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11#include <linux/device.h>
12#include <linux/leds.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/usb.h>
16
17struct usbport_trig_data {
18 struct led_classdev *led_cdev;
19 struct list_head ports;
20 struct notifier_block nb;
21 int count;
22};
23
24struct usbport_trig_port {
25 struct usbport_trig_data *data;
26 struct usb_device *hub;
27 int portnum;
28 char *port_name;
29 bool observed;
30 struct device_attribute attr;
31 struct list_head list;
32};
33
34
35
36
37
38
39
40
41static bool usbport_trig_usb_dev_observed(struct usbport_trig_data *usbport_data,
42 struct usb_device *usb_dev)
43{
44 struct usbport_trig_port *port;
45
46 if (!usb_dev->parent)
47 return false;
48
49 list_for_each_entry(port, &usbport_data->ports, list) {
50 if (usb_dev->parent == port->hub &&
51 usb_dev->portnum == port->portnum)
52 return port->observed;
53 }
54
55 return false;
56}
57
58static int usbport_trig_usb_dev_check(struct usb_device *usb_dev, void *data)
59{
60 struct usbport_trig_data *usbport_data = data;
61
62 if (usbport_trig_usb_dev_observed(usbport_data, usb_dev))
63 usbport_data->count++;
64
65 return 0;
66}
67
68
69
70
71static void usbport_trig_update_count(struct usbport_trig_data *usbport_data)
72{
73 struct led_classdev *led_cdev = usbport_data->led_cdev;
74
75 usbport_data->count = 0;
76 usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check);
77 led_cdev->brightness_set(led_cdev,
78 usbport_data->count ? LED_FULL : LED_OFF);
79}
80
81
82
83
84
85static ssize_t usbport_trig_port_show(struct device *dev,
86 struct device_attribute *attr, char *buf)
87{
88 struct usbport_trig_port *port = container_of(attr,
89 struct usbport_trig_port,
90 attr);
91
92 return sprintf(buf, "%d\n", port->observed) + 1;
93}
94
95static ssize_t usbport_trig_port_store(struct device *dev,
96 struct device_attribute *attr,
97 const char *buf, size_t size)
98{
99 struct usbport_trig_port *port = container_of(attr,
100 struct usbport_trig_port,
101 attr);
102
103 if (!strcmp(buf, "0") || !strcmp(buf, "0\n"))
104 port->observed = 0;
105 else if (!strcmp(buf, "1") || !strcmp(buf, "1\n"))
106 port->observed = 1;
107 else
108 return -EINVAL;
109
110 usbport_trig_update_count(port->data);
111
112 return size;
113}
114
115static struct attribute *ports_attrs[] = {
116 NULL,
117};
118static const struct attribute_group ports_group = {
119 .name = "ports",
120 .attrs = ports_attrs,
121};
122
123
124
125
126
127static int usbport_trig_add_port(struct usbport_trig_data *usbport_data,
128 struct usb_device *usb_dev,
129 const char *hub_name, int portnum)
130{
131 struct led_classdev *led_cdev = usbport_data->led_cdev;
132 struct usbport_trig_port *port;
133 size_t len;
134 int err;
135
136 port = kzalloc(sizeof(*port), GFP_KERNEL);
137 if (!port) {
138 err = -ENOMEM;
139 goto err_out;
140 }
141
142 port->data = usbport_data;
143 port->hub = usb_dev;
144 port->portnum = portnum;
145
146 len = strlen(hub_name) + 8;
147 port->port_name = kzalloc(len, GFP_KERNEL);
148 if (!port->port_name) {
149 err = -ENOMEM;
150 goto err_free_port;
151 }
152 snprintf(port->port_name, len, "%s-port%d", hub_name, portnum);
153
154 port->attr.attr.name = port->port_name;
155 port->attr.attr.mode = S_IRUSR | S_IWUSR;
156 port->attr.show = usbport_trig_port_show;
157 port->attr.store = usbport_trig_port_store;
158
159 err = sysfs_add_file_to_group(&led_cdev->dev->kobj, &port->attr.attr,
160 ports_group.name);
161 if (err)
162 goto err_free_port_name;
163
164 list_add_tail(&port->list, &usbport_data->ports);
165
166 return 0;
167
168err_free_port_name:
169 kfree(port->port_name);
170err_free_port:
171 kfree(port);
172err_out:
173 return err;
174}
175
176static int usbport_trig_add_usb_dev_ports(struct usb_device *usb_dev,
177 void *data)
178{
179 struct usbport_trig_data *usbport_data = data;
180 int i;
181
182 for (i = 1; i <= usb_dev->maxchild; i++)
183 usbport_trig_add_port(usbport_data, usb_dev,
184 dev_name(&usb_dev->dev), i);
185
186 return 0;
187}
188
189static void usbport_trig_remove_port(struct usbport_trig_data *usbport_data,
190 struct usbport_trig_port *port)
191{
192 struct led_classdev *led_cdev = usbport_data->led_cdev;
193
194 list_del(&port->list);
195 sysfs_remove_file_from_group(&led_cdev->dev->kobj, &port->attr.attr,
196 ports_group.name);
197 kfree(port->port_name);
198 kfree(port);
199}
200
201static void usbport_trig_remove_usb_dev_ports(struct usbport_trig_data *usbport_data,
202 struct usb_device *usb_dev)
203{
204 struct usbport_trig_port *port, *tmp;
205
206 list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
207 if (port->hub == usb_dev)
208 usbport_trig_remove_port(usbport_data, port);
209 }
210}
211
212
213
214
215
216static int usbport_trig_notify(struct notifier_block *nb, unsigned long action,
217 void *data)
218{
219 struct usbport_trig_data *usbport_data =
220 container_of(nb, struct usbport_trig_data, nb);
221 struct led_classdev *led_cdev = usbport_data->led_cdev;
222 struct usb_device *usb_dev = data;
223 bool observed;
224
225 observed = usbport_trig_usb_dev_observed(usbport_data, usb_dev);
226
227 switch (action) {
228 case USB_DEVICE_ADD:
229 usbport_trig_add_usb_dev_ports(usb_dev, usbport_data);
230 if (observed && usbport_data->count++ == 0)
231 led_cdev->brightness_set(led_cdev, LED_FULL);
232 return NOTIFY_OK;
233 case USB_DEVICE_REMOVE:
234 usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev);
235 if (observed && --usbport_data->count == 0)
236 led_cdev->brightness_set(led_cdev, LED_OFF);
237 return NOTIFY_OK;
238 }
239
240 return NOTIFY_DONE;
241}
242
243static void usbport_trig_activate(struct led_classdev *led_cdev)
244{
245 struct usbport_trig_data *usbport_data;
246 int err;
247
248 usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL);
249 if (!usbport_data)
250 return;
251 usbport_data->led_cdev = led_cdev;
252
253
254 INIT_LIST_HEAD(&usbport_data->ports);
255 err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group);
256 if (err)
257 goto err_free;
258 usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports);
259
260
261 usbport_data->nb.notifier_call = usbport_trig_notify,
262 led_cdev->trigger_data = usbport_data;
263 usb_register_notify(&usbport_data->nb);
264
265 led_cdev->activated = true;
266 return;
267
268err_free:
269 kfree(usbport_data);
270}
271
272static void usbport_trig_deactivate(struct led_classdev *led_cdev)
273{
274 struct usbport_trig_data *usbport_data = led_cdev->trigger_data;
275 struct usbport_trig_port *port, *tmp;
276
277 if (!led_cdev->activated)
278 return;
279
280 list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
281 usbport_trig_remove_port(usbport_data, port);
282 }
283
284 usb_unregister_notify(&usbport_data->nb);
285
286 sysfs_remove_group(&led_cdev->dev->kobj, &ports_group);
287
288 kfree(usbport_data);
289
290 led_cdev->activated = false;
291}
292
293static struct led_trigger usbport_led_trigger = {
294 .name = "usbport",
295 .activate = usbport_trig_activate,
296 .deactivate = usbport_trig_deactivate,
297};
298
299static int __init usbport_trig_init(void)
300{
301 return led_trigger_register(&usbport_led_trigger);
302}
303
304static void __exit usbport_trig_exit(void)
305{
306 led_trigger_unregister(&usbport_led_trigger);
307}
308
309module_init(usbport_trig_init);
310module_exit(usbport_trig_exit);
311
312MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
313MODULE_DESCRIPTION("USB port trigger");
314MODULE_LICENSE("GPL v2");
315
