1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Greybus "Core"
4 *
5 * Copyright 2014-2015 Google Inc.
6 * Copyright 2014-2015 Linaro Ltd.
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #define CREATE_TRACE_POINTS
12 #include <linux/greybus.h>
13 #include "greybus_trace.h"
14
15 #define GB_BUNDLE_AUTOSUSPEND_MS 3000
16
17 /* Allow greybus to be disabled at boot if needed */
18 static bool nogreybus;
19 #ifdef MODULE
20 module_param(nogreybus, bool, 0444);
21 #else
22 core_param(nogreybus, nogreybus, bool, 0444);
23 #endif
greybus_disabled(void)24 int greybus_disabled(void)
25 {
26 return nogreybus;
27 }
28 EXPORT_SYMBOL_GPL(greybus_disabled);
29
greybus_match_one_id(struct gb_bundle * bundle,const struct greybus_bundle_id * id)30 static bool greybus_match_one_id(struct gb_bundle *bundle,
31 const struct greybus_bundle_id *id)
32 {
33 if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
34 (id->vendor != bundle->intf->vendor_id))
35 return false;
36
37 if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
38 (id->product != bundle->intf->product_id))
39 return false;
40
41 if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
42 (id->class != bundle->class))
43 return false;
44
45 return true;
46 }
47
48 static const struct greybus_bundle_id *
greybus_match_id(struct gb_bundle * bundle,const struct greybus_bundle_id * id)49 greybus_match_id(struct gb_bundle *bundle, const struct greybus_bundle_id *id)
50 {
51 if (!id)
52 return NULL;
53
54 for (; id->vendor || id->product || id->class || id->driver_info;
55 id++) {
56 if (greybus_match_one_id(bundle, id))
57 return id;
58 }
59
60 return NULL;
61 }
62
greybus_match_device(struct device * dev,struct device_driver * drv)63 static int greybus_match_device(struct device *dev, struct device_driver *drv)
64 {
65 struct greybus_driver *driver = to_greybus_driver(drv);
66 struct gb_bundle *bundle;
67 const struct greybus_bundle_id *id;
68
69 if (!is_gb_bundle(dev))
70 return 0;
71
72 bundle = to_gb_bundle(dev);
73
74 id = greybus_match_id(bundle, driver->id_table);
75 if (id)
76 return 1;
77 /* FIXME - Dynamic ids? */
78 return 0;
79 }
80
greybus_uevent(struct device * dev,struct kobj_uevent_env * env)81 static int greybus_uevent(struct device *dev, struct kobj_uevent_env *env)
82 {
83 struct gb_host_device *hd;
84 struct gb_module *module = NULL;
85 struct gb_interface *intf = NULL;
86 struct gb_control *control = NULL;
87 struct gb_bundle *bundle = NULL;
88 struct gb_svc *svc = NULL;
89
90 if (is_gb_host_device(dev)) {
91 hd = to_gb_host_device(dev);
92 } else if (is_gb_module(dev)) {
93 module = to_gb_module(dev);
94 hd = module->hd;
95 } else if (is_gb_interface(dev)) {
96 intf = to_gb_interface(dev);
97 module = intf->module;
98 hd = intf->hd;
99 } else if (is_gb_control(dev)) {
100 control = to_gb_control(dev);
101 intf = control->intf;
102 module = intf->module;
103 hd = intf->hd;
104 } else if (is_gb_bundle(dev)) {
105 bundle = to_gb_bundle(dev);
106 intf = bundle->intf;
107 module = intf->module;
108 hd = intf->hd;
109 } else if (is_gb_svc(dev)) {
110 svc = to_gb_svc(dev);
111 hd = svc->hd;
112 } else {
113 dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
114 return -EINVAL;
115 }
116
117 if (add_uevent_var(env, "BUS=%u", hd->bus_id))
118 return -ENOMEM;
119
120 if (module) {
121 if (add_uevent_var(env, "MODULE=%u", module->module_id))
122 return -ENOMEM;
123 }
124
125 if (intf) {
126 if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
127 return -ENOMEM;
128 if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
129 intf->vendor_id, intf->product_id))
130 return -ENOMEM;
131 }
132
133 if (bundle) {
134 // FIXME
135 // add a uevent that can "load" a bundle type
136 // This is what we need to bind a driver to so use the info
137 // in gmod here as well
138
139 if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
140 return -ENOMEM;
141 if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
142 return -ENOMEM;
143 }
144
145 return 0;
146 }
147
greybus_shutdown(struct device * dev)148 static void greybus_shutdown(struct device *dev)
149 {
150 if (is_gb_host_device(dev)) {
151 struct gb_host_device *hd;
152
153 hd = to_gb_host_device(dev);
154 gb_hd_shutdown(hd);
155 }
156 }
157
158 struct bus_type greybus_bus_type = {
159 .name = "greybus",
160 .match = greybus_match_device,
161 .uevent = greybus_uevent,
162 .shutdown = greybus_shutdown,
163 };
164
greybus_probe(struct device * dev)165 static int greybus_probe(struct device *dev)
166 {
167 struct greybus_driver *driver = to_greybus_driver(dev->driver);
168 struct gb_bundle *bundle = to_gb_bundle(dev);
169 const struct greybus_bundle_id *id;
170 int retval;
171
172 /* match id */
173 id = greybus_match_id(bundle, driver->id_table);
174 if (!id)
175 return -ENODEV;
176
177 retval = pm_runtime_get_sync(&bundle->intf->dev);
178 if (retval < 0) {
179 pm_runtime_put_noidle(&bundle->intf->dev);
180 return retval;
181 }
182
183 retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
184 if (retval) {
185 pm_runtime_put(&bundle->intf->dev);
186 return retval;
187 }
188
189 /*
190 * Unbound bundle devices are always deactivated. During probe, the
191 * Runtime PM is set to enabled and active and the usage count is
192 * incremented. If the driver supports runtime PM, it should call
193 * pm_runtime_put() in its probe routine and pm_runtime_get_sync()
194 * in remove routine.
195 */
196 pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
197 pm_runtime_use_autosuspend(dev);
198 pm_runtime_get_noresume(dev);
199 pm_runtime_set_active(dev);
200 pm_runtime_enable(dev);
201
202 retval = driver->probe(bundle, id);
203 if (retval) {
204 /*
205 * Catch buggy drivers that fail to destroy their connections.
206 */
207 WARN_ON(!list_empty(&bundle->connections));
208
209 gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
210
211 pm_runtime_disable(dev);
212 pm_runtime_set_suspended(dev);
213 pm_runtime_put_noidle(dev);
214 pm_runtime_dont_use_autosuspend(dev);
215 pm_runtime_put(&bundle->intf->dev);
216
217 return retval;
218 }
219
220 pm_runtime_put(&bundle->intf->dev);
221
222 return 0;
223 }
224
greybus_remove(struct device * dev)225 static int greybus_remove(struct device *dev)
226 {
227 struct greybus_driver *driver = to_greybus_driver(dev->driver);
228 struct gb_bundle *bundle = to_gb_bundle(dev);
229 struct gb_connection *connection;
230 int retval;
231
232 retval = pm_runtime_get_sync(dev);
233 if (retval < 0)
234 dev_err(dev, "failed to resume bundle: %d\n", retval);
235
236 /*
237 * Disable (non-offloaded) connections early in case the interface is
238 * already gone to avoid unceccessary operation timeouts during
239 * driver disconnect. Otherwise, only disable incoming requests.
240 */
241 list_for_each_entry(connection, &bundle->connections, bundle_links) {
242 if (gb_connection_is_offloaded(connection))
243 continue;
244
245 if (bundle->intf->disconnected)
246 gb_connection_disable_forced(connection);
247 else
248 gb_connection_disable_rx(connection);
249 }
250
251 driver->disconnect(bundle);
252
253 /* Catch buggy drivers that fail to destroy their connections. */
254 WARN_ON(!list_empty(&bundle->connections));
255
256 if (!bundle->intf->disconnected)
257 gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
258
259 pm_runtime_put_noidle(dev);
260 pm_runtime_disable(dev);
261 pm_runtime_set_suspended(dev);
262 pm_runtime_dont_use_autosuspend(dev);
263 pm_runtime_put_noidle(dev);
264
265 return 0;
266 }
267
greybus_register_driver(struct greybus_driver * driver,struct module * owner,const char * mod_name)268 int greybus_register_driver(struct greybus_driver *driver, struct module *owner,
269 const char *mod_name)
270 {
271 int retval;
272
273 if (greybus_disabled())
274 return -ENODEV;
275
276 driver->driver.bus = &greybus_bus_type;
277 driver->driver.name = driver->name;
278 driver->driver.probe = greybus_probe;
279 driver->driver.remove = greybus_remove;
280 driver->driver.owner = owner;
281 driver->driver.mod_name = mod_name;
282
283 retval = driver_register(&driver->driver);
284 if (retval)
285 return retval;
286
287 pr_info("registered new driver %s\n", driver->name);
288 return 0;
289 }
290 EXPORT_SYMBOL_GPL(greybus_register_driver);
291
greybus_deregister_driver(struct greybus_driver * driver)292 void greybus_deregister_driver(struct greybus_driver *driver)
293 {
294 driver_unregister(&driver->driver);
295 }
296 EXPORT_SYMBOL_GPL(greybus_deregister_driver);
297
gb_init(void)298 static int __init gb_init(void)
299 {
300 int retval;
301
302 if (greybus_disabled())
303 return -ENODEV;
304
305 BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);
306
307 gb_debugfs_init();
308
309 retval = bus_register(&greybus_bus_type);
310 if (retval) {
311 pr_err("bus_register failed (%d)\n", retval);
312 goto error_bus;
313 }
314
315 retval = gb_hd_init();
316 if (retval) {
317 pr_err("gb_hd_init failed (%d)\n", retval);
318 goto error_hd;
319 }
320
321 retval = gb_operation_init();
322 if (retval) {
323 pr_err("gb_operation_init failed (%d)\n", retval);
324 goto error_operation;
325 }
326 return 0; /* Success */
327
328 error_operation:
329 gb_hd_exit();
330 error_hd:
331 bus_unregister(&greybus_bus_type);
332 error_bus:
333 gb_debugfs_cleanup();
334
335 return retval;
336 }
337 module_init(gb_init);
338
gb_exit(void)339 static void __exit gb_exit(void)
340 {
341 gb_operation_exit();
342 gb_hd_exit();
343 bus_unregister(&greybus_bus_type);
344 gb_debugfs_cleanup();
345 tracepoint_synchronize_unregister();
346 }
347 module_exit(gb_exit);
348 MODULE_LICENSE("GPL v2");
349 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
350