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