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 */
18static bool nogreybus;
19#ifdef MODULE
20module_param(nogreybus, bool, 0444);
21#else
22core_param(nogreybus, nogreybus, bool, 0444);
23#endif
24int greybus_disabled(void)
25{
26	return nogreybus;
27}
28EXPORT_SYMBOL_GPL(greybus_disabled);
29
30static int is_gb_host_device(const struct device *dev)
31{
32	return dev->type == &greybus_hd_type;
33}
34
35static int is_gb_module(const struct device *dev)
36{
37	return dev->type == &greybus_module_type;
38}
39
40static int is_gb_interface(const struct device *dev)
41{
42	return dev->type == &greybus_interface_type;
43}
44
45static int is_gb_control(const struct device *dev)
46{
47	return dev->type == &greybus_control_type;
48}
49
50static int is_gb_bundle(const struct device *dev)
51{
52	return dev->type == &greybus_bundle_type;
53}
54
55static int is_gb_svc(const struct device *dev)
56{
57	return dev->type == &greybus_svc_type;
58}
59
60static bool greybus_match_one_id(struct gb_bundle *bundle,
61				 const struct greybus_bundle_id *id)
62{
63	if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
64	    (id->vendor != bundle->intf->vendor_id))
65		return false;
66
67	if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
68	    (id->product != bundle->intf->product_id))
69		return false;
70
71	if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
72	    (id->class != bundle->class))
73		return false;
74
75	return true;
76}
77
78static const struct greybus_bundle_id *
79greybus_match_id(struct gb_bundle *bundle, const struct greybus_bundle_id *id)
80{
81	if (!id)
82		return NULL;
83
84	for (; id->vendor || id->product || id->class || id->driver_info;
85									id++) {
86		if (greybus_match_one_id(bundle, id))
87			return id;
88	}
89
90	return NULL;
91}
92
93static int greybus_match_device(struct device *dev, struct device_driver *drv)
94{
95	struct greybus_driver *driver = to_greybus_driver(drv);
96	struct gb_bundle *bundle;
97	const struct greybus_bundle_id *id;
98
99	if (!is_gb_bundle(dev))
100		return 0;
101
102	bundle = to_gb_bundle(dev);
103
104	id = greybus_match_id(bundle, driver->id_table);
105	if (id)
106		return 1;
107	/* FIXME - Dynamic ids? */
108	return 0;
109}
110
111static int greybus_uevent(const struct device *dev, struct kobj_uevent_env *env)
112{
113	const struct gb_host_device *hd;
114	const struct gb_module *module = NULL;
115	const struct gb_interface *intf = NULL;
116	const struct gb_control *control = NULL;
117	const struct gb_bundle *bundle = NULL;
118	const struct gb_svc *svc = NULL;
119
120	if (is_gb_host_device(dev)) {
121		hd = to_gb_host_device(dev);
122	} else if (is_gb_module(dev)) {
123		module = to_gb_module(dev);
124		hd = module->hd;
125	} else if (is_gb_interface(dev)) {
126		intf = to_gb_interface(dev);
127		module = intf->module;
128		hd = intf->hd;
129	} else if (is_gb_control(dev)) {
130		control = to_gb_control(dev);
131		intf = control->intf;
132		module = intf->module;
133		hd = intf->hd;
134	} else if (is_gb_bundle(dev)) {
135		bundle = to_gb_bundle(dev);
136		intf = bundle->intf;
137		module = intf->module;
138		hd = intf->hd;
139	} else if (is_gb_svc(dev)) {
140		svc = to_gb_svc(dev);
141		hd = svc->hd;
142	} else {
143		dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
144		return -EINVAL;
145	}
146
147	if (add_uevent_var(env, "BUS=%u", hd->bus_id))
148		return -ENOMEM;
149
150	if (module) {
151		if (add_uevent_var(env, "MODULE=%u", module->module_id))
152			return -ENOMEM;
153	}
154
155	if (intf) {
156		if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
157			return -ENOMEM;
158		if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
159				   intf->vendor_id, intf->product_id))
160			return -ENOMEM;
161	}
162
163	if (bundle) {
164		// FIXME
165		// add a uevent that can "load" a bundle type
166		// This is what we need to bind a driver to so use the info
167		// in gmod here as well
168
169		if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
170			return -ENOMEM;
171		if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
172			return -ENOMEM;
173	}
174
175	return 0;
176}
177
178static void greybus_shutdown(struct device *dev)
179{
180	if (is_gb_host_device(dev)) {
181		struct gb_host_device *hd;
182
183		hd = to_gb_host_device(dev);
184		gb_hd_shutdown(hd);
185	}
186}
187
188const struct bus_type greybus_bus_type = {
189	.name =		"greybus",
190	.match =	greybus_match_device,
191	.uevent =	greybus_uevent,
192	.shutdown =	greybus_shutdown,
193};
194
195static int greybus_probe(struct device *dev)
196{
197	struct greybus_driver *driver = to_greybus_driver(dev->driver);
198	struct gb_bundle *bundle = to_gb_bundle(dev);
199	const struct greybus_bundle_id *id;
200	int retval;
201
202	/* match id */
203	id = greybus_match_id(bundle, driver->id_table);
204	if (!id)
205		return -ENODEV;
206
207	retval = pm_runtime_get_sync(&bundle->intf->dev);
208	if (retval < 0) {
209		pm_runtime_put_noidle(&bundle->intf->dev);
210		return retval;
211	}
212
213	retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
214	if (retval) {
215		pm_runtime_put(&bundle->intf->dev);
216		return retval;
217	}
218
219	/*
220	 * Unbound bundle devices are always deactivated. During probe, the
221	 * Runtime PM is set to enabled and active and the usage count is
222	 * incremented. If the driver supports runtime PM, it should call
223	 * pm_runtime_put() in its probe routine and pm_runtime_get_sync()
224	 * in remove routine.
225	 */
226	pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
227	pm_runtime_use_autosuspend(dev);
228	pm_runtime_get_noresume(dev);
229	pm_runtime_set_active(dev);
230	pm_runtime_enable(dev);
231
232	retval = driver->probe(bundle, id);
233	if (retval) {
234		/*
235		 * Catch buggy drivers that fail to destroy their connections.
236		 */
237		WARN_ON(!list_empty(&bundle->connections));
238
239		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
240
241		pm_runtime_disable(dev);
242		pm_runtime_set_suspended(dev);
243		pm_runtime_put_noidle(dev);
244		pm_runtime_dont_use_autosuspend(dev);
245		pm_runtime_put(&bundle->intf->dev);
246
247		return retval;
248	}
249
250	pm_runtime_put(&bundle->intf->dev);
251
252	return 0;
253}
254
255static int greybus_remove(struct device *dev)
256{
257	struct greybus_driver *driver = to_greybus_driver(dev->driver);
258	struct gb_bundle *bundle = to_gb_bundle(dev);
259	struct gb_connection *connection;
260	int retval;
261
262	retval = pm_runtime_get_sync(dev);
263	if (retval < 0)
264		dev_err(dev, "failed to resume bundle: %d\n", retval);
265
266	/*
267	 * Disable (non-offloaded) connections early in case the interface is
268	 * already gone to avoid unceccessary operation timeouts during
269	 * driver disconnect. Otherwise, only disable incoming requests.
270	 */
271	list_for_each_entry(connection, &bundle->connections, bundle_links) {
272		if (gb_connection_is_offloaded(connection))
273			continue;
274
275		if (bundle->intf->disconnected)
276			gb_connection_disable_forced(connection);
277		else
278			gb_connection_disable_rx(connection);
279	}
280
281	driver->disconnect(bundle);
282
283	/* Catch buggy drivers that fail to destroy their connections. */
284	WARN_ON(!list_empty(&bundle->connections));
285
286	if (!bundle->intf->disconnected)
287		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
288
289	pm_runtime_put_noidle(dev);
290	pm_runtime_disable(dev);
291	pm_runtime_set_suspended(dev);
292	pm_runtime_dont_use_autosuspend(dev);
293	pm_runtime_put_noidle(dev);
294
295	return 0;
296}
297
298int greybus_register_driver(struct greybus_driver *driver, struct module *owner,
299			    const char *mod_name)
300{
301	int retval;
302
303	if (greybus_disabled())
304		return -ENODEV;
305
306	driver->driver.bus = &greybus_bus_type;
307	driver->driver.name = driver->name;
308	driver->driver.probe = greybus_probe;
309	driver->driver.remove = greybus_remove;
310	driver->driver.owner = owner;
311	driver->driver.mod_name = mod_name;
312
313	retval = driver_register(&driver->driver);
314	if (retval)
315		return retval;
316
317	pr_info("registered new driver %s\n", driver->name);
318	return 0;
319}
320EXPORT_SYMBOL_GPL(greybus_register_driver);
321
322void greybus_deregister_driver(struct greybus_driver *driver)
323{
324	driver_unregister(&driver->driver);
325}
326EXPORT_SYMBOL_GPL(greybus_deregister_driver);
327
328static int __init gb_init(void)
329{
330	int retval;
331
332	if (greybus_disabled())
333		return -ENODEV;
334
335	BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);
336
337	gb_debugfs_init();
338
339	retval = bus_register(&greybus_bus_type);
340	if (retval) {
341		pr_err("bus_register failed (%d)\n", retval);
342		goto error_bus;
343	}
344
345	retval = gb_hd_init();
346	if (retval) {
347		pr_err("gb_hd_init failed (%d)\n", retval);
348		goto error_hd;
349	}
350
351	retval = gb_operation_init();
352	if (retval) {
353		pr_err("gb_operation_init failed (%d)\n", retval);
354		goto error_operation;
355	}
356	return 0;	/* Success */
357
358error_operation:
359	gb_hd_exit();
360error_hd:
361	bus_unregister(&greybus_bus_type);
362error_bus:
363	gb_debugfs_cleanup();
364
365	return retval;
366}
367module_init(gb_init);
368
369static void __exit gb_exit(void)
370{
371	gb_operation_exit();
372	gb_hd_exit();
373	bus_unregister(&greybus_bus_type);
374	gb_debugfs_cleanup();
375	tracepoint_synchronize_unregister();
376}
377module_exit(gb_exit);
378MODULE_LICENSE("GPL v2");
379MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
380