1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Pegasus Mobile Notetaker Pen input tablet driver
4  *
5  * Copyright (c) 2016 Martin Kepplinger <martink@posteo.de>
6  */
7 
8 /*
9  * request packet (control endpoint):
10  * |-------------------------------------|
11  * | Report ID | Nr of bytes | command   |
12  * | (1 byte)  | (1 byte)    | (n bytes) |
13  * |-------------------------------------|
14  * | 0x02      | n           |           |
15  * |-------------------------------------|
16  *
17  * data packet after set xy mode command, 0x80 0xb5 0x02 0x01
18  * and pen is in range:
19  *
20  * byte	byte name		value (bits)
21  * --------------------------------------------
22  * 0	status			0 1 0 0 0 0 X X
23  * 1	color			0 0 0 0 H 0 S T
24  * 2	X low
25  * 3	X high
26  * 4	Y low
27  * 5	Y high
28  *
29  * X X	battery state:
30  *	no state reported	0x00
31  *	battery low		0x01
32  *	battery good		0x02
33  *
34  * H	Hovering
35  * S	Switch 1 (pen button)
36  * T	Tip
37  */
38 
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/input.h>
42 #include <linux/usb/input.h>
43 #include <linux/slab.h>
44 #include <linux/workqueue.h>
45 #include <linux/mutex.h>
46 
47 /* USB HID defines */
48 #define USB_REQ_GET_REPORT		0x01
49 #define USB_REQ_SET_REPORT		0x09
50 
51 #define USB_VENDOR_ID_PEGASUSTECH	0x0e20
52 #define USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100	0x0101
53 
54 /* device specific defines */
55 #define NOTETAKER_REPORT_ID		0x02
56 #define NOTETAKER_SET_CMD		0x80
57 #define NOTETAKER_SET_MODE		0xb5
58 
59 #define NOTETAKER_LED_MOUSE		0x02
60 #define PEN_MODE_XY			0x01
61 
62 #define SPECIAL_COMMAND			0x80
63 #define BUTTON_PRESSED			0xb5
64 #define COMMAND_VERSION			0xa9
65 
66 /* in xy data packet */
67 #define BATTERY_NO_REPORT		0x40
68 #define BATTERY_LOW			0x41
69 #define BATTERY_GOOD			0x42
70 #define PEN_BUTTON_PRESSED		BIT(1)
71 #define PEN_TIP				BIT(0)
72 
73 struct pegasus {
74 	unsigned char *data;
75 	u8 data_len;
76 	dma_addr_t data_dma;
77 	struct input_dev *dev;
78 	struct usb_device *usbdev;
79 	struct usb_interface *intf;
80 	struct urb *irq;
81 
82 	/* serialize access to open/suspend */
83 	struct mutex pm_mutex;
84 	bool is_open;
85 
86 	char name[128];
87 	char phys[64];
88 	struct work_struct init;
89 };
90 
91 static int pegasus_control_msg(struct pegasus *pegasus, u8 *data, int len)
92 {
93 	const int sizeof_buf = len + 2;
94 	int result;
95 	int error;
96 	u8 *cmd_buf;
97 
98 	cmd_buf = kmalloc(sizeof_buf, GFP_KERNEL);
99 	if (!cmd_buf)
100 		return -ENOMEM;
101 
102 	cmd_buf[0] = NOTETAKER_REPORT_ID;
103 	cmd_buf[1] = len;
104 	memcpy(cmd_buf + 2, data, len);
105 
106 	result = usb_control_msg(pegasus->usbdev,
107 				 usb_sndctrlpipe(pegasus->usbdev, 0),
108 				 USB_REQ_SET_REPORT,
109 				 USB_TYPE_VENDOR | USB_DIR_OUT,
110 				 0, 0, cmd_buf, sizeof_buf,
111 				 USB_CTRL_SET_TIMEOUT);
112 
113 	kfree(cmd_buf);
114 
115 	if (unlikely(result != sizeof_buf)) {
116 		error = result < 0 ? result : -EIO;
117 		dev_err(&pegasus->usbdev->dev, "control msg error: %d\n",
118 			error);
119 		return error;
120 	}
121 
122 	return 0;
123 }
124 
125 static int pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
126 {
127 	u8 cmd[] = { NOTETAKER_SET_CMD, NOTETAKER_SET_MODE, led, mode };
128 
129 	return pegasus_control_msg(pegasus, cmd, sizeof(cmd));
130 }
131 
132 static void pegasus_parse_packet(struct pegasus *pegasus)
133 {
134 	unsigned char *data = pegasus->data;
135 	struct input_dev *dev = pegasus->dev;
136 	u16 x, y;
137 
138 	switch (data[0]) {
139 	case SPECIAL_COMMAND:
140 		/* device button pressed */
141 		if (data[1] == BUTTON_PRESSED)
142 			schedule_work(&pegasus->init);
143 
144 		break;
145 
146 	/* xy data */
147 	case BATTERY_LOW:
148 		dev_warn_once(&dev->dev, "Pen battery low\n");
149 		fallthrough;
150 
151 	case BATTERY_NO_REPORT:
152 	case BATTERY_GOOD:
153 		x = le16_to_cpup((__le16 *)&data[2]);
154 		y = le16_to_cpup((__le16 *)&data[4]);
155 
156 		/* pen-up event */
157 		if (x == 0 && y == 0)
158 			break;
159 
160 		input_report_key(dev, BTN_TOUCH, data[1] & PEN_TIP);
161 		input_report_key(dev, BTN_RIGHT, data[1] & PEN_BUTTON_PRESSED);
162 		input_report_key(dev, BTN_TOOL_PEN, 1);
163 		input_report_abs(dev, ABS_X, (s16)x);
164 		input_report_abs(dev, ABS_Y, y);
165 
166 		input_sync(dev);
167 		break;
168 
169 	default:
170 		dev_warn_once(&pegasus->usbdev->dev,
171 			      "unknown answer from device\n");
172 	}
173 }
174 
175 static void pegasus_irq(struct urb *urb)
176 {
177 	struct pegasus *pegasus = urb->context;
178 	struct usb_device *dev = pegasus->usbdev;
179 	int retval;
180 
181 	switch (urb->status) {
182 	case 0:
183 		pegasus_parse_packet(pegasus);
184 		usb_mark_last_busy(pegasus->usbdev);
185 		break;
186 
187 	case -ECONNRESET:
188 	case -ENOENT:
189 	case -ESHUTDOWN:
190 		dev_err(&dev->dev, "%s - urb shutting down with status: %d",
191 			__func__, urb->status);
192 		return;
193 
194 	default:
195 		dev_err(&dev->dev, "%s - nonzero urb status received: %d",
196 			__func__, urb->status);
197 		break;
198 	}
199 
200 	retval = usb_submit_urb(urb, GFP_ATOMIC);
201 	if (retval)
202 		dev_err(&dev->dev, "%s - usb_submit_urb failed with result %d",
203 			__func__, retval);
204 }
205 
206 static void pegasus_init(struct work_struct *work)
207 {
208 	struct pegasus *pegasus = container_of(work, struct pegasus, init);
209 	int error;
210 
211 	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
212 	if (error)
213 		dev_err(&pegasus->usbdev->dev, "pegasus_set_mode error: %d\n",
214 			error);
215 }
216 
217 static int pegasus_open(struct input_dev *dev)
218 {
219 	struct pegasus *pegasus = input_get_drvdata(dev);
220 	int error;
221 
222 	error = usb_autopm_get_interface(pegasus->intf);
223 	if (error)
224 		return error;
225 
226 	mutex_lock(&pegasus->pm_mutex);
227 	pegasus->irq->dev = pegasus->usbdev;
228 	if (usb_submit_urb(pegasus->irq, GFP_KERNEL)) {
229 		error = -EIO;
230 		goto err_autopm_put;
231 	}
232 
233 	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
234 	if (error)
235 		goto err_kill_urb;
236 
237 	pegasus->is_open = true;
238 	mutex_unlock(&pegasus->pm_mutex);
239 	return 0;
240 
241 err_kill_urb:
242 	usb_kill_urb(pegasus->irq);
243 	cancel_work_sync(&pegasus->init);
244 err_autopm_put:
245 	mutex_unlock(&pegasus->pm_mutex);
246 	usb_autopm_put_interface(pegasus->intf);
247 	return error;
248 }
249 
250 static void pegasus_close(struct input_dev *dev)
251 {
252 	struct pegasus *pegasus = input_get_drvdata(dev);
253 
254 	mutex_lock(&pegasus->pm_mutex);
255 	usb_kill_urb(pegasus->irq);
256 	cancel_work_sync(&pegasus->init);
257 	pegasus->is_open = false;
258 	mutex_unlock(&pegasus->pm_mutex);
259 
260 	usb_autopm_put_interface(pegasus->intf);
261 }
262 
263 static int pegasus_probe(struct usb_interface *intf,
264 			 const struct usb_device_id *id)
265 {
266 	struct usb_device *dev = interface_to_usbdev(intf);
267 	struct usb_endpoint_descriptor *endpoint;
268 	struct pegasus *pegasus;
269 	struct input_dev *input_dev;
270 	int error;
271 	int pipe;
272 
273 	/* We control interface 0 */
274 	if (intf->cur_altsetting->desc.bInterfaceNumber >= 1)
275 		return -ENODEV;
276 
277 	/* Sanity check that the device has an endpoint */
278 	if (intf->cur_altsetting->desc.bNumEndpoints < 1) {
279 		dev_err(&intf->dev, "Invalid number of endpoints\n");
280 		return -EINVAL;
281 	}
282 
283 	endpoint = &intf->cur_altsetting->endpoint[0].desc;
284 
285 	pegasus = kzalloc(sizeof(*pegasus), GFP_KERNEL);
286 	input_dev = input_allocate_device();
287 	if (!pegasus || !input_dev) {
288 		error = -ENOMEM;
289 		goto err_free_mem;
290 	}
291 
292 	mutex_init(&pegasus->pm_mutex);
293 
294 	pegasus->usbdev = dev;
295 	pegasus->dev = input_dev;
296 	pegasus->intf = intf;
297 
298 	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
299 	pegasus->data_len = usb_maxpacket(dev, pipe);
300 
301 	pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, GFP_KERNEL,
302 					   &pegasus->data_dma);
303 	if (!pegasus->data) {
304 		error = -ENOMEM;
305 		goto err_free_mem;
306 	}
307 
308 	pegasus->irq = usb_alloc_urb(0, GFP_KERNEL);
309 	if (!pegasus->irq) {
310 		error = -ENOMEM;
311 		goto err_free_dma;
312 	}
313 
314 	usb_fill_int_urb(pegasus->irq, dev, pipe,
315 			 pegasus->data, pegasus->data_len,
316 			 pegasus_irq, pegasus, endpoint->bInterval);
317 
318 	pegasus->irq->transfer_dma = pegasus->data_dma;
319 	pegasus->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
320 
321 	if (dev->manufacturer)
322 		strscpy(pegasus->name, dev->manufacturer,
323 			sizeof(pegasus->name));
324 
325 	if (dev->product) {
326 		if (dev->manufacturer)
327 			strlcat(pegasus->name, " ", sizeof(pegasus->name));
328 		strlcat(pegasus->name, dev->product, sizeof(pegasus->name));
329 	}
330 
331 	if (!strlen(pegasus->name))
332 		snprintf(pegasus->name, sizeof(pegasus->name),
333 			 "USB Pegasus Device %04x:%04x",
334 			 le16_to_cpu(dev->descriptor.idVendor),
335 			 le16_to_cpu(dev->descriptor.idProduct));
336 
337 	usb_make_path(dev, pegasus->phys, sizeof(pegasus->phys));
338 	strlcat(pegasus->phys, "/input0", sizeof(pegasus->phys));
339 
340 	INIT_WORK(&pegasus->init, pegasus_init);
341 
342 	usb_set_intfdata(intf, pegasus);
343 
344 	input_dev->name = pegasus->name;
345 	input_dev->phys = pegasus->phys;
346 	usb_to_input_id(dev, &input_dev->id);
347 	input_dev->dev.parent = &intf->dev;
348 
349 	input_set_drvdata(input_dev, pegasus);
350 
351 	input_dev->open = pegasus_open;
352 	input_dev->close = pegasus_close;
353 
354 	__set_bit(EV_ABS, input_dev->evbit);
355 	__set_bit(EV_KEY, input_dev->evbit);
356 
357 	__set_bit(ABS_X, input_dev->absbit);
358 	__set_bit(ABS_Y, input_dev->absbit);
359 
360 	__set_bit(BTN_TOUCH, input_dev->keybit);
361 	__set_bit(BTN_RIGHT, input_dev->keybit);
362 	__set_bit(BTN_TOOL_PEN, input_dev->keybit);
363 
364 	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
365 	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);
366 
367 	input_set_abs_params(input_dev, ABS_X, -1500, 1500, 8, 0);
368 	input_set_abs_params(input_dev, ABS_Y, 1600, 3000, 8, 0);
369 
370 	error = input_register_device(pegasus->dev);
371 	if (error)
372 		goto err_free_urb;
373 
374 	return 0;
375 
376 err_free_urb:
377 	usb_free_urb(pegasus->irq);
378 err_free_dma:
379 	usb_free_coherent(dev, pegasus->data_len,
380 			  pegasus->data, pegasus->data_dma);
381 err_free_mem:
382 	input_free_device(input_dev);
383 	kfree(pegasus);
384 	usb_set_intfdata(intf, NULL);
385 
386 	return error;
387 }
388 
389 static void pegasus_disconnect(struct usb_interface *intf)
390 {
391 	struct pegasus *pegasus = usb_get_intfdata(intf);
392 
393 	input_unregister_device(pegasus->dev);
394 
395 	usb_free_urb(pegasus->irq);
396 	usb_free_coherent(interface_to_usbdev(intf),
397 			  pegasus->data_len, pegasus->data,
398 			  pegasus->data_dma);
399 
400 	kfree(pegasus);
401 	usb_set_intfdata(intf, NULL);
402 }
403 
404 static int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
405 {
406 	struct pegasus *pegasus = usb_get_intfdata(intf);
407 
408 	mutex_lock(&pegasus->pm_mutex);
409 	usb_kill_urb(pegasus->irq);
410 	cancel_work_sync(&pegasus->init);
411 	mutex_unlock(&pegasus->pm_mutex);
412 
413 	return 0;
414 }
415 
416 static int pegasus_resume(struct usb_interface *intf)
417 {
418 	struct pegasus *pegasus = usb_get_intfdata(intf);
419 	int retval = 0;
420 
421 	mutex_lock(&pegasus->pm_mutex);
422 	if (pegasus->is_open && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
423 		retval = -EIO;
424 	mutex_unlock(&pegasus->pm_mutex);
425 
426 	return retval;
427 }
428 
429 static int pegasus_reset_resume(struct usb_interface *intf)
430 {
431 	struct pegasus *pegasus = usb_get_intfdata(intf);
432 	int retval = 0;
433 
434 	mutex_lock(&pegasus->pm_mutex);
435 	if (pegasus->is_open) {
436 		retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
437 					  NOTETAKER_LED_MOUSE);
438 		if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
439 			retval = -EIO;
440 	}
441 	mutex_unlock(&pegasus->pm_mutex);
442 
443 	return retval;
444 }
445 
446 static const struct usb_device_id pegasus_ids[] = {
447 	{ USB_DEVICE(USB_VENDOR_ID_PEGASUSTECH,
448 		     USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100) },
449 	{ }
450 };
451 MODULE_DEVICE_TABLE(usb, pegasus_ids);
452 
453 static struct usb_driver pegasus_driver = {
454 	.name		= "pegasus_notetaker",
455 	.probe		= pegasus_probe,
456 	.disconnect	= pegasus_disconnect,
457 	.suspend	= pegasus_suspend,
458 	.resume		= pegasus_resume,
459 	.reset_resume	= pegasus_reset_resume,
460 	.id_table	= pegasus_ids,
461 	.supports_autosuspend = 1,
462 };
463 
464 module_usb_driver(pegasus_driver);
465 
466 MODULE_AUTHOR("Martin Kepplinger <martink@posteo.de>");
467 MODULE_DESCRIPTION("Pegasus Mobile Notetaker Pen tablet driver");
468 MODULE_LICENSE("GPL");
469