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8#include <linux/device.h>
9#include <linux/leds.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/slab.h>
13#include <linux/usb.h>
14#include <linux/usb/of.h>
15
16struct usbport_trig_data {
17 struct led_classdev *led_cdev;
18 struct list_head ports;
19 struct notifier_block nb;
20 int count;
21};
22
23struct usbport_trig_port {
24 struct usbport_trig_data *data;
25 struct usb_device *hub;
26 int portnum;
27 char *port_name;
28 bool observed;
29 struct device_attribute attr;
30 struct list_head list;
31};
32
33
34
35
36
37
38
39
40static bool usbport_trig_usb_dev_observed(struct usbport_trig_data *usbport_data,
41 struct usb_device *usb_dev)
42{
43 struct usbport_trig_port *port;
44
45 if (!usb_dev->parent)
46 return false;
47
48 list_for_each_entry(port, &usbport_data->ports, list) {
49 if (usb_dev->parent == port->hub &&
50 usb_dev->portnum == port->portnum)
51 return port->observed;
52 }
53
54 return false;
55}
56
57static int usbport_trig_usb_dev_check(struct usb_device *usb_dev, void *data)
58{
59 struct usbport_trig_data *usbport_data = data;
60
61 if (usbport_trig_usb_dev_observed(usbport_data, usb_dev))
62 usbport_data->count++;
63
64 return 0;
65}
66
67
68
69
70static void usbport_trig_update_count(struct usbport_trig_data *usbport_data)
71{
72 struct led_classdev *led_cdev = usbport_data->led_cdev;
73
74 usbport_data->count = 0;
75 usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check);
76 led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF);
77}
78
79
80
81
82
83static ssize_t usbport_trig_port_show(struct device *dev,
84 struct device_attribute *attr, char *buf)
85{
86 struct usbport_trig_port *port = container_of(attr,
87 struct usbport_trig_port,
88 attr);
89
90 return sprintf(buf, "%d\n", port->observed) + 1;
91}
92
93static ssize_t usbport_trig_port_store(struct device *dev,
94 struct device_attribute *attr,
95 const char *buf, size_t size)
96{
97 struct usbport_trig_port *port = container_of(attr,
98 struct usbport_trig_port,
99 attr);
100
101 if (!strcmp(buf, "0") || !strcmp(buf, "0\n"))
102 port->observed = 0;
103 else if (!strcmp(buf, "1") || !strcmp(buf, "1\n"))
104 port->observed = 1;
105 else
106 return -EINVAL;
107
108 usbport_trig_update_count(port->data);
109
110 return size;
111}
112
113static struct attribute *ports_attrs[] = {
114 NULL,
115};
116static const struct attribute_group ports_group = {
117 .name = "ports",
118 .attrs = ports_attrs,
119};
120
121
122
123
124
125
126
127
128static bool usbport_trig_port_observed(struct usbport_trig_data *usbport_data,
129 struct usb_device *usb_dev, int port1)
130{
131 struct device *dev = usbport_data->led_cdev->dev;
132 struct device_node *led_np = dev->of_node;
133 struct of_phandle_args args;
134 struct device_node *port_np;
135 int count, i;
136
137 if (!led_np)
138 return false;
139
140
141
142
143
144
145 port_np = usb_of_get_device_node(usb_dev, port1);
146 if (!port_np)
147 return false;
148
149 of_node_put(port_np);
150
151
152 count = of_count_phandle_with_args(led_np, "trigger-sources",
153 "#trigger-source-cells");
154 if (count < 0) {
155 dev_warn(dev, "Failed to get trigger sources for %pOF\n",
156 led_np);
157 return false;
158 }
159
160
161 for (i = 0; i < count; i++) {
162 int err;
163
164 err = of_parse_phandle_with_args(led_np, "trigger-sources",
165 "#trigger-source-cells", i,
166 &args);
167 if (err) {
168 dev_err(dev, "Failed to get trigger source phandle at index %d: %d\n",
169 i, err);
170 continue;
171 }
172
173 of_node_put(args.np);
174
175 if (args.np == port_np)
176 return true;
177 }
178
179 return false;
180}
181
182static int usbport_trig_add_port(struct usbport_trig_data *usbport_data,
183 struct usb_device *usb_dev,
184 const char *hub_name, int portnum)
185{
186 struct led_classdev *led_cdev = usbport_data->led_cdev;
187 struct usbport_trig_port *port;
188 size_t len;
189 int err;
190
191 port = kzalloc(sizeof(*port), GFP_KERNEL);
192 if (!port) {
193 err = -ENOMEM;
194 goto err_out;
195 }
196
197 port->data = usbport_data;
198 port->hub = usb_dev;
199 port->portnum = portnum;
200 port->observed = usbport_trig_port_observed(usbport_data, usb_dev,
201 portnum);
202
203 len = strlen(hub_name) + 8;
204 port->port_name = kzalloc(len, GFP_KERNEL);
205 if (!port->port_name) {
206 err = -ENOMEM;
207 goto err_free_port;
208 }
209 snprintf(port->port_name, len, "%s-port%d", hub_name, portnum);
210
211 sysfs_attr_init(&port->attr.attr);
212 port->attr.attr.name = port->port_name;
213 port->attr.attr.mode = S_IRUSR | S_IWUSR;
214 port->attr.show = usbport_trig_port_show;
215 port->attr.store = usbport_trig_port_store;
216
217 err = sysfs_add_file_to_group(&led_cdev->dev->kobj, &port->attr.attr,
218 ports_group.name);
219 if (err)
220 goto err_free_port_name;
221
222 list_add_tail(&port->list, &usbport_data->ports);
223
224 return 0;
225
226err_free_port_name:
227 kfree(port->port_name);
228err_free_port:
229 kfree(port);
230err_out:
231 return err;
232}
233
234static int usbport_trig_add_usb_dev_ports(struct usb_device *usb_dev,
235 void *data)
236{
237 struct usbport_trig_data *usbport_data = data;
238 int i;
239
240 for (i = 1; i <= usb_dev->maxchild; i++)
241 usbport_trig_add_port(usbport_data, usb_dev,
242 dev_name(&usb_dev->dev), i);
243
244 return 0;
245}
246
247static void usbport_trig_remove_port(struct usbport_trig_data *usbport_data,
248 struct usbport_trig_port *port)
249{
250 struct led_classdev *led_cdev = usbport_data->led_cdev;
251
252 list_del(&port->list);
253 sysfs_remove_file_from_group(&led_cdev->dev->kobj, &port->attr.attr,
254 ports_group.name);
255 kfree(port->port_name);
256 kfree(port);
257}
258
259static void usbport_trig_remove_usb_dev_ports(struct usbport_trig_data *usbport_data,
260 struct usb_device *usb_dev)
261{
262 struct usbport_trig_port *port, *tmp;
263
264 list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
265 if (port->hub == usb_dev)
266 usbport_trig_remove_port(usbport_data, port);
267 }
268}
269
270
271
272
273
274static int usbport_trig_notify(struct notifier_block *nb, unsigned long action,
275 void *data)
276{
277 struct usbport_trig_data *usbport_data =
278 container_of(nb, struct usbport_trig_data, nb);
279 struct led_classdev *led_cdev = usbport_data->led_cdev;
280 struct usb_device *usb_dev = data;
281 bool observed;
282
283 observed = usbport_trig_usb_dev_observed(usbport_data, usb_dev);
284
285 switch (action) {
286 case USB_DEVICE_ADD:
287 usbport_trig_add_usb_dev_ports(usb_dev, usbport_data);
288 if (observed && usbport_data->count++ == 0)
289 led_set_brightness(led_cdev, LED_FULL);
290 return NOTIFY_OK;
291 case USB_DEVICE_REMOVE:
292 usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev);
293 if (observed && --usbport_data->count == 0)
294 led_set_brightness(led_cdev, LED_OFF);
295 return NOTIFY_OK;
296 }
297
298 return NOTIFY_DONE;
299}
300
301static void usbport_trig_activate(struct led_classdev *led_cdev)
302{
303 struct usbport_trig_data *usbport_data;
304 int err;
305
306 usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL);
307 if (!usbport_data)
308 return;
309 usbport_data->led_cdev = led_cdev;
310
311
312 INIT_LIST_HEAD(&usbport_data->ports);
313 err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group);
314 if (err)
315 goto err_free;
316 usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports);
317 usbport_trig_update_count(usbport_data);
318
319
320 usbport_data->nb.notifier_call = usbport_trig_notify,
321 led_cdev->trigger_data = usbport_data;
322 usb_register_notify(&usbport_data->nb);
323
324 led_cdev->activated = true;
325 return;
326
327err_free:
328 kfree(usbport_data);
329}
330
331static void usbport_trig_deactivate(struct led_classdev *led_cdev)
332{
333 struct usbport_trig_data *usbport_data = led_cdev->trigger_data;
334 struct usbport_trig_port *port, *tmp;
335
336 if (!led_cdev->activated)
337 return;
338
339 list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) {
340 usbport_trig_remove_port(usbport_data, port);
341 }
342
343 usb_unregister_notify(&usbport_data->nb);
344
345 sysfs_remove_group(&led_cdev->dev->kobj, &ports_group);
346
347 kfree(usbport_data);
348
349 led_cdev->activated = false;
350}
351
352static struct led_trigger usbport_led_trigger = {
353 .name = "usbport",
354 .activate = usbport_trig_activate,
355 .deactivate = usbport_trig_deactivate,
356};
357
358static int __init usbport_trig_init(void)
359{
360 return led_trigger_register(&usbport_led_trigger);
361}
362
363static void __exit usbport_trig_exit(void)
364{
365 led_trigger_unregister(&usbport_led_trigger);
366}
367
368module_init(usbport_trig_init);
369module_exit(usbport_trig_exit);
370
371MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
372MODULE_DESCRIPTION("USB port trigger");
373MODULE_LICENSE("GPL v2");
374
