summaryrefslogtreecommitdiff
path: root/drivers/usb/typec/mux.c
blob: 5baf0f416c73c6016080eac0af64715753446ba4 (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
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
// SPDX-License-Identifier: GPL-2.0
/*
 * USB Type-C Multiplexer/DeMultiplexer Switch support
 *
 * Copyright (C) 2018 Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 *         Hans de Goede <hdegoede@redhat.com>
 */

#include <linux/device.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/usb/typec_mux.h>

#include "bus.h"

static int name_match(struct device *dev, const void *name)
{
	return !strcmp((const char *)name, dev_name(dev));
}

static bool dev_name_ends_with(struct device *dev, const char *suffix)
{
	const char *name = dev_name(dev);
	const int name_len = strlen(name);
	const int suffix_len = strlen(suffix);

	if (suffix_len > name_len)
		return false;

	return strcmp(name + (name_len - suffix_len), suffix) == 0;
}

static int switch_fwnode_match(struct device *dev, const void *fwnode)
{
	return dev_fwnode(dev) == fwnode && dev_name_ends_with(dev, "-switch");
}

static void *typec_switch_match(struct device_connection *con, int ep,
				void *data)
{
	struct device *dev;

	if (con->fwnode) {
		if (con->id && !fwnode_property_present(con->fwnode, con->id))
			return NULL;

		dev = class_find_device(&typec_mux_class, NULL, con->fwnode,
					switch_fwnode_match);
	} else {
		dev = class_find_device(&typec_mux_class, NULL,
					con->endpoint[ep], name_match);
	}

	return dev ? to_typec_switch(dev) : ERR_PTR(-EPROBE_DEFER);
}

/**
 * typec_switch_get - Find USB Type-C orientation switch
 * @dev: The caller device
 *
 * Finds a switch linked with @dev. Returns a reference to the switch on
 * success, NULL if no matching connection was found, or
 * ERR_PTR(-EPROBE_DEFER) when a connection was found but the switch
 * has not been enumerated yet.
 */
struct typec_switch *typec_switch_get(struct device *dev)
{
	struct typec_switch *sw;

	sw = device_connection_find_match(dev, "orientation-switch", NULL,
					  typec_switch_match);
	if (!IS_ERR_OR_NULL(sw))
		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));

	return sw;
}
EXPORT_SYMBOL_GPL(typec_switch_get);

/**
 * typec_put_switch - Release USB Type-C orientation switch
 * @sw: USB Type-C orientation switch
 *
 * Decrement reference count for @sw.
 */
void typec_switch_put(struct typec_switch *sw)
{
	if (!IS_ERR_OR_NULL(sw)) {
		module_put(sw->dev.parent->driver->owner);
		put_device(&sw->dev);
	}
}
EXPORT_SYMBOL_GPL(typec_switch_put);

static void typec_switch_release(struct device *dev)
{
	kfree(to_typec_switch(dev));
}

static const struct device_type typec_switch_dev_type = {
	.name = "orientation_switch",
	.release = typec_switch_release,
};

/**
 * typec_switch_register - Register USB Type-C orientation switch
 * @parent: Parent device
 * @desc: Orientation switch description
 *
 * This function registers a switch that can be used for routing the correct
 * data pairs depending on the cable plug orientation from the USB Type-C
 * connector to the USB controllers. USB Type-C plugs can be inserted
 * right-side-up or upside-down.
 */
struct typec_switch *
typec_switch_register(struct device *parent,
		      const struct typec_switch_desc *desc)
{
	struct typec_switch *sw;
	int ret;

	if (!desc || !desc->set)
		return ERR_PTR(-EINVAL);

	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
	if (!sw)
		return ERR_PTR(-ENOMEM);

	sw->set = desc->set;

	device_initialize(&sw->dev);
	sw->dev.parent = parent;
	sw->dev.fwnode = desc->fwnode;
	sw->dev.class = &typec_mux_class;
	sw->dev.type = &typec_switch_dev_type;
	sw->dev.driver_data = desc->drvdata;
	dev_set_name(&sw->dev, "%s-switch", dev_name(parent));

	ret = device_add(&sw->dev);
	if (ret) {
		dev_err(parent, "failed to register switch (%d)\n", ret);
		put_device(&sw->dev);
		return ERR_PTR(ret);
	}

	return sw;
}
EXPORT_SYMBOL_GPL(typec_switch_register);

/**
 * typec_switch_unregister - Unregister USB Type-C orientation switch
 * @sw: USB Type-C orientation switch
 *
 * Unregister switch that was registered with typec_switch_register().
 */
void typec_switch_unregister(struct typec_switch *sw)
{
	if (!IS_ERR_OR_NULL(sw))
		device_unregister(&sw->dev);
}
EXPORT_SYMBOL_GPL(typec_switch_unregister);

void typec_switch_set_drvdata(struct typec_switch *sw, void *data)
{
	dev_set_drvdata(&sw->dev, data);
}
EXPORT_SYMBOL_GPL(typec_switch_set_drvdata);

void *typec_switch_get_drvdata(struct typec_switch *sw)
{
	return dev_get_drvdata(&sw->dev);
}
EXPORT_SYMBOL_GPL(typec_switch_get_drvdata);

/* ------------------------------------------------------------------------- */

static int mux_fwnode_match(struct device *dev, const void *fwnode)
{
	return dev_fwnode(dev) == fwnode && dev_name_ends_with(dev, "-mux");
}

static void *typec_mux_match(struct device_connection *con, int ep, void *data)
{
	const struct typec_altmode_desc *desc = data;
	struct device *dev;
	bool match;
	int nval;
	u16 *val;
	int i;

	if (!con->fwnode) {
		dev = class_find_device(&typec_mux_class, NULL,
					con->endpoint[ep], name_match);

		return dev ? to_typec_switch(dev) : ERR_PTR(-EPROBE_DEFER);
	}

	/*
	 * Check has the identifier already been "consumed". If it
	 * has, no need to do any extra connection identification.
	 */
	match = !con->id;
	if (match)
		goto find_mux;

	/* Accessory Mode muxes */
	if (!desc) {
		match = fwnode_property_present(con->fwnode, "accessory");
		if (match)
			goto find_mux;
		return NULL;
	}

	/* Alternate Mode muxes */
	nval = fwnode_property_count_u16(con->fwnode, "svid");
	if (nval <= 0)
		return NULL;

	val = kcalloc(nval, sizeof(*val), GFP_KERNEL);
	if (!val)
		return ERR_PTR(-ENOMEM);

	nval = fwnode_property_read_u16_array(con->fwnode, "svid", val, nval);
	if (nval < 0) {
		kfree(val);
		return ERR_PTR(nval);
	}

	for (i = 0; i < nval; i++) {
		match = val[i] == desc->svid;
		if (match) {
			kfree(val);
			goto find_mux;
		}
	}
	kfree(val);
	return NULL;

find_mux:
	dev = class_find_device(&typec_mux_class, NULL, con->fwnode,
				mux_fwnode_match);

	return dev ? to_typec_switch(dev) : ERR_PTR(-EPROBE_DEFER);
}

/**
 * typec_mux_get - Find USB Type-C Multiplexer
 * @dev: The caller device
 * @desc: Alt Mode description
 *
 * Finds a mux linked to the caller. This function is primarily meant for the
 * Type-C drivers. Returns a reference to the mux on success, NULL if no
 * matching connection was found, or ERR_PTR(-EPROBE_DEFER) when a connection
 * was found but the mux has not been enumerated yet.
 */
struct typec_mux *typec_mux_get(struct device *dev,
				const struct typec_altmode_desc *desc)
{
	struct typec_mux *mux;

	mux = device_connection_find_match(dev, "mode-switch", (void *)desc,
					   typec_mux_match);
	if (!IS_ERR_OR_NULL(mux))
		WARN_ON(!try_module_get(mux->dev.parent->driver->owner));

	return mux;
}
EXPORT_SYMBOL_GPL(typec_mux_get);

/**
 * typec_mux_put - Release handle to a Multiplexer
 * @mux: USB Type-C Connector Multiplexer/DeMultiplexer
 *
 * Decrements reference count for @mux.
 */
void typec_mux_put(struct typec_mux *mux)
{
	if (!IS_ERR_OR_NULL(mux)) {
		module_put(mux->dev.parent->driver->owner);
		put_device(&mux->dev);
	}
}
EXPORT_SYMBOL_GPL(typec_mux_put);

static void typec_mux_release(struct device *dev)
{
	kfree(to_typec_mux(dev));
}

static const struct device_type typec_mux_dev_type = {
	.name = "mode_switch",
	.release = typec_mux_release,
};

/**
 * typec_mux_register - Register Multiplexer routing USB Type-C pins
 * @parent: Parent device
 * @desc: Multiplexer description
 *
 * USB Type-C connectors can be used for alternate modes of operation besides
 * USB when Accessory/Alternate Modes are supported. With some of those modes,
 * the pins on the connector need to be reconfigured. This function registers
 * multiplexer switches routing the pins on the connector.
 */
struct typec_mux *
typec_mux_register(struct device *parent, const struct typec_mux_desc *desc)
{
	struct typec_mux *mux;
	int ret;

	if (!desc || !desc->set)
		return ERR_PTR(-EINVAL);

	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
	if (!mux)
		return ERR_PTR(-ENOMEM);

	mux->set = desc->set;

	device_initialize(&mux->dev);
	mux->dev.parent = parent;
	mux->dev.fwnode = desc->fwnode;
	mux->dev.class = &typec_mux_class;
	mux->dev.type = &typec_mux_dev_type;
	mux->dev.driver_data = desc->drvdata;
	dev_set_name(&mux->dev, "%s-mux", dev_name(parent));

	ret = device_add(&mux->dev);
	if (ret) {
		dev_err(parent, "failed to register mux (%d)\n", ret);
		put_device(&mux->dev);
		return ERR_PTR(ret);
	}

	return mux;
}
EXPORT_SYMBOL_GPL(typec_mux_register);

/**
 * typec_mux_unregister - Unregister Multiplexer Switch
 * @mux: USB Type-C Connector Multiplexer/DeMultiplexer
 *
 * Unregister mux that was registered with typec_mux_register().
 */
void typec_mux_unregister(struct typec_mux *mux)
{
	if (!IS_ERR_OR_NULL(mux))
		device_unregister(&mux->dev);
}
EXPORT_SYMBOL_GPL(typec_mux_unregister);

void typec_mux_set_drvdata(struct typec_mux *mux, void *data)
{
	dev_set_drvdata(&mux->dev, data);
}
EXPORT_SYMBOL_GPL(typec_mux_set_drvdata);

void *typec_mux_get_drvdata(struct typec_mux *mux)
{
	return dev_get_drvdata(&mux->dev);
}
EXPORT_SYMBOL_GPL(typec_mux_get_drvdata);

struct class typec_mux_class = {
	.name = "typec_mux",
	.owner = THIS_MODULE,
};