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/kernel.h>
9#include <linux/errno.h>
10#include <linux/slab.h>
11#include <linux/module.h>
12#include <linux/uaccess.h>
13#include <linux/usb.h>
14#include <linux/usb/input.h>
15#include <linux/mutex.h>
16#include <linux/input.h>
17
18#define PXRC_VENDOR_ID		0x1781
19#define PXRC_PRODUCT_ID		0x0898
20
21struct pxrc {
22	struct input_dev	*input;
23	struct usb_interface	*intf;
24	struct urb		*urb;
25	struct mutex		pm_mutex;
26	bool			is_open;
27	char			phys[64];
28};
29
30static void pxrc_usb_irq(struct urb *urb)
31{
32	struct pxrc *pxrc = urb->context;
33	u8 *data = urb->transfer_buffer;
34	int error;
35
36	switch (urb->status) {
37	case 0:
38		/* success */
39		break;
40	case -ETIME:
41		/* this urb is timing out */
42		dev_dbg(&pxrc->intf->dev,
43			"%s - urb timed out - was the device unplugged?\n",
44			__func__);
45		return;
46	case -ECONNRESET:
47	case -ENOENT:
48	case -ESHUTDOWN:
49	case -EPIPE:
50		/* this urb is terminated, clean up */
51		dev_dbg(&pxrc->intf->dev, "%s - urb shutting down with status: %d\n",
52			__func__, urb->status);
53		return;
54	default:
55		dev_dbg(&pxrc->intf->dev, "%s - nonzero urb status received: %d\n",
56			__func__, urb->status);
57		goto exit;
58	}
59
60	if (urb->actual_length == 8) {
61		input_report_abs(pxrc->input, ABS_X, data[0]);
62		input_report_abs(pxrc->input, ABS_Y, data[2]);
63		input_report_abs(pxrc->input, ABS_RX, data[3]);
64		input_report_abs(pxrc->input, ABS_RY, data[4]);
65		input_report_abs(pxrc->input, ABS_RUDDER, data[5]);
66		input_report_abs(pxrc->input, ABS_THROTTLE, data[6]);
67		input_report_abs(pxrc->input, ABS_MISC, data[7]);
68
69		input_report_key(pxrc->input, BTN_A, data[1]);
70	}
71
72exit:
73	/* Resubmit to fetch new fresh URBs */
74	error = usb_submit_urb(urb, GFP_ATOMIC);
75	if (error && error != -EPERM)
76		dev_err(&pxrc->intf->dev,
77			"%s - usb_submit_urb failed with result: %d",
78			__func__, error);
79}
80
81static int pxrc_open(struct input_dev *input)
82{
83	struct pxrc *pxrc = input_get_drvdata(input);
84	int retval;
85
86	mutex_lock(&pxrc->pm_mutex);
87	retval = usb_submit_urb(pxrc->urb, GFP_KERNEL);
88	if (retval) {
89		dev_err(&pxrc->intf->dev,
90			"%s - usb_submit_urb failed, error: %d\n",
91			__func__, retval);
92		retval = -EIO;
93		goto out;
94	}
95
96	pxrc->is_open = true;
97
98out:
99	mutex_unlock(&pxrc->pm_mutex);
100	return retval;
101}
102
103static void pxrc_close(struct input_dev *input)
104{
105	struct pxrc *pxrc = input_get_drvdata(input);
106
107	mutex_lock(&pxrc->pm_mutex);
108	usb_kill_urb(pxrc->urb);
109	pxrc->is_open = false;
110	mutex_unlock(&pxrc->pm_mutex);
111}
112
113static void pxrc_free_urb(void *_pxrc)
114{
115	struct pxrc *pxrc = _pxrc;
116
117	usb_free_urb(pxrc->urb);
118}
119
120static int pxrc_probe(struct usb_interface *intf,
121		      const struct usb_device_id *id)
122{
123	struct usb_device *udev = interface_to_usbdev(intf);
124	struct pxrc *pxrc;
125	struct usb_endpoint_descriptor *epirq;
126	size_t xfer_size;
127	void *xfer_buf;
128	int error;
129
130	/*
131	 * Locate the endpoint information. This device only has an
132	 * interrupt endpoint.
133	 */
134	error = usb_find_common_endpoints(intf->cur_altsetting,
135					  NULL, NULL, &epirq, NULL);
136	if (error) {
137		dev_err(&intf->dev, "Could not find endpoint\n");
138		return error;
139	}
140
141	pxrc = devm_kzalloc(&intf->dev, sizeof(*pxrc), GFP_KERNEL);
142	if (!pxrc)
143		return -ENOMEM;
144
145	mutex_init(&pxrc->pm_mutex);
146	pxrc->intf = intf;
147
148	usb_set_intfdata(pxrc->intf, pxrc);
149
150	xfer_size = usb_endpoint_maxp(epirq);
151	xfer_buf = devm_kmalloc(&intf->dev, xfer_size, GFP_KERNEL);
152	if (!xfer_buf)
153		return -ENOMEM;
154
155	pxrc->urb = usb_alloc_urb(0, GFP_KERNEL);
156	if (!pxrc->urb)
157		return -ENOMEM;
158
159	error = devm_add_action_or_reset(&intf->dev, pxrc_free_urb, pxrc);
160	if (error)
161		return error;
162
163	usb_fill_int_urb(pxrc->urb, udev,
164			 usb_rcvintpipe(udev, epirq->bEndpointAddress),
165			 xfer_buf, xfer_size, pxrc_usb_irq, pxrc, 1);
166
167	pxrc->input = devm_input_allocate_device(&intf->dev);
168	if (!pxrc->input) {
169		dev_err(&intf->dev, "couldn't allocate input device\n");
170		return -ENOMEM;
171	}
172
173	pxrc->input->name = "PXRC Flight Controller Adapter";
174
175	usb_make_path(udev, pxrc->phys, sizeof(pxrc->phys));
176	strlcat(pxrc->phys, "/input0", sizeof(pxrc->phys));
177	pxrc->input->phys = pxrc->phys;
178
179	usb_to_input_id(udev, &pxrc->input->id);
180
181	pxrc->input->open = pxrc_open;
182	pxrc->input->close = pxrc_close;
183
184	input_set_capability(pxrc->input, EV_KEY, BTN_A);
185	input_set_abs_params(pxrc->input, ABS_X, 0, 255, 0, 0);
186	input_set_abs_params(pxrc->input, ABS_Y, 0, 255, 0, 0);
187	input_set_abs_params(pxrc->input, ABS_RX, 0, 255, 0, 0);
188	input_set_abs_params(pxrc->input, ABS_RY, 0, 255, 0, 0);
189	input_set_abs_params(pxrc->input, ABS_RUDDER, 0, 255, 0, 0);
190	input_set_abs_params(pxrc->input, ABS_THROTTLE, 0, 255, 0, 0);
191	input_set_abs_params(pxrc->input, ABS_MISC, 0, 255, 0, 0);
192
193	input_set_drvdata(pxrc->input, pxrc);
194
195	error = input_register_device(pxrc->input);
196	if (error)
197		return error;
198
199	return 0;
200}
201
202static void pxrc_disconnect(struct usb_interface *intf)
203{
204	/* All driver resources are devm-managed. */
205}
206
207static int pxrc_suspend(struct usb_interface *intf, pm_message_t message)
208{
209	struct pxrc *pxrc = usb_get_intfdata(intf);
210
211	mutex_lock(&pxrc->pm_mutex);
212	if (pxrc->is_open)
213		usb_kill_urb(pxrc->urb);
214	mutex_unlock(&pxrc->pm_mutex);
215
216	return 0;
217}
218
219static int pxrc_resume(struct usb_interface *intf)
220{
221	struct pxrc *pxrc = usb_get_intfdata(intf);
222	int retval = 0;
223
224	mutex_lock(&pxrc->pm_mutex);
225	if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
226		retval = -EIO;
227
228	mutex_unlock(&pxrc->pm_mutex);
229	return retval;
230}
231
232static int pxrc_pre_reset(struct usb_interface *intf)
233{
234	struct pxrc *pxrc = usb_get_intfdata(intf);
235
236	mutex_lock(&pxrc->pm_mutex);
237	usb_kill_urb(pxrc->urb);
238	return 0;
239}
240
241static int pxrc_post_reset(struct usb_interface *intf)
242{
243	struct pxrc *pxrc = usb_get_intfdata(intf);
244	int retval = 0;
245
246	if (pxrc->is_open && usb_submit_urb(pxrc->urb, GFP_KERNEL) < 0)
247		retval = -EIO;
248
249	mutex_unlock(&pxrc->pm_mutex);
250
251	return retval;
252}
253
254static int pxrc_reset_resume(struct usb_interface *intf)
255{
256	return pxrc_resume(intf);
257}
258
259static const struct usb_device_id pxrc_table[] = {
260	{ USB_DEVICE(PXRC_VENDOR_ID, PXRC_PRODUCT_ID) },
261	{ }
262};
263MODULE_DEVICE_TABLE(usb, pxrc_table);
264
265static struct usb_driver pxrc_driver = {
266	.name =		"pxrc",
267	.probe =	pxrc_probe,
268	.disconnect =	pxrc_disconnect,
269	.id_table =	pxrc_table,
270	.suspend	= pxrc_suspend,
271	.resume		= pxrc_resume,
272	.pre_reset	= pxrc_pre_reset,
273	.post_reset	= pxrc_post_reset,
274	.reset_resume	= pxrc_reset_resume,
275};
276
277module_usb_driver(pxrc_driver);
278
279MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
280MODULE_DESCRIPTION("PhoenixRC Flight Controller Adapter");
281MODULE_LICENSE("GPL v2");
282