summaryrefslogtreecommitdiff
path: root/drivers/greybus/core.c
blob: 5714be7404707b767da8d7dc7b6ad19a57769410 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
// SPDX-License-Identifier: GPL-2.0
/*
 * Greybus "Core"
 *
 * Copyright 2014-2015 Google Inc.
 * Copyright 2014-2015 Linaro Ltd.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define CREATE_TRACE_POINTS
#include <linux/greybus.h>
#include "greybus_trace.h"

#define GB_BUNDLE_AUTOSUSPEND_MS	3000

/* Allow greybus to be disabled at boot if needed */
static bool nogreybus;
#ifdef MODULE
module_param(nogreybus, bool, 0444);
#else
core_param(nogreybus, nogreybus, bool, 0444);
#endif
int greybus_disabled(void)
{
	return nogreybus;
}
EXPORT_SYMBOL_GPL(greybus_disabled);

static bool greybus_match_one_id(struct gb_bundle *bundle,
				 const struct greybus_bundle_id *id)
{
	if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
	    (id->vendor != bundle->intf->vendor_id))
		return false;

	if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
	    (id->product != bundle->intf->product_id))
		return false;

	if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
	    (id->class != bundle->class))
		return false;

	return true;
}

static const struct greybus_bundle_id *
greybus_match_id(struct gb_bundle *bundle, const struct greybus_bundle_id *id)
{
	if (!id)
		return NULL;

	for (; id->vendor || id->product || id->class || id->driver_info;
									id++) {
		if (greybus_match_one_id(bundle, id))
			return id;
	}

	return NULL;
}

static int greybus_match_device(struct device *dev, struct device_driver *drv)
{
	struct greybus_driver *driver = to_greybus_driver(drv);
	struct gb_bundle *bundle;
	const struct greybus_bundle_id *id;

	if (!is_gb_bundle(dev))
		return 0;

	bundle = to_gb_bundle(dev);

	id = greybus_match_id(bundle, driver->id_table);
	if (id)
		return 1;
	/* FIXME - Dynamic ids? */
	return 0;
}

static int greybus_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
	const struct gb_host_device *hd;
	const struct gb_module *module = NULL;
	const struct gb_interface *intf = NULL;
	const struct gb_control *control = NULL;
	const struct gb_bundle *bundle = NULL;
	const struct gb_svc *svc = NULL;

	if (is_gb_host_device(dev)) {
		hd = to_gb_host_device(dev);
	} else if (is_gb_module(dev)) {
		module = to_gb_module(dev);
		hd = module->hd;
	} else if (is_gb_interface(dev)) {
		intf = to_gb_interface(dev);
		module = intf->module;
		hd = intf->hd;
	} else if (is_gb_control(dev)) {
		control = to_gb_control(dev);
		intf = control->intf;
		module = intf->module;
		hd = intf->hd;
	} else if (is_gb_bundle(dev)) {
		bundle = to_gb_bundle(dev);
		intf = bundle->intf;
		module = intf->module;
		hd = intf->hd;
	} else if (is_gb_svc(dev)) {
		svc = to_gb_svc(dev);
		hd = svc->hd;
	} else {
		dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
		return -EINVAL;
	}

	if (add_uevent_var(env, "BUS=%u", hd->bus_id))
		return -ENOMEM;

	if (module) {
		if (add_uevent_var(env, "MODULE=%u", module->module_id))
			return -ENOMEM;
	}

	if (intf) {
		if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
			return -ENOMEM;
		if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
				   intf->vendor_id, intf->product_id))
			return -ENOMEM;
	}

	if (bundle) {
		// FIXME
		// add a uevent that can "load" a bundle type
		// This is what we need to bind a driver to so use the info
		// in gmod here as well

		if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
			return -ENOMEM;
		if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
			return -ENOMEM;
	}

	return 0;
}

static void greybus_shutdown(struct device *dev)
{
	if (is_gb_host_device(dev)) {
		struct gb_host_device *hd;

		hd = to_gb_host_device(dev);
		gb_hd_shutdown(hd);
	}
}

struct bus_type greybus_bus_type = {
	.name =		"greybus",
	.match =	greybus_match_device,
	.uevent =	greybus_uevent,
	.shutdown =	greybus_shutdown,
};

static int greybus_probe(struct device *dev)
{
	struct greybus_driver *driver = to_greybus_driver(dev->driver);
	struct gb_bundle *bundle = to_gb_bundle(dev);
	const struct greybus_bundle_id *id;
	int retval;

	/* match id */
	id = greybus_match_id(bundle, driver->id_table);
	if (!id)
		return -ENODEV;

	retval = pm_runtime_get_sync(&bundle->intf->dev);
	if (retval < 0) {
		pm_runtime_put_noidle(&bundle->intf->dev);
		return retval;
	}

	retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
	if (retval) {
		pm_runtime_put(&bundle->intf->dev);
		return retval;
	}

	/*
	 * Unbound bundle devices are always deactivated. During probe, the
	 * Runtime PM is set to enabled and active and the usage count is
	 * incremented. If the driver supports runtime PM, it should call
	 * pm_runtime_put() in its probe routine and pm_runtime_get_sync()
	 * in remove routine.
	 */
	pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	retval = driver->probe(bundle, id);
	if (retval) {
		/*
		 * Catch buggy drivers that fail to destroy their connections.
		 */
		WARN_ON(!list_empty(&bundle->connections));

		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

		pm_runtime_disable(dev);
		pm_runtime_set_suspended(dev);
		pm_runtime_put_noidle(dev);
		pm_runtime_dont_use_autosuspend(dev);
		pm_runtime_put(&bundle->intf->dev);

		return retval;
	}

	pm_runtime_put(&bundle->intf->dev);

	return 0;
}

static int greybus_remove(struct device *dev)
{
	struct greybus_driver *driver = to_greybus_driver(dev->driver);
	struct gb_bundle *bundle = to_gb_bundle(dev);
	struct gb_connection *connection;
	int retval;

	retval = pm_runtime_get_sync(dev);
	if (retval < 0)
		dev_err(dev, "failed to resume bundle: %d\n", retval);

	/*
	 * Disable (non-offloaded) connections early in case the interface is
	 * already gone to avoid unceccessary operation timeouts during
	 * driver disconnect. Otherwise, only disable incoming requests.
	 */
	list_for_each_entry(connection, &bundle->connections, bundle_links) {
		if (gb_connection_is_offloaded(connection))
			continue;

		if (bundle->intf->disconnected)
			gb_connection_disable_forced(connection);
		else
			gb_connection_disable_rx(connection);
	}

	driver->disconnect(bundle);

	/* Catch buggy drivers that fail to destroy their connections. */
	WARN_ON(!list_empty(&bundle->connections));

	if (!bundle->intf->disconnected)
		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

	pm_runtime_put_noidle(dev);
	pm_runtime_disable(dev);
	pm_runtime_set_suspended(dev);
	pm_runtime_dont_use_autosuspend(dev);
	pm_runtime_put_noidle(dev);

	return 0;
}

int greybus_register_driver(struct greybus_driver *driver, struct module *owner,
			    const char *mod_name)
{
	int retval;

	if (greybus_disabled())
		return -ENODEV;

	driver->driver.bus = &greybus_bus_type;
	driver->driver.name = driver->name;
	driver->driver.probe = greybus_probe;
	driver->driver.remove = greybus_remove;
	driver->driver.owner = owner;
	driver->driver.mod_name = mod_name;

	retval = driver_register(&driver->driver);
	if (retval)
		return retval;

	pr_info("registered new driver %s\n", driver->name);
	return 0;
}
EXPORT_SYMBOL_GPL(greybus_register_driver);

void greybus_deregister_driver(struct greybus_driver *driver)
{
	driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(greybus_deregister_driver);

static int __init gb_init(void)
{
	int retval;

	if (greybus_disabled())
		return -ENODEV;

	BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);

	gb_debugfs_init();

	retval = bus_register(&greybus_bus_type);
	if (retval) {
		pr_err("bus_register failed (%d)\n", retval);
		goto error_bus;
	}

	retval = gb_hd_init();
	if (retval) {
		pr_err("gb_hd_init failed (%d)\n", retval);
		goto error_hd;
	}

	retval = gb_operation_init();
	if (retval) {
		pr_err("gb_operation_init failed (%d)\n", retval);
		goto error_operation;
	}
	return 0;	/* Success */

error_operation:
	gb_hd_exit();
error_hd:
	bus_unregister(&greybus_bus_type);
error_bus:
	gb_debugfs_cleanup();

	return retval;
}
module_init(gb_init);

static void __exit gb_exit(void)
{
	gb_operation_exit();
	gb_hd_exit();
	bus_unregister(&greybus_bus_type);
	gb_debugfs_cleanup();
	tracepoint_synchronize_unregister();
}
module_exit(gb_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");