summaryrefslogtreecommitdiff
path: root/drivers/usb/core/ledtrig-usbport.c
blob: 9dbb429cd471abf89da60fc0fa8cd854a842de59 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * USB port LED trigger
 *
 * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl>
 */

#include <linux/device.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/of.h>

struct usbport_trig_data {
	struct led_classdev *led_cdev;
	struct list_head ports;
	struct notifier_block nb;
	int count; /* Amount of connected matching devices */
};

struct usbport_trig_port {
	struct usbport_trig_data *data;
	struct usb_device *hub;
	int portnum;
	char *port_name;
	bool observed;
	struct device_attribute attr;
	struct list_head list;
};

/***************************************
 * Helpers
 ***************************************/

/**
 * usbport_trig_usb_dev_observed - Check if dev is connected to observed port
 */
static bool usbport_trig_usb_dev_observed(struct usbport_trig_data *usbport_data,
					  struct usb_device *usb_dev)
{
	struct usbport_trig_port *port;

	if (!usb_dev->parent)
		return false;

	list_for_each_entry(port, &usbport_data->ports, list) {
		if (usb_dev->parent == port->hub &&
		    usb_dev->portnum == port->portnum)
			return port->observed;
	}

	return false;
}

static int usbport_trig_usb_dev_check(struct usb_device *usb_dev, void *data)
{
	struct usbport_trig_data *usbport_data = data;

	if (usbport_trig_usb_dev_observed(usbport_data, usb_dev))
		usbport_data->count++;

	return 0;
}

/**
 * usbport_trig_update_count - Recalculate amount of connected matching devices
 */
static void usbport_trig_update_count(struct usbport_trig_data *usbport_data)
{
	struct led_classdev *led_cdev = usbport_data->led_cdev;

	usbport_data->count = 0;
	usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check);
	led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF);
}

/***************************************
 * Device attr
 ***************************************/

static ssize_t usbport_trig_port_show(struct device *dev,
				      struct device_attribute *attr, char *buf)
{
	struct usbport_trig_port *port = container_of(attr,
						      struct usbport_trig_port,
						      attr);

	return sprintf(buf, "%d\n", port->observed) + 1;
}

static ssize_t usbport_trig_port_store(struct device *dev,
				       struct device_attribute *attr,
				       const char *buf, size_t size)
{
	struct usbport_trig_port *port = container_of(attr,
						      struct usbport_trig_port,
						      attr);

	if (!strcmp(buf, "0") || !strcmp(buf, "0\n"))
		port->observed = 0;
	else if (!strcmp(buf, "1") || !strcmp(buf, "1\n"))
		port->observed = 1;
	else
		return -EINVAL;

	usbport_trig_update_count(port->data);

	return size;
}

static struct attribute *ports_attrs[] = {
	NULL,
};
static const struct attribute_group ports_group = {
	.name = "ports",
	.attrs = ports_attrs,
};

/***************************************
 * Adding & removing ports
 ***************************************/

/**
 * usbport_trig_port_observed - Check if port should be observed
 */
static bool usbport_trig_port_observed(struct usbport_trig_data *usbport_data,
				       struct usb_device *usb_dev, int port1)
{
	struct device *dev = usbport_data->led_cdev->dev;
	struct device_node *led_np = dev->of_node;
	struct of_phandle_args args;
	struct device_node *port_np;
	int count, i;

	if (!led_np)
		return false;

	/* Get node of port being added */
	port_np = usb_of_get_child_node(usb_dev->dev.of_node, port1);
	if (!port_np)
		return false;

	/* Amount of trigger sources for this LED */
	count = of_count_phandle_with_args(led_np, "trigger-sources",
					   "#trigger-source-cells");
	if (count < 0) {
		dev_warn(dev, "Failed to get trigger sources for %pOF\n",
			 led_np);
		return false;
	}

	/* Check list of sources for this specific port */
	for (i = 0; i < count; i++) {
		int err;

		err = of_parse_phandle_with_args(led_np, "trigger-sources",
						 "#trigger-source-cells", i,
						 &args);
		if (err) {
			dev_err(dev, "Failed to get trigger source phandle at index %d: %d\n",
				i, err);
			continue;
		}

		of_node_put(args.np);

		if (args.np == port_np)
			return true;
	}

	return false;
}

static int usbport_trig_add_port(struct usbport_trig_data *usbport_data,
				 struct usb_device *usb_dev,
				 const char *hub_name, int portnum)
{
	struct led_classdev *led_cdev = usbport_data->led_cdev;
	struct usbport_trig_port *port;
	size_t len;
	int err;

	port = kzalloc(sizeof(*port), GFP_KERNEL);
	if (!port) {
		err = -ENOMEM;
		goto err_out;
	}

	port->data = usbport_data;
	port->hub = usb_dev;
	port->portnum = portnum;
	port->observed = usbport_trig_port_observed(usbport_data, usb_dev,
						    portnum);

	len = strlen(hub_name) + 8;
	port->port_name = kzalloc(len, GFP_KERNEL);
	if (!port->port_name) {
		err = -ENOMEM;
		goto err_free_port;
	}
	snprintf(port->port_name, len, "%s-port%d", hub_name, portnum);

	sysfs_attr_init(&port->attr.attr);
	port->attr.attr.name = port->port_name;
	port->attr.attr.mode = S_IRUSR | S_IWUSR;
	port->attr.show = usbport_trig_port_show;
	port->attr.store = usbport_trig_port_store;

	err = sysfs_add_file_to_group(&led_cdev->dev->kobj, &port->attr.attr,
				      ports_group.name);
	if (err)
		goto err_free_port_name;

	list_add_tail(&port->list, &usbport_data->ports);

	return 0;

err_free_port_name:
	kfree(port->port_name);
err_free_port:
	kfree(port);
err_out:
	return err;
}

static int usbport_trig_add_usb_dev_ports(struct usb_device *usb_dev,
					  void *data)
{
	struct usbport_trig_data *usbport_data = data;
	int i;

	for (i = 1; i <= usb_dev->maxchild; i++)
		usbport_trig_add_port(usbport_data, usb_dev,
				      dev_name(&usb_dev->dev), i);

	return 0;
}

static void usbport_trig_remove_port(struct usbport_trig_data *usbport_data,
				     struct usbport_trig_port *port)
{
	struct led_classdev *led_cdev = usbport_data->led_cdev;

	list_del(&port->list);
	sysfs_remove_file_from_group(&led_cdev->dev->kobj, &port->attr.attr,
				     ports_group.name);
	kfree(port->port_name);
	kfree(port);
}

static void usbport_trig_remove_usb_dev_ports(struct usbport_trig_data *usbport_data,
					      struct usb_device *usb_dev)
{
	struct usbport_trig_port *port, *tmp;

	list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
		if (port->hub == usb_dev)
			usbport_trig_remove_port(usbport_data, port);
	}
}

/***************************************
 * Init, exit, etc.
 ***************************************/

static int usbport_trig_notify(struct notifier_block *nb, unsigned long action,
			       void *data)
{
	struct usbport_trig_data *usbport_data =
		container_of(nb, struct usbport_trig_data, nb);
	struct led_classdev *led_cdev = usbport_data->led_cdev;
	struct usb_device *usb_dev = data;
	bool observed;

	observed = usbport_trig_usb_dev_observed(usbport_data, usb_dev);

	switch (action) {
	case USB_DEVICE_ADD:
		usbport_trig_add_usb_dev_ports(usb_dev, usbport_data);
		if (observed && usbport_data->count++ == 0)
			led_set_brightness(led_cdev, LED_FULL);
		return NOTIFY_OK;
	case USB_DEVICE_REMOVE:
		usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev);
		if (observed && --usbport_data->count == 0)
			led_set_brightness(led_cdev, LED_OFF);
		return NOTIFY_OK;
	}

	return NOTIFY_DONE;
}

static void usbport_trig_activate(struct led_classdev *led_cdev)
{
	struct usbport_trig_data *usbport_data;
	int err;

	usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL);
	if (!usbport_data)
		return;
	usbport_data->led_cdev = led_cdev;

	/* List of ports */
	INIT_LIST_HEAD(&usbport_data->ports);
	err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group);
	if (err)
		goto err_free;
	usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports);
	usbport_trig_update_count(usbport_data);

	/* Notifications */
	usbport_data->nb.notifier_call = usbport_trig_notify,
	led_cdev->trigger_data = usbport_data;
	usb_register_notify(&usbport_data->nb);

	led_cdev->activated = true;
	return;

err_free:
	kfree(usbport_data);
}

static void usbport_trig_deactivate(struct led_classdev *led_cdev)
{
	struct usbport_trig_data *usbport_data = led_cdev->trigger_data;
	struct usbport_trig_port *port, *tmp;

	if (!led_cdev->activated)
		return;

	list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
		usbport_trig_remove_port(usbport_data, port);
	}

	usb_unregister_notify(&usbport_data->nb);

	sysfs_remove_group(&led_cdev->dev->kobj, &ports_group);

	kfree(usbport_data);

	led_cdev->activated = false;
}

static struct led_trigger usbport_led_trigger = {
	.name     = "usbport",
	.activate = usbport_trig_activate,
	.deactivate = usbport_trig_deactivate,
};

static int __init usbport_trig_init(void)
{
	return led_trigger_register(&usbport_led_trigger);
}

static void __exit usbport_trig_exit(void)
{
	led_trigger_unregister(&usbport_led_trigger);
}

module_init(usbport_trig_init);
module_exit(usbport_trig_exit);

MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
MODULE_DESCRIPTION("USB port trigger");
MODULE_LICENSE("GPL v2");