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
 23struct 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
 32static 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
 74exit:
 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
 83static 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
101static 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
110static void pxrc_free_urb(void *_pxrc)
111{
112	struct pxrc *pxrc = _pxrc;
113
114	usb_free_urb(pxrc->urb);
115}
116
117static 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
199static void pxrc_disconnect(struct usb_interface *intf)
200{
201	/* All driver resources are devm-managed. */
202}
203
204static 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
215static 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
226static 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
235static 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
248static int pxrc_reset_resume(struct usb_interface *intf)
249{
250	return pxrc_resume(intf);
251}
252
253static const struct usb_device_id pxrc_table[] = {
254	{ USB_DEVICE(PXRC_VENDOR_ID, PXRC_PRODUCT_ID) },
255	{ }
256};
257MODULE_DEVICE_TABLE(usb, pxrc_table);
258
259static 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
271module_usb_driver(pxrc_driver);
272
273MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
274MODULE_DESCRIPTION("PhoenixRC Flight Controller Adapter");
275MODULE_LICENSE("GPL v2");