1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for Phoenix RC Flight Controller Adapter
4 *
5 * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
6 */
7
8 #include <linux/cleanup.h>
9 #include <linux/errno.h>
10 #include <linux/input.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/slab.h>
15 #include <linux/uaccess.h>
16
17 #include <linux/usb.h>
18 #include <linux/usb/input.h>
19
20 #define PXRC_VENDOR_ID 0x1781
21 #define PXRC_PRODUCT_ID 0x0898
22
23 struct pxrc {
24 struct input_dev *input;
25 struct usb_interface *intf;
26 struct urb *urb;
27 struct mutex pm_mutex;
28 bool is_open;
29 char phys[64];
30 };
31
pxrc_usb_irq(struct urb * urb)32 static void pxrc_usb_irq(struct urb *urb)
33 {
34 struct pxrc *pxrc = urb->context;
35 u8 *data = urb->transfer_buffer;
36 int error;
37
38 switch (urb->status) {
39 case 0:
40 /* success */
41 break;
42 case -ETIME:
43 /* this urb is timing out */
44 dev_dbg(&pxrc->intf->dev,
45 "%s - urb timed out - was the device unplugged?\n",
46 __func__);
47 return;
48 case -ECONNRESET:
49 case -ENOENT:
50 case -ESHUTDOWN:
51 case -EPIPE:
52 /* this urb is terminated, clean up */
53 dev_dbg(&pxrc->intf->dev, "%s - urb shutting down with status: %d\n",
54 __func__, urb->status);
55 return;
56 default:
57 dev_dbg(&pxrc->intf->dev, "%s - nonzero urb status received: %d\n",
58 __func__, urb->status);
59 goto exit;
60 }
61
62 if (urb->actual_length == 8) {
63 input_report_abs(pxrc->input, ABS_X, data[0]);
64 input_report_abs(pxrc->input, ABS_Y, data[2]);
65 input_report_abs(pxrc->input, ABS_RX, data[3]);
66 input_report_abs(pxrc->input, ABS_RY, data[4]);
67 input_report_abs(pxrc->input, ABS_RUDDER, data[5]);
68 input_report_abs(pxrc->input, ABS_THROTTLE, data[6]);
69 input_report_abs(pxrc->input, ABS_MISC, data[7]);
70
71 input_report_key(pxrc->input, BTN_A, data[1]);
72 }
73
74 exit:
75 /* Resubmit to fetch new fresh URBs */
76 error = usb_submit_urb(urb, GFP_ATOMIC);
77 if (error && error != -EPERM)
78 dev_err(&pxrc->intf->dev,
79 "%s - usb_submit_urb failed with result: %d",
80 __func__, error);
81 }
82
pxrc_open(struct input_dev * input)83 static int pxrc_open(struct input_dev *input)
84 {
85 struct pxrc *pxrc = input_get_drvdata(input);
86 int error;
87
88 guard(mutex)(&pxrc->pm_mutex);
89 error = usb_submit_urb(pxrc->urb, GFP_KERNEL);
90 if (error) {
91 dev_err(&pxrc->intf->dev,
92 "%s - usb_submit_urb failed, error: %d\n",
93 __func__, error);
94 return -EIO;
95 }
96
97 pxrc->is_open = true;
98 return 0;
99 }
100
pxrc_close(struct input_dev * input)101 static void pxrc_close(struct input_dev *input)
102 {
103 struct pxrc *pxrc = input_get_drvdata(input);
104
105 guard(mutex)(&pxrc->pm_mutex);
106 usb_kill_urb(pxrc->urb);
107 pxrc->is_open = false;
108 }
109
pxrc_free_urb(void * _pxrc)110 static void pxrc_free_urb(void *_pxrc)
111 {
112 struct pxrc *pxrc = _pxrc;
113
114 usb_free_urb(pxrc->urb);
115 }
116
pxrc_probe(struct usb_interface * intf,const struct usb_device_id * id)117 static int pxrc_probe(struct usb_interface *intf,
118 const struct usb_device_id *id)
119 {
120 struct usb_device *udev = interface_to_usbdev(intf);
121 struct pxrc *pxrc;
122 struct usb_endpoint_descriptor *epirq;
123 size_t xfer_size;
124 void *xfer_buf;
125 int error;
126
127 /*
128 * Locate the endpoint information. This device only has an
129 * interrupt endpoint.
130 */
131 error = usb_find_common_endpoints(intf->cur_altsetting,
132 NULL, NULL, &epirq, NULL);
133 if (error) {
134 dev_err(&intf->dev, "Could not find endpoint\n");
135 return error;
136 }
137
138 pxrc = devm_kzalloc(&intf->dev, sizeof(*pxrc), GFP_KERNEL);
139 if (!pxrc)
140 return -ENOMEM;
141
142 mutex_init(&pxrc->pm_mutex);
143 pxrc->intf = intf;
144
145 usb_set_intfdata(pxrc->intf, pxrc);
146
147 xfer_size = usb_endpoint_maxp(epirq);
148 xfer_buf = devm_kmalloc(&intf->dev, xfer_size, GFP_KERNEL);
149 if (!xfer_buf)
150 return -ENOMEM;
151
152 pxrc->urb = usb_alloc_urb(0, GFP_KERNEL);
153 if (!pxrc->urb)
154 return -ENOMEM;
155
156 error = devm_add_action_or_reset(&intf->dev, pxrc_free_urb, pxrc);
157 if (error)
158 return error;
159
160 usb_fill_int_urb(pxrc->urb, udev,
161 usb_rcvintpipe(udev, epirq->bEndpointAddress),
162 xfer_buf, xfer_size, pxrc_usb_irq, pxrc, 1);
163
164 pxrc->input = devm_input_allocate_device(&intf->dev);
165 if (!pxrc->input) {
166 dev_err(&intf->dev, "couldn't allocate input device\n");
167 return -ENOMEM;
168 }
169
170 pxrc->input->name = "PXRC Flight Controller Adapter";
171
172 usb_make_path(udev, pxrc->phys, sizeof(pxrc->phys));
173 strlcat(pxrc->phys, "/input0", sizeof(pxrc->phys));
174 pxrc->input->phys = pxrc->phys;
175
176 usb_to_input_id(udev, &pxrc->input->id);
177
178 pxrc->input->open = pxrc_open;
179 pxrc->input->close = pxrc_close;
180
181 input_set_capability(pxrc->input, EV_KEY, BTN_A);
182 input_set_abs_params(pxrc->input, ABS_X, 0, 255, 0, 0);
183 input_set_abs_params(pxrc->input, ABS_Y, 0, 255, 0, 0);
184 input_set_abs_params(pxrc->input, ABS_RX, 0, 255, 0, 0);
185 input_set_abs_params(pxrc->input, ABS_RY, 0, 255, 0, 0);
186 input_set_abs_params(pxrc->input, ABS_RUDDER, 0, 255, 0, 0);
187 input_set_abs_params(pxrc->input, ABS_THROTTLE, 0, 255, 0, 0);
188 input_set_abs_params(pxrc->input, ABS_MISC, 0, 255, 0, 0);
189
190 input_set_drvdata(pxrc->input, pxrc);
191
192 error = input_register_device(pxrc->input);
193 if (error)
194 return error;
195
196 return 0;
197 }
198
pxrc_disconnect(struct usb_interface * intf)199 static void pxrc_disconnect(struct usb_interface *intf)
200 {
201 /* All driver resources are devm-managed. */
202 }
203
pxrc_suspend(struct usb_interface * intf,pm_message_t message)204 static int pxrc_suspend(struct usb_interface *intf, pm_message_t message)
205 {
206 struct pxrc *pxrc = usb_get_intfdata(intf);
207
208 guard(mutex)(&pxrc->pm_mutex);
209 if (pxrc->is_open)
210 usb_kill_urb(pxrc->urb);
211
212 return 0;
213 }
214
pxrc_resume(struct usb_interface * intf)215 static int pxrc_resume(struct usb_interface *intf)
216 {
217 struct pxrc *pxrc = usb_get_intfdata(intf);
218
219 guard(mutex)(&pxrc->pm_mutex);
220 if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
221 return -EIO;
222
223 return 0;
224 }
225
pxrc_pre_reset(struct usb_interface * intf)226 static int pxrc_pre_reset(struct usb_interface *intf)
227 {
228 struct pxrc *pxrc = usb_get_intfdata(intf);
229
230 mutex_lock(&pxrc->pm_mutex);
231 usb_kill_urb(pxrc->urb);
232 return 0;
233 }
234
pxrc_post_reset(struct usb_interface * intf)235 static int pxrc_post_reset(struct usb_interface *intf)
236 {
237 struct pxrc *pxrc = usb_get_intfdata(intf);
238 int retval = 0;
239
240 if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
241 retval = -EIO;
242
243 mutex_unlock(&pxrc->pm_mutex);
244
245 return retval;
246 }
247
pxrc_reset_resume(struct usb_interface * intf)248 static int pxrc_reset_resume(struct usb_interface *intf)
249 {
250 return pxrc_resume(intf);
251 }
252
253 static const struct usb_device_id pxrc_table[] = {
254 { USB_DEVICE(PXRC_VENDOR_ID, PXRC_PRODUCT_ID) },
255 { }
256 };
257 MODULE_DEVICE_TABLE(usb, pxrc_table);
258
259 static struct usb_driver pxrc_driver = {
260 .name = "pxrc",
261 .probe = pxrc_probe,
262 .disconnect = pxrc_disconnect,
263 .id_table = pxrc_table,
264 .suspend = pxrc_suspend,
265 .resume = pxrc_resume,
266 .pre_reset = pxrc_pre_reset,
267 .post_reset = pxrc_post_reset,
268 .reset_resume = pxrc_reset_resume,
269 };
270
271 module_usb_driver(pxrc_driver);
272
273 MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
274 MODULE_DESCRIPTION("PhoenixRC Flight Controller Adapter");
275 MODULE_LICENSE("GPL v2");
276