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