pm_domain_attach(dev, true); | |
70 | if (ret) { | |
71 | dev_warn(dev, "Failed to attach to PM Domain : %d\n", ret); | |
72 | return ret; | |
73 | } | |
74 | ||
75 | ret = auxdrv->probe(auxdev, auxiliary_match_id(auxdrv->id_table, auxdev)); | |
76 | if (ret) | |
77 | dev_pm_domain_detach(dev, true); | |
78 | ||
79 | return ret; | |
80 | } | |
81 | ||
82 | static int auxiliary_bus_remove(struct device *dev) | |
83 | { | |
84 | struct auxiliary_driver *auxdrv = to_auxiliary_drv(dev->driver); | |
85 | struct auxiliary_device *auxdev = to_auxiliary_dev(dev); | |
7de3697e DE |
86 | |
87 | if (auxdrv->remove) | |
8142a46c | 88 | auxdrv->remove(auxdev); |
7de3697e DE |
89 | dev_pm_domain_detach(dev, true); |
90 | ||
8142a46c | 91 | return 0; |
7de3697e DE |
92 | } |
93 | ||
94 | static void auxiliary_bus_shutdown(struct device *dev) | |
95 | { | |
784b2c48 DJ |
96 | struct auxiliary_driver *auxdrv = NULL; |
97 | struct auxiliary_device *auxdev; | |
98 | ||
99 | if (dev->driver) { | |
100 | auxdrv = to_auxiliary_drv(dev->driver); | |
101 | auxdev = to_auxiliary_dev(dev); | |
102 | } | |
7de3697e | 103 | |
784b2c48 | 104 | if (auxdrv && auxdrv->shutdown) |
7de3697e DE |
105 | auxdrv->shutdown(auxdev); |
106 | } | |
107 | ||
108 | static struct bus_type auxiliary_bus_type = { | |
109 | .name = "auxiliary", | |
110 | .probe = auxiliary_bus_probe, | |
111 | .remove = auxiliary_bus_remove, | |
112 | .shutdown = auxiliary_bus_shutdown, | |
113 | .match = auxiliary_match, | |
114 | .uevent = auxiliary_uevent, | |
115 | .pm = &auxiliary_dev_pm_ops, | |
116 | }; | |
117 | ||
118 | /** | |
119 | * auxiliary_device_init - check auxiliary_device and initialize | |
120 | * @auxdev: auxiliary device struct | |
121 | * | |
0d2bf11a GKH |
122 | * This is the first step in the two-step process to register an |
123 | * auxiliary_device. | |
7de3697e | 124 | * |
0d2bf11a GKH |
125 | * When this function returns an error code, then the device_initialize will |
126 | * *not* have been performed, and the caller will be responsible to free any | |
127 | * memory allocated for the auxiliary_device in the error path directly. | |
7de3697e | 128 | * |
0d2bf11a GKH |
129 | * It returns 0 on success. On success, the device_initialize has been |
130 | * performed. After this point any error unwinding will need to include a call | |
131 | * to auxiliary_device_uninit(). In this post-initialize error scenario, a call | |
132 | * to the device's .release callback will be triggered, and all memory clean-up | |
133 | * is expected to be handled there. | |
7de3697e DE |
134 | */ |
135 | int auxiliary_device_init(struct auxiliary_device *auxdev) | |
136 | { | |
137 | struct device *dev = &auxdev->dev; | |
138 | ||
139 | if (!dev->parent) { | |
140 | pr_err("auxiliary_device has a NULL dev->parent\n"); | |
141 | return -EINVAL; | |
142 | } | |
143 | ||
144 | if (!auxdev->name) { | |
145 | pr_err("auxiliary_device has a NULL name\n"); | |
146 | return -EINVAL; | |
147 | } | |
148 | ||
149 | dev->bus = &auxiliary_bus_type; | |
150 | device_initialize(&auxdev->dev); | |
151 | return 0; | |
152 | } | |
153 | EXPORT_SYMBOL_GPL(auxiliary_device_init); | |
154 | ||
155 | /** | |
156 | * __auxiliary_device_add - add an auxiliary bus device | |
157 | * @auxdev: auxiliary bus device to add to the bus | |
158 | * @modname: name of the parent device's driver module | |
159 | * | |
0d2bf11a GKH |
160 | * This is the second step in the two-step process to register an |
161 | * auxiliary_device. | |
7de3697e | 162 | * |
0d2bf11a GKH |
163 | * This function must be called after a successful call to |
164 | * auxiliary_device_init(), which will perform the device_initialize. This | |
165 | * means that if this returns an error code, then a call to | |
166 | * auxiliary_device_uninit() must be performed so that the .release callback | |
167 | * will be triggered to free the memory associated with the auxiliary_device. | |
7de3697e | 168 | * |
0d2bf11a GKH |
169 | * The expectation is that users will call the "auxiliary_device_add" macro so |
170 | * that the caller's KBUILD_MODNAME is automatically inserted for the modname | |
171 | * parameter. Only if a user requires a custom name would this version be | |
172 | * called directly. | |
7de3697e DE |
173 | */ |
174 | int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) | |
175 | { | |
176 | struct device *dev = &auxdev->dev; | |
177 | int ret; | |
178 | ||
179 | if (!modname) { | |
0d2bf11a | 180 | dev_err(dev, "auxiliary device modname is NULL\n"); |
7de3697e DE |
181 | return -EINVAL; |
182 | } | |
183 | ||
184 | ret = dev_set_name(dev, "%s.%s.%d", modname, auxdev->name, auxdev->id); | |
185 | if (ret) { | |
0d2bf11a | 186 | dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret); |
7de3697e DE |
187 | return ret; |
188 | } | |
189 | ||
190 | ret = device_add(dev); | |
191 | if (ret) | |
192 | dev_err(dev, "adding auxiliary device failed!: %d\n", ret); | |
193 | ||
194 | return ret; | |
195 | } | |
196 | EXPORT_SYMBOL_GPL(__auxiliary_device_add); | |
197 | ||
198 | /** | |
199 | * auxiliary_find_device - auxiliary device iterator for locating a particular device. | |
200 | * @start: Device to begin with | |
201 | * @data: Data to pass to match function | |
202 | * @match: Callback function to check device | |
203 | * | |
204 | * This function returns a reference to a device that is 'found' | |
205 | * for later use, as determined by the @match callback. | |
206 | * | |
207 | * The callback should return 0 if the device doesn't match and non-zero | |
208 | * if it does. If the callback returns non-zero, this function will | |
209 | * return to the caller and not iterate over any more devices. | |
210 | */ | |
0d2bf11a GKH |
211 | struct auxiliary_device *auxiliary_find_device(struct device *start, |
212 | const void *data, | |
213 | int (*match)(struct device *dev, const void *data)) | |
7de3697e DE |
214 | { |
215 | struct device *dev; | |
216 | ||
217 | dev = bus_find_device(&auxiliary_bus_type, start, data, match); | |
218 | if (!dev) | |
219 | return NULL; | |
220 | ||
221 | return to_auxiliary_dev(dev); | |
222 | } | |
223 | EXPORT_SYMBOL_GPL(auxiliary_find_device); | |
224 | ||
225 | /** | |
226 | * __auxiliary_driver_register - register a driver for auxiliary bus devices | |
227 | * @auxdrv: auxiliary_driver structure | |
228 | * @owner: owning module/driver | |
229 | * @modname: KBUILD_MODNAME for parent driver | |
230 | */ | |
0d2bf11a GKH |
231 | int __auxiliary_driver_register(struct auxiliary_driver *auxdrv, |
232 | struct module *owner, const char *modname) | |
7de3697e | 233 | { |
4afa0c22 PU |
234 | int ret; |
235 | ||
7de3697e DE |
236 | if (WARN_ON(!auxdrv->probe) || WARN_ON(!auxdrv->id_table)) |
237 | return -EINVAL; | |
238 | ||
239 | if (auxdrv->name) | |
0d2bf11a GKH |
240 | auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s.%s", modname, |
241 | auxdrv->name); | |
7de3697e DE |
242 | else |
243 | auxdrv->driver.name = kasprintf(GFP_KERNEL, "%s", modname); | |
244 | if (!auxdrv->driver.name) | |
245 | return -ENOMEM; | |
246 | ||
247 | auxdrv->driver.owner = owner; | |
248 | auxdrv->driver.bus = &auxiliary_bus_type; | |
249 | auxdrv->driver.mod_name = modname; | |
250 | ||
4afa0c22 PU |
251 | ret = driver_register(&auxdrv->driver); |
252 | if (ret) | |
253 | kfree(auxdrv->driver.name); | |
254 | ||
255 | return ret; | |
7de3697e DE |
256 | } |
257 | EXPORT_SYMBOL_GPL(__auxiliary_driver_register); | |
258 | ||
259 | /** | |
260 | * auxiliary_driver_unregister - unregister a driver | |
261 | * @auxdrv: auxiliary_driver structure | |
262 | */ | |
263 | void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv) | |
264 | { | |
265 | driver_unregister(&auxdrv->driver); | |
266 | kfree(auxdrv->driver.name); | |
267 | } | |
268 | EXPORT_SYMBOL_GPL(auxiliary_driver_unregister); | |
269 | ||
471b12c4 | 270 | void __init auxiliary_bus_init(void) |
7de3697e | 271 | { |
471b12c4 | 272 | WARN_ON(bus_register(&auxiliary_bus_type)); |
7de3697e | 273 | } |