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